label.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

	* the bitmap or icon.  Any attempt to set alignment bits
	* such as SS_CENTER cause the label to display text.  The
	* fix is to disallow alignment.
	*
	* NOTE: SS_BITMAP and SS_ICON are not single bit
	* masks so it is necessary to test for all of the
	* bits in these masks.
	*/
	if ((bits & OS.SS_BITMAP) == OS.SS_BITMAP) return;
	if ((bits & OS.SS_ICON) == OS.SS_ICON) return;
	bits &= ~(OS.SS_LEFTNOWORDWRAP | OS.SS_CENTER | OS.SS_RIGHT);
	if ((style & SWT.LEFT) != 0 && (style & SWT.WRAP) == 0) {
		bits |= OS.SS_LEFTNOWORDWRAP;
	}
	if ((style & SWT.CENTER) != 0) bits |= OS.SS_CENTER;
	if ((style & SWT.RIGHT) != 0) bits |= OS.SS_RIGHT;
	OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
	OS.InvalidateRect (handle, null, true);
}

/**
 * Sets the receiver's image to the argument, which may be
 * null indicating that no image should be displayed.
 *
 * @param image the image to display on the receiver (may be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</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>
 */
public void setImage (Image image) {
	checkWidget ();
	if ((style & SWT.SEPARATOR) != 0) return;
	int hImage = 0, imageBits = 0, fImageType = 0;
	if (image != null) {
		if (image.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
		hImage = image.handle;
		switch (image.type) {
			case SWT.BITMAP:
				imageBits = OS.SS_BITMAP;
				fImageType = OS.IMAGE_BITMAP;
				break;
			case SWT.ICON:
				imageBits = OS.SS_ICON;
				fImageType = OS.IMAGE_ICON;
				break;
			default:
				return;
		}
	}
	this.image = image;
	RECT rect = new RECT ();
	OS.GetWindowRect (handle, rect);
	int newBits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	int oldBits = newBits;
	newBits &= ~(OS.SS_BITMAP | OS.SS_ICON);
	newBits |= imageBits | OS.SS_REALSIZEIMAGE | OS.SS_CENTERIMAGE;
	if (newBits != oldBits) {
		OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
	}
	OS.SendMessage (handle, OS.STM_SETIMAGE, fImageType, hImage);
	/*
	* Feature in Windows.  When STM_SETIMAGE is used to set the
	* image for a static control, Windows either streches the image
	* to fit the control or shrinks the control to fit the image.
	* While not stricly wrong, neither of these is desirable.
	* The fix is to stop Windows from stretching the image by
	* using SS_REALSIZEIMAGE and SS_CENTERIMAGE, allow Windows
	* to shrink the control, and then restore the control to the
	* original size.
	*/
	int flags = OS.SWP_NOZORDER | OS.SWP_DRAWFRAME | OS.SWP_NOACTIVATE | OS.SWP_NOMOVE;
	SetWindowPos (handle, 0, 0, 0, rect.right - rect.left, rect.bottom - rect.top, flags);
	OS.InvalidateRect (handle, null, true);
}

/**
 * Sets the receiver's text.
 * <p>
 * This method sets the widget label.  The label may include
 * the mnemonic character and line delimiters.
 * </p>
 * <p>
 * Mnemonics are indicated by an '&amp' that causes the next
 * character to be the mnemonic.  When the user presses a
 * key sequence that matches the mnemonic, focus is assigned
 * to the control that follows the label. On most platforms,
 * the mnemonic appears underlined but may be emphasised in a
 * platform specific manner.  The mnemonic indicator character
 *'&amp' can be escaped by doubling it in the string, causing
 * a single '&amp' to be displayed.
 * </p>
 * 
 * @param string the new text
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the text 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>
 */
public void setText (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	if ((style & SWT.SEPARATOR) != 0) return;
	/*
	* Feature in Windows.  For some reason, SetWindowText() for
	* static controls redraws the control, even when the text has
	* has not changed.  The fix is to check for this case and do
	* nothing.
	*/
	if (string.equals (text)) return;
	text = string;
	int newBits = OS.GetWindowLong (handle, OS.GWL_STYLE), oldBits = newBits;
	newBits &= ~(OS.SS_BITMAP | OS.SS_ICON | OS.SS_REALSIZEIMAGE | OS.SS_CENTERIMAGE);
	if ((style & SWT.LEFT) != 0 && (style & SWT.WRAP) == 0) newBits |= OS.SS_LEFTNOWORDWRAP;
	if ((style & SWT.CENTER) != 0) newBits |= OS.SS_CENTER;
	if ((style & SWT.RIGHT) != 0) newBits |= OS.SS_RIGHT;
	if (newBits != oldBits) {
		/*
		* Bug in Windows.  When the style of a label is SS_BITMAP
		* or SS_ICON, the label does not remember the font that is
		* set in WM_SETFONT.  The fix is to remember the font and
		* return the font in WM_GETFONT and to reset the font when
		* the style is changed from SS_BITMAP or SS_ICON to a style
		* that displays text.
		*/
		int hFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
		OS.SetWindowLong (handle, OS.GWL_STYLE, newBits);
		if (hFont != 0) OS.SendMessage (handle, OS.WM_SETFONT, hFont, 0);
	}
	string = Display.withCrLf (string);
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	OS.SetWindowText (handle, buffer);
}

