Bug 123496 [IDE] Use operation validation API for IDE actions
We should use the Resources/Core operation validation API in the IDE actions for manipulating resources.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/ErrorDialog.java
*            a mask as per <code>IStatus.matches</code>
     * @return <code>true</code> if the given status should be displayed, and
     *         <code>false</code> otherwise
     * @see org.eclipse.core.runtime.IStatus#matches(int)
     */
    protected static boolean shouldDisplay(IStatus status, int mask) {
        IStatus[] children = status.getChildren();
        if (children == null || children.length == 0) {
            return status.matches(mask);
        }
        for (int i = 0; i < children.length; i++) {
            if (children[i].matches(mask))
                return true;
        }
        return false;
    }
    /**
     * Toggles the unfolding of the details area. This is triggered by the user
     * pressing the details button.
     */
    private void toggleDetailsArea() {
        Point windowSize = getShell().getSize();
        Point oldSize = getShell().computeSize(SWT.DEFAULT, SWT.DEFAULT);
        if (listCreated) {
            list.dispose();
            listCreated = false;
            detailsButton.setText(IDialogConstants.SHOW_DETAILS_LABEL);
        } else {
            list = createDropDownList((Composite) getContents());
            detailsButton.setText(IDialogConstants.HIDE_DETAILS_LABEL);