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带有x11/xlib的全局热键

xlib hotkeys x11

28

cheshirekow · 技术社区 · 14 年前

我的目标是有一个在后台睡觉的程序,但是用户可以通过一些“热键”来激活它。通过深入了解XLIB手册和XLIB O'Reilly手册,我认为正确的方法是使用XGrabKey。然而,我对这个过程的理解是错误的,因为一个简单的概念证明是行不通的。

我的理解是,如果我使用根窗口作为抓取窗口调用xgrabkey,并且owner事件为false,那么每当按下热键时,都会发送事件。只有到根窗口。如果我从根窗口中选择key press events,然后监听x事件,我应该在按下热键时得到一个keypress事件。我在下面粘贴了一个最小的示例。

我所期望的是,当程序运行时,无论哪个窗口有焦点,如果按下ctrl+shift+k,程序都应该输出“热键按下!”在控制台中,然后终止。

此外,据我所知,如果XGrabKey失败,默认的错误处理程序将显示一条消息,因为它不成功,所以我假设调用成功。

显然,我的理解有缺陷。有人能给我指出正确的方向吗?

#include <iostream>
#include <X11/Xlib.h>
#include <X11/Xutil.h>


using namespace std;


int main()
{
    Display*    dpy     = XOpenDisplay(0);
    Window      root    = DefaultRootWindow(dpy);
    XEvent      ev;

    unsigned int    modifiers       = ControlMask | ShiftMask;
    int             keycode         = XKeysymToKeycode(dpy,XK_Y);
    Window          grab_window     =  root;
    Bool            owner_events    = False;
    int             pointer_mode    = GrabModeAsync;
    int             keyboard_mode   = GrabModeAsync;

    XGrabKey(dpy, keycode, modifiers, grab_window, owner_events, pointer_mode,
             keyboard_mode);

    XSelectInput(dpy, root, KeyPressMask );
    while(true)
    {
        bool shouldQuit = false;
        XNextEvent(dpy, &ev);
        switch(ev.type)
        {
            case KeyPress:
                cout << "Hot key pressed!" << endl;
                XUngrabKey(dpy,keycode,modifiers,grab_window);
                shouldQuit = true;

            default:
                break;
        }

        if(shouldQuit)
            break;
    }

    XCloseDisplay(dpy);
    return 0;
}

3 回复 | 直到 9 年前

1

21

Havoc P 14 年前

/* Grab/ungrab, ignoring all annoying modifiers like NumLock etc. */
static void
meta_change_keygrab (MetaDisplay *display,
                     Window       xwindow,
                     gboolean     grab,
                     int          keysym,
                     unsigned int keycode,
                     int          modmask)
{
  unsigned int ignored_mask;

  /* Grab keycode/modmask, together with
   * all combinations of ignored modifiers.
   * X provides no better way to do this.
   */

  meta_topic (META_DEBUG_KEYBINDINGS,
              "%s keybinding %s keycode %d mask 0x%x on 0x%lx\n",
              grab ? "Grabbing" : "Ungrabbing",
              keysym_name (keysym), keycode,
              modmask, xwindow);

  /* efficiency, avoid so many XSync() */
  meta_error_trap_push (display);

  ignored_mask = 0;
  while (ignored_mask <= display->ignored_modifier_mask)
    {
      if (ignored_mask & ~(display->ignored_modifier_mask))
        {
          /* Not a combination of ignored modifiers
           * (it contains some non-ignored modifiers)
           */
          ++ignored_mask;
          continue;
        }

      if (meta_is_debugging ())
        meta_error_trap_push_with_return (display);
      if (grab)
        XGrabKey (display->xdisplay, keycode,
                  modmask | ignored_mask,
                  xwindow,
                  True,
                  GrabModeAsync, GrabModeSync);
      else
        XUngrabKey (display->xdisplay, keycode,
                    modmask | ignored_mask,
                    xwindow);

      if (meta_is_debugging ())
        {
          int result;

          result = meta_error_trap_pop_with_return (display, FALSE);

          if (grab && result != Success)
            {      
              if (result == BadAccess)
                meta_warning (_("Some other program is already using the key %s with modifiers %x as a binding\n"), keysym_name (keysym), modmask | ignored_mask);
              else
                meta_topic (META_DEBUG_KEYBINDINGS,
                            "Failed to grab key %s with modifiers %x\n",
                            keysym_name (keysym), modmask | ignored_mask);
            }
        }

      ++ignored_mask;
    }

  meta_error_trap_pop (display, FALSE);
}

2

9

Christian Hujer 10 年前

ControlMask | ShiftMask

XGrabKey()
AnyModifier event.xkey.state

<X.h> ShiftMask LockMask ControlMask Mod1Mask Mod2Mask Mod3Mask Mod4Mask Mod5Mask

Mask        | Value | Key
------------+-------+------------
ShiftMask   |     1 | Shift
LockMask    |     2 | Caps Lock
ControlMask |     4 | Ctrl
Mod1Mask    |     8 | Alt
Mod2Mask    |    16 | Num Lock
Mod3Mask    |    32 | Scroll Lock
Mod4Mask    |    64 | Windows
Mod5Mask    |   128 | ???

ModNMask

ShiftMask | CtrlMask Mod1Mask | Mod4Mask

XGrabKey(dpy, keycode, AnyModifier, grab_window, owner_events, pointer_mode, keyboard_mode);

switch (ev.type)  {
case KeyPress:
    if ((ev.xkey.state & (ShiftMask | CtrlMask | Mod1Mask | Mod4Mask)) == (ShiftMask | CtrlMask))
        // ...
}

3

8

Community CDub 8 年前

https://github.com/engla/keybinder

here