Java tutorial
/******************************************************************************* * Copyright (c) 2005, 2010 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.thym.ui.plugins.internal; import java.util.*; import java.util.List; import org.eclipse.jface.layout.GridDataFactory; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.viewers.*; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.ScrolledComposite; import org.eclipse.swt.events.*; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.*; /** * Based on {@link org.eclipse.equinox.internal.p2.ui.discovery.util.ControlListViewer}. * */ @SuppressWarnings("restriction") public abstract class PluginControlListViewer extends StructuredViewer { Composite control; private final ScrolledComposite scrolled; private final Composite noEntryArea; protected boolean hasFocus; /** * Create a new instance of the receiver with a control that is a child of parent with style style. * * @param parent * @param style */ public PluginControlListViewer(Composite parent, int style) { scrolled = new ScrolledComposite(parent, style | SWT.V_SCROLL); int height = JFaceResources.getDefaultFont().getFontData()[0].getHeight(); scrolled.getVerticalBar().setIncrement(height * 2); scrolled.setExpandHorizontal(true); scrolled.setExpandVertical(true); // bug 311276: can cause unintended scrolling of viewer //scrolled.setShowFocusedControl(true); control = new Composite(scrolled, SWT.NONE) { // @Override // public boolean setFocus() { // forceFocus(); // return true; // } @Override public void setVisible(boolean visible) { super.setVisible(visible); if (visible) { updateSize(control); } } }; GridLayout layout = new GridLayout(); layout.marginHeight = 0; layout.marginWidth = 0; layout.horizontalSpacing = 0; layout.verticalSpacing = 0; control.setLayout(layout); control.setBackgroundMode(SWT.INHERIT_FORCE); control.addControlListener(new ControlListener() { public void controlMoved(ControlEvent e) { updateVisibleItems(); } public void controlResized(ControlEvent e) { updateVisibleItems(); } }); scrolled.setContent(control); hookControl(control); noEntryArea = new Composite(scrolled, SWT.NONE); doCreateNoEntryArea(noEntryArea); scrolled.setExpandHorizontal(true); scrolled.setExpandVertical(true); scrolled.addControlListener(new ControlAdapter() { @Override public void controlResized(ControlEvent e) { updateSize(scrolled.getContent()); } }); control.addTraverseListener(new TraverseListener() { private boolean handleEvent = true; public void keyTraversed(TraverseEvent event) { if (!handleEvent) { return; } switch (event.detail) { case SWT.TRAVERSE_ARROW_PREVIOUS: { Control[] children = control.getChildren(); if (children.length > 0) { boolean selected = false; for (int i = 0; i < children.length; i++) { ControlListItem<?> item = (ControlListItem<?>) children[i]; if (item.isSelected()) { selected = true; if (i > 0) { setSelection(new StructuredSelection(children[i - 1].getData()), true); } break; } } if (!selected) { setSelection(new StructuredSelection(children[children.length - 1].getData()), true); } } break; } case SWT.TRAVERSE_ARROW_NEXT: { Control[] children = control.getChildren(); if (children.length > 0) { boolean selected = false; for (int i = 0; i < children.length; i++) { ControlListItem<?> item = (ControlListItem<?>) children[i]; if (item.isSelected()) { selected = true; if (i < children.length - 1) { setSelection(new StructuredSelection(children[i + 1].getData()), true); } break; } } if (!selected) { setSelection(new StructuredSelection(children[0].getData()), true); } } break; } default: handleEvent = false; event.doit = true; Control control = PluginControlListViewer.this.control; Shell shell = control.getShell(); while (control != null) { if (control.traverse(event.detail)) { break; } if (!event.doit || control == shell) { break; } control = control.getParent(); } handleEvent = true; break; } } }); } protected void doCreateNoEntryArea(Composite parent) { } public void add(Object[] elements) { ViewerComparator sorter = getComparator(); // Use a Set in case we are getting something added that exists Set<Object> newItems = new HashSet<Object>(elements.length); Control[] existingChildren = control.getChildren(); for (Control element : existingChildren) { if (element.getData() != null) { newItems.add(element.getData()); } } for (Object element : elements) { if (element != null) { newItems.add(element); } } Object[] infos = new Object[newItems.size()]; newItems.toArray(infos); if (sorter != null) { sorter.sort(this, infos); } // Update with the new elements to prevent flash for (Control element : existingChildren) { ((ControlListItem<?>) element).dispose(); } for (int i = 0; i < infos.length; i++) { createNewItem(infos[i]); } control.layout(true); doUpdateContent(); } private void updateSize(Control c) { if (c == null) { return; } // XXX need a small offset in case the list has a scroll bar Point size = c.computeSize(scrolled.getClientArea().width - 20, SWT.DEFAULT, true); c.setSize(size); scrolled.setMinSize(size); } protected void doUpdateContent() { if (control.getChildren().length > 0) { updateSize(control); scrolled.setContent(control); updateSize(control); } else { updateSize(noEntryArea); scrolled.setContent(noEntryArea); } } /** * Create a new item for info. * * @param element * @return ControlListItem */ private ControlListItem<?> createNewItem(Object element) { final ControlListItem<?