Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2019 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation * Tom Schindl <tom.schindl@bestsolution.at> - bug 153993, bug 167323, bug 175192 * Lasse Knudsen, bug 205700 * Micah Hainline, bug 210448 * Michael Schneider, bug 210747 * Bruce Sutton, bug 221768 * Matthew Hall, bug 221988 * Julien Desgats, bug 203950 * Alexander Fedorov <alexander.fedorov@arsysop.ru> - Bug 548314 *******************************************************************************/ package org.eclipse.jface.viewers; import java.util.ArrayList; import java.util.Arrays; import java.util.LinkedList; import java.util.List; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.ListenerList; import org.eclipse.core.runtime.Status; import org.eclipse.jface.internal.InternalPolicy; import org.eclipse.jface.util.Policy; import org.eclipse.jface.util.SafeRunnable; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.BusyIndicator; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.events.TreeEvent; import org.eclipse.swt.events.TreeListener; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Item; import org.eclipse.swt.widgets.Widget; /** * Abstract base implementation for tree-structure-oriented viewers (trees and * table trees). * <p> * Nodes in the tree can be in either an expanded or a collapsed state, * depending on whether the children on a node are visible. This class * introduces public methods for controlling the expanding and collapsing of * nodes. * </p> * <p> * As of 3.2, AbstractTreeViewer supports multiple equal elements (each with a * different parent chain) in the tree. This support requires that clients * enable the element map by calling <code>setUseHashlookup(true)</code>. * </p> * <p> * Content providers for abstract tree viewers must implement one of the * interfaces <code>ITreeContentProvider</code> or (as of 3.2, to support * multiple equal elements) <code>ITreePathContentProvider</code>. * </p> * <p> * <strong> This class is not intended to be subclassed outside of the JFace * viewers framework.</strong> * </p> * * @see TreeViewer */ public abstract class AbstractTreeViewer extends ColumnViewer { /** * Constant indicating that all levels of the tree should be expanded or * collapsed. * * @see #expandToLevel(int) * @see #collapseToLevel(Object, int) */ public static final int ALL_LEVELS = -1; /** * List of registered tree listeners (element type: * <code>TreeListener</code>). */ private ListenerList<ITreeViewerListener> treeListeners = new ListenerList<>(); /** * The level to which the tree is automatically expanded each time the * viewer's input is changed (that is, by <code>setInput</code>). A value * of 0 means that auto-expand is off. * * @see #setAutoExpandLevel */ private int expandToLevel = 0; /** * Indicates if filters should be checked to determine expandability of * a tree node. */ private boolean isExpandableCheckFilters = false; /** * Safe runnable used to update an item. */ class UpdateItemSafeRunnable extends SafeRunnable { private Object element; private Item item; UpdateItemSafeRunnable(Item item, Object element) { this.item = item; this.element = element; } @Override public void run() { doUpdateItem(item, element); } } /** * Creates an abstract tree viewer. The viewer has no input, no content * provider, a default label provider, no sorter, no filters, and has * auto-expand turned off. */ protected AbstractTreeViewer() { // do nothing } /** * Adds the given child elements to this viewer as children of the given * parent element. If this viewer does not have a sorter, the elements are * added at the end of the parent's list of children in the order given; * otherwise, the elements are inserted at the appropriate positions. * <p> * This method should be called (by the content provider) when elements have * been added to the model, in order to cause the viewer to accurately * reflect the model. This method only affects the viewer, not the model. * </p> * * @param parentElementOrTreePath * the parent element * @param childElements * the child elements to add */ public void add(Object parentElementOrTreePath, Object... childElements) { Assert.isNotNull(parentElementOrTreePath); assertElementsNotNull(childElements); if (checkBusy()) return; Widget[] widgets = internalFindItems(parentElementOrTreePath); // If parent hasn't been realized yet, just ignore the add. if (widgets.length == 0) { return; } for (Widget widget : widgets) { internalAdd(widget, parentElementOrTreePath, childElements); } } /** * Find the items for the given element of tree path * * @param parentElementOrTreePath * the element or tree path * @return the items for that element * * @since 3.3 */ final protected Widget[] internalFindItems(Object parentElementOrTreePath) { Widget[] widgets; if (parentElementOrTreePath instanceof TreePath) { TreePath path = (TreePath) parentElementOrTreePath; Widget w = internalFindItem(path); if (w == null) { widgets = new Widget[] {}; } else { widgets = new Widget[] { w }; } } else { widgets = findItems(parentElementOrTreePath); } return widgets; } /** * Return the item at the given path or <code>null</code> * * @param path * the path * @return {@link Widget} the item at that path */ private Widget internalFindItem(TreePath path) { Widget[] widgets = findItems(path.getLastSegment()); for (Widget widget : widgets) { if (widget instanceof Item) { Item item = (Item) widget; TreePath p = getTreePathFromItem(item); if (p.equals(path)) { return widget; } } } return null; } /** * Adds the given child elements to this viewer as children of the given * parent element. * <p> * EXPERIMENTAL. Not to be used except by JDT. This method was added to * support JDT's explorations into grouping by working sets. This method * cannot be removed without breaking binary backwards compatibility, but * should not be called by clients. * </p> * * @param widget * the widget for the parent element * @param parentElementOrTreePath * the parent element * @param childElements * the child elements to add * @since 3.1 */ protected void internalAdd(Widget widget, Object parentElementOrTreePath, Object[] childElements) { Object parent; TreePath path; if (parentElementOrTreePath instanceof TreePath) { path = (TreePath) parentElementOrTreePath; parent = path.getLastSegment(); } else { parent = parentElementOrTreePath; path = null; } // optimization! // if the widget is not expanded we just invalidate the subtree if (widget instanceof Item) { Item ti = (Item) widget; if (!getExpanded(ti)) { boolean needDummy = isExpandable(ti, path, parent); boolean haveDummy = false; // remove all children Item[] items = getItems(ti); for (Item item : items) { if (item.getData() != null) { disassociate(item); item.dispose(); } else { if (needDummy && !haveDummy) { haveDummy = true; } else { item.dispose(); } } } // append a dummy if necessary if (needDummy && !haveDummy) { newItem(ti, SWT.NULL, -1); } return; } } if (childElements.length > 0) { // TODO: Add filtering back? Object[] filtered = filter(parentElementOrTreePath, childElements); ViewerComparator comparator = getComparator(); if (comparator != null) { if (comparator instanceof TreePathViewerSorter) { TreePathViewerSorter tpvs = (TreePathViewerSorter) comparator; if (path == null) { path = internalGetSorterParentPath(widget, comparator); } tpvs.sort(this, path, filtered); } else { comparator.sort(this, filtered); } } createAddedElements(widget, filtered); if (InternalPolicy.DEBUG_LOG_EQUAL_VIEWER_ELEMENTS) { Item[] children = getChildren(widget); Object[] elements = new Object[children.length]; for (int i = 0; i < children.length; i++) { elements[i] = children[i].getData(); } assertElementsNotNull(parent, elements); } } } /** * Filter the children elements. * * @param parentElementOrTreePath * the parent element or path * @param elements * the child elements * @return the filter list of children */ private Object[] filter(Object parentElementOrTreePath, Object[] elements) { ViewerFilter[] filters = getFilters(); if (filters != null) { List<Object> filtered = new ArrayList<>(elements.length); for (Object element : elements) { boolean add = true; for (ViewerFilter filter : filters) { add = filter.select(this, parentElementOrTreePath, element); if (!add) { break; } } if (add) { filtered.add(element); } } return filtered.toArray(); } return elements; } /** * Create the new elements in the parent widget. If the child already exists * do nothing. * * @param widget * @param elements * Sorted list of elements to add. */ private void createAddedElements(Widget widget, Object[] elements) { if (elements.length == 1) { if (equals(elements[0], widget.getData())) { return; } } ViewerComparator comparator = getComparator(); TreePath parentPath = internalGetSorterParentPath(widget, comparator); Item[] items = getChildren(widget); // Optimize for the empty case if (items.length == 0) { for (Object element : elements) { createTreeItem(widget, element, -1); } return; } // Optimize for no comparator if (comparator == null) { for (Object element : elements) { if (itemExists(items, element)) { internalRefresh(element); } else { createTreeItem(widget, element, -1); } } return; } // As the items are sorted already we optimize for a // start position. This is the insertion position relative to the // original item array. int indexInItems = 0; // Count of elements we have added. See bug 205700 for why this is needed. int newItems = 0; elementloop: for (Object element : elements) { // update the index relative to the original item array indexInItems = insertionPosition(items, comparator, indexInItems, element, parentPath); if (indexInItems == items.length) { createTreeItem(widget, element, -1); newItems++; } else { // Search for an item for the element. The comparator might // regard elements as equal when they are not. // Use a separate index variable to search within the existing // elements that compare equally, see // TreeViewerTestBug205700.testAddEquallySortedElements. int insertionIndexInItems = indexInItems; while (insertionIndexInItems < items.length && internalCompare(comparator, parentPath, element, items[insertionIndexInItems].getData()) == 0) { // As we cannot assume the sorter is consistent with // equals() - therefore we can // just check against the item prior to this index (if // any) if (items[insertionIndexInItems].getData().equals(element)) { // Found the item for the element. // Refresh the element in case it has new children. internalRefresh(element); // Do not create a new item - continue with