Question

我为eclipse打印命令添加了一个处理程序：

  <handler
        class="org.acme.PrintHandler"
        commandId="org.eclipse.ui.file.print">
     <activeWhen>
        <with variable="activePart">
           <test property="org.acme.printable" />
        </with>
     </activeWhen>
  </handler>

哪个效果很好。但有时即使活动部分没有，命令的启用也会改变。所以我想强制重新评估activeWhen部分。我该怎么做？

我试过这样的事情：

    ICommandService service = (ICommandService) PlatformUI.getWorkbench().getService(ICommandService.class);
    Command printCommand = service.getCommand("org.eclipse.ui.file.print");
    EvaluationContext context = new EvaluationContext(null, lastEditor);
    context.addVariable(ISources.ACTIVE_PART_NAME, lastEditor);
    ExecutionEvent event = new ExecutionEvent(printCommand, Collections.EMPTY_MAP, null, context);

    // this does nothing
    printCommand.setEnabled(context);
    // this does nothing as well
    service.refreshElements("org.eclipse.ui.file.print", null);
    // this executes the command 
    // (but at least re-evaluates it's enablement before)
    printCommand.executeWithChecks(event);

Answer 1

我认为IEvaluationService.requestEvaluation方法可以做你想做的事情：

IEvaluationService evalService = (IEvaluationService) PlatformUI.getWorkbench().getService(IEvaluationService.class);

evalService.requestEvaluation("org.acme.printable");

JavaDoc说

请求此服务重新评估所有已注册的核心表达式包含给定属性名称的属性测试器。

强制重新评估命令启用

1 个答案: