gc.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 *
 * @param x the x coordinate of the upper-left corner of the arc to be drawn
 * @param y the y coordinate of the upper-left corner of the arc to be drawn
 * @param width the width of the arc to be drawn
 * @param height the height of the arc to be drawn
 * @param startAngle the beginning angle
 * @param arcAngle the angular extent of the arc, relative to the start angle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawArc (int x, int y, int width, int height, int startAngle, int arcAngle) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (width < 0) {
		x = x + width;
		width = -width;
	}
	if (height < 0) {
		y = y + height;
		height = -height;
	}
	if (width == 0 || height == 0 || arcAngle == 0) return;
	/*
	* Feature in WinCE.  The function Arc is not present in the
	* WinCE SDK.  The fix is to emulate arc drawing by using
	* Polyline.
	*/
	if (OS.IsWinCE) {
		/* compute arc with a simple linear interpolation */
		if (arcAngle < 0) {
			startAngle += arcAngle;
			arcAngle = -arcAngle;
		}
		if (arcAngle > 360) arcAngle = 360;
		int[] points = new int[(arcAngle + 1) * 2];		
		int cteX = 2 * x + width;
		int cteY = 2 * y + height;
		int index = 0;
		for (int i = 0; i <= arcAngle; i++) {
			points[index++] = (Compatibility.cos(startAngle + i, width) + cteX) >> 1;
			points[index++] = (cteY - Compatibility.sin(startAngle + i, height)) >> 1;
		} 
		OS.Polyline(handle, points, points.length / 2);
	} else {	
		int x1, y1, x2, y2,tmp;
		boolean isNegative;
		if (arcAngle >= 360 || arcAngle <= -360) {
			x1 = x2 = x + width;
			y1 = y2 = y + height / 2;
		} else {
			isNegative = arcAngle < 0;
	
			arcAngle = arcAngle + startAngle;
			if (isNegative) {
				// swap angles
			   	tmp = startAngle;
				startAngle = arcAngle;
				arcAngle = tmp;
			}
			x1 = Compatibility.cos(startAngle, width) + x + width/2;
			y1 = -1 * Compatibility.sin(startAngle, height) + y + height/2;
			
			x2 = Compatibility.cos(arcAngle, width) + x + width/2;
			y2 = -1 * Compatibility.sin(arcAngle, height) + y + height/2; 		
		}
		int nullBrush = OS.GetStockObject(OS.NULL_BRUSH);
		int oldBrush = OS.SelectObject(handle, nullBrush);
		OS.Arc(handle, x, y, x + width + 1, y + height + 1, x1, y1, x2, y2);
		OS.SelectObject(handle, oldBrush);
	}
}

/** 
 * Draws a rectangle, based on the specified arguments, which has
 * the appearance of the platform's <em>focus rectangle</em> if the
 * platform supports such a notion, and otherwise draws a simple
 * rectangle in the receiver's foreground color.
 *
 * @param x the x coordinate of the rectangle
 * @param y the y coordinate of the rectangle
 * @param width the width of the rectangle
 * @param height the height of the rectangle
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 *
 * @see #drawRectangle
 */	 
public void drawFocus (int x, int y, int width, int height) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	RECT rect = new RECT();
	OS.SetRect(rect, x, y, x + width, y + height);
	OS.DrawFocusRect(handle, rect);
}

/**
 * Draws the given image in the receiver at the specified
 * coordinates.
 *
 * @param image the image to draw
 * @param x the x coordinate of where to draw
 * @param y the y coordinate of where to draw
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the image is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the given coordinates are outside the bounds of the image</li>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if no handles are available to perform the operation</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawImage(Image image, int x, int y) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (image == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	drawImage(image, 0, 0, -1, -1, x, y, -1, -1, true);
}

/**
 * Copies a rectangular area from the source image into a (potentially
 * different sized) rectangular area in the receiver. If the source
 * and destination areas are of differing sizes, then the source
 * area will be stretched or shrunk to fit the destination area
 * as it is copied. The copy fails if any part of the source rectangle
 * lies outside the bounds of the source image, or if any of the width
 * or height arguments are negative.
 *
 * @param image the source image
 * @param srcX the x coordinate in the source image to copy from
 * @param srcY the y coordinate in the source image to copy from
 * @param srcWidth the width in pixels to copy from the source
 * @param srcHeight the height in pixels to copy from the source
 * @param destX the x coordinate in the destination to copy to
 * @param destY the y coordinate in the destination to copy to
 * @param destWidth the width in pixels of the destination rectangle
 * @param destHeight the height in pixels of the destination rectangle
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the image is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 *    <li>ERROR_INVALID_ARGUMENT - if any of the width or height arguments are negative.
 *    <li>ERROR_INVALID_ARGUMENT - if the source rectangle is not contained within the bounds of the source image</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES - if no handles are available to perform the operation</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void drawImage(Image image, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (srcWidth == 0 || srcHeight == 0 || destWidth == 0 || destHeight == 0) return;
	if (srcX < 0 || srcY < 0 || srcWidth < 0 || srcHeight < 0 || destWidth < 0 || destHeight < 0) {
		SWT.error (SWT.ERROR_INVALID_ARGUMENT);
	}
	if (image == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (image.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	drawImage(image, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, false);	
}

void drawImage(Image srcImage, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight, boolean simple) {
	switch (srcImage.type) {
		case SWT.BITMAP:
			drawBitmap(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple);
			break;
		case SWT.ICON:
			drawIcon(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple);
			break;
		default:
			SWT.error(SWT.ERROR_UNSUPPORTED_FORMAT);
	}
}

void drawIcon(Image srcImage, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight, boolean simple) {
	int technology = OS.GetDeviceCaps(handle, OS.TECHNOLOGY);

	/* Simple case: no stretching, entire icon */
	if (simple && technology != OS.DT_RASPRINTER) {
		OS.DrawIconEx(handle, destX, destY, srcImage.handle, 0, 0, 0, 0, OS.DI_NORMAL);
		return;
	}

	/* Get the icon info */
	ICONINFO srcIconInfo = new ICONINFO();
	if (OS.IsWinCE) {
		Image.GetIconInfo(srcImage, srcIconInfo);
	} else {
		OS.GetIconInfo(srcImage.handle, srcIconInfo);
	}

	/* Get the icon width and height */
	int hBitmap = srcIconInfo.hbmColor;
	if (hBitmap == 0) hBitmap = srcIconInfo.hbmMask;
	BITMAP bm = new BITMAP();
	OS.GetObject(hBitmap, BITMAP.sizeof, bm);
	int iconWidth = bm.bmWidth, iconHeight = bm.bmHeight;
	if (hBitmap == srcIconInfo.hbmMask) iconHeight /= 2;
	
	if (simple) {
		srcWidth = destWidth = iconWidth;
		srcHeight = destHeight = iconHeight;
	}

	/* Draw the icon */
	boolean failed = srcX + srcWidth > iconWidth || srcY + srcHeight > iconHeight;
	if (!failed) {
		simple = srcX == 0 && srcY == 0 &&
			srcWidth == destWidth && srcHeight == destHeight &&
			srcWidth == iconWidth && srcHeight == iconHeight;
		if (simple && technology != OS.DT_RASPRINTER)	{
			/* Simple case: no stretching, entire icon */
			OS.DrawIconEx(handle, destX, destY, srcImage.handle, 0, 0, 0, 0, OS.DI_NORMAL);
		} else {
			/* Get the HDC for the device */
			Device device = data.device;
 			int hDC = device.internal_new_GC(null);
 	
 			/* Create the icon info and HDC's */
			ICONINFO newIconInfo = new ICONINFO();
			newIconInfo.fIcon = true;
			int srcHdc = OS.CreateCompatibleDC(hDC);
			int dstHdc = OS.CreateCompatibleDC(hDC);
						
			/* Blt the color bitmap */
			int srcColorY = srcY;
			int srcColor = srcIconInfo.hbmColor;
			if (srcColor == 0) {
				srcColor = srcIconInfo.hbmMask;
				srcColorY += iconHeight;
			}
			int oldSrcBitmap = OS.SelectObject(srcHdc, srcColor);
			newIconInfo.hbmColor = OS.CreateCompatibleBitmap(srcHdc, destWidth, destHeight);
			if (newIconInfo.hbmColor == 0) SWT.error(SWT.ERROR_NO_HANDLES);
			int oldDestBitmap = OS.SelectObject(dstHdc, newIconInfo.hbmColor);
			boolean stretch = !simple && (srcWidth != destWidth || srcHeight != destHeight);
			if (stretch) {
				if (!OS.IsWinCE) OS.SetStretchBltMode(dstHdc, OS.COLORONCOLOR);
				OS.StretchBlt(dstHdc, 0, 0, destWidth, destHeight, srcHdc, srcX, srcColorY, srcWidth, srcHeight, OS.SRCCOPY);
			} else {
				OS.BitBlt(dstHdc, 0, 0, destWidth, destHeight, srcHdc, srcX, srcColorY, OS.SRCCOPY);
			}
			
