Question

是否可以做这样的事情

while (view.mouseover == true) {
    preform action
}

只要鼠标位于特定视图上，我希望重复操作（在laszlo用户邮件列表中询问）

Answer 1

由于ActionScript和JavaScript都是单线程的，因此不可能在每次循环迭代之间都有一个while循环暂停。在SWF10 / 11运行时，您需要确保每个方法或函数中的代码可以在一个框架内执行（持续时间取决于SWF剪辑的帧速率）。

作为一种解决方法，您可以使用计时器，这是一个示例：

<canvas debug="true">

    <class name="mouseoverview" extends="view">        <attribute name="timer" type="object" value="null" />
        <!-- lz.Delegate instance used by the timer -->
        <attribute name="timerdel" type="object" value="null" />
        <attribute name="timeractive" type="boolean" value="false" />
        <!-- milliseconds to pause before each call to doWhileMouseover method -->
        <attribute name="tick" type="number" value="500" />
        <handler name="onmouseover">
            Debug.info('mouseover');
            if (this.timeractive == false) {
                this.setAttribute('timeractive', true);
                this.timerdel = new lz.Delegate( this, "timerCallback" );
                this.timer = lz.Timer.addTimer( this.timerdel, this.tick );
                // When the timer is activated, do one call to the method
                // containing the loop logic. The following calls will be
                // handled by the timer and delegate.
                this.doWhileMouseover();
            }
        </handler>
        <handler name="onmouseout">
            Debug.info('mouseout');
            if (this.timeractive) {
                this.setAttribute('timeractive', false);
                lz.Timer.removeTimer(this.timerdel);
            }
        </handler>
        <method name="timerCallback" args="millis">
            if (this.timeractive) {
                lz.Timer.resetTimer(this.timerdel, this.tick);
                this.doWhileMouseover();
            }
        </method>
        <method name="doWhileMouseover">
            Debug.info("This is your virtual while loop for mouseover");
        </method>
    </class>

    <mouseoverview x="100"
          y="100"
          width="400"
          height="400"
          bgcolor="#33aaff"
          tick="250">

    </mouseoverview>

</canvas>

发生鼠标悬停时，使用timerdel（lz.Delegate的一个实例）启动计时器。然后直接调用doWhileMouseover（）方法，然后重复使用计时器，只要没有onmouseout事件发生。

Answer 2

好吧，在我测试我的解决方案以确保它正常工作时，您似乎回答了自己的问题，但这是一个替代解决方案，适用于OpenLaszlo 4.9.0 SWF10和OpenLaszlo 4.9.0 DHTML运行时：

<canvas width="1000" height="665" debug="true">

  <view id="v" bgcolor="0xcccccc" width="200" height="200">

    <!--- @param boolean mouseisover: true when the mouse is over -->
    <attribute name="mouseisover" type="boolean" value="false" />

    <!--- @keywords private -->
    <!--- @param lz.Delegate dlgt_repeat: stores the lz.Delegate object --> 
    <attribute name="dlgt_repeat" type="expression" />

    <!--
    Called when the 'onmouseover' event occurs
    -->
    <handler name="onmouseover">

      // Step 1) unregister any existing delegate 
      // mark it for garbage collection 
      // and prevent its event from triggering:

      if (this['dlgt_repeat'])
        this.dlgt_repeat.unregisterAll(); 

      // Step 2) update this.mouseisover flag:

      if (!this.mouseisover)
        this.setAttribute('mouseisover', true);

      // Step 3) create an event Delegate and call it 
      // on the next application idle event:

      var objDlgt = new lz.Delegate(this, 'doSomething');       
      this.setAttribute('dlgt_repeat', objDlgt);

      lz.Idle.callOnIdle(this.dlgt_repeat);

    </handler>

    <!--
    Called when the 'onmouseout' event occurs
    --> 
    <handler name="onmouseout">

      // Step 1) unregister any existing delegate 
      // mark it for garbage collection 
      // and prevent its event from triggering: 

      if (this['dlgt_repeat'])
        this.dlgt_repeat.unregisterAll();   

      // Step 2) Update this.mouseisover flag:

      if (this.mouseisover)
        this.setAttribute('mouseisover', false);    

    </handler>

    <!--- @keywords private -->
    <!--- 
    Called on application idle event by lz.Idle repeatedly 
    when the mouse is down.

    @param ??? objDummy: required for SWF9+ run-times for methods 
    called by delegates due to AS3 (ActionScript3 compiler 
    requirements). Just set default to null to make compiler 
    happy and ignore...
    -->
    <method name="doSomething" args="objDummy=null">
    <![CDATA[

      // Note: CDATA allows '&&' to be used in script below, 
      // alternatively omit CDATA and use '&amp;&amp;' instead
      // of '&&'

      // Step 1) Execute your code you want to run here:  

      if ($debug) Debug.debug('Do something...');

      // Step 2): If mouse is still over and the event 
      // delegate exists then schedule the event to be 
      // executed upon the next application idle state:

     if (this.mouseisover && this['dlgt_repeat'] != null)
       lz.Idle.callOnIdle(this.dlgt_repeat);

   ]]>
   </method>

    <text text="Move mouse over" />

  </view>

</canvas>

是否可以在OpenLaszlo应用程序中将while循环连接到鼠标悬停状态？

2 个答案: