我正在尝试实现启用或禁用的操作(在应用程序顶部菜单中,右键单击节点上的弹出菜单中),具体取决于当前节点/节点状态。
@ActionID(
category = "Application",
id = "it.cre.app.tree.actions.ShowEventsAction")
@ActionRegistration(
iconBase = "it/cre/app/tree/actions/show.png",
displayName = "#CTL_ShowAction")
@ActionReferences({
@ActionReference(path = "Menu/Edit", position = 100),
@ActionReference(path = "Toolbars/File", position = 300),
@ActionReference(path = "Application/edit", position = 0)})
@NbBundle.Messages("CTL_ShowAction=Show Events")
public class ShowEventsAction implements ActionListener {
private ShowAuditEventsCapability showAuditEventsCapability;
public ShowEventsAction(ShowAuditEventsCapability context) {
showAuditEventsCapability = context;
}
@Override
public void actionPerformed(ActionEvent e) {
if (showAuditEventsCapability != null) {
doSomething();
}
}
}
例如:默认情况下,此操作仅在选择了一个节点时启用,否则将被禁用(可见但禁用)。我想要相同的行为,但也要基于所选节点的状态。
我的所有节点都实现了我的界面:
public interface INode {
//obviously the state of the node could change at runtime
public boolean someState();
}
所以我可以通过以下某种方式获取节点的状态:
boolean state = Utilities.actionsGlobalContext().lookup(INode.class).someState();
当我选择节点时,如何使用前面的代码片段来启用/禁用操作,同样如果选择多个节点时禁用此操作?
有什么建议吗?
答案 0 :(得分:0)
我找到了解决方案here:
public class ShowEventsAction extends AbstractAction implements LookupListener, ContextAwareAction {
private Lookup context;
Lookup.Result<ShowAuditEventsCapability> lkpInfo;
public ShowEventsAction() {
this(Utilities.actionsGlobalContext());
}
public ShowEventsAction(Lookup context) {
super("Show Audit Events", ImageUtilities.loadImageIcon("it/cre/myapp/audittree/actions/show.png", false));
this.context = context;
}
void init() {
assert SwingUtilities.isEventDispatchThread() : "this shall be called just from AWT thread";
if (lkpInfo != null) {
return;
}
//The thing we want to listen for the presence or absence of
//on the global selection
lkpInfo = context.lookupResult(ShowAuditEventsCapability.class);
lkpInfo.addLookupListener(this);
resultChanged(null);
}
@Override
public boolean isEnabled() {
init();
return super.isEnabled();
}
@Override
public void actionPerformed(ActionEvent e) {
init();
for (ShowAuditEventsCapability showAuditEventsCapability : lkpInfo.allInstances()) {
showAuditEventsCapability.doSomething();
}
}
@Override
public void resultChanged(LookupEvent ev) {
int selected = lkpInfo.allInstances().size();
if (selected == 0) {
setEnabled(false);
return;
}
for (EasyDbNode node : Utilities.actionsGlobalContext().lookupAll(INode.class)) {
if (!node.isEnabled()) {
setEnabled(false);
return;
}
}
setEnabled(true);
}
@Override
public Action createContextAwareInstance(Lookup actionContext) {
return new ShowEventsAction(context);
}
}
有效!但我认为将方法isEnabled()放在Capability而不是Node中应该更好,因为是启用了属性的Capability:
public void resultChanged(LookupEvent ev) {
for(ShowAuditEventsCapability capability : lkpInfo.allInstances()) {
if(!capability.isEnabled()) {
setEnabled(false);
return;
}
}
setEnabled(true);
}