Java tutorial
/******************************************************************************* * Copyright (c) 2008, 2016 Innoopract Informationssysteme GmbH 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: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.widgets; import static org.eclipse.swt.internal.widgets.MarkupUtil.isMarkupEnabledFor; import org.eclipse.rap.rwt.RWT; import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCA; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.events.ControlAdapter; import org.eclipse.swt.events.ControlEvent; import org.eclipse.swt.events.ExpandAdapter; import org.eclipse.swt.events.ExpandEvent; import org.eclipse.swt.events.ExpandListener; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.internal.widgets.IExpandBarAdapter; import org.eclipse.swt.internal.widgets.IItemHolderAdapter; import org.eclipse.swt.internal.widgets.ItemHolder; import org.eclipse.swt.internal.widgets.expandbarkit.ExpandBarLCA; /** * Instances of this class support the layout of selectable expand bar items. * <p> * The item children that may be added to instances of this class must be of * type <code>ExpandItem</code>. * </p> * <p> * <dl> * <dt><b>Styles:</b></dt> * <dd>V_SCROLL</dd> * <dt><b>Events:</b></dt> * <dd>Expand, Collapse</dd> * </dl> * </p> * <p> * IMPORTANT: This class is <em>not</em> intended to be subclassed. * </p> * * @see ExpandItem * @see ExpandEvent * @see ExpandListener * @see ExpandAdapter * @since 1.2 */ public class ExpandBar extends Composite { ExpandItem focusItem; int spacing; int allItemsHeight; private transient IExpandBarAdapter expandBarAdapter; private final ItemHolder<ExpandItem> itemHolder; private final ResizeListener resizeListener; /** * Constructs a new instance of this class given its parent and a style value * describing its behavior and appearance. * <p> * The style value is either one of the style constants defined in class * <code>SWT</code> which is applicable to instances of this class, or must * be built by <em>bitwise OR</em>'ing together (that is, using the * <code>int</code> "|" operator) two or more of those <code>SWT</code> * style constants. The class description lists the style constants that are * applicable to the class. Style bits are also inherited from superclasses. * </p> * * @param parent a composite control which will be the parent of the new * instance (cannot be null) * @param style the style of control to construct * @exception IllegalArgumentException * <ul> * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the parent</li> * <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed * subclass</li> * </ul> * @see Widget#checkSubclass * @see Widget#getStyle */ public ExpandBar(Composite parent, int style) { super(parent, checkStyle(style)); spacing = 4; resizeListener = new ResizeListener(); addControlListener(resizeListener); itemHolder = new ItemHolder<>(ExpandItem.class); } /** * Adds the listener to the collection of listeners who will be notified when * an item in the receiver is expanded or collapsed by sending it one of the * messages defined in the <code>ExpandListener</code> interface. * * @param listener the listener which should be notified * @exception IllegalArgumentException * <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> * @see ExpandListener * @see #removeExpandListener */ public void addExpandListener(ExpandListener listener) { checkWidget(); if (listener == null) { error(SWT.ERROR_NULL_ARGUMENT); } TypedListener typedListener = new TypedListener(listener); addListener(SWT.Expand, typedListener); addListener(SWT.Collapse, typedListener); } /** * Removes the listener from the collection of listeners who will be notified * when items in the receiver are expanded or collapsed. * * @param listener the listener which should no longer be notified * @exception IllegalArgumentException * <ul> * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> * @see ExpandListener * @see #addExpandListener */ public void removeExpandListener(ExpandListener listener) { checkWidget(); if (listener == null) { error(SWT.ERROR_NULL_ARGUMENT); } removeListener(SWT.Expand, listener); removeListener(SWT.Collapse, listener); } @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); int