Support pen in TouchEventConverterEvdev

ui/events/ozone/evdev/touch_event_converter_evdev.cc

 // Copyright 2014 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/events/ozone/evdev/touch_event_converter_evdev.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <poll.h>
@@ skipping 60 matching lines @@
       return ABS_MT_POSITION_Y;
     case ABS_PRESSURE:
       return ABS_MT_PRESSURE;
     case ABS_DISTANCE:
       return ABS_MT_DISTANCE;
     default:
       return -1;
   }
 }
 
-ui::EventPointerType GetPointerTypeFromEvent(
+ui::PointerDetails GetEventPointerDetails(
     const ui::InProgressTouchEvdev& event) {
-  return (event.tool_code == BTN_TOOL_PEN)
-             ? ui::EventPointerType::POINTER_TYPE_PEN
-             : ui::EventPointerType::POINTER_TYPE_TOUCH;
+  ui::EventPointerType type;
+  switch (event.tool_code) {
+    case BTN_TOOL_PEN:
+      type = ui::EventPointerType::POINTER_TYPE_PEN;
+      break;
+    default:
+      type = ui::EventPointerType::POINTER_TYPE_TOUCH;
+  }
+  return ui::PointerDetails(type, event.radius_x, event.radius_y,
+                            event.pressure,
+                            /* tilt_x */ 0.0f,
+                            /* tilt_y */ 0.0f);
 }
 
 const int kTrackingIdForUnusedSlot = -1;
 
 }  // namespace
 
 namespace ui {
 
 TouchEventConverterEvdev::TouchEventConverterEvdev(
     int fd,
@@ skipping 214 matching lines @@
           event.value ? NextTrackingId() : kTrackingIdForUnusedSlot;
       ProcessMultitouchEvent(emulated_event);
     }
   }
 }
 
 void TouchEventConverterEvdev::ProcessKey(const input_event& input) {
   switch (input.code) {
     case BTN_TOUCH:
     case BTN_LEFT:
+      ProcessButton(BTN_LEFT, input);
+      break;
+    case BTN_STYLUS:
+      ProcessButton(BTN_RIGHT, input);
+      break;
+    case BTN_STYLUS2:
+      ProcessButton(BTN_MIDDLE, input);
       break;
     case BTN_TOOL_PEN:
+      // Do not change tool types while touching to prevent inconsistencies
+      // from switching between Mouse and TouchEvents.
+      if (events_[current_slot_].was_touching)

[spang, 2016/08/16 21:36:21]

Does this actually happen?

[denniskempin, 2016/08/17 21:47:17]

I think a kernel driver shouldn't be allowed to do this. 
BUT I put it there since this could theoretically get us into a state where
buttons are stuck if a device would do this. 
I don't feel strongly about keeping it.. it's mostly been an 'I feel safer this
way' kind of decision. 

+        break;
+
       if (input.value > 0) {
         events_[current_slot_].tool_code = input.code;
       } else {
         events_[current_slot_].tool_code = 0;
       }
       break;
     default:
       NOTIMPLEMENTED() << "invalid code for EV_KEY: " << input.code;
   }
 }
 
+void TouchEventConverterEvdev::ProcessButton(unsigned int button,
+                                             const input_event& input) {
+  const InProgressTouchEvdev& event = events_[current_slot_];
+
+  // Don't handle buttons for touch slots
+  if (event.tool_code == 0)
+    return;
+
+  bool down = input.value;
+  dispatcher_->DispatchMouseButtonEvent(MouseButtonEventParams(
+      input_device_.id, EF_DIRECT_INPUT, gfx::PointF(event.x, event.y), button,

[spang, 2016/08/16 21:36:21]

There's no guarantee the X/Y position is updated by the time this code runs. All
events between two SYN_REPORT events are considered simultaneous.

So if you get ABS_X, ABS_Y, SYN_REPORT, BTN_LEFT, ABS_X, ABS_Y, SYN_REPORT in
order then the left click should happen at the 2nd position, not the first.

So I think you need to add some member variables

 btn_left_
 btn_right_
 btn_middle_

and just update those here.

At the end of the packet, in ReportEvents(), you can use them to send clicks as
necessary.

[denniskempin, 2016/08/17 21:47:17]

Done.

+      down, false /* allow_remap */, GetEventPointerDetails(event),
+      TimeTicksFromInputEvent(input)));
+}
+
 void TouchEventConverterEvdev::ProcessAbs(const input_event& input) {
   switch (input.code) {
     case ABS_MT_TOUCH_MAJOR:
       // TODO(spang): If we have all of major, minor, and orientation,
       // we can scale the ellipse correctly. However on the Pixel we get
       // neither minor nor orientation, so this is all we can do.
       events_[current_slot_].radius_x = input.value / 2.0f;
       break;
     case ABS_MT_TOUCH_MINOR:
       events_[current_slot_].radius_y = input.value / 2.0f;
@@ skipping 50 matching lines @@
     if (touch.touching && !touch.was_touching)
       return ET_UNKNOWN;
     return ET_TOUCH_CANCELLED;
   }
 
   if (touch.touching)
     return touch.was_touching ? ET_TOUCH_MOVED : ET_TOUCH_PRESSED;
   return touch.was_touching ? ET_TOUCH_RELEASED : ET_UNKNOWN;
 }
 
-void TouchEventConverterEvdev::ReportEvent(const InProgressTouchEvdev& event,
-                                           EventType event_type,
-                                           base::TimeTicks timestamp) {
-  PointerDetails details(GetPointerTypeFromEvent(event), event.radius_x,
-                         event.radius_y, event.pressure,
-                         /* tilt_x */ 0.0f,
-                         /* tilt_y */ 0.0f);
-  dispatcher_->DispatchTouchEvent(
-      TouchEventParams(input_device_.id, event.slot, event_type,
-                       gfx::PointF(event.x, event.y), details, timestamp));
+void TouchEventConverterEvdev::ReportTouchEvent(
+    const InProgressTouchEvdev& event,
+    EventType event_type,
+    base::TimeTicks timestamp) {
+  dispatcher_->DispatchTouchEvent(TouchEventParams(
+      input_device_.id, event.slot, event_type, gfx::PointF(event.x, event.y),
+      GetEventPointerDetails(event), timestamp));
+}
+
+void TouchEventConverterEvdev::ReportStylusEvent(
+    const InProgressTouchEvdev& event,
+    base::TimeTicks timestamp) {
+  dispatcher_->DispatchMouseMoveEvent(MouseMoveEventParams(
+      input_device_.id, EF_DIRECT_INPUT, gfx::PointF(event.x, event.y),
+      GetEventPointerDetails(event), timestamp));
 }
 
 void TouchEventConverterEvdev::ReportEvents(base::TimeTicks timestamp) {
   if (dropped_events_) {
     Reinitialize();
     dropped_events_ = false;
   }
 
   if (touch_noise_finder_)
     touch_noise_finder_->HandleTouches(events_, timestamp);
 
   for (size_t i = 0; i < events_.size(); i++) {
     InProgressTouchEvdev* event = &events_[i];
     if (!event->altered)
       continue;
 
-    EventType event_type = GetEventTypeForTouch(*event);
-    if (event_type == ET_UNKNOWN || event_type == ET_TOUCH_CANCELLED)
-      event->cancelled = true;
+    if (event->tool_code > 0) {
+      ReportStylusEvent(*event, timestamp);
+    } else {
+      EventType event_type = GetEventTypeForTouch(*event);
+      if (event_type == ET_UNKNOWN || event_type == ET_TOUCH_CANCELLED)
+        event->cancelled = true;
 
-    if (event_type != ET_UNKNOWN)
-      ReportEvent(*event, event_type, timestamp);
+      if (event_type != ET_UNKNOWN)
+        ReportTouchEvent(*event, event_type, timestamp);
+    }
 
     event->was_touching = event->touching;
     event->altered = false;
   }
 }
 
 void TouchEventConverterEvdev::UpdateTrackingId(int slot, int tracking_id) {
   InProgressTouchEvdev* event = &events_[slot];
 
   if (event->tracking_id == tracking_id)
@@ skipping 19 matching lines @@
   if (pressure_max_ - pressure_min_)
     pressure /= pressure_max_ - pressure_min_;
   return pressure;
 }
 
 int TouchEventConverterEvdev::NextTrackingId() {
   return next_tracking_id_++ & kMaxTrackingId;
 }
 
 }  // namespace ui