Bug 172000 [Wizards] WizardNewFileCreationPage should support overwriting existing resources
In the WizardNewFileCreationPage, there should be a method to set allowExistingResources flag for ResourceAndContainerGroup member. It is useful when both "create" and "renew/overwrite" operations are meaningful for a wizard.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/misc/ResourceAndContainerGroup.java
* @see ResourceAndContainerGroup#setResourceExtension(String)
     * @return <code>true</code> if the preconditions are met; otherwise, 
     *         <code>false</code>.
     * @since 3.3
     */
    private boolean useResourceExtension() {
    	String resource = resourceNameField.getText();
    	if ((resourceExtension != null) &&
    			(resourceExtension.length() > 0) &&
    			(resource.length() > 0) &&
    			(resource.endsWith('.' + resourceExtension) == false)) {
    		return true;
    	}
    	return false;
    }
    /**
	 * Handle the focus lost event from the resource name field.
	 * <br>
	 * Adds the resource extension to the resource name field when it
     * loses focus (if the preconditions are met).
	 * @see ResourceNameFocusListener
	 * @see ResourceAndContainerGroup#setResourceExtension(String)
     * @since 3.3
	 */
	private void handleResourceNameFocusLostEvent() {
    	if (useResourceExtension()) {
    		setResource(resourceNameField.getText() + '.' + resourceExtension);
    	}
	}