> item = doCreateItem(control, element); // item.getChildren()[0].addPaintListener(new PaintListener() { // public void paintControl(PaintEvent e) { // if (hasFocus && item.isSelected()) { // Point size = item.getSize(); // e.gc.setForeground(e.gc.getDevice().getSystemColor(SWT.COLOR_DARK_GRAY)); // e.gc.setLineDash(new int[] { 1, 2 }); // e.gc.drawRoundRectangle(0, 0, size.x - 1, size.y - 1, 5, 5); // } // } // }); item.setIndexListener(new ControlListItem.IndexListener() { public void selectNext() { Control[] children = control.getChildren(); for (int i = 0; i < children.length; i++) { if (item == children[i]) { if (i < children.length - 1) { setSelection(new StructuredSelection(children[i + 1].getData())); } break; } } } public void selectPrevious() { Control[] children = control.getChildren(); for (int i = 0; i < children.length; i++) { if (item == children[i]) { if (i > 0) { setSelection(new StructuredSelection(children[i - 1].getData())); } break; } } } public void select() { setSelection(new StructuredSelection(item.getData())); setFocus(); } public void open() { handleOpen(); } }); GridDataFactory.fillDefaults().grab(true, false).applyTo(item); // Refresh to populate with the current tasks return item; } protected abstract ControlListItem<?> doCreateItem(Composite parent, Object element); @Override protected ControlListItem<?> doFindInputItem(Object element) { return null; } @Override protected ControlListItem<?> doFindItem(Object element) { Control[] children = control.getChildren(); for (Control child : children) { if (child.isDisposed() || child.getData() == null) { continue; } if (child.getData().equals(element)) { return (ControlListItem<?>) child; } } return null; } @Override protected void doUpdateItem(Widget item, Object element, boolean fullMap) { if (usingElementMap()) { unmapElement(item); } item.dispose(); add(new Object[] { element }); } @Override public ScrolledComposite getControl() { return scrolled; } @Override protected List<?> getSelectionFromWidget() { Control[] children = control.getChildren(); ArrayList<Object> selection = new ArrayList<Object>(children.length); for (Control child : children) { ControlListItem<?> item = (ControlListItem<?>) child; if (item.isSelected() && item.getData() != null) { selection.add(item.getData()); } } return selection; } protected void handleOpen() { Control c = getControl(); if (c != null && !c.isDisposed()) { ISelection selection = getSelection(); fireOpen(new OpenEvent(this, selection)); } } @Override protected void inputChanged(Object input, Object oldInput) { super.inputChanged(input, oldInput); refreshAll(); doUpdateContent(); } @Override protected void internalRefresh(Object element) { if (element == null) { return; } if (element.equals(getRoot())) { refreshAll(); return; } Widget widget = findItem(element); if (widget == null) { add(new Object[] { element }); return; } ((ControlListItem<?>) widget).refresh(); updateSize(control); } public void remove(Object[] elements) { for (Object element : elements) { Widget item = doFindItem(element); if (item != null) { unmapElement(element); item.dispose(); } } control.layout(true); doUpdateContent(); } @Override public void reveal(Object element) { Control control = doFindItem(element); if (control != null) { revealControl(control); } } private void revealControl(Control control) { Rectangle clientArea = scrolled.getClientArea(); Point origin = scrolled.getOrigin(); Point location = control.getLocation(); Point size = control.getSize(); if (location.y + size.y > origin.y + clientArea.height) { scrolled.setOrigin(origin.x, location.y + size.y - clientArea.height); } if (location.y < origin.y) { scrolled.setOrigin(origin.x, location.y); } } @SuppressWarnings({ "rawtypes", "unchecked" }) @Override protected void setSelectionToWidget(List list, boolean reveal) { if (list != null) { //see bug 423628. This should be suppressed as: //1. it will cause warning at build time. //2. should be possible to fix once swt/jface enables generics for good. HashSet<Object> elements = new HashSet<Object>(list); Control[] children = control.getChildren(); for (Control c : children) { ControlListItem child = (ControlListItem) c; boolean selected = elements.contains(child.getData()); if (selected != child.isSelected()) { child.setSelected(selected); } if (reveal && selected) { revealControl(child); reveal = false; } } } else { Control[] children = control.getChildren(); for (Control c : children) { ControlListItem child = (ControlListItem) c; if (child.isSelected()) { child.setSelected(false); } } } } /** * Set focus on the current selection. */ public void setFocus() { Control[] children = control.getChildren(); if (children.length > 0) { // causes the item's tool bar to get focus when clicked which is undesirable // for (Control element : children) { // ControlListItem item = (ControlListItem) element; // if (item.isSelected()) { // if (item.setFocus()) { // return; // } // } // } control.forceFocus(); } else { noEntryArea.setFocus(); } } /** * Refresh everything as the root is being refreshed. */ private void refreshAll() { Object[] infos = getSortedChildren(getRoot()); Control[] existingChildren = control.getChildren(); for (Control element : existingChildren) { element.dispose(); } for (int i = 0; i < infos.length; i++) { createNewItem(infos[i]); } control.layout(true); doUpdateContent(); } /** * Set the virtual items to be visible or not depending on the displayed area. */ private void updateVisibleItems() { Control[] children = control.getChildren(); int top = scrolled.getOrigin().y; int bottom = top + scrolled.getParent().getBounds().height; for (Control element : children) { ControlListItem<?> item = (ControlListItem<?>) element; item.setDisplayed(top, bottom); } control.layout(true); } }