Linux X11 - 全局键盘挂钩
是否有可能（或如何）创建一种机制（在 Linux X11、C++ 中），其工作方式类似于 Windows 中的全局钩子（SetWindowsHookEx()）？
我希望能够捕获关键事件，但具有进一步传播的可能性。我正在尝试使用 XGrabKey< /a> 解决方案（如 xbindkeys 中所示），但是当我设置捕获密钥时事件，该事件被“消耗”。
此机制的要求如下：
- 全局/系统范围 - 无论具有焦点的窗口如何捕获事件
- “catch-hold”和“catch-pass through”的可能性 strong>
- 一定很快
示例代码如下所示：
bool myFlagIsSet = false;
XEvent event;
while (true) {
while (XPending(display) > 0) {
usleep(SLEEP_TIME);
}
XNextEvent(display, &event);
switch (e.type) {
case KeyPress:
if (myFlagIsSet) {
//do not propagate
}
// propagate
break;
case KeyRelease:
if (myFlagIsSet) {
//do not propagate
}
// propagate
break;
}
}
在 Windows 上我简单地写道：
if(event.isConsumed()) {
return LRESULT(1);
}
//...
return CallNextHookEx(hookHandle, nCode, wParam, lParam);
我还尝试过使用 XUngrabKey 和 XSendEvent：
switch (event.type) {
case KeyPress:
if (myFlagIsSet) {
//do not propagate
}
// propagate
XUngrabKey(...);
XSendEvent(..., &event);
XGrabKey(...);
break;
case KeyRelease:
...
}
不幸的是，由于我未知的原因，XSendEvent - 即使 XGrabKey 行被注释，也不要发送此事件。
这种方法有可能成功完成吗？
如果我注定失败，请建议其他方法
编辑
我想使用 Compiz 窗口管理器在 Ubuntu Gnome 上实现此方法
Is it possible (or how) to create a mechanism (in Linux X11, C++) that works like a global hook in windows (SetWindowsHookEx())?
I would like to be able to catch the key event but with the possibility of further propagation. I'm trying to use a XGrabKey solution (like in xbindkeys) but when I set capturing the key event, this event is "consumed".
Requirements for this mechanism are the following:
- Global / system-wide - catching events regardless of the window that has focus
- The possibility of "catch-hold" and "catch-pass through"
- It must be quite fast
Sample code looks like this:
bool myFlagIsSet = false;
XEvent event;
while (true) {
while (XPending(display) > 0) {
usleep(SLEEP_TIME);
}
XNextEvent(display, &event);
switch (e.type) {
case KeyPress:
if (myFlagIsSet) {
//do not propagate
}
// propagate
break;
case KeyRelease:
if (myFlagIsSet) {
//do not propagate
}
// propagate
break;
}
}
On Windows I simply wrote:
if(event.isConsumed()) {
return LRESULT(1);
}
//...
return CallNextHookEx(hookHandle, nCode, wParam, lParam);
I've also tried using XUngrabKey and XSendEvent:
switch (event.type) {
case KeyPress:
if (myFlagIsSet) {
//do not propagate
}
// propagate
XUngrabKey(...);
XSendEvent(..., &event);
XGrabKey(...);
break;
case KeyRelease:
...
}
Unfortunately XSendEvent for unknown reasons to me - do not send this event even if XGrabKey line is commented.
Is it possible to successfully complete this approach?
Please suggest some other approach if I am condemned to failure
EDIT
I would like to implement this on Ubuntu Gnome using Compiz Window Manager
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尝试从此页面编译简单的代码：
http://webhamster.ru/site/page /index/articles/comp/367
这是获取全局键盘事件的示例。这个小应用程序作为xinput工作。
备注1：将设备ID写入mian.cpp（通过不带参数运行xinput获取ID）：
备注2：编译命令：
Remakr 3：编译前，安装libxi-dev包：
文件main.h
文件main.cpp
Try compile easy code from this page:
http://webhamster.ru/site/page/index/articles/comp/367
It's sample of get global keyboard event. This small app working as xinput.
Remark 1: Write device ID to mian.cpp (get ID by running xinput without parameters):
Remark 2: Compile command:
Remakr 3: Before compile, install libxi-dev package:
File main.h
File main.cpp
使用 XTest 扩展库 中的 XTestFakeKeyEvent() 进行传播假按键按下/释放事件。
Use XTestFakeKeyEvent() from the XTest extension library to propagate fake key press / release events.
我建议不要在 X11 级别上执行此操作，而是在输入设备级别上执行此操作。
/dev/input/event为您提供输入事件。您可以在那里读取按键并决定它们是否应该进一步传播或被消耗。不幸的是，没有真正的文档，但头文件 linux/include/input.h 是非常不言自明的。 evdev 维护者也很乐意回复电子邮件。Instead of doing this on the X11 level I recommend to do it on the input device level.
/dev/input/event<n>give you the input events. You can read off the keypresses there and decide if they should propagate further or be consumed. Unfortunately there's no real documentation for this, but the header filelinux/include/input.his quite self explanatory. Also the evdev maintainer will gladly answer emails.XSendEvent()可能确实发送了它；但由于它被广泛认为是一个安全漏洞，因此大多数程序都会忽略设置了send_event标志的 UI 事件。标准 X11 协议不允许这样做。 XInput 2.0 扩展可能会，但我对此表示怀疑；虽然 Windows 假定每个程序都侦听一个事件队列，以便程序可以拦截事件并防止将其从队列发送到其他侦听器，但每个 X11 客户端都有自己独立的队列，并且所有对某个事件感兴趣的客户端事件在其队列中接收它的独立副本。这意味着在正常情况下，错误的程序不可能阻止其他程序的运行；但这也意味着，当客户端必须阻止其他客户端时，它必须执行服务器抓取以防止服务器处理任何其他客户端的事件。
XSendEvent()probably does send it; but as it's widely regarded as a security hole, most programs ignore UI events with thesend_eventflag set.The standard X11 protocol doesn't allow this. The XInput 2.0 extension might, but I doubt it; while Windows assumes a single event queue that every program listens to, so that a program can intercept an event and prevent it from being sent down the queue to other listeners, every X11 client has its own independent queue and all clients that register interest in an event receive an independent copy of it in their queue. This means that under normal circumstances it's impossible for an errant program to block other programs from running; but it also means that, for those times when a client must block other clients, it must do a server grab to prevent the server from processing events for any other client.
不知道这是否有帮助，但我刚刚在一些代码中发现了这一点：
no idea if this helps, but I just found this in some code: