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/layout/GridLayoutFactory.java
* @param vSpacing vertical spacing (pixels)
     * @return this
     * @see #margins
     */
    public GridLayoutFactory spacing(int hSpacing, int vSpacing) {
        l.horizontalSpacing = hSpacing;
        l.verticalSpacing = vSpacing;
        return this;
    }
    /**
     * Sets the spacing for layouts created with this factory. The spacing
     * is the distance between cells within the layout. 
     * 
     * @param spacing space between controls in the layout (pixels)
     * @return this
     * @see #margins
     */
    public GridLayoutFactory spacing(Point spacing) {
        l.horizontalSpacing = spacing.x;
        l.verticalSpacing = spacing.y;
        return this;
    }
    /**
     * Sets the margins for layouts created with this factory. The margins
     * are the distance between the outer cells and the edge of the layout.
     * 
     * @param margins margin size (pixels)
     * @return this
     * @see #spacing
     */