actioncontributionitem.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 org.eclipse.jface.action.ExternalActionManager.IBindingManagerCallback;
import org.eclipse.jface.bindings.Trigger;
import org.eclipse.jface.bindings.TriggerSequence;
import org.eclipse.jface.bindings.keys.IKeyLookup;
import org.eclipse.jface.bindings.keys.KeyLookupFactory;
import org.eclipse.jface.bindings.keys.KeyStroke;
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.Policy;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;
import org.eclipse.swt.widgets.Widget;

/**
 * A contribution item which delegates to an action.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 */
public class ActionContributionItem extends ContributionItem {

    /**
     * Mode bit: Show text on tool items, even if an image is present.
     * If this mode bit is not set, text is only shown on tool items if there is 
     * no image present.
     * 
     * @since 3.0
     */
    public static int MODE_FORCE_TEXT = 1;

    /** a string inserted in the middle of text that has been shortened */
    private static final String ellipsis = "..."; //$NON-NLS-1$

    private static boolean USE_COLOR_ICONS = true;

    /**
     * Returns whether color icons should be used in toolbars.
     * 
     * @return <code>true</code> if color icons should be used in toolbars, 
     *   <code>false</code> otherwise
     */
    public static boolean getUseColorIconsInToolbars() {
        return USE_COLOR_ICONS;
    }

    /**
     * Sets whether color icons should be used in toolbars.
     * 
     * @param useColorIcons <code>true</code> if color icons should be used in toolbars, 
     *   <code>false</code> otherwise
     */
    public static void setUseColorIconsInToolbars(boolean useColorIcons) {
        USE_COLOR_ICONS = useColorIcons;
    }

    /**
     * The presentation mode.
     */
    private int mode = 0;

    /**
     * The action.
     */
    private IAction action;

    /**
     * The listener for changes to the text of the action contributed by an
     * external source.
     */
    private final IPropertyChangeListener actionTextListener = new IPropertyChangeListener() {

        /**
         * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent)
         */
        public void propertyChange(PropertyChangeEvent event) {
            update(event.getProperty());
        }
    };

    /**
     * Remembers all images in use by this contribution item
     */
    private LocalResourceManager imageManager;
    
    /**
     * Listener for SWT button widget events.
     */
    private Listener buttonListener;

    /**
     * Listener for SWT menu item widget events.
     */
    private Listener menuItemListener;

    /**
     * Listener for action property change notifications.
     */
    private final IPropertyChangeListener propertyListener = new IPropertyChangeListener() {
        public void propertyChange(PropertyChangeEvent event) {
            actionPropertyChange(event);
        }
    };

    /**
     * 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 Widget widget = null;

    /**
     * Creates a new contribution item from the given action. The id of the
     * action is used as the id of the item.
     * 
     * @param action
     *            the action
     */
    public ActionContributionItem(IAction action) {
        super(action.getId());
        this.action = action;
    }

    /**
     * Handles a property change event on the action (forwarded by nested listener).
     */
    private void actionPropertyChange(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());
                    }
                });
            }

        }
    }

    /**
     * Compares this action contribution item with another object.
     * Two action contribution items are equal if they refer to the identical Action.
     */
    public boolean equals(Object o) {
        if (!(o instanceof ActionContributionItem)) {
            return false;
        }
        return action.equals(((ActionContributionItem) o).action);
    }

    /**
     * The <code>ActionContributionItem</code> implementation of this
     * <code>IContributionItem</code> method creates an SWT <code>Button</code> for
     * the action using the action's style. If the action's checked property has
     * been set, the button is created and primed to the value of the checked
     * property.
     */
    public void fill(Composite parent) {
        if (widget == null && parent != null) {
            int flags = SWT.PUSH;
            if (action != null) {
                if (action.getStyle() == IAction.AS_CHECK_BOX) {
					flags = SWT.TOGGLE;
				}
                if (action.getStyle() == IAction.AS_RADIO_BUTTON) {
					flags = SWT.RADIO;
				}
            }

