Implements Touch calibrator controller and a skeleton for touch calibrator view.

chrome/browser/chromeos/display/touch_calibrator/touch_calibrator_controller.cc

+// Copyright 2016 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 "chrome/browser/chromeos/display/touch_calibrator/touch_calibrator_controller.h"
+
+#include "ash/shell.h"
+#include "ash/touch/touch_transformer_controller.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/chromeos/display/touch_calibrator/touch_calibrator_view.h"
+#include "ui/display/screen.h"
+#include "ui/events/event.h"
+#include "ui/events/event_constants.h"
+
+namespace chromeos {
+namespace {
+
+// Time interval after a touch event during which all other touch events are
+// ignored during calibration.
+// If modified also update the value in touch_calibrator_controller_unittest.cc.
+const auto kTouchIntervalThreshold = base::TimeDelta::FromMilliseconds(200);

[stevenjb, 2016/12/22 01:14:20]

If this is used in a test it should really be a static member defined in the
header.
Also, this is not a good use of auto, explicitly declare the type here.

[malaykeshav, 2016/12/22 11:50:07]

Done. 

+
+// Returns the index corresponding to the state the touch point is in currently.
+// Will return -1 if the touch point is not in a state where it is ready for
+// input(eg. will return -1 if the touch point is being animated or if the touch
+// point is currently not visible,)
+int GetDisplayPointStateIndex(TouchCalibratorView::State state) {
+  switch (state) {
+    case TouchCalibratorView::DISPLAY_POINT_1:
+      return 0;
+    case TouchCalibratorView::DISPLAY_POINT_2:
+      return 1;
+    case TouchCalibratorView::DISPLAY_POINT_3:
+      return 2;
+    case TouchCalibratorView::DISPLAY_POINT_4:
+      return 3;
+    default:
+      return -1;
+  }
+}
+
+// Returns true if the touch event needs to be processed for the given touch
+// calibration view state.
+bool CanTouch(TouchCalibratorView::State state) {
+  if (GetDisplayPointStateIndex(state) + 1)

[stevenjb, 2016/12/22 01:14:20]

nit: This is confusing, just use if (GetDisplayPointStateIndex(state) >= 0)

[malaykeshav, 2016/12/22 11:50:07]

Done

+    return true;
+  if (state == TouchCalibratorView::CALIBRATION_COMPLETE)
+    return true;

[stevenjb, 2016/12/22 01:14:20]

nit: Test this first (simpler test)

[malaykeshav, 2016/12/22 11:50:07]

Done

+  return false;
+}
+
+}  // namespace
+
+TouchCalibratorController::TouchCalibratorController()
+    : last_touch_timestamp_(base::Time::Now()) {
+  ash::Shell::GetInstance()->window_tree_host_manager()->AddObserver(this);
+}
+
+TouchCalibratorController::~TouchCalibratorController() {
+  ash::Shell::GetInstance()->window_tree_host_manager()->RemoveObserver(this);
+  touch_calibrator_views_.clear();
+  StopCalibration();
+}
+
+void TouchCalibratorController::OnDisplayConfigurationChanged() {
+  touch_calibrator_views_.clear();
+  StopCalibration();
+}
+
+void TouchCalibratorController::StartCalibration(
+    const display::Display& target_display) {
+  is_calibrating_ = true;
+  target_display_ = target_display;
+
+  // Clear all touch calibrator views used in any previous calibration.
+  touch_calibrator_views_.clear();
+
+  // Reset the calibration data.
+  touch_point_quad_.fill(std::make_pair(gfx::Point(0, 0), gfx::Point(0, 0)));
+
+  std::vector<display::Display> displays =
+      display::Screen::GetScreen()->GetAllDisplays();
+
+  for (const display::Display& display : displays) {
+    touch_calibrator_views_[display.id()] =
+        base::MakeUnique<TouchCalibratorView>(
+            display, display.id() == target_display_.id());

[stevenjb, 2016/12/22 01:14:20]

nit: Define a local var for display.id() == target_display_.id() to document
what the argument is.

