menu.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;

 
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;

/**
 * Instances of this class are user interface objects that contain
 * menu items.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>BAR, DROP_DOWN, POP_UP, NO_RADIO_GROUP</dd>
 * <dd>LEFT_TO_RIGHT, RIGHT_TO_LEFT</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Help, Hide, Show </dd>
 * </dl>
 * <p>
 * Note: Only one of BAR, DROP_DOWN and POP_UP may be specified.
 * Only one of LEFT_TO_RIGHT or RIGHT_TO_LEFT may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */

public class Menu extends Widget {
	/**
	 * the handle to the OS resource 
	 * (Warning: This field is platform dependent)
	 */
	public int handle;
	
	int x, y, hwndCB, id0, id1;
	boolean hasLocation;
	MenuItem cascade;
	Decorations parent;
	ImageList imageList;
	
	/* Resource ID for SHMENUBARINFO */
	static final int ID_PPC = 100;
	
	/* SmartPhone SoftKeyBar resource ids */
	static final int ID_SPMM = 102;
	static final int ID_SPBM = 103;
	static final int ID_SPMB = 104;
	static final int ID_SPBB = 105;
	static final int ID_SPSOFTKEY0 = 106; 
	static final int ID_SPSOFTKEY1 = 107;

/**
 * Constructs a new instance of this class given its parent,
 * and sets the style for the instance so that the instance
 * will be a popup menu on the given parent's shell.
 *
 * @param parent a control which will be the parent of the new instance (cannot be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#POP_UP
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Control parent) {
	this (checkNull (parent).menuShell (), SWT.POP_UP);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>Decorations</code>) and a style value
 * describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a decorations control which will be the parent of the new instance (cannot be null)
 * @param style the style of menu to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#BAR
 * @see SWT#DROP_DOWN
 * @see SWT#POP_UP
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Decorations parent, int style) {
	this (parent, checkStyle (style), 0);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>Menu</code>) and sets the style
 * for the instance so that the instance will be a drop-down
 * menu on the given parent's parent.
 *
 * @param parentMenu a menu which will be the parent of the new instance (cannot be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#DROP_DOWN
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (Menu parentMenu) {
	this (checkNull (parentMenu).parent, SWT.DROP_DOWN);
}

/**
 * Constructs a new instance of this class given its parent
 * (which must be a <code>MenuItem</code>) and sets the style
 * for the instance so that the instance will be a drop-down
 * menu on the given parent's parent menu.
 *
 * @param parentItem a menu item which will be the parent of the new instance (cannot be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#DROP_DOWN
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Menu (MenuItem parentItem) {
	this (checkNull (parentItem).parent);
}

Menu (Decorations parent, int style, int handle) {
	super (parent, checkStyle (style));
	this.parent = parent;
	this.handle = handle;
	/*
	* Bug in IBM JVM 1.3.1.  For some reason, when the checkOrientation() is
	* called from createWidget(), the JVM issues this error:
	*
	* JVM Exception 0x2 (subcode 0x0) occurred in thread "main" (TID:0x9F19D8)
	* 
	* In addition, on Windows XP, a dialog appears with following error message,
	* indicating that the problem may be in the JIT:
	* 
	* AppName: java.exe	 AppVer: 0.0.0.0	 ModName: jitc.dll
	* ModVer: 0.0.0.0	 Offset: 000b6912
	* 
	* The fix is to call checkOrientation() from here.
	*/
	checkOrientation (parent);
	createWidget ();
}

