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MenuBuildUtils.javaAPI DocAzureus 3.0.3.49907Fri Aug 03 11:30:14 BST 2007org.gudy.azureus2.ui.swt

MenuBuildUtils

public class MenuBuildUtils extends Object
A class which helps generate build SWT menus. It provides two main functions. The first provides the ability to create regenerateable menus (it will dispose old items when not displayed and invoke a callback method to regenerate it). The second provides the ability to create SWT menus based on the plugin API for menu creation - this allows internal code that generates menus to include plugins to append to their own internal menus.
author
Allan Crooks

Fields Summary
public static final PluginMenuController
BASIC_MENU_ITEM_CONTROLLER
An instance of MenuItemPluginMenuControllerImpl with a default value of null - this will be the value passed when notifying selection and fill listeners.
Constructors Summary
Methods Summary
public static voidaddMaintenanceListenerForMenu(org.eclipse.swt.widgets.Menu menu, org.gudy.azureus2.ui.swt.MenuBuildUtils$MenuBuilder builder)
Creates and adds a listener object to implement regeneratable menus. The first piece of functionality it offers is the ability to call a callback method to generate the menu when it is about to be displayed (the callback method is done by passing an object implementing the MenuBuilder interface). This means that the caller of this method only needs to provide the logic to construct the menu's contents. This is helpful if you want to update an existing menu. The second piece of functionality is that it automatically does what is required to dispose of existing menu items when the menu is hidden.


		// Was taken from TableView.java
		menu.addMenuListener(new MenuListener() {
			boolean bShown = false;

			public void menuHidden(MenuEvent e) {
				bShown = false;

				if (Constants.isOSX)
					return;

				// Must dispose in an asyncExec, otherwise SWT.Selection doesn't
				// get fired (async workaround provided by Eclipse Bug #87678)
				e.widget.getDisplay().asyncExec(new AERunnable() {
					public void runSupport() {
						if (bShown || menu.isDisposed())
							return;
						org.eclipse.swt.widgets.MenuItem[] items = menu
								.getItems();
						for (int i = 0; i < items.length; i++) {
							items[i].dispose();
						}
					}
				});
			};

			public void menuShown(MenuEvent e) {
				org.eclipse.swt.widgets.MenuItem[] items = menu.getItems();
				for (int i = 0; i < items.length; i++)
					items[i].dispose();

				bShown = true;
				builder.buildMenu(menu);
			}
		});
public static voidaddPluginMenuItems(org.eclipse.swt.widgets.Composite composite, org.gudy.azureus2.plugins.ui.menus.MenuItem[] items, org.eclipse.swt.widgets.Menu parent, boolean prev_was_separator, boolean enable_items, org.gudy.azureus2.ui.swt.MenuBuildUtils$PluginMenuController controller)
Creates menu items inside the given menu based on the plugin API MenuItem instances provided. This method is provided mainly as a utility method to make it easier for menus to incorporate menu components specified by plugins. Usually, the list of array items will be extracted from a class like MenuItemManager or TableContextMenuManager, where plugins will usually register menu items they have created.

param
composite Some composite to get a shell from.
param
items The list of plugin MenuItem to add
param
parent The SWT Menu to add to.
param
prev_was_separator Indicates if the previous item in the menu is a separator or not
param
enable_items Indicates whether you want generated items to be enabled or not. If false, all items will be disabled. If true, then the items *may* be enabled, depending on how each MenuItem is configured.
param
controller The callback object used by this method when creating the SWT menus (used for invoking fill and selection listeners).


	                                                                                                                                                                                                                           	 
	    
			   	 
			    
		
		for (int i = 0; i < items.length; i++) {
			final MenuItemImpl az_menuitem = (MenuItemImpl) items[i];
			
			controller.notifyFillListeners(az_menuitem);
			if (!az_menuitem.isVisible()) {continue;}
			
			final int style = az_menuitem.getStyle();
			final int swt_style;

			boolean this_is_separator = false;

			// Do we have any children? If so, we override any manually defined
			// style.
			boolean is_container = false;
			

			if (style == TableContextMenuItem.STYLE_MENU) {
				swt_style = SWT.CASCADE;
				is_container = true;
			} else if (style == TableContextMenuItem.STYLE_PUSH) {
				swt_style = SWT.PUSH;
			} else if (style == TableContextMenuItem.STYLE_CHECK) {
				swt_style = SWT.CHECK;
			} else if (style == TableContextMenuItem.STYLE_RADIO) {
				swt_style = SWT.RADIO;
			} else if (style == TableContextMenuItem.STYLE_SEPARATOR) {
				this_is_separator = true;
				swt_style = SWT.SEPARATOR;
			} else {
				swt_style = SWT.PUSH;
			}

			final org.eclipse.swt.widgets.MenuItem menuItem = new org.eclipse.swt.widgets.MenuItem(
					parent, swt_style);

			if (swt_style == SWT.SEPARATOR) {continue;}
			
			if (prev_was_separator && this_is_separator) {continue;} // Skip contiguous separators
			if (this_is_separator && i == items.length - 1) {continue;} // Skip trailing separator

			prev_was_separator = this_is_separator;

			if (enable_items) {

				if (style == TableContextMenuItem.STYLE_CHECK
						|| style == TableContextMenuItem.STYLE_RADIO) {

					Boolean selection_value = (Boolean) az_menuitem.getData();
					if (selection_value == null) {
						throw new RuntimeException(
								"MenuItem with resource name \""
										+ az_menuitem.getResourceKey()
										+ "\" needs to have a boolean value entered via setData before being used!");
					}
					menuItem.setSelection(selection_value.booleanValue());
				}
			}
			
			final Listener main_listener = controller.makeSelectionListener(az_menuitem);
			menuItem.addListener(SWT.Selection, new Listener() {
				public void handleEvent(Event e) {
					if (az_menuitem.getStyle() == MenuItem.STYLE_CHECK
							|| az_menuitem.getStyle() == MenuItem.STYLE_RADIO) {
						if (!menuItem.isDisposed()) {
							az_menuitem.setData(new Boolean(menuItem.getSelection()));
						}
					}
					main_listener.handleEvent(e);
				}
			});
			
			if (is_container) {
				Menu this_menu = new Menu(composite.getShell(), SWT.DROP_DOWN);
				menuItem.setMenu(this_menu);
				addPluginMenuItems(composite, az_menuitem.getItems(), this_menu, false,
						enable_items, controller);
			}
			
			String custom_title = az_menuitem.getText();
			menuItem.setText(custom_title);

			Graphic g = az_menuitem.getGraphic();
			if (g instanceof UISWTGraphic) {
				Utils.setMenuItemImage(menuItem, ((UISWTGraphic) g).getImage());
			}

			menuItem.setEnabled(enable_items && az_menuitem.isEnabled());

		}