graphicsutils.java

自己建立的项目

package com.swtSample.graphics;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.Display;

/**
 * This class contains utility methods for drawing graphics
 */
public class GraphicsUtils {
  /**
   * Draws text vertically (rotates plus or minus 90 degrees). Uses the current
   * font, color, and background.
   * <dl>
   * <dt><b>Styles: </b></dt>
   * <dd>UP, DOWN</dd>
   * </dl>
   * 
   * @param string the text to draw
   * @param x the x coordinate of the top left corner of the drawing rectangle
   * @param y the y coordinate of the top left corner of the drawing rectangle
   * @param gc the GC on which to draw the text
   * @param style the style (SWT.UP or SWT.DOWN)
   *          <p>
   *          Note: Only one of the style UP or DOWN may be specified.
   *          </p>
   */
  public static void drawVerticalText(String string, int x, int y, GC gc,
      int style) {
    // Get the current display
    Display display = Display.getCurrent();
    if (display == null) SWT.error(SWT.ERROR_THREAD_INVALID_ACCESS);

    // Determine string's dimensions
    FontMetrics fm = gc.getFontMetrics();
    Point pt = gc.textExtent(string);

    // Create an image the same size as the string
    Image stringImage = new Image(display, pt.x, pt.y);

    // Create a GC so we can draw the image
    GC stringGc = new GC(stringImage);

    // Set attributes from the original GC to the new GC
    stringGc.setForeground(gc.getForeground());
    stringGc.setBackground(gc.getBackground());
    stringGc.setFont(gc.getFont());

    // Draw the text onto the image
    stringGc.drawText(string, 0, 0);

    // Draw the image vertically onto the original GC
    drawVerticalImage(stringImage, x, y, gc, style);

    // Dispose the new GC
    stringGc.dispose();

    // Dispose the image
    stringImage.dispose();
  }

  /**
   * Draws an image vertically (rotates plus or minus 90 degrees)
   * <dl>
   * <dt><b>Styles: </b></dt>
   * <dd>UP, DOWN</dd>
   * </dl>
   * 
   * @param image the image to draw
   * @param x the x coordinate of the top left corner of the drawing rectangle
   * @param y the y coordinate of the top left corner of the drawing rectangle
   * @param gc the GC on which to draw the image
   * @param style the style (SWT.UP or SWT.DOWN)
   *          <p>
   *          Note: Only one of the style UP or DOWN may be specified.
   *          </p>
   */
  public static void drawVerticalImage(Image image, int x, int y, GC gc, int style) {
    // Get the current display
    Display display = Display.getCurrent();
    if (display == null) SWT.error(SWT.ERROR_THREAD_INVALID_ACCESS);

    // Use the image's data to create a rotated image's data
    ImageData sd = image.getImageData();
    ImageData dd = new ImageData(sd.height, sd.width, sd.depth, sd.palette);

    // Determine which way to rotate, depending on up or down
    boolean up = (style & SWT.UP) == SWT.UP;

    // Run through the horizontal pixels
    for (int sx = 0; sx < sd.width; sx++) {
      // Run through the vertical pixels
      for (int sy = 0; sy < sd.height; sy++) {
        // Determine where to move pixel to in destination image data
        int dx = up ? sy : sd.height - sy - 1;
        int dy = up ? sd.width - sx - 1 : sx;

        // Swap the x, y source data to y, x in the destination
        dd.setPixel(dx, dy, sd.getPixel(sx, sy));
      }
    }

    // Create the vertical image
    Image vertical = new Image(display, dd);

    // Draw the vertical image onto the original GC
    gc.drawImage(vertical, x, y);

    // Dispose the vertical image
    vertical.dispose();
  }

  /**
   * Creates an image containing the specified text, rotated either plus or minus
   * 90 degrees.
   * <dl>
   * <dt><b>Styles: </b></dt>
   * <dd>UP, DOWN</dd>
   * </dl>
   * 
   * @param text the text to rotate
   * @param font the font to use
   * @param foreground the color for the text
   * @param background the background color
   * @param style direction to rotate (up or down)
   * @return Image
   *         <p>
   *         Note: Only one of the style UP or DOWN may be specified.
   *         </p>
   */
  public static Image createRotatedText(String text, Font font, Color foreground,
      Color background, int style) {
    // Get the current display
    Display display = Display.getCurrent();
    if (display == null) SWT.error(SWT.ERROR_THREAD_INVALID_ACCESS);

    // Create a GC to calculate font's dimensions
    GC gc = new GC(display);
    gc.setFont(font);

    // Determine string's dimensions
    FontMetrics fm = gc.getFontMetrics();
    Point pt = gc.textExtent(text);

    // Dispose that gc
    gc.dispose();

    // Create an image the same size as the string
    Image stringImage = new Image(display, pt.x, pt.y);

    // Create a gc for the image
    gc = new GC(stringImage);
    gc.setFont(font);
    gc.setForeground(foreground);
    gc.setBackground(background);

    // Draw the text onto the image
    gc.drawText(text, 0, 0);

    // Draw the image vertically onto the original GC
    Image image = createRotatedImage(stringImage, style);

    // Dispose the new GC
    gc.dispose();

    // Dispose the horizontal image
    stringImage.dispose();

    // Return the rotated image
    return image;
  }

  /**
   * Creates a rotated image (plus or minus 90 degrees)
   * <dl>
   * <dt><b>Styles: </b></dt>
   * <dd>UP, DOWN</dd>
   * </dl>
   * 
   * @param image the image to rotate
   * @param style direction to rotate (up or down)
   * @return Image
   *         <p>
   *         Note: Only one of the style UP or DOWN may be specified.
   *         </p>
   */
  public static Image createRotatedImage(Image image, int style) {
    // Get the current display
    Display display = Display.getCurrent();
    if (display == null) SWT.error(SWT.ERROR_THREAD_INVALID_ACCESS);

    // Use the image's data to create a rotated image's data
    ImageData sd = image.getImageData();
    ImageData dd = new ImageData(sd.height, sd.width, sd.depth, sd.palette);

    // Determine which way to rotate, depending on up or down
    boolean up = (style & SWT.UP) == SWT.UP;

    // Run through the horizontal pixels
    for (int sx = 0; sx < sd.width; sx++) {
      // Run through the vertical pixels
      for (int sy = 0; sy < sd.height; sy++) {
        // Determine where to move pixel to in destination image data
        int dx = up ? sy : sd.height - sy - 1;
        int dy = up ? sd.width - sx - 1 : sx;

        // Swap the x, y source data to y, x in the destination
        dd.setPixel(dx, dy, sd.getPixel(sx, sy));
      }
    }

    // Create the vertical image
    return new Image(display, dd);
  }
}