toolbarcontributionitem.java

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/*******************************************************************************
 * Copyright (c) 2000, 2006 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.jface.action;

import java.util.ArrayList;
import java.util.Iterator;

import org.eclipse.jface.util.Assert;
import org.eclipse.jface.util.Policy;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.CoolBar;
import org.eclipse.swt.widgets.CoolItem;
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;

/**
 * The <code>ToolBarContributionItem</code> class provides a wrapper for tool
 * bar managers when used in cool bar managers. It extends <code>ContributionItem</code>
 * but and provides some additional methods to customize the size of the cool
 * item and to retrieve the underlying tool bar manager.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * 
 * @since 3.0
 */
public class ToolBarContributionItem extends ContributionItem {

    /**
     * A constant used by <code>setMinimumItemsToShow</code> and <code>getMinimumItemsToShow</code>
     * to indicate that all tool items should be shown in the cool item.
     */
    public static final int SHOW_ALL_ITEMS = -1;

    /**
     * The pull down menu used to list all hidden tool items if the current
     * size is less than the preffered size.
     */
    private MenuManager chevronMenuManager = null;

    /**
     * The widget created for this item; <code>null</code> before creation
     * and after disposal.
     */
    private CoolItem coolItem = null;

    /**
     * Current height of cool item
     */
    private int currentHeight = -1;

    /**
     * Current width of cool item.
     */
    private int currentWidth = -1;

    /**
     * A flag indicating that this item has been disposed. This prevents future
     * method invocations from doing things they shouldn't.
     */
    private boolean disposed = false;

    /**
     * Mininum number of tool items to show in the cool item widget.
     */
    private int minimumItemsToShow = SHOW_ALL_ITEMS;

    /**
     * The tool bar manager used to manage the tool items contained in the cool
     * item widget.
     */
    private ToolBarManager toolBarManager = null;

    /**
     * Enable/disable chevron support.
     */
    private boolean useChevron = true;

    /**
     * Convenience method equivalent to <code>ToolBarContributionItem(new ToolBarManager(), null)</code>.
     */
    public ToolBarContributionItem() {
        this(new ToolBarManager(), null);
    }

    /**
     * Convenience method equivalent to <code>ToolBarContributionItem(toolBarManager, null)</code>.
     * 
     * @param toolBarManager
     *            the tool bar manager
     */
    public ToolBarContributionItem(IToolBarManager toolBarManager) {
        this(toolBarManager, null);
    }

    /**
     * Creates a tool bar contribution item.
     * 
     * @param toolBarManager
     *            the tool bar manager to wrap
     * @param id
     *            the contribution item id, or <code>null</code> if none
     */
    public ToolBarContributionItem(IToolBarManager toolBarManager, String id) {
        super(id);
        Assert.isTrue(toolBarManager instanceof ToolBarManager);
        this.toolBarManager = (ToolBarManager) toolBarManager;
    }

    /**
     * Checks whether this contribution item has been disposed. If it has, and
     * the tracing options are active, then it prints some debugging
     * information.
     * 
     * @return <code>true</code> if the item is disposed; <code>false</code>
     *         otherwise.
     *  
     */
    private final boolean checkDisposed() {
        if (disposed) {
            if (Policy.TRACE_TOOLBAR) {
                System.out
                        .println("Method invocation on a disposed tool bar contribution item."); //$NON-NLS-1$
                new Exception().printStackTrace(System.out);
            }

            return true;
        }

        return false;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.action.IContributionItem#dispose()
     */
    public void dispose() {
        // Dispose of the ToolBar and all its contributions
        if (toolBarManager != null) {
            toolBarManager.dispose();
            toolBarManager = null;
        }

        /*
         * We need to dispose the cool item or we might be left holding a cool
         * item with a disposed control.
         */
        if ((coolItem != null) && (!coolItem.isDisposed())) {
            coolItem.dispose();
            coolItem = null;
        }

