[fuchsia] Fixes the HID usage handling

shell/platform/fuchsia/flutter/keyboard.cc

@@ -285,7 +285,7 @@ bool Keyboard::IsShift() {
 }
 
 bool Keyboard::IsKeys() {
-  return (static_cast<uint64_t>(last_event_.key()) & 0xFFFF0000) == 0x00070000;
+  return LastHIDUsagePage() == 0x7;
 }
 
 uint32_t Keyboard::Modifiers() {
@@ -298,21 +298,39 @@ uint32_t Keyboard::Modifiers() {
 }
 
 uint32_t Keyboard::LastCodePoint() {
+  // TODO(https://github.com/flutter/flutter/issues/93891):
+  // `KeyEvent::key_meaning` should be used here to do key mapping before US
+  // QWERTY is applied. The US QWERTY should be applied only if `key_meaning`
+  // is not available.
   static const int qwerty_map_size =
       sizeof(QWERTY_TO_CODE_POINTS) / sizeof(QWERTY_TO_CODE_POINTS[0]);
   if (!IsKeys()) {
     return 0;
   }
-  const auto usage = LastHIDUsage();
+  const auto usage = LastHIDUsageID();
   if (usage < qwerty_map_size) {
     return QWERTY_TO_CODE_POINTS[usage][IsShift() & 1];
   }
   // Any other keys don't have a code point.
   return 0;
 }
 
+uint32_t Keyboard::GetLastKey() {
+  // TODO(https://github.com/flutter/flutter/issues/93898): key is not always
+  // set. Figure out what to do then.
+  return static_cast<uint32_t>(last_event_.key());
+}
+
 uint32_t Keyboard::LastHIDUsage() {
-  return static_cast<uint64_t>(last_event_.key()) & 0xFFFF;
+  return GetLastKey() & 0xFFFFFFFF;
+}
+
+uint16_t Keyboard::LastHIDUsageID() {
+  return GetLastKey() & 0xFFFF;
+}
+
+uint16_t Keyboard::LastHIDUsagePage() {
+  return (GetLastKey() >> 16) & 0xFFFF;
 }
 
 }  // namespace flutter_runner

shell/platform/fuchsia/flutter/keyboard.h

@@ -28,9 +28,26 @@ class Keyboard final {
   // the state of the modifier keys.
   uint32_t LastCodePoint();
 
-  // Gets the last encountered HID usage.
+  // Gets the last encountered HID usage.  This is a 32-bit number, with the
+  // upper 16 bits equal to `LastHidUsagePage()`, and the lower 16 bits equal
+  // to `LastHIDUsageID()`.
+  //
+  // The key corresponding to A will have the usage 0x7004. This function will
+  // return 0x7004 in that case.
   uint32_t LastHIDUsage();
 
+  // Gets the last encountered HID usage page.
+  //
+  // The key corresponding to A will have the usage 0x7004. This function will
+  // return 0x7 in that case.
+  uint16_t LastHIDUsagePage();
+
+  // Gets the last encountered HID usage ID.
+  //
+  // The key corresponding to A will have the usage 0x7004. This function will
+  // return 0x4 in that case.
+  uint16_t LastHIDUsageID();
+
  private:
   // Return true if any level shift is active.
   bool IsShift();
@@ -39,6 +56,9 @@ class Keyboard final {
   // point associated.
   bool IsKeys();
 
+  // Returns the value of the last key as a uint32_t.
+  uint32_t GetLastKey();
+
   // Set to false until any event is received.
   bool any_events_received_ : 1;
 

shell/platform/fuchsia/flutter/keyboard_unittest.cc

@@ -60,12 +60,40 @@ class KeyboardTest : public testing::Test {
   }
 
   // Converts a pressed key to usage value.
-  uint32_t ToUsage(Key key) { return static_cast<uint64_t>(key) & 0xFFFF; }
+  uint32_t ToUsage(Key key) { return static_cast<uint64_t>(key) & 0xFFFFFFFF; }
 
  private:
   zx_time_t timestamp_ = 0;
 };
 
