Java tutorial
/******************************************************************************* * Copyright (c) 2011 Wind River Systems, Inc. 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: * Wind River Systems - initial API and implementation *******************************************************************************/ package org.eclipse.tm.te.ui.trees; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.action.IMenuListener; import org.eclipse.jface.action.IMenuManager; import org.eclipse.jface.action.MenuManager; import org.eclipse.jface.action.Separator; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ISelectionChangedListener; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.viewers.ViewerComparator; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.graphics.Cursor; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.ToolBar; import org.eclipse.tm.te.ui.WorkbenchPartControl; import org.eclipse.tm.te.ui.forms.CustomFormToolkit; import org.eclipse.ui.IWorkbenchActionConstants; import org.eclipse.ui.IWorkbenchPart; import org.eclipse.ui.forms.widgets.Section; /** * Abstract tree control implementation. */ public abstract class AbstractTreeControl extends WorkbenchPartControl { // Reference to the tree viewer instance private TreeViewer viewer; // Reference to the selection changed listener private ISelectionChangedListener selectionChangedListener; /** * Constructor. */ public AbstractTreeControl() { super(); } /** * Constructor. * * @param parentPart The parent workbench part this control is embedded in or <code>null</code>. */ public AbstractTreeControl(IWorkbenchPart parentPart) { super(parentPart); } /* (non-Javadoc) * @see org.eclipse.tm.te.ui.WorkbenchPartControl#dispose() */ @Override public void dispose() { // Unregister the selection changed listener if (selectionChangedListener != null) { if (getViewer() != null) { getViewer().removeSelectionChangedListener(selectionChangedListener); } selectionChangedListener = null; } super.dispose(); } /* (non-Javadoc) * @see org.eclipse.tm.te.ui.WorkbenchPartControl#setupFormPanel(org.eclipse.swt.widgets.Composite, org.eclipse.tm.te.ui.forms.CustomFormToolkit) */ @Override public void setupFormPanel(Composite parent, CustomFormToolkit toolkit) { super.setupFormPanel(parent, toolkit); // Create the tree viewer viewer = doCreateTreeViewer(parent); // And configure the tree viewer configureTreeViewer(viewer); // Prepare popup menu and toolbar createContributionItems(viewer); } /** * Creates the tree viewer instance. * * @param parent The parent composite. Must not be <code>null</code>. * @return The tree viewer. */ protected TreeViewer doCreateTreeViewer(Composite parent) { Assert.isNotNull(parent); return new TreeViewer(parent, SWT.FULL_SELECTION | SWT.SINGLE); } /** * Configure the tree viewer. * * @param viewer The tree viewer. Must not be <code>null</code>. */ protected void configureTreeViewer(TreeViewer viewer) { Assert.isNotNull(viewer); viewer.setAutoExpandLevel(getAutoExpandLevel()); viewer.setLabelProvider(doCreateTreeViewerLabelProvider(viewer)); viewer.setContentProvider(doCreateTreeViewerContentProvider(viewer)); viewer.setComparator(doCreateTreeViewerComparator(viewer)); viewer.getTree().setLayoutData(doCreateTreeViewerLayoutData(viewer)); // Attach the selection changed listener selectionChangedListener = doCreateTreeViewerSelectionChangedListener(viewer); if (selectionChangedListener != null) { viewer.addSelectionChangedListener(selectionChangedListener); } } /** * Returns the number of levels to auto expand. * If the method returns <code>0</code>, no auto expansion will happen * * @return The number of levels to auto expand or <code>0</code>. */ protected int getAutoExpandLevel() { return 2; } /** * Creates the tree viewer layout data instance. * * @param viewer The tree viewer. Must not be <code>null</code>. * @return The tree viewer layout data instance. */ protected Object doCreateTreeViewerLayoutData(TreeViewer viewer) { return new GridData(GridData.FILL_BOTH); } /** * Creates the tree viewer label provider instance. * * @param viewer The tree viewer. Must not be <code>null</code>. * @return The tree viewer label provider instance. */ protected abstract ILabelProvider doCreateTreeViewerLabelProvider(TreeViewer viewer); /** * Creates the tree viewer content provider instance. * * @param viewer The tree viewer. Must not be <code>null</code>. * @return The tree viewer content provider instance. */ protected abstract ITreeContentProvider doCreateTreeViewerContentProvider(TreeViewer viewer); /** * Creates the tree viewer comparator instance. * * @param viewer The tree viewer. Must not be <code>null</code>. * @return The tree viewer comparator instance or <code>null</code> to turn of sorting. */ protected ViewerComparator doCreateTreeViewerComparator(TreeViewer viewer) { Assert.isNotNull(viewer); return null; } /** * Creates a new selection changed listener instance. * * @param viewer The tree viewer. Must not be <code>null</code>. * @return The selection changed listener instance. */ protected abstract ISelectionChangedListener doCreateTreeViewerSelectionChangedListener(TreeViewer viewer); /** * Create the context menu and toolbar groups. * * @param viewer The tree viewer instance. Must not be <code>null</code>. */ protected void createContributionItems(TreeViewer viewer) { Assert.isNotNull(viewer); // Create the menu manager MenuManager manager = new MenuManager("#PopupMenu"); //$NON-NLS-1$ // Attach the menu listener manager.addMenuListener(new IMenuListener() { @Override public void menuAboutToShow(IMenuManager manager) { manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS)); } }); // All items are removed when menu is closing manager.setRemoveAllWhenShown(true); // Associated with the tree viewer.getTree().setMenu(manager.createContextMenu(viewer.getTree())); // Register the context menu at the parent workbench part site. if (getParentPart() != null && getParentPart().getSite() != null && getContextMenuId() != null) { getParentPart().getSite().registerContextMenu(getContextMenuId(), manager, viewer); } // The toolbar is a bit more complicated as we want to have the // toolbar placed within the section title. createToolbarContributionItem(viewer); } /** * Returns the context menu id. * * @return The context menu id. */ protected abstract String getContextMenuId(); /** * Creates the toolbar within the section parent of the given tree viewer. * * @param viewer The tree viewer instance. Must not be <code>null</code>. */ protected void createToolbarContributionItem(TreeViewer viewer) { Assert.isNotNull(viewer); // Determine the section parent from the tree viewer Composite parent = viewer.getTree().getParent(); while (parent != null && !(parent instanceof Section)) { parent = parent.getParent(); } // We are done here if we cannot find a section parent or the parent is disposed if (parent == null || parent.isDisposed()) { return; } // Create the toolbar control ToolBar toolbar = new ToolBar(parent, SWT.FLAT | SWT.HORIZONTAL | SWT.RIGHT); // The cursor within the toolbar shall change to an hand final Cursor handCursor = new Cursor(parent.getDisplay(), SWT.CURSOR_HAND); toolbar.setCursor(handCursor); // Cursor needs to be explicitly disposed toolbar.addDisposeListener(new DisposeListener() { @Override public void widgetDisposed(DisposeEvent e) { if (handCursor.isDisposed() == false) { handCursor.dispose(); } } }); // If the parent composite is a forms section, set the toolbar // as text client to the section header if (parent instanceof Section) { Section section = (Section) parent; // Set the toolbar as text client section.setTextClient(toolbar); } // create the toolbar items createToolBarItems(toolbar); } /** * Create the toolbar items to be added to the toolbar. Override * to add the wanted toolbar items. * <p> * <b>Note:</b> The toolbar items are added from left to right. * * @param toolbar The toolbar to add the toolbar items too. Must not be <code>null</code>. */ protected void createToolBarItems(ToolBar toolbar) { Assert.isNotNull(toolbar); } /** * Returns the viewer instance. * * @return The viewer instance or <code>null</code>. */ public Viewer getViewer() { return viewer; } /* (non-Javadoc) * @see org.eclipse.core.runtime.IAdaptable#getAdapter(java.lang.Class) */ @Override public Object getAdapter(Class adapter) { if (Viewer.class.isAssignableFrom(adapter)) { // We have to double check if our real viewer is assignable to // the requested Viewer class. Viewer viewer = getViewer(); if (!adapter.isAssignableFrom(viewer.getClass())) { viewer = null; } return viewer; } return super.getAdapter(adapter); } }