Java tutorial
/* ****************************************************************************** * Copyright (c) 2006-2012 XMind Ltd. and others. * * This file is a part of XMind 3. XMind releases 3 and * above are dual-licensed under the Eclipse Public License (EPL), * which is available at http://www.eclipse.org/legal/epl-v10.html * and the GNU Lesser General Public License (LGPL), * which is available at http://www.gnu.org/licenses/lgpl.html * See http://www.xmind.net/license.html for details. * * Contributors: * XMind Ltd. - initial API and implementation *******************************************************************************/ package org.xmind.ui.richtext; import java.util.ArrayList; import java.util.List; import org.eclipse.jface.action.Action; import org.eclipse.jface.action.ContributionItem; import org.eclipse.jface.action.ExternalActionManager; import org.eclipse.jface.action.IAction; import org.eclipse.jface.action.IContributionManagerOverrides; import org.eclipse.jface.action.IMenuListener; import org.eclipse.jface.action.IMenuManager; import org.eclipse.jface.action.MenuManager; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.resource.LocalResourceManager; import org.eclipse.jface.resource.ResourceManager; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Menu; import org.eclipse.swt.widgets.ToolBar; import org.eclipse.swt.widgets.ToolItem; import org.eclipse.swt.widgets.Widget; public class AlignmentGroup extends ContributionItem { private List<IAction> actions = new ArrayList<IAction>(); private IAction currentAction = null; private IPropertyChangeListener actionListener = null; /** * Listener for SWT tool item widget events. */ private Listener toolItemListener; /** * The widget created for this item; <code>null</code> before creation and * after disposal. */ private ToolItem widget = null; /** * Listener for action property change notifications. */ private IPropertyChangeListener currentActionListener = null; private MenuManager dropDownMenuManager = null; /** * Remembers all images in use by this contribution item */ private LocalResourceManager imageManager; public void add(IAction action) { actions.add(action); action.addPropertyChangeListener(getActionListener()); if (currentAction == null) { setCurrentAction(action); } } public void remove(IAction action) { action.removePropertyChangeListener(getActionListener()); actions.remove(action); if (currentAction == action) { setCurrentAction(actions.isEmpty() ? null : actions.get(0)); } } public IAction getCurrentAction() { return currentAction; } public void setCurrentAction(IAction action) { if (this.currentAction != null && currentActionListener != null) { this.currentAction.removePropertyChangeListener(currentActionListener); } this.currentAction = action; if (action != null) { action.setChecked(true); } for (IAction a : actions) { if (a != action) { a.setChecked(false); } } if (action != null) { if (widget != null && !widget.isDisposed()) { action.addPropertyChangeListener(getCurrentActionListener()); } } update(null); } private IPropertyChangeListener getActionListener() { if (actionListener == null) { actionListener = new IPropertyChangeListener() { public void propertyChange(PropertyChangeEvent event) { actionPropertyChange(event); } }; } return actionListener; } protected void actionPropertyChange(PropertyChangeEvent event) { IAction triggerAction = (IAction) event.getSource(); String property = event.getProperty(); if (IAction.CHECKED.equals(property) && Boolean.TRUE.equals(event.getNewValue())) { setCurrentAction(triggerAction); } } // public void fill(Menu menu, int index) { // for (IAction action : actions) { // new ActionContributionItem(action).fill(menu, index++); // } // } // public void fill(ToolBar parent, int index) { if (widget == null && parent != null) { int flags = SWT.DROP_DOWN; ToolItem ti = null; if (index >= 0) { ti = new ToolItem(parent, flags, index); } else { ti = new ToolItem(parent, flags); } ti.setData(this); ti.addListener(SWT.Selection, getToolItemListener()); ti.addListener(SWT.Dispose, getToolItemListener()); widget = ti; update(null); // Attach some extra listeners. if (currentAction != null) currentAction.addPropertyChangeListener(getCurrentActionListener()); // } } } private IPropertyChangeListener getCurrentActionListener() { if (currentActionListener == null) { currentActionListener = new IPropertyChangeListener() { public void propertyChange(PropertyChangeEvent event) { currentActionPropertyChange(event); } }; } return currentActionListener; } private void currentActionPropertyChange(final PropertyChangeEvent e) { // This code should be removed. Avoid using free asyncExec if (isVisible() && widget != null) { Display display = widget.getDisplay(); if (display.getThread() == Thread.currentThread()) { update(e.getProperty()); } else { display.asyncExec(new Runnable() { public void run() { update(e.getProperty()); } }); } } } public void update() { update(null); } public void update(String propertyName) { if (widget == null || currentAction == null) return; boolean textChanged = propertyName == null || propertyName.equals(IAction.TEXT); boolean imageChanged = propertyName == null || propertyName.equals(IAction.IMAGE); boolean tooltipTextChanged = propertyName == null || propertyName.equals(IAction.TOOL_TIP_TEXT); boolean enableStateChanged = propertyName == null || propertyName.equals(IAction.ENABLED) || propertyName.equals(IContributionManagerOverrides.P_ENABLED); boolean checkChanged = (currentAction.getStyle() == IAction.AS_CHECK_BOX || currentAction.getStyle() == IAction.AS_RADIO_BUTTON) && (propertyName == null || propertyName.equals(IAction.CHECKED)); ToolItem ti = (ToolItem) widget; String text = currentAction.getText(); // the set text is shown only if there is no image or if forced // by