Bug 161902 [JFace] Enhancements to GridLayoutFactory.margins
This enhancement requests the following: 1. Rename the new GridLayoutFactory.margins(int,int,int,int) to GridLayoutFactory.extendedMargins(int,int,int,int) 2. Add a GridLayoutFactory.extendedMargins(Rectangle) method that accepts a difference rectangle. 3. Add static methods to Geometry in order to easily construct difference rectangles. Why? 1. We should not use overloaded methods in GridLayoutFactory unless they really do set the same thing. Since the four-argument margins(...) method and the two-argument margins(...) method set independent values, we should give them different names or clients will expect a call to margins(int, int, int, int) to overwrite a previous call to margins(int, int). 2. All methods on GridLayoutFactory and GridDataFactory should have vector initializers, so that clients can store and reuse standard margin settings in a single variable. 3. Vector initializers are only a convenience if there is a convenient way to construct the vector.
bundles/org.eclipse.jface/src/org/eclipse/jface/util/Geometry.java
* @param rect rectangle being computed
     * @return a Point at the center of the given rectangle.
     * @since 3.0
     */
    public static Point centerPoint(Rectangle rect) {
        return new Point(rect.x + rect.width / 2, rect.y + rect.height / 2);
    }
    /**
     * Returns a copy of the given point
     * 
     * @param toCopy point to copy
     * @return a copy of the given point
     */
    public static Point copy(Point toCopy) {
        return new Point(toCopy.x, toCopy.y);
    }
    
    /**
     * Sets result equal to toCopy
     * 
     * @param result object that will be modified
     * @param toCopy object that will be copied
     * @since 3.1
     */
    public static void set(Point result, Point toCopy) {
    	result.x = toCopy.x;
    	result.y = toCopy.y;
    }
    
    /**