        // Mark this item as disposed.
        disposed = true;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.action.IContributionItem#fill(org.eclipse.swt.widgets.CoolBar,
     *      int)
     */
    public void fill(CoolBar coolBar, int index) {
        if (checkDisposed()) {
            return;
        }

        if (coolItem == null && coolBar != null) {
            ToolBar oldToolBar = toolBarManager.getControl();
            ToolBar toolBar = toolBarManager.createControl(coolBar);
            if ((oldToolBar != null) && (oldToolBar.equals(toolBar))) {
                // We are using an old tool bar, so we need to update.
                toolBarManager.update(true);
            }

            // Do not create a coolItem if the toolbar is empty
            if (toolBar.getItemCount() < 1) {
				return;
			}
            int flags = SWT.DROP_DOWN;
            if (index >= 0) {
                coolItem = new CoolItem(coolBar, flags, index);
            } else {
                coolItem = new CoolItem(coolBar, flags);
            }
            // sets the back reference
            coolItem.setData(this);
            // Add the toolbar to the CoolItem widget
            coolItem.setControl(toolBar);

            // Handle Context Menu
            // ToolBarManager.createControl can actually return a pre-existing control.
            // Only add the listener if the toolbar was newly created (bug 62097).
            if (oldToolBar != toolBar) {
	            toolBar.addListener(SWT.MenuDetect, new Listener() {
	
	                public void handleEvent(Event event) {
	                    // if the toolbar does not have its own context menu then
	                    // handle the event
	                    if (toolBarManager.getContextMenuManager() == null) {
	                        handleContextMenu(event);
	                    }
	                }
	            });
            }

            // Handle for chevron clicking
            if (getUseChevron()) {
                // Chevron Support
                coolItem.addSelectionListener(new SelectionAdapter() {

                    public void widgetSelected(SelectionEvent event) {
                        if (event.detail == SWT.ARROW) {
                            handleChevron(event);
                        }
                    }
                });
            }

            // Handle for disposal
            coolItem.addDisposeListener(new DisposeListener() {

                public void widgetDisposed(DisposeEvent event) {
                    handleWidgetDispose(event);
                }
            });

            // Sets the size of the coolItem
            updateSize(true);
        }
    }

    /**
     * Returns a consistent set of wrap indices. The return value will always
     * include at least one entry and the first entry will always be zero.
     * CoolBar.getWrapIndices() is inconsistent in whether or not it returns an
     * index for the first row.
     */
    private int[] getAdjustedWrapIndices(int[] wraps) {
        int[] adjustedWrapIndices;
        if (wraps.length == 0) {
            adjustedWrapIndices = new int[] { 0 };
        } else {
            if (wraps[0] != 0) {
                adjustedWrapIndices = new int[wraps.length + 1];
                adjustedWrapIndices[0] = 0;
                for (int i = 0; i < wraps.length; i++) {
                    adjustedWrapIndices[i + 1] = wraps[i];
                }
            } else {
                adjustedWrapIndices = wraps;
            }
        }
        return adjustedWrapIndices;
    }

    /**
     * Returns the current height of the corresponding cool item.
     * 
     * @return the current height
     */
    public int getCurrentHeight() {
        if (checkDisposed()) {
            return -1;
        }
        return currentHeight;
    }

    /**
     * Returns the current width of the corresponding cool item.
     * 
     * @return the current size
     */
    public int getCurrentWidth() {
        if (checkDisposed()) {
            return -1;
        }
        return currentWidth;
    }

    /**
     * Returns the minimum number of tool items to show in the cool item.
     * 
     * @return the minimum number of tool items to show, or <code>SHOW_ALL_ITEMS</code>
     *         if a value was not set
     * @see #setMinimumItemsToShow(int)
     */
    public int getMinimumItemsToShow() {
        if (checkDisposed()) {
            return -1;
        }
        return minimumItemsToShow;
    }

    /**
     * Returns the internal tool bar manager of the contribution item.
     * 
     * @return the tool bar manager, or <code>null</code> if one is not
     *         defined.
     * @see IToolBarManager
     */
    public IToolBarManager getToolBarManager() {
        if (checkDisposed()) {
            return null;
        }
        return toolBarManager;
    }

    /**
     * Returns whether chevron support is enabled.
     * 
     * @return <code>true</code> if chevron support is enabled, <code>false</code>
     *         otherwise
     */
    public boolean getUseChevron() {
        if (checkDisposed()) {