			/* Blt the mask bitmap */
			OS.SelectObject(srcHdc, srcIconInfo.hbmMask);
			newIconInfo.hbmMask = OS.CreateBitmap(destWidth, destHeight, 1, 1, null);
			if (newIconInfo.hbmMask == 0) SWT.error(SWT.ERROR_NO_HANDLES);
			OS.SelectObject(dstHdc, newIconInfo.hbmMask);
			if (stretch) {
				OS.StretchBlt(dstHdc, 0, 0, destWidth, destHeight, srcHdc, srcX, srcY, srcWidth, srcHeight, OS.SRCCOPY);
			} else {
				OS.BitBlt(dstHdc, 0, 0, destWidth, destHeight, srcHdc, srcX, srcY, OS.SRCCOPY);
			}
			
			if (technology == OS.DT_RASPRINTER) {
				OS.SelectObject(srcHdc, newIconInfo.hbmColor);
				OS.SelectObject(dstHdc, srcIconInfo.hbmMask);
				drawBitmapTransparentByClipping(srcHdc, dstHdc, 0, 0, destWidth, destHeight, destX, destY, destWidth, destHeight, true, destWidth, destHeight);	
				OS.SelectObject(srcHdc, oldSrcBitmap);
				OS.SelectObject(dstHdc, oldDestBitmap);
			} else {
				OS.SelectObject(srcHdc, oldSrcBitmap);
				OS.SelectObject(dstHdc, oldDestBitmap);
				int hIcon = OS.CreateIconIndirect(newIconInfo);
				if (hIcon == 0) SWT.error(SWT.ERROR_NO_HANDLES);
				OS.DrawIconEx(handle, destX, destY, hIcon, destWidth, destHeight, 0, 0, OS.DI_NORMAL);
				OS.DestroyIcon(hIcon);
			}
			
			/* Destroy the new icon src and mask and hdc's*/
			OS.DeleteObject(newIconInfo.hbmMask);
			OS.DeleteObject(newIconInfo.hbmColor);
			OS.DeleteDC(dstHdc);
			OS.DeleteDC(srcHdc);

			/* Release the HDC for the device */
			device.internal_dispose_GC(hDC, null);
		}
	}

	/* Free icon info */
	OS.DeleteObject(srcIconInfo.hbmMask);
	if (srcIconInfo.hbmColor != 0) {
		OS.DeleteObject(srcIconInfo.hbmColor);
	}
	
	if (failed) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}

void drawBitmap(Image srcImage, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight, boolean simple) {
	BITMAP bm = new BITMAP();
	OS.GetObject(srcImage.handle, BITMAP.sizeof, bm);
	int imgWidth = bm.bmWidth;
	int imgHeight = bm.bmHeight;
	if (simple) {
		srcWidth = destWidth = imgWidth;
		srcHeight = destHeight = imgHeight;
	} else {
		if (srcX + srcWidth > imgWidth || srcY + srcHeight > imgHeight) {
			SWT.error (SWT.ERROR_INVALID_ARGUMENT);
		}
		simple = srcX == 0 && srcY == 0 && 
			srcWidth == destWidth && destWidth == imgWidth &&
			srcHeight == destHeight && destHeight == imgHeight;
	}
	boolean mustRestore = false;
	GC memGC = srcImage.memGC;
	if (memGC != null && !memGC.isDisposed()) {
		mustRestore = true;
		GCData data = memGC.data;
		if (data.hNullBitmap != 0) {
			OS.SelectObject(memGC.handle, data.hNullBitmap);
			data.hNullBitmap = 0;
		}
	}
	if (srcImage.alpha != -1 || srcImage.alphaData != null) {
		drawBitmapAlpha(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple, bm, imgWidth, imgHeight);
	} else if (srcImage.transparentPixel != -1) {
		drawBitmapTransparent(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple, bm, imgWidth, imgHeight);
	} else {
		drawBitmap(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple, bm, imgWidth, imgHeight);
	}
	if (mustRestore) {
		int hOldBitmap = OS.SelectObject(memGC.handle, srcImage.handle);
		memGC.data.hNullBitmap = hOldBitmap;
	}
}

void drawBitmapAlpha(Image srcImage, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight, boolean simple, BITMAP bm, int imgWidth, int imgHeight) {
	/* Simple cases */
	if (srcImage.alpha == 0) return;
	if (srcImage.alpha == 255) {
		drawBitmap(srcImage, srcX, srcY, srcWidth, srcHeight, destX, destY, destWidth, destHeight, simple, bm, imgWidth, imgHeight);
		return;
	}

	/* Check clipping */
	Rectangle rect = getClipping();