the next element. continue elementloop; } insertionIndexInItems++; } // Did we get to the end? if (insertionIndexInItems == items.length) { createTreeItem(widget, element, -1); newItems++; } else { // InsertionIndexInItems is the index in the original array. We // need to correct by the number of new items we have // created. See bug 205700. createTreeItem(widget, element, insertionIndexInItems + newItems); newItems++; } } } } /** * See if element is the data of one of the elements in items. * * @param items * @param element * @return <code>true</code> if the element matches. */ private boolean itemExists(Item[] items, Object element) { if (usingElementMap()) { Widget[] existingItems = findItems(element); // optimization for two common cases if (existingItems.length == 0) { return false; } else if (existingItems.length == 1) { if (items.length > 0 && existingItems[0] instanceof Item) { Item existingItem = (Item) existingItems[0]; return getParentItem(existingItem) == getParentItem(items[0]); } } } for (Item item : items) { if (item.getData().equals(element)) { return true; } } return false; } /** * Returns the index where the item should be inserted. It uses sorter to * determine the correct position, if sorter is not assigned, returns the * index of the element after the last. * * @param items * the items to search * @param comparator * The comparator to use. * @param lastInsertion * the start index to start search for position from this allows * optimizing search for multiple elements that are sorted * themselves. * @param element * element to find position for. * @param parentPath * the tree path for the element's parent or <code>null</code> * if the element is a root element or the sorter is not a * {@link TreePathViewerSorter} * @return the index to use when inserting the element. * */ private int insertionPosition(Item[] items, ViewerComparator comparator, int lastInsertion, Object element, TreePath parentPath) { int size = items.length; if (comparator == null) { return size; } int min = lastInsertion, max = size - 1; while (min <= max) { int mid = (min + max) / 2; Object data = items[mid].getData(); int compare = internalCompare(comparator, parentPath, data, element); if (compare == 0) { return mid;// Return if we already match } if (compare < 0) { min = mid + 1; } else { max = mid - 1; } } return min; } /** * Returns the index where the item should be inserted. It uses sorter to * determine the correct position, if sorter is not assigned, returns the * index of the element after the last. * * @param parent * The parent widget * @param sorter * The sorter to use. * @param startIndex * the start index to start search for position from this allows * optimizing search for multiple elements that are sorted * themselves. * @param element * element to find position for. * @param currentSize * the current size of the collection * @return the index to use when inserting the element. * */ /** * Returns the index where the item should be inserted. * * @param parent * The parent widget the element will be inserted into. * @param element * The element to insert. * @return the index of the element */ protected int indexForElement(Widget parent, Object element) { ViewerComparator comparator = getComparator(); TreePath parentPath = internalGetSorterParentPath(parent, comparator); Item[] items = getChildren(parent); int count = items.length; if (comparator == null) { return count; } int min = 0, max = count - 1; while (min <= max) { int mid = (min + max) / 2; Object data = items[mid].getData(); int compare = internalCompare(comparator, parentPath, data, element); if (compare == 0) { // find first item > element while (compare == 0) { ++mid; if (mid >= count) { break; } data = items[mid].getData(); compare = internalCompare(comparator, parentPath, data, element); } return mid; } if (compare < 0) { min = mid + 1; } else { max = mid - 1; } } return min; } /** * Return the tree path that should be used as the parent path for the given * widget and sorter. A <code>null</code> is returned if either the sorter * is not a {@link TreePathViewerSorter} or if the parent widget is not an * {@link Item} (i.e. is the root of the tree). * * @param parent * the parent widget * @param comparator * the sorter * @return the tree path that should be used as the parent path for the * given widget and sorter */ private TreePath internalGetSorterParentPath(Widget parent, ViewerComparator comparator) { TreePath path; if (comparator instanceof TreePathViewerSorter && parent instanceof Item) { Item item = (Item) parent; path = getTreePathFromItem(item); } else { path = null; } return path; } /** * Compare the two elements using the given sorter. If the sorter is a * {@link TreePathViewerSorter}, the provided tree path will be used. If * the tree path is null and the sorter is a tree path sorter, then the * elements are root elements * * @param comparator * the sorter * @param parentPath * the path of the elements' parent * @param e1 * the first element * @param e2 * the second element * @return the result of comparing the two elements */ private int internalCompare(ViewerComparator comparator, TreePath parentPath, Object e1, Object e2) { if (comparator instanceof TreePathViewerSorter) { TreePathViewerSorter tpvs = (TreePathViewerSorter) comparator; return tpvs.compare(this, parentPath, e1, e2); } return comparator.compare(this, e1, e2); } @Override protected Object[] getSortedChildren(Object parentElementOrTreePath) { Object[] result = getFilteredChildren(parentElementOrTreePath); ViewerComparator comparator = getComparator(); if (parentElementOrTreePath != null && comparator instanceof TreePathViewerSorter) { TreePathViewerSorter tpvs = (TreePathViewerSorter) comparator; // be sure we're not modifying the original array from the model result = result.clone(); TreePath path = null; if (parentElementOrTreePath instanceof TreePath) { path = (TreePath) parentElementOrTreePath; } else { Object parent = parentElementOrTreePath; Widget w = internalGetWidgetToSelect(parent); if (w != null) { path = internalGetSorterParentPath(w, comparator); } } tpvs.sort(this, path, result); } else if (comparator != null) { // be sure we're not modifying the original array from the model result = result.clone(); comparator.sort(this, result); } return result; } /** * Adds the given child element to this viewer as a child of the given * parent element. If this viewer does not have a sorter, the element is * added at the end of the parent's list of children; otherwise, the element * is inserted at the appropriate position. * <p> * This method should be called (by the content provider) when a single * element has been added to the model, in order to cause the viewer to * accurately reflect the model. This method only affects the viewer, not * the model. Note that there is another method for efficiently processing * the simultaneous addition of multiple elements. * </p> * * @param parentElementOrTreePath * the parent element or path * @param childElement * the child element */ public void add(Object parentElementOrTreePath, Object childElement) { add(parentElementOrTreePath, new Object[] { childElement }); } /** * Adds the given SWT selection listener to the given SWT control. * * @param control * the SWT control * @param listener * the SWT selection listener * @deprecated */ @Deprecated protected void addSelectionListener(Control control, SelectionListener listener) { // do nothing } /** * Adds a listener for expand and collapse events in this viewer. Has no * effect if an identical listener is already registered. * * @param listener * a tree viewer listener */ public void addTreeListener(ITreeViewerListener listener) { treeListeners.add(listener); } /** * Adds the given SWT tree listener to the given SWT control. * * @param control * the SWT control * @param listener * the SWT tree listener */ protected abstract void addTreeListener(Control control, TreeListener listener); @Override protected void associate(Object element, Item item) { Object data = item.getData(); if (data != null && data != element && equals(data, element)) { // workaround for PR 1FV62BT // assumption: elements are equal but not identical // -> remove from map but don't touch children unmapElement(data, item); item.setData(element); mapElement(element, item); } else { // recursively disassociate all super.associate(element, item); } } /** * Collapses all nodes of the viewer's tree, starting with the root. This method * is equivalent to <code>collapseToLevel(ALL_LEVELS)</code>. */ public void collapseAll() { Object root = getRoot(); if (root != null) { collapseToLevel(root, ALL_LEVELS); } } /** * Collapses the subtree rooted at the given element or tree path to the given * level. * <p> * Note that the default implementation of this method does turn redraw off via * this operation via a call to <code>setRedraw</code> * </p> * * @param elementOrTreePath the element or tree path * @param level non-negative level, or <code>ALL_LEVELS</code> to * collapse all levels of the tree */ public void collapseToLevel(Object elementOrTreePath, int level) { Assert.isNotNull(elementOrTreePath); Control control = getControl(); try { control.setRedraw(false); Widget w = internalGetWidgetToSelect(elementOrTreePath); if (w != null) { internalCollapseToLevel(w, level); } } finally { control.setRedraw(true); } } /** * Creates all children for the given widget. * <p> * The default implementation of this framework method assumes that * <code>widget.getData()</code> returns the element corresponding to the * node. Note: the node is not visually expanded! You may have to call * <code>parent.setExpanded(true)</code>. * </p> * * @param widget * the widget */ protected void createChildren(final Widget widget) { createChildren(widget, true); } /** * Creates all children for the given widget. * <p> * The default implementation of this framework method assumes that * <code>widget.getData()</code> returns the element corresponding to the * node. Note: the node is not visually expanded! You may have to call * <code>parent.setExpanded(true)</code>. * </p> * * @param widget * the widget * @param materialize * true if children are expected to be fully materialized */ void createChildren(final Widget widget, boolean materialize) { boolean oldBusy = isBusy(); setBusy(true); try { final Item[] items = getChildren(widget); if (items != null && items.length > 0) { Object data = items[0].getData(); if (data != null) { return; // children already there! } } // fix for PR 1FW89L7: // don't