IAction定义了setMenuCreator()和getMenuCreator(),他们的作用在于为IAction提供下拉框样式的Action,
通过IMenuCreator实现将多个相关Action组合在一起.
*代码参考
eclipse中的org.eclipse.ui.internal.ide.actions.OpenWorkspaceAction使用了这种样式实现,
下面的代码借用了他的IMenuCreator实现方式:
import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.ActionContributionItem;
import org.eclipse.jface.action.IContributionItem;
import org.eclipse.jface.action.IMenuCreator;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Menu;
public class MenuCreatorActionTest extends Action implements IMenuCreator {
private MenuManager dropDownMenuMgr;
public MenuCreatorActionTest(){
setText("MenuCreatorActionTest");
setId("test.MenuCreatorActionTest");
setMenuCreator(this); //设置IMenuCreator
}
public void run(){
System.out.println("MenuCreatorActionTest");
}
private void createDropDownMenuMgr() {
if (dropDownMenuMgr == null) {
dropDownMenuMgr = new MenuManager();
dropDownMenuMgr.add(new InnerAction("One"));
dropDownMenuMgr.add(new InnerAction("Two"));
}
}
@Override
public void dispose() {
if (dropDownMenuMgr != null) {
dropDownMenuMgr.dispose();
dropDownMenuMgr = null;
}
}
@Override
public Menu getMenu(Control parent) { //在工具栏被调用
createDropDownMenuMgr();
return dropDownMenuMgr.createContextMenu(parent);
}
@Override
public Menu getMenu(Menu parent) { //在菜单栏被调用
createDropDownMenuMgr();
Menu menu = new Menu(parent);
IContributionItem[] items = dropDownMenuMgr.getItems();
for (int i = 0; i < items.length; i++) {
IContributionItem item = items[i];
IContributionItem newItem = item;
if (item instanceof ActionContributionItem) {
newItem = new ActionContributionItem(
((ActionContributionItem) item).getAction());
}
newItem.fill(menu, -1);
}
return menu;
}
class InnerAction extends Action{
private String text;
public InnerAction(String text){
super(text);
this.text =text;
}
public void run(){
System.out.println(text);
}
}
}
效果截图