+// Checks whether the HID usage, page and ID values are reported correctly.
+TEST_F(KeyboardTest, UsageValues) {
+  std::vector<KeyEvent> keys;
+  keys.emplace_back(NewKeyEvent(KeyEventType::SYNC, Key::CAPS_LOCK));
+  Keyboard keyboard;
+  ConsumeEvents(&keyboard, keys);
+
+  // Values for Caps Lock.
+  // See spec at:
+  // https://cs.opensource.google/fuchsia/fuchsia/+/main:sdk/fidl/fuchsia.input/keys.fidl;l=177;drc=e3b39f2b57e720770773b857feca4f770ee0619e
+  EXPECT_EQ(0x07u, keyboard.LastHIDUsagePage());
+  EXPECT_EQ(0x39u, keyboard.LastHIDUsageID());
+  EXPECT_EQ(0x70039u, keyboard.LastHIDUsage());
+
+  // Try also an usage that is not on page 7. This one is on page 0x0C.
+  // See spec at:
+  // https://cs.opensource.google/fuchsia/fuchsia/+/main:sdk/fidl/fuchsia.input/keys.fidl;l=339;drc=e3b39f2b57e720770773b857feca4f770ee0619e
+  // Note that Fuchsia does not define constants for every key you may think of,
+  // rather only those that we had the need for.  However it is not an issue
+  // to add more keys if needed.
+  keys.clear();
+  keys.emplace_back(NewKeyEvent(KeyEventType::SYNC, Key::MEDIA_MUTE));
+  ConsumeEvents(&keyboard, keys);
+  EXPECT_EQ(0x0Cu, keyboard.LastHIDUsagePage());
+  EXPECT_EQ(0xE2u, keyboard.LastHIDUsageID());
+  EXPECT_EQ(0xC00E2u, keyboard.LastHIDUsage());
+}
+
 // This test checks that if a caps lock has been pressed when we didn't have
 // focus, the effect of caps lock remains.  Only this first test case is
 // commented to explain how the test case works.

shell/platform/fuchsia/flutter/platform_view_unittest.cc

@@ -1250,49 +1250,50 @@ TEST_F(PlatformViewTests, OnKeyEvent) {
 
   std::vector<EventFlow> events;
   // Press A.  Get 'a'.
+  // The HID usage for the key A is 0x70004, or 458756.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::PRESSED, std::nullopt,
                 fuchsia::input::Key::A),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keydown","keymap":"fuchsia","hidUsage":4,"codePoint":97,"modifiers":0})",
+      R"({"type":"keydown","keymap":"fuchsia","hidUsage":458756,"codePoint":97,"modifiers":0})",
   });
   // Release A. Get 'a' release.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::RELEASED, std::nullopt,
                 fuchsia::input::Key::A),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keyup","keymap":"fuchsia","hidUsage":4,"codePoint":97,"modifiers":0})",
+      R"({"type":"keyup","keymap":"fuchsia","hidUsage":458756,"codePoint":97,"modifiers":0})",
   });
   // Press CAPS_LOCK.  Modifier now active.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::PRESSED,
                 fuchsia::ui::input3::Modifiers::CAPS_LOCK,
                 fuchsia::input::Key::CAPS_LOCK),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keydown","keymap":"fuchsia","hidUsage":57,"codePoint":0,"modifiers":1})",
+      R"({"type":"keydown","keymap":"fuchsia","hidUsage":458809,"codePoint":0,"modifiers":1})",
   });
-  // Pres A.  Get 'A'.
+  // Press A.  Get 'A'.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::PRESSED, std::nullopt,
                 fuchsia::input::Key::A),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keydown","keymap":"fuchsia","hidUsage":4,"codePoint":65,"modifiers":1})",
+      R"({"type":"keydown","keymap":"fuchsia","hidUsage":458756,"codePoint":65,"modifiers":1})",
   });
   // Release CAPS_LOCK.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::RELEASED,
                 fuchsia::ui::input3::Modifiers::CAPS_LOCK,
                 fuchsia::input::Key::CAPS_LOCK),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keyup","keymap":"fuchsia","hidUsage":57,"codePoint":0,"modifiers":1})",
+      R"({"type":"keyup","keymap":"fuchsia","hidUsage":458809,"codePoint":0,"modifiers":1})",
   });
   // Press A again.  This time get 'A'.
   // CAPS_LOCK is latched active even if it was just released.
   events.emplace_back(EventFlow{
       MakeEvent(fuchsia::ui::input3::KeyEventType::PRESSED, std::nullopt,
                 fuchsia::input::Key::A),
       fuchsia::ui::input3::KeyEventStatus::HANDLED,
-      R"({"type":"keydown","keymap":"fuchsia","hidUsage":4,"codePoint":65,"modifiers":1})",
+      R"({"type":"keydown","keymap":"fuchsia","hidUsage":458756,"codePoint":65,"modifiers":1})",
   });
 
   for (const auto& event : events) {