ozone: Handle on-screen stylus support consistently

ui/events/ozone/evdev/tablet_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/tablet_event_converter_evdev.h"
 
 #include <errno.h>
 #include <linux/input.h>
 
 #include "base/message_loop/message_loop.h"
+#include "base/time/time.h"
 #include "ui/events/event.h"
 
 namespace ui {
 
 TabletEventConverterEvdev::TabletEventConverterEvdev(
     int fd,
     base::FilePath path,
     int id,
     InputDeviceType type,
     EventModifiersEvdev* modifiers,
     CursorDelegateEvdev* cursor,
     const EventDeviceInfo& info,
     const EventDispatchCallback& callback)
     : EventConverterEvdev(fd, path, id, type),
       cursor_(cursor),
       modifiers_(modifiers),
       callback_(callback),
       stylus_(0),
-      abs_value_dirty_(false) {
+      abs_value_dirty_(false),
+      on_screen_stylus_(false) {
   x_abs_min_ = info.GetAbsMinimum(ABS_X);
   x_abs_range_ = info.GetAbsMaximum(ABS_X) - x_abs_min_ + 1;
   y_abs_min_ = info.GetAbsMinimum(ABS_Y);
   y_abs_range_ = info.GetAbsMaximum(ABS_Y) - y_abs_min_ + 1;
+  pressure_min_ = info.GetAbsMinimum(ABS_PRESSURE);
+  pressure_range_ = info.GetAbsMaximum(ABS_PRESSURE) - pressure_min_ + 1;
+  on_screen_stylus_ = !info.HasProp(INPUT_PROP_POINTER);
 }
 
 TabletEventConverterEvdev::~TabletEventConverterEvdev() {
   Stop();
   close(fd_);
 }
 
 void TabletEventConverterEvdev::OnFileCanReadWithoutBlocking(int fd) {
   input_event inputs[4];
   ssize_t read_size = read(fd, inputs, sizeof(inputs));
@@ skipping 18 matching lines @@
   for (int i = 0; i < count; ++i) {
     const input_event& input = inputs[i];
     switch (input.type) {
       case EV_KEY:
         ConvertKeyEvent(input);
         break;
       case EV_ABS:
         ConvertAbsEvent(input);
         break;
       case EV_SYN:
-        FlushEvents();
+        FlushEvents(input);
         break;
     }
   }
 }
 
 void TabletEventConverterEvdev::ConvertKeyEvent(const input_event& input) {
   // Only handle other events if we have a stylus in proximity
   if (input.code >= BTN_TOOL_PEN && input.code <= BTN_TOOL_LENS) {
     if (input.value == 1)
       stylus_ = input.code;
     else if (input.value == 0)
       stylus_ = 0;
     else
       LOG(WARNING) << "Unexpected value: " << input.value
                    << " for code: " << input.code;
   }
 
   if (input.code >= BTN_TOUCH && input.code <= BTN_STYLUS2) {
-    DispatchMouseButton(input);
-    return;
+    if (input.code == BTN_TOUCH && on_screen_stylus_) {
+      DispatchTouch(input);
+    } else {
+      DispatchMouseButton(input);
+    }
   }
 }
 
 void TabletEventConverterEvdev::ConvertAbsEvent(const input_event& input) {
   if (!cursor_)
     return;
 
   switch (input.code) {
     case ABS_X:
       x_abs_location_ = input.value;
       abs_value_dirty_ = true;
       break;
     case ABS_Y:
       y_abs_location_ = input.value;
       abs_value_dirty_ = true;
       break;
+    case ABS_PRESSURE:
+      pressure_ = input.value;
+      break;
   }
 }
 
 void TabletEventConverterEvdev::UpdateCursor() {
   gfx::Rect display_bounds = cursor_->GetCursorDisplayBounds();
 
   int x =
       ((x_abs_location_ - x_abs_min_) * display_bounds.width()) / x_abs_range_;
   int y =
       ((y_abs_location_ - y_abs_min_) * display_bounds.height()) / y_abs_range_;
 
   x += display_bounds.x();
   y += display_bounds.y();
 
