widget.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

	eventTable = null;
	data = null;
}

/**
 * Removes the listener from the collection of listeners who will
 * be notifed when an event of the given type occurs.
 *
 * @param eventType the type of event to listen for
 * @param listener the listener which should no longer be notified when the event occurs
 *
 * @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 Listener
 * @see #addListener
 */
public void removeListener (int eventType, Listener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (eventType, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notifed when an event of the given type occurs.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the SWT
 * public API. It is marked public only so that it can be shared
 * within the packages provided by SWT. It should never be
 * referenced from application code.
 * </p>
 *
 * @param eventType the type of event to listen for
 * @param listener the listener which should no longer be notified when the event occurs
 *
 * @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 Listener
 * @see #addListener
 */
protected void removeListener (int eventType, SWTEventListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (eventType, listener);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notifed when the widget is disposed.
 *
 * @param listener the listener which should no longer be notified when the receiver is disposed
 *
 * @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 DisposeListener
 * @see #addDisposeListener
 */
public void removeDisposeListener (DisposeListener listener) {
	checkWidget();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Dispose, listener);
}

void sendEvent (Event event) {
	Display display = event.display;
	if (!display.filterEvent (event)) {
		if (eventTable != null) eventTable.sendEvent (event);
	}
}

void sendEvent (int eventType) {
	sendEvent (eventType, null, true);
}

void sendEvent (int eventType, Event event) {
	sendEvent (eventType, event, true);
}

void sendEvent (int eventType, Event event, boolean send) {
	if (eventTable == null && !display.filters (eventType)) {
		return;
	}
	if (event == null) event = new Event ();
	event.type = eventType;
	event.display = display;
	event.widget = this;
	if (event.time == 0) {
		event.time = display.getLastEventTime ();
	}
	if (send) {
		sendEvent (event);
	} else {
		display.postEvent (event);
	}
}

/**
 * Sets the application defined widget data associated
 * with the receiver to be the argument. The <em>widget
 * data</em> is a single, unnamed field that is stored
 * with every widget. 
 * <p>
 * Applications may put arbitrary objects in this field. If
 * the object stored in the widget data needs to be notified
 * when the widget is disposed of, it is the application's
 * responsibility to hook the Dispose event on the widget and
 * do so.
 * </p>
 *
 * @param data the widget data
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - when the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - when called from the wrong thread</li>
 * </ul>
 */
public void setData (Object data) {
	checkWidget();
	if ((state & KEYED_DATA) != 0) {
		((Object []) this.data) [0] = data;
	} else {
		this.data = data;
	}
}

/**
 * Sets the application defined property of the receiver
 * with the specified name to the given value.
 * <p>
 * Applications may associate arbitrary objects with the
 * receiver in this fashion. If the objects stored in the
 * properties need to be notified when the widget is disposed
 * of, it is the application's responsibility to hook the
 * Dispose event on the widget and do so.
 * </p>
 *
 * @param key the name of the property
 * @param value the new value for the property
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the key 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 #getData
 */
public void setData (String key, Object value) {
	checkWidget();
	if (key == null) error (SWT.ERROR_NULL_ARGUMENT);
	int index = 1;
	Object [] table = null;
	if ((state & KEYED_DATA) != 0) {
		table = (Object []) data;
		while (index < table.length) {
			if (key.equals (table [index])) break;
			index += 2;
		}
	}
	if (value != null) {
		if ((state & KEYED_DATA) != 0) {
			if (index == table.length) {
				Object [] newTable = new Object [table.length + 2];
				System.arraycopy (table, 0, newTable, 0, table.length);
				data = table = newTable;
			}
		} else {
			table = new Object [3];
			table [0] = data;
			data = table;
			state |= KEYED_DATA;
		}
		table [index] = key;
		table [index + 1] = value;
	} else {
		if ((state & KEYED_DATA) != 0) {
			if (index != table.length) {
				int length = table.length - 2;
				if (length == 1) {
					data = table [0];
					state &= ~KEYED_DATA;
				} else {
					Object [] newTable = new Object [length];
					System.arraycopy (table, 0, newTable, 0, index);
					System.arraycopy (table, index + 2, newTable, index, length - index);
					data = newTable;
				}
			}
		}
	}
}

boolean setInputState (Event event, int type) {
	if (OS.GetKeyState (OS.VK_MENU) < 0) event.stateMask |= SWT.ALT;
	if (OS.GetKeyState (OS.VK_SHIFT) < 0) event.stateMask |= SWT.SHIFT;
	if (OS.GetKeyState (OS.VK_CONTROL) < 0) event.stateMask |= SWT.CONTROL;
	if (OS.GetKeyState (OS.VK_LBUTTON) < 0) event.stateMask |= SWT.BUTTON1;
	if (OS.GetKeyState (OS.VK_MBUTTON) < 0) event.stateMask |= SWT.BUTTON2;
	if (OS.GetKeyState (OS.VK_RBUTTON) < 0) event.stateMask |= SWT.BUTTON3;
	switch (type) {
		case SWT.MouseDown:
		case SWT.MouseDoubleClick:
			if (event.button == 1) event.stateMask &= ~SWT.BUTTON1;
			if (event.button == 2) event.stateMask &= ~SWT.BUTTON2;
			if (event.button == 3) event.stateMask &= ~SWT.BUTTON3;
			break;
		case SWT.MouseUp:
			if (event.button == 1) event.stateMask |= SWT.BUTTON1;
			if (event.button == 2) event.stateMask |= SWT.BUTTON2;
			if (event.button == 3) event.stateMask |= SWT.BUTTON3;
			break;
		case SWT.KeyDown:
		case SWT.Traverse:
			if (event.keyCode == SWT.ALT) event.stateMask &= ~SWT.ALT;
			if (event.keyCode == SWT.SHIFT) event.stateMask &= ~SWT.SHIFT;
			if (event.keyCode == SWT.CONTROL) event.stateMask &= ~SWT.CONTROL;
			break;
		case SWT.KeyUp:
			if (event.keyCode == SWT.ALT) event.stateMask |= SWT.ALT;
			if (event.keyCode == SWT.SHIFT) event.stateMask |= SWT.SHIFT;
			if (event.keyCode == SWT.CONTROL) event.stateMask |= SWT.CONTROL;
			break;
	}		
	return true;
}

boolean setKeyState (Event event, int type, int wParam, int lParam) {
	
	/*
	* Feature in Windows.  When the user presses Ctrl+Backspace
	* or Ctrl+Enter, Windows sends a WM_CHAR with Delete (0x7F)
	* and '\n' instead of '\b' and '\r'.  This is the correct
	* platform behavior but is not portable.  The fix is to detect
	* these cases and convert the character.
	*/
	switch (display.lastAscii) {
		case SWT.DEL:
			if (display.lastKey == SWT.BS) display.lastAscii = SWT.BS;
			break;
		case SWT.LF:
			if (display.lastKey == SWT.CR) display.lastAscii = SWT.CR;
			break;
	}
	
	/*
	* Feature in Windows.  When the user presses either the Enter
	* key or the numeric keypad Enter key, Windows sends a WM_KEYDOWN
	* with wParam=VK_RETURN in both cases.  In order to distinguish
	* between the keys, the extended key bit is tested. If the bit
	* is set, assume that the numeric keypad Enter was pressed. 
	*/
	if (display.lastKey == SWT.CR && display.lastAscii == SWT.CR) {
		if ((lParam & 0x1000000) != 0) display.lastKey = SWT.KEYPAD_CR;
	}
	
	if (display.lastVirtual) {
		/*
		* Feature in Windows.  The virtual key VK_DELETE is not
		* treated as both a virtual key and an ASCII key by Windows.
		* Therefore, we will not receive a WM_CHAR for this key.
		* The fix is to treat VK_DELETE as a special case and map
		* the ASCII value explictly (Delete is 0x7F).
		*/
		if (display.lastKey == OS.VK_DELETE) display.lastAscii = 0x7F;
		
		/*
		* Feature in Windows.  When the user presses Ctrl+Pause, the
		* VK_CANCEL key is generated and a WM_CHAR is sent with 0x03,
		* possibly to allow an application to look for Ctrl+C and the
		* the Break key at the same time.  This is unexpected and
		* unwanted.  The fix is to detect the case and set the character
		* to zero. 
		*/
		if (display.lastKey == OS.VK_CANCEL) display.lastAscii = 0x0;
		
		event.keyCode = Display.translateKey (display.lastKey);
	} else {
		event.keyCode = display.lastKey;
	}
	if (display.lastAscii != 0 || display.lastNull) {
		event.character = Display.mbcsToWcs ((char) display.lastAscii);
	}
	if (event.keyCode == 0 && event.character == 0) {
		if (!display.lastNull) return false;
	}
	return setInputState (event, type);
}

boolean SetWindowPos (int hWnd, int hWndInsertAfter, int X, int Y, int cx, int cy, int uFlags) {
	if (OS.IsWinCE) {
		/*
		* Feature in Windows.  On Windows CE, SetWindowPos() always causes
		* a WM_SIZE message, even when the new size is the same as the old
		* size.  The fix is to detect that the size has not changed and set
		* SWP_NOSIZE.
		*/
		if ((uFlags & OS.SWP_NOSIZE) == 0) {
			RECT lpRect = new RECT ();
			OS.GetWindowRect (hWnd, lpRect);
			if (cy == lpRect.bottom - lpRect.top && cx == lpRect.right - lpRect.left) {
				/*
				* Feature in Windows.  On Windows CE, SetWindowPos() when called
				* with SWP_DRAWFRAME always causes a WM_SIZE message, even
				* when SWP_NOSIZE is set and when the new size is the same as the
				* old size.  The fix is to clear SWP_DRAWFRAME when the size is
				* the same.
				*/
				uFlags &= ~OS.SWP_DRAWFRAME;
				uFlags |= OS.SWP_NOSIZE;
			}
		}
	}
	return OS.SetWindowPos (hWnd, hWndInsertAfter, X, Y, cx, cy, uFlags);
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	String string = "*Disposed*"; //$NON-NLS-1$
	if (!isDisposed ()) {
		string = "*Wrong Thread*"; //$NON-NLS-1$
		if (isValidThread ()) string = getNameText ();
	}
	return getName () + " {" + string + "}"; //$NON-NLS-1$ //$NON-NLS-2$
}
}