void _setVisible (boolean visible) {
	if ((style & (SWT.BAR | SWT.DROP_DOWN)) != 0) return;
	int hwndParent = parent.handle;
	if (!visible) {
		OS.SendMessage (hwndParent, OS.WM_CANCELMODE, 0, 0);
		return;
	}
	int flags = OS.TPM_LEFTBUTTON;
	if (OS.GetKeyState (OS.VK_LBUTTON) >= 0) flags |= OS.TPM_RIGHTBUTTON;
	if ((style & SWT.RIGHT_TO_LEFT) != 0) flags |= OS.TPM_RIGHTALIGN;
	if ((parent.style & SWT.MIRRORED) != 0) {
		flags &= ~OS.TPM_RIGHTALIGN;
		if ((style & SWT.LEFT_TO_RIGHT) != 0) flags |= OS.TPM_RIGHTALIGN;
	}
	int nX = x, nY = y;
	if (!hasLocation) {
		int pos = OS.GetMessagePos ();
		nX = (short) (pos & 0xFFFF);
		nY = (short) (pos >> 16);
	}
	/*
	* Feature in Windows.  It is legal use TrackPopupMenu ()
	* to display an empty menu as long as menu items are added
	* inside of WM_INITPOPUPMENU.  If no items are added, then
	* TrackPopupMenu () fails and does not send an indication
	* that the menu has been closed.  This is not strictly a
	* bug but leads to unwanted behavior when application code
	* assumes that every WM_INITPOPUPMENU will eventually result
	* in a WM_MENUSELECT, wParam=0xFFFF0000, lParam=0 to indicate
	* that the menu has been closed.  The fix is to detect the
	* case when TrackPopupMenu fails and the number of items in
	* the menu is zero and issue a fake WM_MENUSELECT.
	*/
	boolean success = OS.TrackPopupMenu (handle, flags, nX, nY, 0, hwndParent, null);
	if (!success && GetMenuItemCount (handle) == 0) {
		OS.SendMessage (hwndParent, OS.WM_MENUSELECT, 0xFFFF0000, 0);
	}
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when help events are generated for the control,
 * by sending it one of the messages defined in the
 * <code>HelpListener</code> interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see HelpListener
 * @see #removeHelpListener
 */
public void addHelpListener (HelpListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Help, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when menus are hidden or shown, by sending it
 * one of the messages defined in the <code>MenuListener</code>
 * interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see MenuListener
 * @see #removeMenuListener
 */
public void addMenuListener (MenuListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Hide,typedListener);
	addListener (SWT.Show,typedListener);
}

static Control checkNull (Control control) {
	if (control == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	return control;
}

static Menu checkNull (Menu menu) {
	if (menu == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	return menu;
}

static MenuItem checkNull (MenuItem item) {
	if (item == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	return item;
}

static int checkStyle (int style) {
	return checkBits (style, SWT.POP_UP, SWT.BAR, SWT.DROP_DOWN, 0, 0, 0);
}

void createHandle () {
	if (handle != 0) return;
	if ((style & SWT.BAR) != 0) {
		if (OS.IsPPC) {
			int hwndShell = parent.handle;
			SHMENUBARINFO mbi = new SHMENUBARINFO ();
			mbi.cbSize = SHMENUBARINFO.sizeof;
			mbi.hwndParent = hwndShell;
			mbi.dwFlags = OS.SHCMBF_HIDDEN;
			mbi.nToolBarId = ID_PPC;
			mbi.hInstRes = OS.GetLibraryHandle ();
			boolean success = OS.SHCreateMenuBar (mbi);
			hwndCB = mbi.hwndMB;
			if (!success) error (SWT.ERROR_NO_HANDLES);
			/* Remove the item from the resource file */
			OS.SendMessage (hwndCB, OS.TB_DELETEBUTTON, 0, 0);
			return;
		}
		/*
		* Note in WinCE SmartPhone.  The SoftBar contains only 2 items.
		* An item can either be a menu or a button. 
		* SWT.BAR: creates a SoftBar with 2 menus
		* SWT.BAR | SWT.BUTTON1: creates a SoftBar with 1 button
		*    for button1, and a menu for button2
		* SWT.BAR | SWT.BUTTON1 | SWT.BUTTON2: creates a SoftBar with
		*    2 buttons
		*/
		if (OS.IsSP) {
			/* Determine type of menubar */
			int nToolBarId;
			if ((style & SWT.BUTTON1) != 0) {
				nToolBarId = ((style & SWT.BUTTON2) != 0) ? ID_SPBB : ID_SPBM;
			} else {
				nToolBarId = ((style & SWT.BUTTON2) != 0) ? ID_SPMB : ID_SPMM;
			}
			
			/* Create SHMENUBAR */
			SHMENUBARINFO mbi = new SHMENUBARINFO ();
			mbi.cbSize = SHMENUBARINFO.sizeof;
			mbi.hwndParent = parent.handle;
			mbi.dwFlags = OS.SHCMBF_HIDDEN;
			mbi.nToolBarId = nToolBarId; /* as defined in .rc file */
			mbi.hInstRes = OS.GetLibraryHandle ();
			if (!OS.SHCreateMenuBar (mbi)) error (SWT.ERROR_NO_HANDLES);
			hwndCB = mbi.hwndMB;
			
			/*
			* Feature on WinCE SmartPhone.  The SHCMBF_HIDDEN flag causes the
			* SHMENUBAR to not be drawn. However the keyboard events still go
			* through it.  The workaround is to also hide the SHMENUBAR with
			* ShowWindow ().
			*/
			OS.ShowWindow (hwndCB, OS.SW_HIDE);
			
			TBBUTTONINFO info = new TBBUTTONINFO ();
			info.cbSize = TBBUTTONINFO.sizeof;
			info.dwMask = OS.TBIF_COMMAND;
			MenuItem item;
			
			/* Set first item */
			if (nToolBarId == ID_SPMM || nToolBarId == ID_SPMB) {
				int hMenu = OS.SendMessage (hwndCB, OS.SHCMBM_GETSUBMENU, 0, ID_SPSOFTKEY0);
				/* Remove the item from the resource file */
				OS.RemoveMenu (hMenu, 0, OS.MF_BYPOSITION);
				Menu menu = new Menu (parent, SWT.DROP_DOWN, hMenu);
				item = new MenuItem (this, menu, SWT.CASCADE, 0);
			} else {
				item = new MenuItem (this, null, SWT.PUSH, 0);
			}
			info.idCommand = id0 = item.id;
			OS.SendMessage (hwndCB, OS.TB_SETBUTTONINFO, ID_SPSOFTKEY0, info);	

			/* Set second item */
			if (nToolBarId == ID_SPMM || nToolBarId == ID_SPBM) {
				int hMenu = OS.SendMessage (hwndCB, OS.SHCMBM_GETSUBMENU, 0, ID_SPSOFTKEY1);
				OS.RemoveMenu (hMenu, 0, OS.MF_BYPOSITION);
				Menu menu = new Menu (parent, SWT.DROP_DOWN, hMenu);
				item = new MenuItem (this, menu, SWT.CASCADE, 1);
			} else {
				item = new MenuItem (this, null, SWT.PUSH, 1);
			}
			info.idCommand = id1 = item.id;
			OS.SendMessage (hwndCB, OS.TB_SETBUTTONINFO, ID_SPSOFTKEY1, info);

			/*
			* Override the Back key.  For some reason, the owner of the menubar
			* must be a Dialog or it won't receive the WM_HOTKEY message.  As
			* a result, Shell on WinCE SP must use the class Dialog.
			*/
			int dwMask = OS.SHMBOF_NODEFAULT | OS.SHMBOF_NOTIFY;
			int lParam = dwMask << 16 | dwMask;
			OS.SendMessage (hwndCB, OS.SHCMBM_OVERRIDEKEY, OS.VK_ESCAPE, lParam);
			return;
		}
		handle = OS.CreateMenu ();
		if (handle == 0) error (SWT.ERROR_NO_HANDLES);
		if (OS.IsHPC) {
			int hwndShell = parent.handle;
			hwndCB = OS.CommandBar_Create (OS.GetModuleHandle (null), hwndShell, 1);
			if (hwndCB == 0) error (SWT.ERROR_NO_HANDLES);
			OS.CommandBar_Show (hwndCB, false);
			OS.CommandBar_InsertMenubarEx (hwndCB, 0, handle, 0);
			/*
			* The command bar hosts the 'close' button when the window does not
			* have a caption.
			*/
			if ((parent.style & SWT.CLOSE) != 0 && (parent.style & SWT.TITLE) == 0) {
				OS.CommandBar_AddAdornments (hwndCB, 0, 0);
			}
		}
	} else {
		handle = OS.CreatePopupMenu ();
		if (handle == 0) error (SWT.ERROR_NO_HANDLES);
	}
}

void createItem (MenuItem item, int index) {
	int count = GetMenuItemCount (handle);
	if (!(0 <= index && index <= count)) error (SWT.ERROR_INVALID_RANGE);
	display.addMenuItem (item);
	boolean success = false;
	if ((OS.IsPPC || OS.IsSP) && hwndCB != 0) {
		if (OS.IsSP) return;
		TBBUTTON lpButton = new TBBUTTON ();
		lpButton.idCommand = item.id;
		lpButton.fsStyle = (byte) OS.TBSTYLE_AUTOSIZE;
		if ((item.style & SWT.CASCADE) != 0) lpButton.fsStyle |= OS.TBSTYLE_DROPDOWN | 0x80;
		if ((item.style & SWT.SEPARATOR) != 0) lpButton.fsStyle = (byte) OS.BTNS_SEP;
		lpButton.fsState = (byte) OS.TBSTATE_ENABLED;
		lpButton.iBitmap = OS.I_IMAGENONE;
		success = OS.SendMessage (hwndCB, OS.TB_INSERTBUTTON, index, lpButton) != 0;
	} else {
		if (OS.IsWinCE) {
			int uFlags = OS.MF_BYPOSITION;
			TCHAR lpNewItem = null;
			if ((item.style & SWT.SEPARATOR) != 0) {
				uFlags |= OS.MF_SEPARATOR;
			} else {
				lpNewItem = new TCHAR (0, " ", true);
			}
			success = OS.InsertMenu (handle, index, uFlags, item.id, lpNewItem);
			if (success) {
				MENUITEMINFO info = new MENUITEMINFO ();
				info.cbSize = MENUITEMINFO.sizeof;