   cursor_->MoveCursorTo(gfx::PointF(x, y));
 }
 
+void TabletEventConverterEvdev::DispatchTouch(const input_event& input) {
+  if (abs_value_dirty_) {
+    UpdateCursor();
+    abs_value_dirty_ = false;
+  }
+
+  // Start making motion events touch motion rather than mouse
+  emit_touch_ = input.value;
+
+  base::TimeDelta delta = base::TimeDelta::FromMicroseconds(
+      input.time.tv_sec * 1000000 + input.time.tv_usec);
+  scoped_ptr<TouchEvent> touch_event(new TouchEvent(
+      input.value ? ET_TOUCH_PRESSED : ET_TOUCH_RELEASED,
+      cursor_->GetLocation(),
+      /* flags */ 0,
+      /* touch_id */ 1,
+      /* delta */ delta,
+      /* radius_x */ 1.0,
+      /* radius_y */ 1.0,
+      /* angle */ 0.,
+      /* force */ (float)(pressure_ - pressure_min_) / pressure_range_));
+  touch_event->set_source_device_id(id_);
+  callback_.Run(touch_event.Pass());
+}
+
 void TabletEventConverterEvdev::DispatchMouseButton(const input_event& input) {
   if (!cursor_)
     return;
 
   unsigned int modifier;
   // These are the same as X11 behaviour
   if (input.code == BTN_TOUCH)
     modifier = EVDEV_MODIFIER_LEFT_MOUSE_BUTTON;
   else if (input.code == BTN_STYLUS2)
     modifier = EVDEV_MODIFIER_RIGHT_MOUSE_BUTTON;
   else if (input.code == BTN_STYLUS)
     modifier = EVDEV_MODIFIER_MIDDLE_MOUSE_BUTTON;
   else
     return;
 
   if (abs_value_dirty_) {
     UpdateCursor();
     abs_value_dirty_ = false;
   }
 
   int flag = modifiers_->GetEventFlagFromModifier(modifier);
   modifiers_->UpdateModifier(modifier, input.value);
   callback_.Run(make_scoped_ptr(
       new MouseEvent(input.value ? ET_MOUSE_PRESSED : ET_MOUSE_RELEASED,
                      cursor_->GetLocation(), cursor_->GetLocation(),
                      modifiers_->GetModifierFlags() | flag, flag)));
 }
 
-void TabletEventConverterEvdev::FlushEvents() {
+void TabletEventConverterEvdev::FlushEvents(const input_event& input) {
   if (!cursor_)
     return;
 
   // Prevent propagation of invalid data on stylus lift off
   if (stylus_ == 0) {
     abs_value_dirty_ = false;
     return;
   }
 
   if (!abs_value_dirty_)
     return;
 
   UpdateCursor();
 
+  if (emit_touch_) {
+    base::TimeDelta delta = base::TimeDelta::FromMicroseconds(
+        input.time.tv_sec * 1000000 + input.time.tv_usec);
+    scoped_ptr<TouchEvent> touch_event(new TouchEvent(
+        ET_TOUCH_MOVED,
+        cursor_->GetLocation(),
+        /* flags */ 0,
+        /* touch_id */ 1,

[Rick Byers, 2015/01/19 20:44:20]

What if there is both real touchscreen and stylus contacts present at once?  A
hard-coded touch_id may be problematic in that case.

+        /* delta */ delta,
+        /* radius_x */ 1.0,
+        /* radius_y */ 1.0,
+        /* angle */ 0.,
+        /* force */ (float)(pressure_ - pressure_min_) / pressure_range_));
+    touch_event->set_source_device_id(id_);
+    callback_.Run(touch_event.Pass());
+  } else {
   callback_.Run(make_scoped_ptr(
       new MouseEvent(ui::ET_MOUSE_MOVED, cursor_->GetLocation(),
                      cursor_->GetLocation(), modifiers_->GetModifierFlags(),
                      /* changed_button_flags */ 0)));
-
+  }
   abs_value_dirty_ = false;
 }
 
 }  // namespace ui