MODE_FORCE_TEXT boolean showText = text != null && !hasImages(currentAction); // only do the trimming if the text will be used if (showText && text != null) { text = Action.removeAcceleratorText(text); text = Action.removeMnemonics(text); } if (textChanged) { String textToSet = showText ? text : ""; //$NON-NLS-1$ boolean rightStyle = (ti.getParent().getStyle() & SWT.RIGHT) != 0; if (rightStyle || !ti.getText().equals(textToSet)) { // In addition to being required to update the text if // it // gets nulled out in the action, this is also a // workaround // for bug 50151: Using SWT.RIGHT on a ToolBar leaves // blank space ti.setText(textToSet); } } if (imageChanged) { // only substitute a missing image if it has no text updateImages(!showText); } if (tooltipTextChanged || textChanged) { String toolTip = currentAction.getToolTipText(); if ((toolTip == null) || (toolTip.length() == 0)) { toolTip = text; } ExternalActionManager.ICallback callback = ExternalActionManager.getInstance().getCallback(); String commandId = currentAction.getActionDefinitionId(); if ((callback != null) && (commandId != null) && (toolTip != null)) { String acceleratorText = callback.getAcceleratorText(commandId); if (acceleratorText != null && acceleratorText.length() != 0) { toolTip = JFaceResources.format("Toolbar_Tooltip_Accelerator", //$NON-NLS-1$ new Object[] { toolTip, acceleratorText }); } } // if the text is showing, then only set the tooltip if // different if (!showText || toolTip != null && !toolTip.equals(text)) { ti.setToolTipText(toolTip); } else { ti.setToolTipText(null); } } if (enableStateChanged) { boolean shouldBeEnabled = currentAction.isEnabled() && isEnabledAllowed(); if (ti.getEnabled() != shouldBeEnabled) { ti.setEnabled(shouldBeEnabled); } } if (checkChanged) { boolean bv = currentAction.isChecked(); if (ti.getSelection() != bv) { ti.setSelection(bv); } } } /** * Returns whether the given action has any images. * * @param actionToCheck * the action * @return <code>true</code> if the action has any images, * <code>false</code> if not */ private boolean hasImages(IAction actionToCheck) { return actionToCheck.getImageDescriptor() != null || actionToCheck.getHoverImageDescriptor() != null || actionToCheck.getDisabledImageDescriptor() != null; } /** * Updates the images for this action. * * @param forceImage * <code>true</code> if some form of image is compulsory, and * <code>false</code> if it is acceptable for this item to have * no image * @return <code>true</code> if there are images for this action, * <code>false</code> if not */ private boolean updateImages(boolean forceImage) { ResourceManager parentResourceManager = JFaceResources.getResources(); ImageDescriptor image = currentAction.getHoverImageDescriptor(); if (image == null) { image = currentAction.getImageDescriptor(); } ImageDescriptor disabledImage = currentAction.getDisabledImageDescriptor(); // Make sure there is a valid image. if (image == null && forceImage) { image = ImageDescriptor.getMissingImageDescriptor(); } LocalResourceManager localManager = new LocalResourceManager(parentResourceManager); // performance: more efficient in SWT to set disabled and hot // image before regular image widget.setDisabledImage(disabledImage == null ? null : localManager.createImageWithDefault(disabledImage)); widget.setImage(image == null ? null : localManager.createImageWithDefault(image)); disposeOldImages(); imageManager = localManager; return image != null; } /** * Returns <code>true</code> if this item is allowed to enable, * <code>false</code> otherwise. * * @return if this item is allowed to be enabled * @since 2.0 */ protected boolean isEnabledAllowed() { if (getParent() == null) { return true; } Boolean value = getParent().getOverrides().getEnabled(this); return (value == null) ? true : value.booleanValue(); } /** * Returns the listener for SWT tool item widget events. * * @return a listener for tool item events */ private Listener getToolItemListener() { if (toolItemListener == null) { toolItemListener = new Listener() { public void handleEvent(Event event) { switch (event.type) { case SWT.Dispose: handleWidgetDispose(event); break; case SWT.Selection: Widget ew = event.widget; if (ew != null) { handleWidgetSelection(event, ((ToolItem) ew).getSelection()); } break; } } }; } return toolItemListener; } /** * Handles a widget dispose event for the widget corresponding to this item. */ private void handleWidgetDispose(Event e) { // Check if our widget is the one being disposed. if (e.widget == widget) { if (dropDownMenuManager != null) { dropDownMenuManager.dispose(); dropDownMenuManager = null; } // Unhook all of the listeners. if (currentAction != null && currentActionListener != null) { currentAction.removePropertyChangeListener(currentActionListener); } // Clear the widget field. widget = null; disposeOldImages(); } } private MenuManager getDropDownMenuManager() { if (dropDownMenuManager == null) { dropDownMenuManager = new MenuManager(); dropDownMenuManager.setRemoveAllWhenShown(true); dropDownMenuManager.addMenuListener(new IMenuListener() { public void menuAboutToShow(IMenuManager manager) { for (IAction action : actions) { manager.add(action); } } }); } return dropDownMenuManager; } /** * Handles a widget selection event. */ private void handleWidgetSelection(Event e, boolean selection) { if (e.widget == widget) { MenuManager menuMan = getDropDownMenuManager(); Menu menu = menuMan.createContextMenu(widget.getParent()); if (menu != null) { Rectangle b = widget.getBounds(); Point p = widget.getParent().toDisplay(b.x, b.y + b.height); menu.setLocation(p.x, p.y); menu.setVisible(true); } } } /** * Dispose any images allocated for this contribution item */ private void disposeOldImages() { if (imageManager != null) { imageManager.dispose(); imageManager = null; } } }