FireFox SDK的keydown / keyup事件

问题描述

有没有可能跟踪FireFox插件中的keydown / keyup事件？
我想实现类似于以下的场景：
$ b

• 按下并按住修改键盘面板


• 在按住这些修改键的同时，按其他键将导致面板操作


• 释放修饰键时，面板将消失

解决方案

您需要在每个浏览器窗口中注册您的事件侦听器。高级的SDK API不能直接访问浏览器窗口，但是你必须使用底层的模块，特别是（当前没有记录的） sdk / keyboard / observer 模块。它允许你在所有浏览器窗口中监听关键事件，所以类似这样的应用程序应该可以工作：
$ b

  //在每个浏览器窗口中注册关键事件处理程序
 var {observer} = require（sdk / keyboard / observer）; 
 $ b observer.on（keydown，function（event）{
 //忽略其他地方已经处理的事件（例如通过网页）
 if（event.defaultPrevented ）
 return; 
 
 if（...）
 panel.show（）; 
}）; 
 observer.on（keyup，function（event）{
 //忽略在别处处理的事件（例如通过网页）
 if（event.defaultPrevented）
返回; 
 
 if（...）
 panel.hide（）; 
}）; 
  

注意：

• sdk / keyboard / observer 模块完全没有记录，可能随时改变或完全消失。这里建议使用来自 sdk / window-utils 模块的 WindowTracker ，现在已经不推荐使用了。如果你真的想看自己的浏览器窗口，你现在可以使用（也没有记录的） sdk / windows / observer 模块，它允许监听打开和关闭事件。用来区分浏览器窗口的函数 isBrowser（）现在可以通过。您还需要使用考虑已经打开的窗口，窗口观察者不会自动执行该操作。
  

Is it possible to track keydown/keyup events in FireFox addons?I would like to implement something similar as following scenario:

• After pressing and holding the modifier key panel appears
• While holding these modifier keys, pressing the other keys will cause some actions with the panel
• When modifier key released, the panel disappears

解决方案

You would need to register your event listener in each browser window for that. The high-level SDK API don't give you direct access to the browser window however, you will have to use the low-level modules for that, in particular the (currently undocumented) sdk/keyboard/observer module. It allows you to listen to key events in all browser windows, so something like this should work:

// Register key event handlers in each browser window
var {observer} = require("sdk/keyboard/observer");

observer.on("keydown", function(event) {
  // Ignore events that have been handled elsewhere (e.g. by the web page)
  if (event.defaultPrevented)
    return;

  if (...)
    panel.show();
});
observer.on("keyup", function(event) {
  // Ignore events that have been handled elsewhere (e.g. by the web page)
  if (event.defaultPrevented)
    return;

  if (...)
    panel.hide();
});

Notes:

• sdk/keyboard/observer module is completely undocumented, it might change or go away completely any time.
• Originally the solution proposed here used WindowTracker from the sdk/window-utils module which is now deprecated. If you really want to look at browser windows yourself you would now use the (also undocumented) sdk/windows/observer module which allows listening to open and close events. The function isBrowser() to distinguish browser windows is now available via sdk/window/utils module. You would also need to use windows() function to consider already open windows, the windows observer doesn't do that automatically.

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