Allow pwa/chrome app to consume system key in tablet mode

* Screenshot should still work if the power button is pressed first.

Bug: 1024118
Test: Covered by unittests. Manually tested on Slate.
Change-Id: I14c07d0f8419b5755776346d2c5f5e2e156861c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2130638
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Kuo Jen Wei <inker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758723}

ash/system/power/power_button_screenshot_controller.cc

@@ -5,9 +5,11 @@
 #include "ash/system/power/power_button_screenshot_controller.h"
 
 #include "ash/accelerators/accelerator_controller_impl.h"
+#include "ash/public/cpp/window_properties.h"
 #include "ash/shell.h"
 #include "ash/system/power/power_button_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "ash/wm/window_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/time/tick_clock.h"
@@ -21,6 +23,11 @@ bool IsTabletMode() {
   return Shell::Get()->tablet_mode_controller()->InTabletMode();
 }
 
+bool VolumeKeyMaybeUsedByApp() {
+  aura::Window* active = window_util::GetActiveWindow();
+  return active && active->GetProperty(ash::kCanConsumeSystemKeysKey);
+}
+
 }  // namespace
 
 constexpr base::TimeDelta
@@ -70,9 +77,21 @@ void PowerButtonScreenshotController::OnKeyEvent(ui::KeyEvent* event) {
   if (key_code != ui::VKEY_VOLUME_DOWN && key_code != ui::VKEY_VOLUME_UP)
     return;
 
+  bool did_consume_volume_keys =
+      volume_down_key_pressed_ || volume_up_key_pressed_;
+  bool volume_key_maybe_used_by_app = VolumeKeyMaybeUsedByApp();
+  // Even if the app is requesting to consume volume key, do not give it if
+  // 1) power button is already pressed. This should trigger screenshot.
+  // 2) if this is already handling volume key. We need to continue processing
+  // volume eve after power button is released, until volume keys are released.
+  if (volume_key_maybe_used_by_app && !power_button_pressed_ &&
+      !did_consume_volume_keys) {
+    return;
+  }
+
   const bool is_volume_down = key_code == ui::VKEY_VOLUME_DOWN;
   if (event->type() == ui::ET_KEY_PRESSED) {
-    if (!volume_down_key_pressed_ && !volume_up_key_pressed_) {
+    if (!did_consume_volume_keys) {
       if (is_volume_down) {
         volume_down_key_pressed_ = true;
         volume_down_key_pressed_time_ = tick_clock_->NowTicks();
@@ -86,8 +105,12 @@ void PowerButtonScreenshotController::OnKeyEvent(ui::KeyEvent* event) {
       }
     }
 
-    if (consume_volume_down_ || consume_volume_up_)
+    // Do no pass the event to the app if the events are being
+    // processed
+    if (consume_volume_down_ || consume_volume_up_ ||
+        volume_key_maybe_used_by_app) {
       event->StopPropagation();
+    }
   } else {
     is_volume_down ? volume_down_key_pressed_ = false
                    : volume_up_key_pressed_ = false;

ash/system/power/power_button_screenshot_controller_unittest.cc

@@ -7,6 +7,7 @@
 #include <memory>
 
 #include "ash/login_status.h"
+#include "ash/public/cpp/window_properties.h"
 #include "ash/shell.h"
 #include "ash/system/power/power_button_controller.h"
 #include "ash/system/power/power_button_controller_test_api.h"
@@ -16,10 +17,37 @@
 #include "ash/wm/lock_state_controller_test_api.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "chromeos/dbus/power/fake_power_manager_client.h"
+#include "ui/aura/test/test_window_delegate.h"
 #include "ui/events/event.h"
+#include "ui/wm/core/window_util.h"
 
 namespace ash {
 
+namespace {
+class KeyEventWindowDelegate : public aura::test::TestWindowDelegate {
+ public:
+  KeyEventWindowDelegate() = default;
+  ~KeyEventWindowDelegate() override = default;
+
+  KeyEventWindowDelegate(const KeyEventWindowDelegate&) = delete;
+  KeyEventWindowDelegate& operator=(const KeyEventWindowDelegate&) = delete;
+
+  void OnKeyEvent(ui::KeyEvent* event) override {
+    key_code_ = event->key_code();
+  }
+
+  ui::KeyboardCode GetReceivedKeyCodeAndReset() {
+    ui::KeyboardCode tmp = key_code_;
+    key_code_ = ui::VKEY_UNKNOWN;
+    return tmp;
+  }
+
+ private:
+  ui::KeyboardCode key_code_ = ui::VKEY_UNKNOWN;
+};
+
+}  // namespace
+
 // Test fixture used for testing power button screenshot behavior under tablet
 // power button.
 class PowerButtonScreenshotControllerTest : public PowerButtonTestBase {
@@ -85,9 +113,34 @@ class PowerButtonScreenshotControllerTest : public PowerButtonTestBase {
   DISALLOW_COPY_AND_ASSIGN(PowerButtonScreenshotControllerTest);
 };
 
+class PowerButtonScreenshotControllerWithSystemKeysTest
+    : public PowerButtonScreenshotControllerTest,
+      public ::testing::WithParamInterface<bool> {
+ public:
+  PowerButtonScreenshotControllerWithSystemKeysTest() = default;
+  ~PowerButtonScreenshotControllerWithSystemKeysTest() override = default;
+
+  PowerButtonScreenshotControllerWithSystemKeysTest(
+      const PowerButtonScreenshotControllerWithSystemKeysTest&) = delete;
+  PowerButtonScreenshotControllerWithSystemKeysTest& operator=(
+      const PowerButtonScreenshotControllerWithSystemKeysTest&) = delete;
+
+  void SetUp() override {
+    PowerButtonScreenshotControllerTest::SetUp();
+    if (GetParam()) {
+      aura::Window* window =
+          CreateTestWindowInShellWithDelegate(&delegate_, 1, gfx::Rect());
+      window->SetProperty(ash::kCanConsumeSystemKeysKey, true);
+    }
+  }
+
+ private:
+  KeyEventWindowDelegate delegate_;
+};
+
 // Tests the functionalities that press the power button first and then press
 // volume down and volume up key alternative.
-TEST_F(PowerButtonScreenshotControllerTest,
+TEST_P(PowerButtonScreenshotControllerWithSystemKeysTest,
        PowerButtonPressedFirst_Screenshot) {
   PressPowerButton();
   tick_clock_.Advance(PowerButtonScreenshotController::kScreenshotChordDelay -
@@ -135,6 +188,10 @@ TEST_F(PowerButtonScreenshotControllerTest,
   EXPECT_FALSE(LastKeyConsumed());
 }
 
+INSTANTIATE_TEST_SUITE_P(All,
+                         PowerButtonScreenshotControllerWithSystemKeysTest,
+                         testing::Bool());
+
 // Tests the functionalities that press the volume key first and then press
 // volume down and volume up key alternative.
 TEST_F(PowerButtonScreenshotControllerTest, VolumeKeyPressedFirst_Screenshot) {
@@ -186,6 +243,56 @@ TEST_F(PowerButtonScreenshotControllerTest, VolumeKeyPressedFirst_Screenshot) {
   EXPECT_FALSE(LastKeyConsumed());
 }
 
+// If the window with kConsumeSystemKeysKey property is active in tablet mode,
+// volume keys will be passed to the window if they are pressed first.
+TEST_F(PowerButtonScreenshotControllerTest, WindowWithSystemKeys) {
+  EnableTabletMode(true);
+
+  KeyEventWindowDelegate delegate;
+  std::unique_ptr<aura::Window> window = base::WrapUnique(
+      CreateTestWindowInShellWithDelegate(&delegate, 1, gfx::Rect()));
+  window->SetProperty(ash::kCanConsumeSystemKeysKey, true);
+  ::wm::ActivateWindow(window.get());
+
+  // Tests when volume up pressed first, it's consumed by an app.
+  // screenshot chord.
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_UP, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_VOLUME_UP, delegate.GetReceivedKeyCodeAndReset());
+
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_UP, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_VOLUME_UP, delegate.GetReceivedKeyCodeAndReset());
+  EXPECT_EQ(0, GetScreenshotCount());
+
+  // Tests when volume down pressed first, it's consumed by an app.
+  // screenshot chord.
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_DOWN, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_VOLUME_DOWN, delegate.GetReceivedKeyCodeAndReset());
+
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_DOWN, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_VOLUME_DOWN, delegate.GetReceivedKeyCodeAndReset());
+  EXPECT_EQ(0, GetScreenshotCount());
+
+  // Delete the window, and volume will be consumed by shortcut.
+  // Screenshot using up.
+  window.reset();
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_UP, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_UNKNOWN, delegate.GetReceivedKeyCodeAndReset());
+  PressPowerButton();
+  ReleasePowerButton();
+  GetEventGenerator()->ReleaseKey(ui::VKEY_VOLUME_UP, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_UNKNOWN, delegate.GetReceivedKeyCodeAndReset());
+  EXPECT_EQ(1, GetScreenshotCount());
+
+  // Screenshot using down.
+  GetEventGenerator()->PressKey(ui::VKEY_VOLUME_DOWN, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_UNKNOWN, delegate.GetReceivedKeyCodeAndReset());
+  PressPowerButton();
+  ReleasePowerButton();
+  GetEventGenerator()->ReleaseKey(ui::VKEY_VOLUME_DOWN, ui::EF_NONE);
+  EXPECT_EQ(ui::VKEY_UNKNOWN, delegate.GetReceivedKeyCodeAndReset());
+  EXPECT_EQ(2, GetScreenshotCount());
+}
+
 class PowerButtonScreenshotControllerWithKeyCodeTest
     : public PowerButtonScreenshotControllerTest,
       public testing::WithParamInterface<ui::KeyboardCode> {