complain and remove all "dummies" ... if (items != null) { for (Item item : items) { if (item.getData() != null) { disassociate(item); Assert.isTrue(item.getData() == null, "Second or later child is non -null");//$NON-NLS-1$ } item.dispose(); } } Object d = widget.getData(); if (d != null) { Object parentElement = d; Object[] children; if (isTreePathContentProvider() && widget instanceof Item) { TreePath path = getTreePathFromItem((Item) widget); children = getSortedChildren(path); } else { children = getSortedChildren(parentElement); } for (Object element : children) { createTreeItem(widget, element, -1); } } } finally { setBusy(oldBusy); } } /** * Creates a single item for the given parent and synchronizes it with the * given element. * * @param parent * the parent widget * @param element * the element * @param index * if non-negative, indicates the position to insert the item * into its parent */ protected void createTreeItem(Widget parent, Object element, int index) { Item item = newItem(parent, SWT.NULL, index); updateItem(item, element); updatePlus(item, element); } /** * The <code>AbstractTreeViewer</code> implementation of this method also * recurses over children of the corresponding element. */ @Override protected void disassociate(Item item) { super.disassociate(item); // recursively unmapping the items is only required when // the hash map is used. In the other case disposing // an item will recursively dispose its children. if (usingElementMap()) { disassociateChildren(item); } } /** * Disassociates the children of the given SWT item from their corresponding * elements. * * @param item * the widget */ private void disassociateChildren(Item item) { Item[] items = getChildren(item); for (Item child : items) { if (child.getData() != null) { disassociate(child); } } } @Override protected Widget doFindInputItem(Object element) { // compare with root Object root = getRoot(); if (root == null) { return null; } if (equals(root, element)) { return getControl(); } return null; } @Override protected Widget doFindItem(Object element) { // compare with root Object root = getRoot(); if (root == null) { return null; } Item[] items = getChildren(getControl()); if (items != null) { for (Item item : items) { Widget o = internalFindItem(item, element); if (o != null) { return o; } } } return null; } /** * Copies the attributes of the given element into the given SWT item. * * @param item * the SWT item * @param element * the element */ protected void doUpdateItem(final Item item, Object element) { if (item.isDisposed()) { unmapElement(element, item); return; } int columnCount = doGetColumnCount(); if (columnCount == 0)// If no columns are created then fake one columnCount = 1; ViewerRow viewerRowFromItem = getViewerRowFromItem(item); boolean isVirtual = (getControl().getStyle() & SWT.VIRTUAL) != 0; // If the control is virtual, we cannot use the cached viewer row object. See bug 188663. if (isVirtual) { viewerRowFromItem = (ViewerRow) viewerRowFromItem.clone(); } for (int column = 0; column < columnCount; column++) { ViewerColumn columnViewer = getViewerColumn(column); ViewerCell cellToUpdate = updateCell(viewerRowFromItem, column, element); // If the control is virtual, we cannot use the cached cell object. See bug 188663. if (isVirtual) { cellToUpdate = new ViewerCell(cellToUpdate.getViewerRow(), cellToUpdate.getColumnIndex(), element); } columnViewer.refresh(cellToUpdate); // clear cell (see bug 201280) updateCell(null, 0, null); // As it is possible for user code to run the event // loop check here. if (item.isDisposed()) { unmapElement(element, item); return; } } } /** * Returns <code>true</code> if the given list and array of items refer to * the same model elements. Order is unimportant. * <p> * This method is not intended to be overridden by subclasses. * </p> * * @param items * the list of items * @param current * the array of items * @return <code>true</code> if the refer to the same elements, * <code>false</code> otherwise * * @since 3.1 in TreeViewer, moved to AbstractTreeViewer in 3.3 */ protected boolean isSameSelection(List<Item> items, Item[] current) { // If they are not the same size then they are not equivalent int n = items.size(); if (n != current.length) { return false; } CustomHashtable itemSet = newHashtable(n * 2 + 1); for (Item item : items) { Object element = item.getData(); itemSet.put(element, element); } // Go through the items of the current collection // If there is a mismatch return false for (Item c : current) { if (c.getData() == null || !itemSet.containsKey(c.getData())) { return false; } } return true; } @Override protected void doUpdateItem(Widget widget, Object element, boolean fullMap) { boolean oldBusy = isBusy(); setBusy(true); try { if (widget instanceof Item) { Item item = (Item) widget; // ensure that back pointer is correct if (fullMap) { associate(element, item); } else { Object data = item.getData(); if (data != null) { unmapElement(data, item); } item.setData(element); mapElement(element, item); } // update icon and label SafeRunnable.run(new UpdateItemSafeRunnable(item, element)); } } finally { setBusy(oldBusy); } } /** * Expands all nodes of the viewer's tree, starting with the root. This * method is equivalent to <code>expandToLevel(ALL_LEVELS)</code>. */ public void expandAll() { expandToLevel(ALL_LEVELS, true); } /** * Expands all nodes of the viewer's tree, starting with the root. This method * is equivalent to <code>expandToLevel(ALL_LEVELS)</code>. * * @param disableRedraw * <code>true</code> when drawing operations should be disabled * during expansion. * @since 3.14 */ public void expandAll(boolean disableRedraw) { expandToLevel(ALL_LEVELS, disableRedraw); } /** * Expands the root of the viewer's tree to the given level. * * @param level * non-negative level, or <code>ALL_LEVELS</code> to expand all * levels of the tree */ public void expandToLevel(int level) { expandToLevel(level, true); } /** * Expands the root of the viewer's tree to the given level. * * @param level non-negative level, or <code>ALL_LEVELS</code> to expand * all levels of the tree * @param disableRedraw <code>true</code> when drawing operations should be * disabled during expansion. <code>true</code> when * drawing operations should be enabled during expansion. * Prefer using true as this results in a faster UI * @since 3.14 */ public void expandToLevel(int level, boolean disableRedraw) { BusyIndicator.showWhile(getControl().getDisplay(), () -> { expandToLevel(getRoot(), level, disableRedraw); }); } /** * Expands all ancestors of the given element or tree path so that the given * element becomes visible in this viewer's tree control, and then expands * the subtree rooted at the given element to the given level. * * @param elementOrTreePath * the element * @param level * non-negative level, or <code>ALL_LEVELS</code> to expand all * levels of the tree */ public void expandToLevel(Object elementOrTreePath, int level) { expandToLevel(elementOrTreePath, level, true); } /** * Expands all ancestors of the given element or tree path so that the given * element becomes visible in this viewer's tree control, and then expands the * subtree rooted at the given element to the given level. * * @param elementOrTreePath the element * @param level non-negative level, or <code>ALL_LEVELS</code> to * expand all levels of the tree * @param disableRedraw <code>true</code> when drawing operations should be * disabled during expansion. <code>false</code> when * drawing operations should be enabled during * expansion. Prefer true as this results in a faster * UI. * @since 3.14 */ public void expandToLevel(Object elementOrTreePath, int level, boolean disableRedraw) { if (checkBusy()) return; Control control = getControl(); try { if (disableRedraw) { control.setRedraw(false); } Widget w = internalExpand(elementOrTreePath, true); if (w != null) { internalExpandToLevel(w, level); } } finally { if (disableRedraw) { control.setRedraw(true); } } } /** * Fires a tree collapsed event. Only listeners registered at the time this * method is called are notified. * * @param event * the tree expansion event * @see ITreeViewerListener#treeCollapsed */ protected void fireTreeCollapsed(final TreeExpansionEvent event) { boolean oldBusy = isBusy(); setBusy(true); try { for (ITreeViewerListener l : treeListeners) { SafeRunnable.run(new SafeRunnable() { @Override public void run() { l.treeCollapsed(event); } }); } } finally { setBusy(oldBusy); } } /** * Fires a tree expanded event. Only listeners registered at the time this * method is called are notified. * * @param event * the tree expansion event * @see ITreeViewerListener#treeExpanded */ protected void fireTreeExpanded(final TreeExpansionEvent event) { boolean oldBusy = isBusy(); setBusy(true); try { for (ITreeViewerListener l : treeListeners) { SafeRunnable.run(new SafeRunnable() { @Override public void run() { l.treeExpanded(event); } }); } } finally { setBusy(oldBusy); } } /** * Returns the auto-expand level. * * @return non-negative level, or <code>ALL_LEVELS</code> if all levels of * the tree are expanded automatically * @see #setAutoExpandLevel */ public int getAutoExpandLevel() { return expandToLevel; } /** * Returns the SWT child items for the given SWT widget. * * @param widget * the widget * @return the child items */ protected abstract Item[] getChildren(Widget widget); /** * Get the child for the widget at index. Note that the default * implementation is not very efficient and should be overridden if this * class is implemented. * * @param widget * the widget to check * @param index * the index of the widget * @return Item or <code>null</code> if widget is not a type that can * contain items. * * @throws ArrayIndexOutOfBoundsException * if the index is not valid. * @since 3.1 */ protected Item getChild(Widget widget, int index) { return getChildren(widget)[index]; } /** * Returns whether the given SWT item is expanded or collapsed. * * @param item * the item * @return <code>true</code> if the item is considered expanded and * <code>false</code> if collapsed */ protected abstract boolean getExpanded(Item item); /** * Returns a list of elements corresponding to expanded nodes in this * viewer's tree, including currently hidden ones that are marked as * expanded but are under a collapsed ancestor. * <p> * This method is typically used when preserving the interesting state of a * viewer; <code>setExpandedElements</code> is used during the restore. * </p> * * @return the array of expanded elements * @see #setExpandedElements */ public Object[] getExpandedElements() { ArrayList<Item> items = new ArrayList<>(); internalCollectExpandedItems(items, getControl()); ArrayList<Object> result = new ArrayList<>(items.size()); for (Item item : items) { Object data = item.getData(); if (data != null) { result.add(data); } } return result.toArray(); } /** * Returns whether the node corresponding to the given element or tree path * is expanded or collapsed. * * @param elementOrTreePath * the element * @return <code>true</code> if the node is expanded, and * <code>false</code> if collapsed */ public boolean getExpandedState(Object elementOrTreePath) { Assert.isNotNull(elementOrTreePath); Widget item = internalGetWidgetToSelect(elementOrTreePath); if (item instanceof Item) { return getExpanded((Item) item); } return false; } /** * Returns the number of child items of the given SWT control. * * @param control * the control * @return the number of children */ protected abstract int getItemCount(Control control); /** * Returns the number of child items of the given SWT item. * * @param item * the item * @return the number of children */ protected abstract int getItemCount(Item item); /** * Returns the child items of the given SWT item. * * @param item * the item * @return the child items */ protected abstract Item[] getItems(Item item); /** * Returns the item after the given item in the tree, or <code>null</code> * if there is no next item. * * @param item * the item * @param includeChildren * <code>true</code> if the children are considered in * determining which item is next, and <code>false</code> if * subtrees are ignored * @return the next item, or <code>null</code> if none */ protected Item getNextItem(Item item, boolean includeChildren) { if (item == null) { return null; } if (includeChildren && getExpanded(item)) { Item[] children = getItems(item); if (children != null && children.length > 0) { return children[0]; } } // next item is either next sibling or next sibling of first // parent that has a next sibling. Item parent = getParentItem(item); if (parent == null) { return null; } Item[] siblings = getItems(parent); if (siblings != null) { if (siblings.length <= 1) { return getNextItem(parent, false); } for (int i = 0; i < siblings.length; i++) { if (siblings[i] == item && i < (siblings.length - 1)) { return siblings[i + 1]; } } } return getNextItem(parent, false); } /** * Returns the parent item of the given item in the tree, or * <code>null</code> if there is no parent item. * * @param item * the item * @return the parent item, or <code>null</code> if none */ protected abstract Item getParentItem(Item item); /** * Returns the item before the given item in the tree, or <code>null</code> * if there is no previous item. * * @param item * the item * @return the previous item, or <code>null</code> if none */ protected Item getPreviousItem(Item item) { // previous item is either right-most visible descendent of previous // sibling or parent Item parent = getParentItem(item); if (parent == null) { return null; } Item[] siblings = getItems(parent); if (siblings.length == 0 || siblings[0] == item) { return parent; } Item previous = siblings[0]; for (int i = 1; i < siblings.length; i++) { if (siblings[i] == item) { return rightMostVisibleDescendent(previous); } previous = siblings[i]; } return null; } @Override protected Object[] getRawChildren(Object parentElementOrTreePath) { boolean oldBusy = isBusy(); setBusy(true); try { Object parent; TreePath path; if (parentElementOrTreePath instanceof TreePath) { path = (TreePath) parentElementOrTreePath; parent = path.getLastSegment(); } else { parent = parentElementOrTreePath; path = null; } if (parent != null) { if (equals(parent, getRoot())) { return super.getRawChildren(parent); } IContentProvider cp = getContentProvider(); if (cp instanceof ITreePathContentProvider) { ITreePathContentProvider tpcp = (ITreePathContentProvider) cp; if (path == null) { // A path was not provided so try and find one Widget w = findItem(parent); if (w instanceof Item) { Item item = (Item) w; path = getTreePathFromItem(item); } if (path == null) { path = new TreePath(new Object[] { parent }); } } Object[] result = tpcp.getChildren(path); if (result != null) { assertElementsNotNull(parent, result); return result; } } else if (cp instanceof ITreeContentProvider) { ITreeContentProvider tcp = (ITreeContentProvider) cp; Object[] result = tcp.getChildren(parent); if (result != null) { assertElementsNotNull(parent, result); return result; } } } return new Object[0]; } finally { setBusy(oldBusy); } } /** * Asserts that the given array of elements is itself non- <code>null</code> * and contains no <code>null</code> elements. * * @param parent * the parent element * @param elements * the array to check * * @see #assertElementsNotNull(Object[]) */ private void assertElementsNotNull(Object parent, Object[] elements) { Assert.isNotNull(elements); for (Object element : elements) { Assert.isNotNull(element); } if (InternalPolicy.DEBUG_LOG_EQUAL_VIEWER_ELEMENTS && elements.length > 1) { CustomHashtable elementSet = newHashtable(elements.length * 2); for (Object element : elements) { Object old = elementSet.put(element, element); if (old != null) { String message = "Sibling elements in viewer must not be equal:\n " //$NON-NLS-1$ + old + ",\n " + element + ",\n parent: " + parent; //$NON-NLS-1$ //$NON-NLS-2$ Policy.getLog().log(new Status(IStatus.WARNING, Policy.JFACE, message, new RuntimeException())); return; } } } } /** * Returns all selected items for the given SWT control. * * @param control * the control * @return the list of selected items */ protected abstract Item[] getSelection(Control control); @SuppressWarnings("rawtypes") @Override protected List getSelectionFromWidget() { Widget[] items = getSelection(getControl()); List<Object> list = new ArrayList<>(items.length); for (Widget item : items) { Object e = item.getData(); if (e != null) { list.add(e); } } return list; } /* * Overridden in AbstractTreeViewer to fix bug 108102 (code copied from * StructuredViewer to avoid introducing new API) */ @Override protected void handleDoubleSelect(SelectionEvent event) { // handle case where an earlier selection listener disposed the control. Control control = getControl(); if (control != null && !control.isDisposed()) { // If the double-clicked element can be obtained from the event, use // it // otherwise get it from the control. Some controls like List do // not have the notion of item. // For details, see bug 90161 [Navigator] DefaultSelecting folders // shouldn't always expand first one ISelection selection; if (event.item != null && event.item.getData() != null) { // changes to fix bug 108102 follow TreePath treePath = getTreePathFromItem((Item) event.item); selection = new TreeSelection(treePath); // end of changes } else { selection = getSelection(); updateSelection(selection); } fireDoubleClick(new DoubleClickEvent(this, selection)); } } /** * Handles a tree collapse event from the SWT widget. * * @param event * the SWT tree event */ protected void handleTreeCollapse(TreeEvent event) { if (event.item.getData() != null) { fireTreeCollapsed(new TreeExpansionEvent(this, event.item.getData())); } } /** * Handles a tree expand event from the SWT widget. * * @param event * the SWT tree event */ protected void handleTreeExpand(TreeEvent event) { createChildren(event.item); if (event.item.getData() != null) { fireTreeExpanded(new TreeExpansionEvent(this, event.item.getData())); } } @Override protected void hookControl(Control control) { super.hookControl(control); addTreeListener(control, new TreeListener() { @Override public void treeExpanded(TreeEvent event) { handleTreeExpand(event); } @Override public void treeCollapsed(TreeEvent event) { handleTreeCollapse(event); } }); } @Override protected void inputChanged(Object input, Object oldInput) { preservingSelection(() -> { Control tree = getControl(); tree.setRedraw(false); try { removeAll(tree); tree.setData(getRoot()); internalInitializeTree(tree); } finally { tree.setRedraw(true); } }); } /** * Initializes the tree with root items, expanding to the appropriate * level if necessary. * * @param tree the tree control * @since 3.3 */ protected void internalInitializeTree(Control tree) { createChildren(tree); internalExpandToLevel(tree, expandToLevel); } /** * Recursively collapses the subtree rooted at the given widget to the given * level. * * @param widget the widget * @param level non-negative level, or <code>ALL_LEVELS</code> to collapse all * levels of the tree */ protected void internalCollapseToLevel(Widget widget, int level) { if (level == ALL_LEVELS || level > 0) { if (widget instanceof Item) { Item item = (Item) widget; setExpanded(item, false); Object element = item.getData(); if (element != null && level == ALL_LEVELS) { if (optionallyPruneChildren(item, element)) { return; } } } if (level == ALL_LEVELS || level > 1) { Item[] children = getChildren(widget); if (children != null) { int nextLevel = (level == ALL_LEVELS ? ALL_LEVELS : level - 1); for (Item element : children) { internalCollapseToLevel(element, nextLevel); } } } } } /** * Recursively collects all expanded items from the given widget. * * @param result * a list (element type: <code>Item</code>) into which to * collect the elements * @param widget * the widget */ private void internalCollectExpandedItems(List<Item> result, Widget widget) { Item[] items = getChildren(widget); for (Item item : items) { // Disregard dummy nodes (see bug 287765) if (item.getData() != null) { if (getExpanded(item)) { result.add(item); } internalCollectExpandedItems(result, item); } } } /** * Tries to create a path of tree items for the given element or tree path. * This method recursively walks up towards the root of the tree and in the * case of an element (rather than a tree path) assumes that * <code>getParent</code> returns the correct parent of an element. * * @param elementOrPath * the element * @param expand * <code>true</code> if all nodes on the path should be * expanded, and <code>false</code> otherwise * @return Widget */ protected Widget internalExpand(Object elementOrPath, boolean expand) { if (elementOrPath == null) { return null; } Widget w = internalGetWidgetToSelect(elementOrPath); if (w == null) { if (equals(elementOrPath, getRoot())) { // stop at root return null; } // my parent has to create me Object parent = getParentElement(elementOrPath); if (parent != null) { Widget pw = internalExpand(parent, false); if (pw != null) { // let my parent