Move touch CTM from X into Chrome

ui/aura/window_tree_host_x11.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/window_tree_host_x11.h"
 
 #include <strings.h>
 #include <X11/cursorfont.h>
 #include <X11/extensions/Xfixes.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 790 matching lines @@
   ui::EventType type = ui::EventTypeFromNative(xev);
   XEvent last_event;
   int num_coalesced = 0;
 
   switch (type) {
     case ui::ET_TOUCH_MOVED:
     case ui::ET_TOUCH_PRESSED:
     case ui::ET_TOUCH_CANCELLED:
     case ui::ET_TOUCH_RELEASED: {
 #if defined(OS_CHROMEOS)
-      // Bail out early before generating a ui::TouchEvent if this event
-      // is not within the range of this RootWindow. Converting an xevent
-      // to ui::TouchEvent might change the state of the global touch tracking
-      // state, e.g. touch release event can remove the touch id from the
-      // record, and doing this multiple time when there are multiple
-      // RootWindow will cause problem. So only generate the ui::TouchEvent
-      // when we are sure it belongs to this RootWindow.
-      if (base::SysInfo::IsRunningOnChromeOS() &&
-          !bounds_.Contains(ui::EventLocationFromNative(xev)))
+      // Bail out early before generating a ui::TouchEvent if this event is
+      // not targeting this RootWindow. Converting an xevent to ui::TouchEvent
+      // might change the global touch tracking state, e.g. touch release event
+      // can remove the touch id from the record, and doing this multiple time
+      // when there are multiple RootWindow will cause problem.
+      // If the root window does not have a TouchCTM for the touch device where
+      // the touch event is from, then the touch event is not intended for this
+      // root window.
+      XIDeviceEvent* xiev = static_cast<XIDeviceEvent*>(xev->xcookie.data);
+      if (touch_ctm_map_.find(xiev->deviceid) == touch_ctm_map_.end())

[sadrul, 2014/03/10 20:20:12]

It looks like the display-controller in ash is the only place that sets this?
Does that mean we will never dispatch touch events in non-ash environments? If
that is the case, then we need to change this.

[Yufeng Shen (Slow to review), 2014/03/13 20:55:46]

As discussed, in the new patch I am firstly using mapping from touch_event ->
touch_device_id -> display_id -> root_window to see if the touch event is
targeting this root window. If the mapping information is not available, it
falls back to check if the event is within the bounds of the root window.

         break;
 #endif  // defined(OS_CHROMEOS)
       ui::TouchEvent touchev(xev);
+#if defined(OS_CHROMEOS)
+      TouchCTM ctm = touch_ctm_map_[xiev->deviceid];
+      float transformed_x = touchev.x() * ctm.x_scale + ctm.x_offset;
+      float transformed_y = touchev.y() * ctm.y_scale + ctm.y_offset;
+      touchev.set_location(gfx::PointF(transformed_x, transformed_y));
+      touchev.set_root_location(gfx::PointF(transformed_x, transformed_y));
+#endif  // defined(OS_CHROMEOS)
 #if defined(USE_XI2_MT)
       // Ignore touch events with touch press happening on the side bezel.
       if (!IsSideBezelsEnabled()) {
         uint32 tracking_id = (1 << touchev.touch_id());
         if (type == ui::ET_TOUCH_PRESSED &&
             touch_calibrate_->IsEventOnSideBezels(xev, bounds_))
           bezel_tracking_ids_ |= tracking_id;
         if (bezel_tracking_ids_ & tracking_id) {
           if (type == ui::ET_TOUCH_CANCELLED || type == ui::ET_TOUCH_RELEASED)
             bezel_tracking_ids_ =
                 (bezel_tracking_ids_ | tracking_id) ^ tracking_id;
           return;
         }
       }
 #endif  // defined(USE_XI2_MT)
 #if defined(OS_CHROMEOS)
       if (base::SysInfo::IsRunningOnChromeOS()) {
         // X maps the touch-surface to the size of the X root-window.
         // In multi-monitor setup, Coordinate Transformation Matrix
         // repositions the touch-surface onto part of X root-window
         // containing aura root-window corresponding to the touchscreen.
         // However, if aura root-window has non-zero origin,
         // we need to relocate the event into aura root-window coordinates.
         touchev.Relocate(bounds_.origin());
 #if defined(USE_XI2_MT)
         if (is_internal_display_)
           touch_calibrate_->Calibrate(&touchev, bounds_);

[sadrul, 2014/03/10 20:20:12]

We should get rid of this code, and TouchEventCalibrate altogether. This new
code should make it much easier to detect touch-events on bezels without us
having to do all kinds of weird things in here. We should stuff the 'CTM' stuff
(with a more descriptive name) into DeviceDataManager, and have
ui::EventLocationFromNative() use that information to return the proper
location.

This code in here should essentially look something like this:

  ... [early return because of the unfortunate touch-release issue]
  ui::TouchEvent touchev(xev);
  SendEventToProcessor(&touchev);

[Yufeng Shen (Slow to review), 2014/03/13 20:55:46]

so the new patch is like:

if (!IsTouchEventTargetingThisRootWindow(xev))
      break;
ui::TouchEvent touchev(xev);
CalibrateTouchEvent(xev, &touchev);
SendEventToProcessor(&touchev);


As you suggested, I put the TouchCTM stuff into DeviceDataManager. And in
EventLocationFromNative(), TouchCTM is applied.

As for the TouchEventCalibrate, I still need it here for
1. It is a MessagePumpObserver, and it copies the root_x/y into event_x/y when
it gets touch event.
I found that event_x/y not always has the same value as root_x/y and it is the
root_x/y value that
we need. So it seems we still need this trick/hack.
2. For bezel calibration, the root window's bounds_ information is needed. I
don't have a good way to
access that information in  EventLocationFromNative().
3. The CL is getting too big now. Leaving the calibration code intact here adds
more confident that
the CL does not break existing behavior. If we want to get rid of the
calibration code for cleanness, lets do it in a followup CL.

 #endif  // defined(USE_XI2_MT)
       }
 #endif  // defined(OS_CHROMEOS)
       SendEventToProcessor(&touchev);
       break;
     }
     case ui::ET_MOUSE_MOVED:
     case ui::ET_MOUSE_DRAGGED:
     case ui::ET_MOUSE_PRESSED:
     case ui::ET_MOUSE_RELEASED:
@@ skipping 138 matching lines @@
 }
 
 namespace test {
 
 void SetUseOverrideRedirectWindowByDefault(bool override_redirect) {
   default_override_redirect = override_redirect;
 }
 
 }  // namespace test
 }  // namespace aura