height = 0, width = 0; int itemCount = getItemCount(); if (wHint == SWT.DEFAULT || hHint == SWT.DEFAULT) { if (itemCount > 0) { height += spacing; for (int i = 0; i < itemCount; i++) { ExpandItem item = getItem(i); BoxDimensions itemBorder = item.getItemBorder(); height += item.getHeaderHeight() + itemBorder.top + itemBorder.bottom; if (item.expanded) { height += item.height; } height += spacing; int barPreferredWidth = item.getPreferredWidth() + 2 * spacing; width = Math.max(width, barPreferredWidth); } } } if (width == 0) { width = DEFAULT_WIDTH; } if (height == 0) { height = DEFAULT_HEIGHT; } if (wHint != SWT.DEFAULT) { width = wHint; } if (hHint != SWT.DEFAULT) { height = hHint; } BoxDimensions border = getBorder(); width += border.left + border.right; height += border.top + border.bottom; if ((style & SWT.V_SCROLL) != 0) { width += getVerticalBar().getSize().x; } return new Point(width, height); } void createItem(ExpandItem item, int index) { itemHolder.insert(item, index); if (focusItem == null) { focusItem = item; } layoutItems(index); } void destroyItem(ExpandItem item) { int index = 0; int itemCount = getItemCount(); for (int i = 0; i < itemCount; i++) { if (getItem(i) == item) { index = i; } } if (index != itemCount) { if (item == focusItem) { int focusIndex = index > 0 ? index - 1 : 1; if (focusIndex < itemCount) { focusItem = getItem(focusIndex); } else { focusItem = null; } } itemHolder.remove(item); layoutItems(index); } } @Override Control findBackgroundControl() { Control control = super.findBackgroundControl(); if (!isAppThemed()) { if (control == null) { control = this; } } return control; } /** * Returns the item at the given, zero-relative index in the receiver. Throws * an exception if the index is out of range. * * @param index the index of the item to return * @return the item at the given index * @exception IllegalArgumentException * <ul> * <li>ERROR_INVALID_RANGE - if the index is not between 0 and * the number of elements in the list minus 1 (inclusive)</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public ExpandItem getItem(int index) { checkWidget(); return itemHolder.getItem(index); } /** * Returns the number of items contained in the receiver. * * @return the number of items * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public int getItemCount() { checkWidget(); return itemHolder.size(); } /** * Returns an array of <code>ExpandItem</code>s which are the items in the * receiver. * <p> * Note: This is not the actual structure used by the receiver to maintain its * list of items, so modifying the array will not affect the receiver. * </p> * * @return the items in the receiver * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public ExpandItem[] getItems() { checkWidget(); return itemHolder.getItems(); } /** * Returns the receiver's spacing. * * @return the spacing * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public int getSpacing() { checkWidget(); return spacing; } /** * Searches the receiver's list starting at the first item (index 0) until an * item is found that is equal to the argument, and returns the index of that * item. If no item is found, returns -1. * * @param item the search item * @return the index of the item * @exception IllegalArgumentException * <ul> * <li>ERROR_NULL_ARGUMENT - if the item is null</li> * <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li> * </ul> * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public int indexOf(ExpandItem item) { checkWidget(); if (item == null) { error(SWT.ERROR_NULL_ARGUMENT); } if (item.isDisposed()) { error(SWT.ERROR_INVALID_ARGUMENT); } return itemHolder.indexOf(item); } void layoutItems(int index) { if (!isInDispose()) { int itemCount = getItemCount(); if (index < itemCount) { int y = spacing; for (int i = 0; i < index; i++) { ExpandItem item = getItem(i); if (item.expanded) { y += item.height; } BoxDimensions itemBorder = item.getItemBorder(); y += item.getHeaderHeight() + itemBorder.top + itemBorder.bottom + spacing; } for (int i = index; i < itemCount; i++) { ExpandItem item = getItem(i); item.setBounds(spacing, y, 0, 0, true, false); if (item.expanded) { y += item.height; } BoxDimensions itemBorder = item.getItemBorder(); y += item.getHeaderHeight() + itemBorder.top + itemBorder.bottom + spacing; } } // Calculate all items size if (itemCount > 0) { ExpandItem lastItem = getItem(itemCount - 1); allItemsHeight = lastItem.y + lastItem.getBounds().height; } updateScrollBars(); // Set items width based on scrollbar visibility Rectangle bounds = getBounds(); BoxDimensions border = getBorder(); int scrollBarWidth = getVScrollBarWidth(); for (int i = 0; i < itemCount; i++) { ExpandItem item = getItem(i); Rectangle itemBounds = item.getBounds(); if (isVScrollBarVisible()) { if (this.getOrientation() == SWT.RIGHT_TO_LEFT) { itemBounds.x = spacing + scrollBarWidth; } int width = bounds.width - scrollBarWidth - (border.left + border.right) - 2 * spacing; item.setBounds(itemBounds.x, itemBounds.y, width, item.height, true, true); } else { int width = bounds.width - (border.left + border.right) - 2 * spacing; item.setBounds(spacing, itemBounds.y, width, item.height, true, true); } } } } /** * Sets the receiver's spacing. Spacing specifies the number of pixels * allocated around each item. * * @exception SWTException * <ul> * <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the * thread that created the receiver</li> * </ul> */ public void setSpacing(int spacing) { checkWidget(); if (spacing >= 0) { if (spacing != this.spacing) { this.spacing = spacing; layoutItems(0); } } } @Override public void setOrientation(int orientation) { super.setOrientation(orientation); layoutItems(0); } @Override public void setData(String key, Object value) { if (!RWT.MARKUP_ENABLED.equals(key) || !isMarkupEnabledFor(this)) { super.setData(key, value); } } void showItem(ExpandItem item) { Control control = item.control; if (control != null && !control.isDisposed()) { control.setVisible(item.expanded); } int index = indexOf(item); layoutItems(index + 1); } @Override protected void checkSubclass() { if (!isValidSubclass()) { error(SWT.ERROR_INVALID_SUBCLASS); } } static int checkStyle(int style) { int aStyle = style & ~SWT.H_SCROLL; return aStyle; } boolean isAppThemed() { return false; } private void updateScrollBars() { ScrollBar vScroll = getVerticalBar(); if (vScroll != null) { BoxDimensions border = getBorder(); int availableHeight = getBounds().height - (border.top + border.bottom) - spacing; vScroll.setVisible(allItemsHeight > availableHeight); } } private boolean isVScrollBarVisible() { ScrollBar vScroll = getVerticalBar(); return vScroll != null && vScroll.getVisible(); } Rectangle getBottomSpacingBounds() { return new Rectangle(spacing, allItemsHeight, 10, spacing); } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == IItemHolderAdapter.class) { return (T) itemHolder; } if (adapter == IExpandBarAdapter.class) { if (expandBarAdapter == null) { expandBarAdapter = new ExpandBarAdapter(); } return (T) expandBarAdapter; } if (adapter == WidgetLCA.class) { return (T) ExpandBarLCA.INSTANCE; } return super.getAdapter(adapter); } ///////////////////// // Destroy expand bar @Override void releaseWidget() { if (resizeListener != null) { removeControlListener(resizeListener); } super.releaseWidget(); } @Override void releaseChildren() { Item[] expandItems = new ExpandItem[getItemCount()]; System.arraycopy(getItems(), 0, expandItems, 0, getItems().length); for (int i = 0; i < expandItems.length; i++) { if (expandItems[i] != null) { expandItems[i].dispose(); } } } //////////////////////////// // Helping methods - various @Override int getVScrollBarWidth() { int result = 0; if ((style & SWT.V_SCROLL) != 0) { result = getVerticalBar().getSize().x; } return result; } /////////////////// // Skinning support @Override void reskinChildren(int flags) { ExpandItem[] items = getItems(); if (items != null) { for (int i = 0; i < items.length; i++) { ExpandItem item = items[i]; if (item != null) { item.reskin(flags); } } } super.reskinChildren(flags); } private final class ExpandBarAdapter implements IExpandBarAdapter { @Override public Rectangle getBounds(ExpandItem item) { return item.getBounds(); } @Override public Rectangle getBottomSpacingBounds() { return ExpandBar.this.getBottomSpacingBounds(); } } private final class ResizeListener extends ControlAdapter { @Override public void controlResized(ControlEvent event) { layoutItems(0); } } }