/*
* Not currently used.
*/
void setWrap (boolean wrap) {
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	if ((bits & (OS.SS_RIGHT | OS.SS_CENTER)) != 0) return;
	bits &= ~OS.SS_LEFTNOWORDWRAP;
	if (!wrap) bits |= OS.SS_LEFTNOWORDWRAP;
	OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
	OS.InvalidateRect (handle, null, true);
}

int widgetExtStyle () {
	int bits = super.widgetExtStyle () & ~OS.WS_EX_CLIENTEDGE;
	if ((style & SWT.BORDER) != 0) return bits | OS.WS_EX_STATICEDGE;
	return bits;
}

int widgetStyle () {
	int bits = super.widgetStyle () | OS.SS_NOTIFY;
	if ((style & SWT.SEPARATOR) != 0) return bits | OS.SS_OWNERDRAW;
	if ((style & SWT.CENTER) != 0) return bits | OS.SS_CENTER;
	if ((style & SWT.RIGHT) != 0) return bits | OS.SS_RIGHT;
	if ((style & SWT.WRAP) != 0) return bits | OS.SS_LEFT;
	return bits | OS.SS_LEFTNOWORDWRAP;
}

TCHAR windowClass () {
	return LabelClass;
}

int windowProc () {
	return LabelProc;
}

LRESULT WM_ERASEBKGND (int wParam, int lParam) {
	LRESULT result = super.WM_ERASEBKGND (wParam, lParam);
	if (result != null) return result;
	if ((style & SWT.SEPARATOR) != 0) return LRESULT.ONE;
	/*
	* Bug in Windows.  When a label has the SS_BITMAP
	* or SS_ICON style, the label does not draw the
	* background.  The fix is to draw the background
	* when the label is showing a bitmap or icon.
	*
	* NOTE: SS_BITMAP and SS_ICON are not single bit
	* masks so it is necessary to test for all of the
	* bits in these masks.
	*/
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	boolean isBitmap = (bits & OS.SS_BITMAP) == OS.SS_BITMAP;
	boolean isIcon = (bits & OS.SS_ICON) == OS.SS_ICON;
	if (isBitmap || isIcon) {
		drawBackground (wParam);
		return LRESULT.ONE;
	}
	return result;
}

LRESULT WM_GETFONT (int wParam, int lParam) {
	LRESULT result = super.WM_GETFONT (wParam, lParam);
	if (result != null) return result;
	/*
	* Bug in Windows.  When the style of a label is SS_BITMAP
	* or SS_ICON, the label does not remember the font that is
	* set in WM_SETFONT.  The fix is to remember the font and
	* return the font in WM_GETFONT.
	*/
	if (font == 0) font = defaultFont ();
	return new LRESULT (font);
}

LRESULT WM_SETFONT (int wParam, int lParam) {
	/*
	* Bug in Windows.  When the style of a label is SS_BITMAP
	* or SS_ICON, the label does not remember the font that is
	* set in WM_SETFONT.  The fix is to remember the font and
	* return the font in WM_GETFONT.
	*/
	return super.WM_SETFONT (font = wParam, lParam);
}

LRESULT WM_SIZE (int wParam, int lParam) {
	LRESULT result = super.WM_SIZE (wParam, lParam);
	/*
	* It is possible (but unlikely), that application
	* code could have disposed the widget in the resize
	* event.  If this happens, end the processing of the
	* Windows message by returning the result of the
	* WM_SIZE message.
	*/
	if (isDisposed ()) return result;
	if ((style & SWT.SEPARATOR) != 0) {
		OS.InvalidateRect (handle, null, true);
		return result;
	}
	
	/*
	* Bug in Windows.  For some reason, a label with
	* SS_BITMAP or SS_ICON and SS_CENTER does not redraw
	* properly when resized.  Only the new area is drawn
	* and the old area is not cleared.  The fix is to
	* force the redraw.
	*
	* NOTE: SS_BITMAP and SS_ICON are not single bit
	* masks so it is necessary to test for all of the
	* bits in these masks.
	*/
	int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
	boolean isBitmap = (bits & OS.SS_BITMAP) == OS.SS_BITMAP;
	boolean isIcon = (bits & OS.SS_ICON) == OS.SS_ICON;
	if (isBitmap || isIcon) {
		OS.InvalidateRect (handle, null, true);
		return result;
	}
		
	/*
	* Bug in Windows.  For some reason, a label with
	* style SS_LEFT, SS_CENTER or SS_RIGHT does not
	* redraw the text in the new position when resized.
	* Note that SS_LEFTNOWORDWRAP does not have the
	* problem.  The fix is to force the redraw.
	*/
	if ((style & (SWT.WRAP | SWT.CENTER | SWT.RIGHT)) != 0) {
		OS.InvalidateRect (handle, null, true);
		return result;
	}
	
	return result;
}

LRESULT wmDrawChild (int wParam, int lParam) {
	DRAWITEMSTRUCT struct = new DRAWITEMSTRUCT ();
	OS.MoveMemory (struct, lParam, DRAWITEMSTRUCT.sizeof);
	drawBackground (struct.hDC);
	if ((style & SWT.SHADOW_NONE) != 0) return null;
	RECT rect = new RECT ();
	int lineWidth = OS.GetSystemMetrics (OS.SM_CXBORDER);
	int flags = OS.EDGE_ETCHED;
	if ((style & SWT.SHADOW_IN) != 0) flags = OS.EDGE_SUNKEN;
	if ((style & SWT.HORIZONTAL) != 0) {
		int bottom = struct.top + Math.max (lineWidth * 2, (struct.bottom - struct.top) / 2);
		OS.SetRect (rect, struct.left, struct.top, struct.right, bottom);
		OS.DrawEdge (struct.hDC, rect, flags, OS.BF_BOTTOM);
	} else {
		int right = struct.left + Math.max (lineWidth * 2, (struct.right - struct.left) / 2);
		OS.SetRect (rect, struct.left, struct.top, right, struct.bottom);
		OS.DrawEdge (struct.hDC, rect, flags, OS.BF_RIGHT);
	}
	return null;
}

}