ui/views/widget/desktop_aura/x11_pointer_grab.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/logging.h"
   6 #include "ui/base/x/x11_util.h"
   7 #include "ui/events/devices/x11/device_data_manager_x11.h"
   8 #include "ui/views/widget/desktop_aura/x11_pointer_grab.h"
   9
  10 #include <X11/extensions/XInput2.h>
  11 #include <X11/Xlib.h>
  12
  13 namespace views {
  14
  15 namespace {
  16
  17 // The grab window. None if there are no active pointer grabs.
  18 XID g_grab_window = None;
  19
  20 // The "owner events" parameter used to grab the pointer.
  21 bool g_owner_events = false;
  22
  23 }  // namespace
  24
  25 int GrabPointer(XID window, bool owner_events, ::Cursor cursor) {
  26   int result = GrabInvalidTime;
  27   if (ui::IsXInput2Available()) {
  28     // Do an XInput2 pointer grab. If there is an active XInput2 pointer grab
  29     // as a result of normal button press, XGrabPointer() will fail.
  30     unsigned char mask[XIMaskLen(XI_LASTEVENT)];
  31     memset(mask, 0, sizeof(mask));
  32     XISetMask(mask, XI_ButtonPress);
  33     XISetMask(mask, XI_ButtonRelease);
  34     XISetMask(mask, XI_Motion);
  35     XIEventMask evmask;
  36     evmask.mask_len = sizeof(mask);
  37     evmask.mask = mask;
  38
  39     const std::vector<int>& master_pointers =
  40         ui::DeviceDataManagerX11::GetInstance()->master_pointers();
  41     for (int master_pointer : master_pointers) {
  42       evmask.deviceid = master_pointer;
  43       result = XIGrabDevice(
  44           gfx::GetXDisplay(), master_pointer, window, CurrentTime, cursor,
  45           GrabModeAsync, GrabModeAsync, owner_events, &evmask);
  46       // Assume that the grab will succeed on either all or none of the master
  47       // pointers.
  48       if (result != GrabSuccess) {
  49         // Try core pointer grab.
  50         break;
  51       }
  52     }
  53   }
  54
  55   if (result != GrabSuccess) {
  56     int event_mask = PointerMotionMask | ButtonReleaseMask | ButtonPressMask;
  57     result =
  58         XGrabPointer(gfx::GetXDisplay(), window, owner_events, event_mask,
  59                      GrabModeAsync, GrabModeAsync, None, cursor, CurrentTime);
  60   }
  61
  62   if (result == GrabSuccess) {
  63     g_grab_window = window;
  64     g_owner_events = owner_events;
  65   }
  66   return result;
  67 }
  68
  69 void ChangeActivePointerGrabCursor(::Cursor cursor) {
  70   DCHECK(g_grab_window != None);
  71   GrabPointer(g_grab_window, g_owner_events, cursor);
  72 }
  73
  74 void UngrabPointer() {
  75   g_grab_window = None;
  76   if (ui::IsXInput2Available()) {
  77     const std::vector<int>& master_pointers =
  78         ui::DeviceDataManagerX11::GetInstance()->master_pointers();
  79     for (int master_pointer : master_pointers)
  80       XIUngrabDevice(gfx::GetXDisplay(), master_pointer, CurrentTime);
  81   }
  82   // Try core pointer ungrab in case the XInput2 pointer ungrab failed.
  83   XUngrabPointer(gfx::GetXDisplay(), CurrentTime);
  84 }
  85
  86 }  // namespace views