create me createChildren(pw); Object element = internalToElement(elementOrPath); w = internalFindChild(pw, element); } } } if (expand && w instanceof Item) { // expand parent items top-down Item item = getParentItem((Item) w); LinkedList<Item> toExpandList = new LinkedList<>(); while (item != null) { if (!getExpanded(item)) { toExpandList.addFirst(item); } item = getParentItem(item); } for (Item toExpand : toExpandList) { setExpanded(toExpand, true); } } return w; } /** * If the argument is a tree path, returns its last segment, otherwise * return the argument * * @param elementOrPath * an element or a tree path * @return the element, or the last segment of the tree path */ private Object internalToElement(Object elementOrPath) { if (elementOrPath instanceof TreePath) { return ((TreePath) elementOrPath).getLastSegment(); } return elementOrPath; } /** * This method takes a tree path or an element. If the argument is not a tree * path, returns the parent of the given element or <code>null</code> if the * parent is not known. If the argument is a tree path with more than one * segment, returns its parent tree path, otherwise returns <code>null</code>. * * @param elementOrTreePath the element or path to find parent for * @return the parent element, or parent path, or <code>null</code> * * @since 3.2 */ protected Object getParentElement(Object elementOrTreePath) { if (elementOrTreePath instanceof TreePath) { TreePath treePath = (TreePath) elementOrTreePath; return (treePath).getParentPath(); } IContentProvider cp = getContentProvider(); if (cp instanceof ITreePathContentProvider) { ITreePathContentProvider tpcp = (ITreePathContentProvider) cp; TreePath[] paths = tpcp.getParents(elementOrTreePath); if (paths.length > 0) { if (paths[0].getSegmentCount() == 0) { return getRoot(); } return paths[0].getLastSegment(); } } if (cp instanceof ITreeContentProvider) { ITreeContentProvider tcp = (ITreeContentProvider) cp; return tcp.getParent(elementOrTreePath); } return null; } /** * Returns the widget to be selected for the given element or tree path. * * @param elementOrTreePath * the element or tree path to select * @return the widget to be selected, or <code>null</code> if not found * * @since 3.1 */ protected Widget internalGetWidgetToSelect(Object elementOrTreePath) { if (elementOrTreePath instanceof TreePath) { TreePath treePath = (TreePath) elementOrTreePath; if (treePath.getSegmentCount() == 0) { return getControl(); } Widget[] candidates = findItems(treePath.getLastSegment()); for (Widget candidate : candidates) { if (!(candidate instanceof Item)) { continue; } if (treePath.equals(getTreePathFromItem((Item) candidate), getComparer())) { return candidate; } } return null; } return findItem(elementOrTreePath); } /** * Recursively expands the subtree rooted at the given widget to the given * level. * <p> * Note that the default implementation of this method does not call * <code>setRedraw</code>. * </p> * * @param widget the widget * @param level non-negative level, or <code>ALL_LEVELS</code> to collapse all * levels of the tree */ protected void internalExpandToLevel(Widget widget, int level) { if (level == ALL_LEVELS || level > 0) { if (widget instanceof Item && widget.getData() != null && !isExpandable((Item) widget, null, widget.getData())) { return; } createChildren(widget, false); if (widget instanceof Item) { setExpanded((Item) widget, true); } if (level == ALL_LEVELS || level > 1) { Item[] children = getChildren(widget); if (children != null) { int newLevel = (level == ALL_LEVELS ? ALL_LEVELS : level - 1); for (Item element : children) { internalExpandToLevel(element, newLevel); } } } } } /** * Non-recursively tries to find the given element as a child of the given * parent (item or tree). * * @param parent * the parent item * @param element * the element * @return Widget */ private Widget internalFindChild(Widget parent, Object element) { Item[] items = getChildren(parent); for (Item item : items) { Object data = item.getData(); if (data != null && equals(data, element)) { return item; } } return null; } /** * Recursively tries to find the given element. * * @param parent * the parent item * @param element * the element * @return Widget */ private Widget internalFindItem(Item parent, Object element) { // compare with node Object data = parent.getData(); if (data != null) { if (equals(data, element)) { return parent; } } // recurse over children Item[] items = getChildren(parent); for (Item item : items) { Widget o = internalFindItem(item, element); if (o != null) { return o; } } return null; } @Override protected void internalRefresh(Object element) { internalRefresh(element, true); } @Override protected void internalRefresh(Object element, boolean updateLabels) { // If element is null, do a full refresh. if (element == null) { internalRefresh(getControl(), getRoot(), true, updateLabels); return; } Widget[] items = findItems(element); if (items.length != 0) { for (Widget item : items) { // pick up structure changes too internalRefresh(item, element, true, updateLabels); } } } /** * Refreshes the tree starting at the given widget. * <p> * EXPERIMENTAL. Not to be used except by JDT. This method was added to * support JDT's explorations into grouping by working sets. This method * cannot be removed without breaking binary backwards compatibility, but * should not be called by clients. * </p> * * @param widget * the widget * @param element * the element * @param doStruct * <code>true</code> if structural changes are to be picked up, * and <code>false</code> if only label provider changes are of * interest * @param updateLabels * <code>true</code> to update labels for existing elements, * <code>false</code> to only update labels as needed, assuming * that labels for existing elements are unchanged. * @since 3.1 */ protected void internalRefresh(Widget widget, Object element, boolean doStruct, boolean updateLabels) { if (widget instanceof Item) { if (doStruct) { updatePlus((Item) widget, element); } if (updateLabels || !equals(element, widget.getData())) { doUpdateItem(widget, element, true); } else { associate(element, (Item) widget); } } if (doStruct) { internalRefreshStruct(widget, element, updateLabels); } else { Item[] children = getChildren(widget); if (children != null) { for (Item item : children) { Object data = item.getData(); if (data != null) { internalRefresh(item, data, doStruct, updateLabels); } } } } } /** * Update the structure and recurse. Items are updated in updateChildren, as * needed. * * @param widget * @param element * @param updateLabels */ /* package */void internalRefreshStruct(Widget widget, Object element, boolean updateLabels) { updateChildren(widget, element, null, updateLabels); Item[] children = getChildren(widget); if (children != null) { for (Item item : children) { Object data = item.getData(); if (data != null) { internalRefreshStruct(item, data, updateLabels); } } } } /** * Removes the given elements from this viewer. * <p> * EXPERIMENTAL. Not to be used except by JDT. This method was added to * support JDT's explorations into grouping by working sets. This method * cannot be removed without breaking binary backwards compatibility, but * should not be called by clients. * </p> * * @param elementsOrPaths * the elements or element paths to remove * @since 3.1 */ protected void internalRemove(Object[] elementsOrPaths) { Object input = getInput(); for (Object element : elementsOrPaths) { if (equals(element, input)) { setInput(null); return; } Widget[] childItems = internalFindItems(element); if (childItems.length > 0) { for (Widget childItem : childItems) { if (childItem instanceof Item) { disassociate((Item) childItem); childItem.dispose(); } } } else { // see https://bugs.eclipse.org/bugs/show_bug.cgi?id=210747 Object parent = getParentElement(element); if (parent != null && !equals(parent, getRoot()) && !(parent instanceof TreePath && ((TreePath) parent).getSegmentCount() == 0)) { Widget[] parentItems = internalFindItems(parent); for (Widget parentItem : parentItems) { if (parentItem instanceof Item) { updatePlus((Item) parentItem, parent); } } } } } } /** * Removes the given elements from this viewer, whenever those elements * appear as children of the given parent. * * @param parent the parent element * @param elements * the elements to remove * @since 3.1 */ protected void internalRemove(Object parent, Object[] elements) { CustomHashtable toRemove = new CustomHashtable(getComparer()); for (Object element : elements) { toRemove.put(element, element); } // Find each place the parent appears in the tree Widget[] parentItemArray = findItems(parent); for (Widget parentItem : parentItemArray) { // May happen if parent element is a descendent of of a previously // removed element if (parentItem.isDisposed()) continue; // Iterate over the child items and remove each one Item[] children = getChildren(parentItem); if (children.length == 1 && children[0].getData() == null && parentItem instanceof Item) { // dummy node // Remove plus if parent element has no children updatePlus((Item) parentItem, parent); } else { for (Item child : children) { Object data = child.getData(); if (data != null && toRemove.containsKey(data)) { disassociate(child); child.dispose(); } } } } } /** * Sets the expanded state of all items to correspond to the given set of * expanded elements. * * @param expandedElements * the set (element type: <code>Object</code>) of elements * which are expanded * @param widget * the widget */ private void internalSetExpanded(CustomHashtable expandedElements, Widget widget) { Item[] items = getChildren(widget); for (Item item : items) { Object data = item.getData(); if (data != null) { // remove the element to avoid an infinite loop // if the same element appears on a child item boolean expanded = expandedElements.remove(data) != null; if (expanded != getExpanded(item)) { if (expanded) { createChildren(item); } setExpanded(item, expanded); } } if (expandedElements.size() > 0) { internalSetExpanded(expandedElements, item); } } } /** * Sets the expanded state of all items to correspond to the given set of * expanded tree paths. * * @param expandedTreePaths * the set (element type: <code>TreePath</code>) of elements * which are expanded * @param widget * the widget */ private void internalSetExpandedTreePaths(CustomHashtable expandedTreePaths, Widget widget, TreePath currentPath) { Item[] items = getChildren(widget); for (Item item : items) { Object data = item.getData(); TreePath childPath = data == null ? null : currentPath.createChildPath(data); if (data != null && childPath != null) { // remove the element to avoid an infinite loop // if the same element appears on a child item boolean expanded = expandedTreePaths.remove(childPath) != null; if (expanded != getExpanded(item)) { if (expanded) { createChildren(item); } setExpanded(item, expanded); } } internalSetExpandedTreePaths(expandedTreePaths, item, childPath); } } /** * Return whether the tree node representing the given element or path can * be expanded. Clients should query expandability by path if the viewer's * content provider is an {@link ITreePathContentProvider}. * <p> * The default implementation of this framework method calls * <code>hasChildren</code> on this viewer's content provider. It may be * overridden if necessary. * </p> * @see #setExpandPreCheckFilters(boolean) * @param elementOrTreePath * the element or path * @return <code>true</code> if the tree node representing the given * element can be expanded, or <code>false</code> if not */ public boolean isExpandable(Object elementOrTreePath) { Object element; TreePath path; if (elementOrTreePath instanceof TreePath) { path = (TreePath) elementOrTreePath; element = path.getLastSegment(); } else { element = elementOrTreePath; path = null; } IContentProvider cp = getContentProvider(); if (cp instanceof ITreePathContentProvider) { ITreePathContentProvider tpcp = (ITreePathContentProvider) cp; if (path == null) { // A path was not provided so try and find one Widget w = findItem(element); if (w instanceof Item) { Item item = (Item) w; path = getTreePathFromItem(item); } if (path == null) { path = new TreePath(new Object[] { element }); } } boolean hasChildren = tpcp.hasChildren(path); if (hasChildren && isExpandableCheckFilters && hasFilters()) { return getFilteredChildren(path).length > 0; } return hasChildren; } if (cp instanceof ITreeContentProvider) { ITreeContentProvider tcp = (ITreeContentProvider) cp; boolean hasChildren = tcp.hasChildren(element); if (hasChildren && isExpandableCheckFilters && hasFilters()) { return getFilteredChildren(element).length > 0; } return hasChildren; } return false; } /** * Return whether the given element is expandable. * * @param item * the tree item for the element * @param parentPath * the parent path if it is known or <code>null</code> if it * needs to be determines * @param element * the element * @return whether the given element is expandable */ private boolean isExpandable(Item item, TreePath parentPath, Object element) { Object elementOrTreePath = element; if (isTreePathContentProvider()) { if (parentPath != null) { elementOrTreePath = parentPath.createChildPath(element); } else { elementOrTreePath = getTreePathFromItem(item); } } return isExpandable(elementOrTreePath); } @Override protected void labelProviderChanged() { // we have to walk the (visible) tree and update every item Control tree = getControl(); tree.setRedraw(false); // don't pick up structure changes, but do force label updates internalRefresh(tree, getRoot(), false, true); tree.setRedraw(true); } /** * Creates a new item. * * @param parent * the parent widget * @param style * SWT style bits * @param index * if non-negative, indicates the position to insert the item * into its parent * @return the newly-created item */ protected abstract Item newItem(Widget parent, int style, int index); /** * Removes the given elements from this viewer. The selection is updated if * required. * <p> * This method should be called (by the content provider) when elements have * been removed from the model, in order to cause the viewer to accurately * reflect the model. This method only affects the viewer, not the model. * </p> * * @param elementsOrTreePaths the elements to remove */ public void remove(final Object... elementsOrTreePaths) { assertElementsNotNull(elementsOrTreePaths); if (elementsOrTreePaths.length == 0) { return; } if (checkBusy()) return; preservingSelection(() -> internalRemove(elementsOrTreePaths)); } /** * Removes the given elements from this viewer whenever they appear as * children of the given parent element. If the given elements also appear * as children of some other parent, the other parent will remain unchanged. * The selection is updated if required. * <p> * This method should be called (by the content provider) when elements have * been removed from the model, in order to cause the viewer to accurately * reflect the model. This method only affects the viewer, not the model. * </p> * * @param parent * the parent of the elements to remove * @param elements * the elements to remove * * @since 3.2 */ public void remove(final Object parent, final Object... elements) { assertElementsNotNull(elements); if (elements.length == 0) { return; } if (checkBusy()) return; preservingSelection(() -> internalRemove(parent, elements)); } /** * Removes the given element from the viewer. The selection is updated if * necessary. * <p> * This method should be called (by the content provider) when a single * element has been removed from the model, in order to cause the viewer to * accurately reflect the model. This method only affects the viewer, not * the model. Note that there is another method for efficiently processing * the simultaneous removal of multiple elements. * </p> * * @param elementsOrTreePaths * the element */ public void remove(Object elementsOrTreePaths) { remove(new Object[] { elementsOrTreePaths }); } /** * Removes all items from the given control. * * @param control * the control */ protected abstract void removeAll(Control control); /** * Removes a listener for expand and collapse events in this viewer. Has no * effect if an identical listener is not registered. * * @param listener * a tree viewer listener */ public void removeTreeListener(ITreeViewerListener listener) { treeListeners.remove(listener); } /** * This implementation of reveal() reveals the given element or tree path. */ @Override public void reveal(Object elementOrTreePath) { Assert.isNotNull(elementOrTreePath); Widget w = internalExpand(elementOrTreePath, true); if (w instanceof Item) { showItem((Item) w); } } /** * Returns the rightmost visible descendent of the given item. Returns the * item itself if it has no children. * * @param item * the item to compute the descendent of * @return the rightmost visible descendent or the item itself if it has no * children */ private Item rightMostVisibleDescendent(Item item) { Item[] children = getItems(item); if (getExpanded(item) && children != null && children.length > 0) { return rightMostVisibleDescendent(children[children.length - 1]); } return item; } @Override public Item scrollDown(int x, int y) { Item current = getItem(x, y); if (current != null) { Item next = getNextItem(current, true); showItem(next == null ? current : next); return next; } return null; } @Override public Item scrollUp(int x, int y) { Item current = getItem(x, y); if (current != null) { Item previous = getPreviousItem(current); showItem(previous == null ? current : previous); return previous; } return null; } /** * Sets the auto-expand level to be used when the input of the viewer is set * using {@link #setInput(Object)}. The value 0 means that there is no * auto-expand; 1 means that the invisible root element is expanded (since * most concrete subclasses do not show the root element, there is usually * no practical difference between using the values 0 and 1); 2 means that * top-level elements are expanded, but not their children; 3 means that * top-level elements are expanded, and their children, but not * grandchildren; and so on. * <p> * The value <code>ALL_LEVELS</code> means that all subtrees should be * expanded. * </p> * <p> * Note that in previous releases, the Javadoc for this method had an off-by * one error. See bug 177669 for details. * </p> * * @param level * non-negative level, or <code>ALL_LEVELS</code> to expand all * levels of the tree */ public void setAutoExpandLevel(int level) { expandToLevel = level; } /** * Sets the content provider used by this <code>AbstractTreeViewer</code>. * <p> * Content providers for abstract tree viewers must implement either * {@link ITreeContentProvider} or {@link ITreePathContentProvider}. */ @Override public void setContentProvider(IContentProvider provider) { // the actual check is in assertContentProviderType super.setContentProvider(provider); } @Override protected void assertContentProviderType(IContentProvider provider) { Assert.isTrue(provider instanceof ITreeContentProvider || provider instanceof ITreePathContentProvider, "Instances of AbstractTreeViewer must have a content provider " //$NON-NLS-1$ + "of type ITreeContentProvider or ITreePathContentProvider"); //$NON-NLS-1$ } /** * Sets the expand state of the given item. * * @param item * the item * @param expand * the expand state of the item */ protected abstract void setExpanded(Item item, boolean expand); /** * Sets which nodes are expanded in this viewer's tree. The given list * contains the elements that are to be expanded; all other nodes are to be * collapsed. * <p> * This method is typically used when restoring the interesting state of a * viewer captured by an earlier call to <code>getExpandedElements</code>. * </p> * * @param elements * the array of expanded elements * @see #getExpandedElements */ public void setExpandedElements(Object... elements) { assertElementsNotNull(elements); if (checkBusy()) { return; } CustomHashtable expandedElements = newHashtable(elements.length * 2 + 1); for (Object element : elements) { // Ensure item exists for element. This will materialize items for // each element and their parents, if possible. This is important // to support expanding of inner tree nodes without necessarily // expanding their parents. internalExpand(element, false); expandedElements.put(element, element); } // this will traverse all existing items, and create children for // elements that need to be expanded. If the tree contains multiple // equal elements, and those are in the set of elements to be expanded, // only the first item found for each element will be expanded. internalSetExpanded(expandedElements, getControl()); } /** * Sets which nodes are expanded in this viewer's tree. The given list * contains the tree paths that are to be expanded; all other nodes are to * be collapsed. * <p> * This method is typically used when restoring the interesting state of a * viewer captured by an earlier call to <code>getExpandedTreePaths</code>. * </p> * * @param treePaths * the array of expanded tree paths * @see #getExpandedTreePaths() * * @since 3.2 */ public void setExpandedTreePaths(TreePath... treePaths) { assertElementsNotNull((Object[]) treePaths); if (checkBusy()) return; final IElementComparer comparer = getComparer(); IElementComparer treePathComparer = new IElementComparer() { @Override public boolean equals(Object a, Object b) { return ((TreePath) a).equals(((TreePath) b), comparer); } @Override public int hashCode(Object element) { return ((TreePath) element).hashCode(comparer); } }; CustomHashtable expandedTreePaths = new CustomHashtable(treePaths.length * 2 + 1, treePathComparer); for (TreePath treePath : treePaths) { // Ensure item exists for element. This will materialize items for // each element and their parents, if possible. This is important // to support expanding of inner tree nodes without necessarily // expanding their parents. internalExpand(treePath, false); expandedTreePaths.put(treePath, treePath); } // this will traverse all existing items, and create children for // elements that need to be expanded. If the tree contains multiple // equal elements, and those are in the set of elements to be expanded, // only the first item found for each element will be expanded. internalSetExpandedTreePaths(expandedTreePaths, getControl(), new TreePath(new Object[0])); } /** * Sets whether the node corresponding to the given element or tree path is * expanded or collapsed. * * @param elementOrTreePath * the element * @param expanded * <code>true</code> if the node is expanded, and * <code>false</code> if collapsed */ public void setExpandedState(Object elementOrTreePath, boolean expanded) { Assert.isNotNull(elementOrTreePath); if (checkBusy()) return; Widget item = internalExpand(elementOrTreePath, false); if (item instanceof Item) { if (expanded) { createChildren(item); } setExpanded((Item) item, expanded); } } /** * Sets the selection to the given list of items. * * @param items * list of items (element type: * <code>org.eclipse.swt.widgets.Item</code>) */ protected abstract void setSelection(List<Item> items); /** * This implementation of setSelectionToWidget accepts a list of elements or * a list of tree paths. */ @Override protected void setSelectionToWidget(@SuppressWarnings("rawtypes") List v, boolean reveal) { if (v == null) { setSelection(new ArrayList<>(0)); return; } int size = v.size(); List<Item> newSelection = new ArrayList<>(size); for (int i = 0; i < size; ++i) { Object elementOrTreePath = v.get(i); // Use internalExpand since item may not yet be created. See // 1G6B1AR. Widget w = internalExpand(elementOrTreePath, false); if (w instanceof Item) { newSelection.add((Item) w); } else if (w == null && elementOrTreePath instanceof TreePath) { TreePath treePath = (TreePath) elementOrTreePath; Object element = treePath.getLastSegment(); if (element != null) { w = internalExpand(element, false); if (w instanceof Item) { newSelection.add((Item) w); } } } } setSelection(newSelection); // Although setting the selection in the control should reveal it, // setSelection may be a no-op if the selection is unchanged, // so explicitly reveal items in the selection here. // See bug 100565 for more details. if (reveal && newSelection.size() > 0) { // Iterate backwards so the first item in the list // is the one guaranteed to be visible for (int i = (newSelection.size() - 1); i >= 0; i--) { showItem(newSelection.get(i)); } } } /** * Shows the given item. * * @param item * the item */ protected abstract void showItem(Item item); /** * Updates the tree items to correspond to the child elements of the given * parent element. If null is passed for the children, this method obtains * them (only if needed). * * @param widget * the widget * @param parent * the parent element * @param elementChildren * the child elements, or null * @deprecated this is no longer called by the framework */ @Deprecated protected void updateChildren(Widget widget, Object parent, Object[] elementChildren) { updateChildren(widget, parent, elementChildren, true); } /** * Updates the tree items to correspond to the child elements of the given * parent element. If null is passed for the children, this method obtains * them (only if needed). * * @param widget * the widget * @param parent * the parent element * @param elementChildren * the child elements, or null * @param updateLabels * <code>true</code> to update labels for existing elements, * <code>false</code> to only update labels as needed, assuming * that labels for existing elements are unchanged. * @since 2.1 */ private void updateChildren(Widget widget, Object parent, Object[] elementChildren, boolean updateLabels) { // optimization! prune collapsed subtrees if (widget instanceof Item) { Item ti = (Item) widget; if (!getExpanded(ti)) { if (optionallyPruneChildren(ti, parent)) { // children were pruned, nothing left to do return; } // The following code is being executed if children were not pruned. // This is (as of 3.5) only the case for CheckboxTreeViewer. Item[] its = getItems(ti); if (isExpandable(ti, null, parent)) { if (its.length == 0) { // need dummy node newItem(ti, SWT.NULL, -1); return; } else if (its.length == 1 && its[0].getData() == null) { // dummy node exists, nothing left to do return; } // else fall through to normal update code below } else { for (Item it : its) { if (it.getData() != null) { disassociate(it); } it.dispose(); } // nothing left to do return; } } } // If the children weren't passed in, get them now since they're needed // below. if (elementChildren == null) { if (isTreePathContentProvider() && widget instanceof Item) { TreePath path = getTreePathFromItem((Item) widget); elementChildren = getSortedChildren(path); } else { elementChildren = getSortedChildren(parent); } } Control tree = getControl(); // WORKAROUND int oldCnt = -1; if (widget == tree) { oldCnt = getItemCount(tree); } Item[] items = getChildren(widget); // save the expanded elements CustomHashtable expanded = newHashtable(CustomHashtable.DEFAULT_CAPACITY); // assume // num // expanded // is // small for (Item item : items) { if (getExpanded(item)) { Object element = item.getData(); if (element != null) { expanded.put(element, element); } } } int min = Math.min(elementChildren.length, items.length); // dispose of surplus items, optimizing for the case where elements have // been deleted but not reordered, or all elements have been removed. int numItemsToDispose = items.length - min; if (numItemsToDispose > 0) { CustomHashtable children = newHashtable(elementChildren.length * 2); for (Object elementChild : elementChildren) { children.put(elementChild, elementChild); } int i = 0; while (numItemsToDispose > 0 && i < items.length) { Object data = items[i].getData(); if (data == null || !children.containsKey(data)) { if (data != null) { disassociate(items[i]); } items[i].dispose(); if (i + 1 < items.length) { // The components at positions i+1 through // items.length-1 in the source array are copied into // positions i through items.length-2 System.arraycopy(items, i + 1, items, i, items.length - (i + 1)); } numItemsToDispose--; } else { i++; } } } // compare first min items, and update item if necessary // need to do it in two passes: // 1: disassociate old items // 2: associate new items // because otherwise a later disassociate can remove a mapping made for // a previous associate, // making the map inconsistent for (int i = 0; i < min; ++i) { Item item = items[i]; Object oldElement = item.getData(); if (oldElement != null) { Object newElement = elementChildren[i]; if (newElement != oldElement) { if (equals(newElement, oldElement)) { // update the data to be the new element, since // although the elements // may be equal, they may still have different labels // or children Object data = item.getData(); if (data != null) { unmapElement(data, item); } item.setData(newElement); mapElement(newElement, item); } else { disassociate(item); // Clear the text and image to force a label update item.setImage(null); item.setText("");//$NON-NLS-1$ } } } } for (int i = 0; i < min; ++i) { Item item = items[i]; Object newElement = elementChildren[i]; if (item.getData() == null) { // old and new elements are not equal associate(newElement, item); updatePlus(item, newElement); updateItem(item, newElement); } else { // old and new elements are equal updatePlus(item, newElement); if (updateLabels) { updateItem(item, newElement); } else { associate(newElement, item); } } } // Restore expanded state for items that changed position. // Make sure setExpanded is called after updatePlus, since // setExpanded(false) fails if item has no children. // Need to call setExpanded for both expanded and unexpanded // cases since the expanded state can change either way. // This needs to be done in a second loop, see bug 148025. for (int i = 0; i < min; ++i) { Item item = items[i]; Object newElement = elementChildren[i]; setExpanded(item, expanded.containsKey(newElement)); } // add any remaining elements if (min < elementChildren.length) { for (int i = min; i < elementChildren.length; ++i) { createTreeItem(widget, elementChildren[i], -1); } // Need to restore expanded state in a separate pass // because createTreeItem does not return the new item. // Avoid doing this unless needed. if (expanded.size() > 0) { // get the items again, to include the new items items = getChildren(widget); for (int i = min; i < elementChildren.length; ++i) { // Restore expanded state for items that changed position. // Make sure setExpanded is called after updatePlus (called // in createTreeItem), since // setExpanded(false) fails if item has no children. // Only need to call setExpanded if element was expanded // since new items are initially unexpanded. if (expanded.containsKey(elementChildren[i])) { setExpanded(items[i], true); } } } } // WORKAROUND if (widget == tree && oldCnt == 0 && getItemCount(tree) != 0) { // System.out.println("WORKAROUND setRedraw"); tree.setRedraw(false); tree.setRedraw(true); } } /** Returns true if children were pruned */ /*package*/ boolean optionallyPruneChildren(Item item, Object element) { // need a dummy node if element is expandable; // but try to avoid recreating the dummy node boolean needDummy = isExpandable(item, null, element); boolean haveDummy = false; // remove all children Item[] items = getItems(item); for (Item child : items) { if (child.getData() != null) { disassociate(child); child.dispose(); } else { if (needDummy && !haveDummy) { haveDummy = true; } else { child.dispose(); } } } if (needDummy && !haveDummy) { newItem(item, SWT.NULL, -1); } return true; } /** * Not to be called by clients. Return the items to be refreshed as part of * an update. elementChildren are the new elements. * * @param widget widget to get children for * @param elementChildren unused * @since 3.4 * @return Item[] * * @deprecated This method was inadvertently released as API but is not * intended to be called by clients. */ @Deprecated public Item[] getChildren(Widget widget, Object[] elementChildren) { return getChildren(widget); } /** * Updates the "+"/"-" icon of the tree node from the given element. It * calls <code>isExpandable</code> to determine whether an element is * expandable. * * @param item * the item * @param element * the element */ protected void updatePlus(Item item, Object element) { boolean hasPlus = getItemCount(item) > 0; boolean needsPlus = isExpandable(item, null, element); boolean removeAll = false; boolean addDummy = false; Object data = item.getData(); if (data != null && equals(element, data)) { // item shows same element if (hasPlus != needsPlus) { if (needsPlus) { addDummy = true; } else { removeAll = true; } } } else { // item shows different element removeAll = true; addDummy = needsPlus; // we cannot maintain expand state so collapse it setExpanded(item, false); } if (removeAll) { // remove all children Item[] items = getItems(item); for (Item item2 : items) { if (item2.getData() != null) { disassociate(item2); } item2.dispose(); } } if (addDummy) { newItem(item, SWT.NULL, -1); // append a dummy } } /** * Gets the expanded elements that are visible to the user. An expanded * element is only visible if the parent is expanded. * * @return the visible expanded elements * @since 2.0 */ public Object[] getVisibleExpandedElements() { ArrayList<Object> v = new ArrayList<>(); internalCollectVisibleExpanded(v, getControl()); return v.toArray(); } private void internalCollectVisibleExpanded(ArrayList<Object> result, Widget widget) { Item[] items = getChildren(widget); for (Item item : items) { if (getExpanded(item)) { Object data = item.getData(); if (data != null) { result.add(data); } // Only recurse if it is expanded - if // not then the children aren't visible internalCollectVisibleExpanded(result, item); } } } /** * Returns the tree path for the given item. * * @param item item to get path for * @return {@link TreePath} * * @since 3.2 */ protected TreePath getTreePathFromItem(Item item) { LinkedList<Object> segments = new LinkedList<>(); while (item != null) { Object segment = item.getData(); Assert.isNotNull(segment); segments.addFirst(segment); item = getParentItem(item); } return new TreePath(segments.toArray()); } /** * The <code>AbstractTreeViewer</code> implementation of this method returns * the result as an <code>ITreeSelection</code>. * <p> * Call {@link #getStructuredSelection()} instead to get an instance of * <code>ITreeSelection</code> directly. * </p> * Subclasses do not typically override this method, but implement * <code>getSelectionFromWidget(List)</code> instead. If they override this * method, they should return an <code>ITreeSelection</code> as well. * * @since 3.2 */ @Override public ISelection getSelection() { Control control = getControl(); if (control == null || control.isDisposed()) { return TreeSelection.EMPTY; } Widget[] items = getSelection(getControl()); ArrayList<TreePath> list = new ArrayList<>(items.length); for (Widget item : items) { if (item.getData() != null) { list.add(getTreePathFromItem((Item) item)); } } return new TreeSelection(list.toArray(new TreePath[list.size()]), getComparer()); } /** * Returns the <code>ITreeSelection</code> of this viewer. * <p> * Subclasses whose {@link #getSelection()} specifies to return a more * specific type should also override this method and return that type. * </p> * * @return ITreeSelection * @throws ClassCastException * if the selection of the viewer is not an instance of * ITreeSelection * @since 3.11 */ @Override public ITreeSelection getStructuredSelection() throws ClassCastException { ISelection selection = getSelection(); if (selection instanceof ITreeSelection) { return (ITreeSelection) selection; } throw new ClassCastException(getClass().getName() + " should return an instance of ITreeSelection from its getSelection() method."); //$NON-NLS-1$ } @Override protected void setSelectionToWidget(ISelection selection, boolean reveal) { if (selection instanceof ITreeSelection) { ITreeSelection treeSelection = (ITreeSelection) selection; setSelectionToWidget(Arrays.asList(treeSelection.getPaths()), reveal); } else { super.setSelectionToWidget(selection, reveal); } } /** * Returns a list of tree paths corresponding to expanded nodes in this * viewer's tree, including currently hidden ones that are marked as * expanded but are under a collapsed ancestor. * <p> * This method is typically used when preserving the interesting state of a * viewer; <code>setExpandedElements</code> is used during the restore. * </p> * * @return the array of expanded tree paths * @see #setExpandedElements * * @since 3.2 */ public TreePath[] getExpandedTreePaths() { ArrayList<Item> items = new ArrayList<>(); internalCollectExpandedItems(items, getControl()); ArrayList<TreePath> result = new ArrayList<>(items.size()); for (Item item : items) { TreePath treePath = getTreePathFromItem(item); if (treePath != null) { result.add(treePath); } } return result.toArray(new TreePath[items.size()]); } private boolean isTreePathContentProvider() { return getContentProvider() instanceof ITreePathContentProvider; } /** * Inserts the given element as a new child element of the given parent * element at the given position. If this viewer has a sorter, the position * is ignored and the element is inserted at the correct position in the * sort order. * <p> * This method should be called (by the content provider) when elements have * been added to the model, in order to cause the viewer to accurately * reflect the model. This method only affects the viewer, not the model. * </p> * * @param parentElementOrTreePath * the parent element, or the tree path to the parent * @param element * the element * @param position * a 0-based position relative to the model, or -1 to indicate * the last position * * @since 3.2 */ public void insert(Object parentElementOrTreePath, Object element, int position) { Assert.isNotNull(parentElementOrTreePath); Assert.isNotNull(element); if (checkBusy()) return; if (getComparator() != null || hasFilters()) { add(parentElementOrTreePath, new Object[] { element }); return; } Widget[] items; if (internalIsInputOrEmptyPath(parentElementOrTreePath)) { items = new Widget[] { getControl() }; } else { items = internalFindItems(parentElementOrTreePath); } for (Widget widget : items) { if (widget instanceof Item) { Item item = (Item) widget; Item[] childItems = getChildren(item); if (getExpanded(item) || (childItems.length > 0 && childItems[0].getData() != null)) { // item has real children, go ahead and add int insertionPosition = position; if (insertionPosition == -1) { insertionPosition = getItemCount(item); } createTreeItem(item, element, insertionPosition); } else { Object parentElement = parentElementOrTreePath; if (element instanceof TreePath) parentElement = ((TreePath) parentElement).getLastSegment(); updatePlus(item, parentElement); } } else { int insertionPosition = position; if (insertionPosition == -1) { insertionPosition = getItemCount((Control) widget); } createTreeItem(widget, element, insertionPosition); } } } @Override protected Widget getColumnViewerOwner(int columnIndex) { // Return null by default return null; } /** * This implementation of {@link #getItemAt(Point)} returns null to ensure * API backwards compatibility. Subclasses should override. * * @since 3.3 */ @Override protected Item getItemAt(Point point) { return null; } /** * This implementation of {@link #createViewerEditor()} returns null to ensure * API backwards compatibility. Subclasses should override. * * @since 3.3 */ @Override protected ColumnViewerEditor createViewerEditor() { return null; } /** * Returns the number of columns of this viewer. * <p><b>Subclasses should overwrite this method, which has a default * implementation (returning 0) for API backwards compatility reasons</b></p> * * @return the number of columns * * @since 3.3 */ @Override protected int doGetColumnCount() { return 0; } /** * This implementation of buildLabel handles tree paths as well as elements. * * @param updateLabel * the ViewerLabel to collect the result in * @param elementOrPath * the element or tree path for which a label should be built * * @see org.eclipse.jface.viewers.StructuredViewer#buildLabel(org.eclipse.jface.viewers.ViewerLabel, * java.lang.Object) */ @Override protected void buildLabel(ViewerLabel updateLabel, Object elementOrPath) { Object element; if (elementOrPath instanceof TreePath) { TreePath path = (TreePath) elementOrPath; IBaseLabelProvider provider = getLabelProvider(); if (provider instanceof ITreePathLabelProvider) { ITreePathLabelProvider pprov = (ITreePathLabelProvider) provider; buildLabel(updateLabel, path, pprov); return; } element = path.getLastSegment(); } else { element = elementOrPath; } super.buildLabel(updateLabel, element); } /** * Returns true if the given object is either the input or an empty tree path. * * @param elementOrTreePath an element which could either be the viewer's input, or a tree path * * @return <code>true</code> if the given object is either the input or an empty tree path, * <code>false</code> otherwise. * @since 3.3 */ final protected boolean internalIsInputOrEmptyPath(final Object elementOrTreePath) { if (elementOrTreePath.equals(getRoot())) return true; if (!(elementOrTreePath instanceof TreePath)) return false; return ((TreePath) elementOrTreePath).getSegmentCount() == 0; } /* * Subclasses should implement */ @Override protected ViewerRow getViewerRowFromItem(Widget item) { return null; } /** * Instructs {@link #isExpandable(Object)} to consult filters to more accurately * determine if an item can be expanded. * <p> * Setting this value to <code>true</code> will affect performance of the tree * viewer. * </p><p> * To improve performance, by default the tree viewer does not consult filters when * determining if a tree node could be expanded. * </p> * @param checkFilters <code>true</code> to instruct tree viewer to consult filters * @see #isExpandable(Object) * @since 3.8 */ public void setExpandPreCheckFilters(boolean checkFilters) { if (checkFilters != isExpandableCheckFilters) { this.isExpandableCheckFilters = checkFilters; refresh(); } } }