Bug 297731 [Filters] We could have IResourceFilterDescription#delete instead of IContainer#removeFilter ?
This is the pattern used for resource markers. It is just a minor issue, however would make new API look more consistent.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/ResourceFilterGroup.java
*/
		public void dragStart(DragSourceEvent event) {
			if (getFilterCopySelection().length == 0)
				event.doit = false;
		}
	}
	private static int getMinimumColumnWidth(TreeColumn column, int hint) {
		Assert.isNotNull(column);
		FontMetrics fontMetrics;
		GC gc = new GC(column.getParent());
		try {
			gc.setFont(column.getParent().getFont());
			fontMetrics = gc.getFontMetrics();
		} finally {
			gc.dispose();
		}
		return Math.max(hint, fontMetrics.getAverageCharWidth()
				* column.getText().length());
	}
	private void createButtonGroup(Composite parent) {
		Composite composite = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.marginWidth = 0;
		layout.marginHeight = 0;
		layout.numColumns = 1;
		composite.setLayout(layout);
		GridData data = new GridData(SWT.FILL, SWT.FILL, false, false);
		composite.setLayoutData(data);
		composite.setFont(parent.getFont());
		addButton = new Button(composite, SWT.PUSH);