[malaykeshav, 2016/12/22 11:50:07]

Done

+  }
+
+  // TODO(malaykeshav): Uncomment this when this patch lands.
+  // ash::Shell::GetInstance()->touch_transformer_controller()
+  //                          ->SetForCalibration(true);

[stevenjb, 2016/12/22 01:14:20]

We generally avoid committing commented out code like this, instead just:

TODO(malaykeshav): Call TouchTransformerController::SetForCalibration()

[malaykeshav, 2016/12/22 11:50:07]

Done

+
+  // Add self as an event handler target.
+  ash::Shell::GetInstance()->AddPreTargetHandler(this);
+}
+
+void TouchCalibratorController::StopCalibration() {
+  if (!is_calibrating_)
+    return;
+  is_calibrating_ = false;
+
+  // TODO(malaykeshav): Uncomment this when this patch lands!
+  // ash::Shell::GetInstance()->touch_transformer_controller()
+  //                          ->SetForCalibration(false);

[stevenjb, 2016/12/22 01:14:20]

ditto

[malaykeshav, 2016/12/22 11:50:07]

Done

+
+  // Remove self as the event handler.
+  ash::Shell::GetInstance()->RemovePreTargetHandler(this);
+
+  // Transition all touch calibrator views to their final state for a graceful
+  // exit.
+  for (const auto& it : touch_calibrator_views_)
+    it.second->SkipToFinalState();
+}
+
+// ui::EventHandler:
+void TouchCalibratorController::OnKeyEvent(ui::KeyEvent* key) {
+  if (!is_calibrating_)
+    return;
+  // Detect ESC key press.
+  if (key->type() == ui::ET_KEY_PRESSED && key->key_code() == ui::VKEY_ESCAPE)
+    StopCalibration();
+  key->StopPropagation();
+}
+
+void TouchCalibratorController::OnTouchEvent(ui::TouchEvent* touch) {
+  LOG(ERROR) << "Received touch event";

[stevenjb, 2016/12/22 01:14:20]

VLOG or remove

[malaykeshav, 2016/12/22 11:50:07]

Remnant from when I was testing. Forgot to remove.
Done

+  if (!is_calibrating_)
+    return;
+  if (touch->type() != ui::ET_TOUCH_RELEASED)
+    return;
+  if (base::Time::Now() - last_touch_timestamp_ < kTouchIntervalThreshold)
+    return;
+
+  last_touch_timestamp_ = base::Time::Now();
+
+  TouchCalibratorView* target_screen_calibration_view =
+      touch_calibrator_views_[target_display_.id()].get();
+
+  TouchCalibratorView::State calibrator_view_state =
+      target_screen_calibration_view->GetState();
+
+  // Check if the touch calibrator view is in a state when touch inputs have to
+  // be ignored.
+  if (!CanTouch(calibrator_view_state))
+    return;
+
+  int state_index = GetDisplayPointStateIndex(calibrator_view_state);

[stevenjb, 2016/12/22 01:14:20]

We also call this in CanTouch, which is only called from here, it would probably
be better/simpler just to inline CanTouch().

[malaykeshav, 2016/12/22 11:50:07]

Done

+
+  // Store touch points if the state is a display point state.
+  if (state_index + 1) {

[stevenjb, 2016/12/22 01:14:20]

state_index >= 0

[malaykeshav, 2016/12/22 11:50:07]

Removed. Not required.

+    gfx::Point display_point;
+    if (target_screen_calibration_view->GetTouchPointLocation(&display_point))
+      touch_point_quad_[state_index] =
+          std::make_pair(display_point, touch->location());

[stevenjb, 2016/12/22 01:14:20]

{}

[malaykeshav, 2016/12/22 11:50:07]

done

+  }
+
+  // If this is the final state, then store all calibration data and stop
+  // calibration.
+  if (calibrator_view_state == TouchCalibratorView::CALIBRATION_COMPLETE) {
+    ash::Shell::GetInstance()->display_manager()->SetTouchCalibrationData(
+        target_display_.id(), touch_point_quad_,
+        target_screen_calibration_view->size());
+    StopCalibration();
+    return;
+  }
+
+  target_screen_calibration_view->NextState();
+}
+
+}  // namespace chromeos