exo: Remove modifier_flags_ from exo::Keyboard.

Now modifiers are tracked in XkbTracker, so remove the cache from
exo::Keyboard.
Instead, it is cached in WaylandKeyboardDelegate for re-sending
purpose.

BUG=1123705
TEST=Ran exo_unittests locally.

Change-Id: I2800f507a030a938d2e0d58163e2e5005f1de299
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2426663
Reviewed-by: Jun Mukai <mukai@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810019}

components/exo/keyboard.cc

@@ -33,14 +33,6 @@ namespace {
 // Delay until a key state change expected to be acknowledged is expired.
 const int kExpirationDelayForPendingKeyAcksMs = 1000;
 
-// These modifiers reflect what clients are supposed to be aware of.
-// I.e. EF_SCROLL_LOCK_ON is missing because clients are not supposed
-// to be aware scroll lock.
-const int kModifierMask = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
-                          ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN |
-                          ui::EF_ALTGR_DOWN | ui::EF_MOD3_DOWN |
-                          ui::EF_NUM_LOCK_ON | ui::EF_CAPS_LOCK_ON;
-
 // The accelerator keys reserved to be processed by chrome.
 const struct {
   ui::KeyboardCode keycode;
@@ -286,11 +278,7 @@ void Keyboard::OnKeyEvent(ui::KeyEvent* event) {
       ConsumedByIme(focus_, event);
 
   // Always update modifiers.
-  int modifier_flags = event->flags() & kModifierMask;
-  if (modifier_flags != modifier_flags_) {
-    modifier_flags_ = modifier_flags;
-    delegate_->OnKeyboardModifiers(modifier_flags_);
-  }
+  delegate_->OnKeyboardModifiers(event->flags());
 
   // TODO(yhanada): This is a quick fix for https://crbug.com/859071. Remove
   // ARC-specific code path once we can find a way to manage press/release
@@ -427,9 +415,8 @@ void Keyboard::SetFocus(Surface* surface) {
     pending_key_acks_.clear();
   }
   if (surface) {
-    modifier_flags_ = seat_->modifier_flags() & kModifierMask;
     pressed_keys_ = seat_->pressed_keys();
-    delegate_->OnKeyboardModifiers(modifier_flags_);
+    delegate_->OnKeyboardModifiers(seat_->modifier_flags());
     delegate_->OnKeyboardEnter(surface, pressed_keys_);
     focus_ = surface;
     focus_->AddSurfaceObserver(this);

components/exo/keyboard.h

@@ -117,9 +117,6 @@ class Keyboard : public ui::EventHandler,
   // details.
   base::flat_map<ui::DomCode, ui::DomCode> pressed_keys_;
 
-  // Current set of modifier flags.
-  int modifier_flags_ = 0;
-
   // Key state changes that are expected to be acknowledged.
   using KeyStateChange = std::pair<ui::KeyEvent, base::TimeTicks>;
   base::flat_map<uint32_t, KeyStateChange> pending_key_acks_;

components/exo/keyboard_modifiers.h

@@ -7,6 +7,8 @@
 
 #include <stdint.h>
 
+#include <tuple>
+
 namespace exo {
 
 // Represents keyboard modifiers.
@@ -17,6 +19,12 @@ struct KeyboardModifiers {
   uint32_t group;
 };
 
+inline bool operator==(const KeyboardModifiers& lhs,
+                       const KeyboardModifiers& rhs) {
+  return std::tie(lhs.depressed, lhs.locked, lhs.latched, lhs.group) ==
+         std::tie(rhs.depressed, rhs.locked, rhs.latched, rhs.group);
+}
+
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_KEYBOARD_MODIFIERS_H_

components/exo/wayland/wayland_keyboard_delegate.cc

@@ -90,6 +90,12 @@ uint32_t WaylandKeyboardDelegate::OnKeyboardKey(base::TimeTicks time_stamp,
 
 void WaylandKeyboardDelegate::OnKeyboardModifiers(int modifier_flags) {
   xkb_tracker_->UpdateKeyboardModifiers(modifier_flags);
+
+  // Send the update only when they're different.
+  const KeyboardModifiers modifiers = xkb_tracker_->GetModifiers();
+  if (current_modifiers_ == modifiers)
+    return;
+  current_modifiers_ = modifiers;
   SendKeyboardModifiers();
 }
 
@@ -110,12 +116,11 @@ uint32_t WaylandKeyboardDelegate::DomCodeToKey(ui::DomCode code) const {
 }
 
 void WaylandKeyboardDelegate::SendKeyboardModifiers() {
-  const KeyboardModifiers modifiers = xkb_tracker_->GetModifiers();
   wl_keyboard_send_modifiers(
       keyboard_resource_,
       serial_tracker_->GetNextSerial(SerialTracker::EventType::OTHER_EVENT),
-      modifiers.depressed, modifiers.locked, modifiers.latched,
-      modifiers.group);
+      current_modifiers_.depressed, current_modifiers_.locked,
+      current_modifiers_.latched, current_modifiers_.group);
   wl_client_flush(client());
 }
 

components/exo/wayland/wayland_keyboard_delegate.h

@@ -10,7 +10,7 @@
 #include "base/time/time.h"
 #include "build/buildflag.h"
 #include "components/exo/keyboard_delegate.h"
-#include "components/exo/keyboard_observer.h"
+#include "components/exo/keyboard_modifiers.h"
 #include "components/exo/wayland/server_util.h"
 #include "components/exo/wayland/wayland_input_delegate.h"
 #include "ui/base/buildflags.h"
@@ -79,6 +79,9 @@ class WaylandKeyboardDelegate : public WaylandInputDelegate,
   // zwp_text_input.
   std::unique_ptr<XkbTracker> xkb_tracker_;
 
+  // Tracks the latest modifiers.
+  KeyboardModifiers current_modifiers_{};
+
   DISALLOW_COPY_AND_ASSIGN(WaylandKeyboardDelegate);
 #endif
 };