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 {
+
+// Time interval after a touch event during which all other touch events are
+// ignored during calibration.
+const base::TimeDelta TouchCalibratorController::kTouchIntervalThreshold =
+    base::TimeDelta::FromMilliseconds(200);
+
+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) {
+    bool is_target_display = display.id() == target_display_.id();

[stevenjb, 2016/12/22 18:28:41]

nit: In the constructor the parameter is 'is_primary_view', these should be
consistent.

[malaykeshav, 2016/12/22 20:17:01]

done

+    touch_calibrator_views_[display.id()] =
+        base::MakeUnique<TouchCalibratorView>(display, is_target_display);
+  }
+
+  // TODO(malaykeshav): Call TouchTransformerController::SetForCalibration()
+
+  // Add self as an event handler target.
+  ash::Shell::GetInstance()->AddPreTargetHandler(this);
+}
+
+void TouchCalibratorController::StopCalibration() {
+  if (!is_calibrating_)
+    return;
+  is_calibrating_ = false;
+
+  // TODO(malaykeshav): Call TouchTransformerController::SetForCalibration()
+
+  // 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) {
+  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();
+
+  int state_index;
+  // Maps the state to an integer value. Assigns a non negative integral value
+  // for a state in which the user can interact with the the interface.
+  switch (target_screen_calibration_view->state()) {
+    case TouchCalibratorView::DISPLAY_POINT_1:
+      state_index = 0;
+      break;
+    case TouchCalibratorView::DISPLAY_POINT_2:
+      state_index = 1;
+      break;
+    case TouchCalibratorView::DISPLAY_POINT_3:
+      state_index = 2;
+      break;
+    case TouchCalibratorView::DISPLAY_POINT_4:
+      state_index = 3;
+      break;
+    default:
+      state_index = -1;
+  }
+
+  // Return early if the interface is in a state that does not allow user
+  // interaction.
+  if (state_index < 0)
+    return;

[stevenjb, 2016/12/22 18:28:41]

nit: move early return and comment into 'default' case above.

[malaykeshav, 2016/12/22 20:17:01]

done

+
+  // Store touch point corresponding to its display point.
+  gfx::Point display_point;
+  if (target_screen_calibration_view->GetDisplayPointLocation(&display_point)) {
+    touch_point_quad_[state_index] =
+        std::make_pair(display_point, touch->location());
+  }
+
+  // If this is the final state, then store all calibration data and stop
+  // calibration.
+  if (target_screen_calibration_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->AdvanceToNextState();
+}
+
+}  // namespace chromeos