            Button b = new Button(parent, flags);
            b.setData(this);
            b.addListener(SWT.Dispose, getButtonListener());
            // Don't hook a dispose listener on the parent
            b.addListener(SWT.Selection, getButtonListener());
            if (action.getHelpListener() != null) {
				b.addHelpListener(action.getHelpListener());
			}
            widget = b;

            update(null);

            // Attach some extra listeners.
            action.addPropertyChangeListener(propertyListener);
            if (action != null) {
                String commandId = action.getActionDefinitionId();
                ExternalActionManager.ICallback callback = ExternalActionManager
                        .getInstance().getCallback();

                if ((callback != null) && (commandId != null)) {
                    callback.addPropertyChangeListener(commandId,
                            actionTextListener);
                }
            }
        }
    }

    /**
     * The <code>ActionContributionItem</code> implementation of this
     * <code>IContributionItem</code> method creates an SWT <code>MenuItem</code>
     * for the action using the action's style. If the action's checked property has
     * been set, a button is created and primed to the value of the checked
     * property. If the action's menu creator property has been set, a cascading
     * submenu is created.
     */
    public void fill(Menu parent, int index) {
        if (widget == null && parent != null) {
            Menu subMenu = null;
            int flags = SWT.PUSH;
            if (action != null) {
                int style = action.getStyle();
                if (style == IAction.AS_CHECK_BOX) {
					flags = SWT.CHECK;
				} else if (style == IAction.AS_RADIO_BUTTON) {
					flags = SWT.RADIO;
				} else if (style == IAction.AS_DROP_DOWN_MENU) {
                    IMenuCreator mc = action.getMenuCreator();
                    if (mc != null) {
                        subMenu = mc.getMenu(parent);
                        flags = SWT.CASCADE;
                    }
                }
            }

            MenuItem mi = null;
            if (index >= 0) {
				mi = new MenuItem(parent, flags, index);
			} else {
				mi = new MenuItem(parent, flags);
			}
            widget = mi;

            mi.setData(this);
            mi.addListener(SWT.Dispose, getMenuItemListener());
            mi.addListener(SWT.Selection, getMenuItemListener());
            if (action.getHelpListener() != null) {
				mi.addHelpListener(action.getHelpListener());
			}

            if (subMenu != null) {
				mi.setMenu(subMenu);
			}

            update(null);

            // Attach some extra listeners.
            action.addPropertyChangeListener(propertyListener);
            if (action != null) {
                String commandId = action.getActionDefinitionId();
                ExternalActionManager.ICallback callback = ExternalActionManager
                        .getInstance().getCallback();

                if ((callback != null) && (commandId != null)) {
                    callback.addPropertyChangeListener(commandId,
                            actionTextListener);
                }
            }
        }
    }

    /**
     * The <code>ActionContributionItem</code> implementation of this ,
     * <code>IContributionItem</code> method creates an SWT <code>ToolItem</code>
     * for the action using the action's style. If the action's checked property has
     * been set, a button is created and primed to the value of the checked
     * property. If the action's menu creator property has been set, a drop-down
     * tool item is created.
     */
    public void fill(ToolBar parent, int index) {
        if (widget == null && parent != null) {
            int flags = SWT.PUSH;
            if (action != null) {
                int style = action.getStyle();
                if (style == IAction.AS_CHECK_BOX) {
					flags = SWT.CHECK;
				} else if (style == IAction.AS_RADIO_BUTTON) {
					flags = SWT.RADIO;
				} else if (style == IAction.AS_DROP_DOWN_MENU) {
					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.
            action.addPropertyChangeListener(propertyListener);
            if (action != null) {
                String commandId = action.getActionDefinitionId();
                ExternalActionManager.ICallback callback = ExternalActionManager
                        .getInstance().getCallback();

                if ((callback != null) && (commandId != null)) {
                    callback.addPropertyChangeListener(commandId,
                            actionTextListener);
                }
            }
        }
    }

    /**
     * Returns the action associated with this contribution item.
     *
     * @return the action
     */
    public IAction getAction() {