Prevent touchscreen disable on lid close or user inactivity

In the event of user inactivity or lid close, this patch will prevent
the touchscreens from being disabled if an external touch device is
connected to the system.

Bug: 797411
Change-Id: I12afd55edfe343ff6508bd2fdd0f4d09c93b5a98
Component: backlights settter, touch device, wake up, power manager
Testing: Added ash unittests to check for expected behavior
Reviewed-on: https://chromium-review.googlesource.com/1102151
Commit-Queue: Malay Keshav <malaykeshav@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567710}

ash/system/power/backlights_forced_off_setter.cc

@@ -13,6 +13,7 @@
 #include "base/logging.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/power_manager/backlight.pb.h"
+#include "ui/display/manager/touch_device_manager.h"
 
 namespace ash {
 
@@ -157,9 +158,15 @@ void BacklightsForcedOffSetter::SetBacklightsForcedOff(bool forced_off) {
 }
 
 void BacklightsForcedOffSetter::UpdateTouchscreenStatus() {
+  // If there is an external touch display connected to the device, then we want
+  // to allow users to wake up the device using this external touch device. The
+  // kernel blocks wake up events from internal input devices when the screen is
+  // off or is in the suspended state.
+  // See https://crbug/797411 for more details.
   const bool disable_touchscreen = backlights_forced_off_.value_or(false) ||
                                    (screen_state_ == ScreenState::OFF_AUTO &&
-                                    disable_touchscreen_while_screen_off_);
+                                    disable_touchscreen_while_screen_off_ &&
+                                    !display::HasExternalTouchscreenDevice());
   Shell::Get()->touch_devices_controller()->SetTouchscreenEnabled(
       !disable_touchscreen, TouchDeviceEnabledSource::GLOBAL);
 }

ash/system/power/backlights_forced_off_setter_unittest.cc

@@ -8,12 +8,22 @@
 #include <utility>
 #include <vector>
 
+#include "ash/shell.h"
 #include "ash/system/power/scoped_backlights_forced_off.h"
 #include "ash/test/ash_test_base.h"
+#include "ash/touch/ash_touch_transform_controller.h"
+#include "ash/touch/touch_devices_controller.h"
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/fake_power_manager_client.h"
+#include "services/ui/public/cpp/input_devices/input_device_client_test_api.h"
+#include "ui/display/manager/display_manager.h"
+#include "ui/display/manager/test/touch_transform_controller_test_api.h"
+#include "ui/display/manager/touch_transform_setter.h"
+#include "ui/display/test/display_manager_test_api.h"
+#include "ui/events/devices/touch_device_transform.h"
+#include "ui/events/devices/touchscreen_device.h"
 
 namespace ash {
 
@@ -196,4 +206,100 @@ TEST_F(BacklightsForcedOffSetterTest,
             backlights_forced_off_observer_->forced_off_states());
 }
 
+TEST_F(BacklightsForcedOffSetterTest,
+       ExternalTouchDevicePreventsTouchscreenDisable) {
+  UpdateDisplay("1200x600,600x1000*2");
+  const int64_t kInternalDisplayId =
+      display::test::DisplayManagerTestApi(display_manager())
+          .SetFirstDisplayAsInternalDisplay();
+
+  display::DisplayIdList display_id_list =
+      display_manager()->GetCurrentDisplayIdList();
+
+  // Pick the non internal display Id.
+  const int64_t kExternalDisplayId = display_id_list[0] == kInternalDisplayId
+                                         ? display_id_list[1]
+                                         : display_id_list[0];
+
+  // Initialize an external touch device.
+  ui::TouchscreenDevice external_touchdevice(
+      123, ui::InputDeviceType::INPUT_DEVICE_EXTERNAL,
+      std::string("test external touch device"), gfx::Size(1000, 1000), 1);
+
+  ui::TouchscreenDevice internal_touchdevice(
+      234, ui::InputDeviceType::INPUT_DEVICE_INTERNAL,
+      std::string("test internal touch device"), gfx::Size(1000, 1000), 1);
+  ui::InputDeviceClientTestApi().SetTouchscreenDevices(
+      {external_touchdevice, internal_touchdevice});
+
+  std::vector<ui::TouchDeviceTransform> transforms;
+  ui::TouchDeviceTransform touch_device_transform;
+
+  // Add external touch device to the list.
+  touch_device_transform.display_id = kExternalDisplayId;
+  touch_device_transform.device_id = external_touchdevice.id;
+  transforms.push_back(touch_device_transform);
+
+  // Add internal touch device to the list.
+  touch_device_transform.display_id = kInternalDisplayId;
+  touch_device_transform.device_id = internal_touchdevice.id;
+  transforms.push_back(touch_device_transform);
+
+  // Initialize the transforms and the InputDeviceManager.
+  display::test::TouchTransformControllerTestApi(
+      ash::Shell::Get()->touch_transformer_controller())
+      .touch_transform_setter()
+      ->ConfigureTouchDevices(transforms);
+
+  // The brightness change is due to user inactivity or lid close.
+  power_manager::BacklightBrightnessChange change;
+  change.set_cause(power_manager::BacklightBrightnessChange_Cause_OTHER);
+  change.set_percent(0.0);
+
+  power_manager_client_->SendScreenBrightnessChanged(change);
+
+  // The touchscreens should be enabled.
+  EXPECT_TRUE(Shell::Get()->touch_devices_controller()->GetTouchscreenEnabled(
+      TouchDeviceEnabledSource::GLOBAL));
+}
+
+TEST_F(BacklightsForcedOffSetterTest, TouchscreensDisableOnBrightnessChange) {
+  UpdateDisplay("1200x600,600x1000*2");
+  const int64_t kInternalDisplayId =
+      display::test::DisplayManagerTestApi(display_manager())
+          .SetFirstDisplayAsInternalDisplay();
+
+  display::DisplayIdList display_id_list =
+      display_manager()->GetCurrentDisplayIdList();
+
+  ui::TouchscreenDevice internal_touchdevice(
+      234, ui::InputDeviceType::INPUT_DEVICE_INTERNAL,
+      std::string("test internal touch device"), gfx::Size(1000, 1000), 1);
+  ui::InputDeviceClientTestApi().SetTouchscreenDevices({internal_touchdevice});
+
+  // Add internal touch device to the list.
+  std::vector<ui::TouchDeviceTransform> transforms;
+  ui::TouchDeviceTransform touch_device_transform;
+  touch_device_transform.display_id = kInternalDisplayId;
+  touch_device_transform.device_id = internal_touchdevice.id;
+  transforms.push_back(touch_device_transform);
+
+  // Initialize the transforms and the InputDeviceManager.
+  display::test::TouchTransformControllerTestApi(
+      ash::Shell::Get()->touch_transformer_controller())
+      .touch_transform_setter()
+      ->ConfigureTouchDevices(transforms);
+
+  // The brightness change is due to user inactivity or lid close.
+  power_manager::BacklightBrightnessChange change;
+  change.set_cause(power_manager::BacklightBrightnessChange_Cause_OTHER);
+  change.set_percent(0.0);
+
+  power_manager_client_->SendScreenBrightnessChanged(change);
+
+  // The touchscreens should be disabled.
+  EXPECT_FALSE(Shell::Get()->touch_devices_controller()->GetTouchscreenEnabled(
+      TouchDeviceEnabledSource::GLOBAL));
+}
+
 }  // namespace ash