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     XISetMask(mask, XI_TouchBegin);
  36     XISetMask(mask, XI_TouchUpdate);
  37     XISetMask(mask, XI_TouchEnd);
  38     XIEventMask evmask;
  39     evmask.mask_len = sizeof(mask);
  40     evmask.mask = mask;
  41
  42     const std::vector<int>& master_pointers =
  43         ui::DeviceDataManagerX11::GetInstance()->master_pointers();
  44     for (int master_pointer : master_pointers) {
  45       evmask.deviceid = master_pointer;
  46       result = XIGrabDevice(
  47           gfx::GetXDisplay(), master_pointer, window, CurrentTime, cursor,
  48           GrabModeAsync, GrabModeAsync, owner_events, &evmask);
  49       // Assume that the grab will succeed on either all or none of the master
  50       // pointers.
  51       if (result != GrabSuccess) {
  52         // Try core pointer grab.
  53         break;
  54       }
  55     }
  56   }
  57
  58   if (result != GrabSuccess) {
  59     int event_mask = PointerMotionMask | ButtonReleaseMask | ButtonPressMask;
  60     result =
  61         XGrabPointer(gfx::GetXDisplay(), window, owner_events, event_mask,
  62                      GrabModeAsync, GrabModeAsync, None, cursor, CurrentTime);
  63   }
  64
  65   if (result == GrabSuccess) {
  66     g_grab_window = window;
  67     g_owner_events = owner_events;
  68   }
  69   return result;
  70 }
  71
  72 void ChangeActivePointerGrabCursor(::Cursor cursor) {
  73   DCHECK(g_grab_window != None);
  74   GrabPointer(g_grab_window, g_owner_events, cursor);
  75 }
  76
  77 void UngrabPointer() {
  78   g_grab_window = None;
  79   if (ui::IsXInput2Available()) {
  80     const std::vector<int>& master_pointers =
  81         ui::DeviceDataManagerX11::GetInstance()->master_pointers();
  82     for (int master_pointer : master_pointers)
  83       XIUngrabDevice(gfx::GetXDisplay(), master_pointer, CurrentTime);
  84   }
  85   // Try core pointer ungrab in case the XInput2 pointer ungrab failed.
  86   XUngrabPointer(gfx::GetXDisplay(), CurrentTime);
  87 }
  88
  89 }  // namespace views