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
case SWT.RIGHT:
            bounds.x = toExtrude.x + toExtrude.width - bounds.width;
            break;
        case SWT.BOTTOM:
            bounds.y = toExtrude.y + toExtrude.height - bounds.height;
            break;
        }
        normalize(bounds);
        return bounds;
    }
    /**
     * Returns the opposite of the given direction. That is, returns SWT.LEFT if
     * given SWT.RIGHT and visa-versa.
     * 
     * @param swtDirectionConstant one of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM
     * @return one of SWT.LEFT, SWT.RIGHT, SWT.TOP, or SWT.BOTTOM
     * @since 3.0
     */
    public static int getOppositeSide(int swtDirectionConstant) {
        switch (swtDirectionConstant) {
        case SWT.TOP:
            return SWT.BOTTOM;
        case SWT.BOTTOM:
            return SWT.TOP;
        case SWT.LEFT:
            return SWT.RIGHT;
        case SWT.RIGHT:
            return SWT.LEFT;
        }
        return swtDirectionConstant;