SWTGraphics.java 文件源码

/**
 * Simple implementation of clipping a Path within the context of current
 * clipping rectangle for now (not region) <li>Note that this method wipes
 * out the clipping rectangle area, hence if clients need to reset it call
 * {@link #restoreState()}
 * 
 * @see org.eclipse.draw2d.Graphics#clipPath(org.eclipse.swt.graphics.Path)
 */
public void clipPath(Path path) {
    initTransform(false);
    if (((appliedState.graphicHints ^ currentState.graphicHints) & FILL_RULE_MASK) != 0) {
        // If there is a pending change to the fill rule, apply it first.
        gc.setFillRule(((currentState.graphicHints & FILL_RULE_MASK) >> FILL_RULE_SHIFT)
                - FILL_RULE_WHOLE_NUMBER);
        // As long as the FILL_RULE is stored in a single bit, just toggling
        // it works.
        appliedState.graphicHints ^= FILL_RULE_MASK;
    }
    Rectangle clipping = currentState.relativeClip != null ? getClip(new Rectangle())
            : new Rectangle();
    if (!clipping.isEmpty()) {
        Path flatPath = new Path(path.getDevice(), path, 0.01f);
        PathData pathData = flatPath.getPathData();
        flatPath.dispose();
        Region region = new Region(path.getDevice());
        loadPath(region, pathData.points, pathData.types);
        region.intersect(new org.eclipse.swt.graphics.Rectangle(clipping.x,
                clipping.y, clipping.width, clipping.height));
        gc.setClipping(region);
        appliedState.relativeClip = currentState.relativeClip = null;
        region.dispose();
    }
}