[ozone/wayland] Hook zaura_shell 'layout_mode' event

This CL hooks ozone/wayland with the newly added 'layout_mode'
event, from zaura_shell EXO extension.

It also introduces a new path to set the global tablet state:
display::DisplayObserver.

Next, ash/wm/tablet_mode/tablet_more_controller.cc|h will switch
over to it, and rest chromeos::TabletState.

BUG=1113900

R=jamescook@chromium.org, rjkroege@chromium.org

Change-Id: Iae832c4247c04c47429255721ff69c3ba0762455
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491517Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#823948}

chromeos/ui/base/tablet_state.cc

@@ -5,6 +5,7 @@
 #include "chromeos/ui/base/tablet_state.h"
 
 #include "base/check_op.h"
+#include "ui/display/screen.h"
 
 namespace chromeos {
 
@@ -19,11 +20,13 @@ TabletState* TabletState::Get() {
 TabletState::TabletState() {
   DCHECK_EQ(nullptr, g_instance);
   g_instance = this;
+  display::Screen::GetScreen()->AddObserver(this);
 }
 
 TabletState::~TabletState() {
   DCHECK_EQ(this, g_instance);
   g_instance = nullptr;
+  display::Screen::GetScreen()->RemoveObserver(this);
 }
 
 void TabletState::AddObserver(Observer* observer) {
@@ -46,4 +49,8 @@ void TabletState::SetState(display::TabletState state) {
     observer.OnTabletStateChanged(state_);
 }
 
+void TabletState::OnDisplayTabletStateChanged(display::TabletState state) {
+  SetState(state);
+}
+
 }  // namespace chromeos

chromeos/ui/base/tablet_state.h

@@ -7,6 +7,7 @@
 
 #include "base/component_export.h"
 #include "base/observer_list.h"
+#include "ui/display/display_observer.h"
 #include "ui/display/tablet_state.h"
 
 namespace ash {
@@ -19,7 +20,8 @@ namespace chromeos {
 //
 // The idea is that only the creator of this class in Ash or Lacros/Ozone code
 // is able to set the state.
-class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState {
+class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState
+    : public display::DisplayObserver {
  public:
   // Returns the singleton instance.
   static TabletState* Get();
@@ -35,7 +37,7 @@ class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState {
   TabletState();
   TabletState(const TabletState&) = delete;
   TabletState& operator=(const TabletState&) = delete;
-  ~TabletState();
+  ~TabletState() override;
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
@@ -45,6 +47,9 @@ class COMPONENT_EXPORT(CHROMEOS_UI_BASE) TabletState {
 
   display::TabletState state() const { return state_; }
 
+  // display::DisplayObserver:
+  void OnDisplayTabletStateChanged(display::TabletState state) override;
+
  private:
   // The friend class declaration here is used to control classes that can set
   // the tablet state.

ui/display/display_observer.cc

@@ -4,6 +4,8 @@
 
 #include "ui/display/display_observer.h"
 
+#include "ui/display/tablet_state.h"
+
 namespace display {
 
 DisplayObserver::~DisplayObserver() {}
@@ -22,4 +24,6 @@ void DisplayObserver::OnDisplayMetricsChanged(const Display& display,
 void DisplayObserver::OnCurrentWorkspaceChanged(
     const std::string& new_workspace) {}
 
+void DisplayObserver::OnDisplayTabletStateChanged(TabletState state) {}
+
 }  // namespace display

ui/display/display_observer.h

@@ -12,6 +12,7 @@
 
 namespace display {
 class Display;
+enum class TabletState;
 
 // Observers for display configuration changes.
 class DISPLAY_EXPORT DisplayObserver : public base::CheckedObserver {
@@ -55,6 +56,9 @@ class DISPLAY_EXPORT DisplayObserver : public base::CheckedObserver {
   // |new_workspace|.
   virtual void OnCurrentWorkspaceChanged(const std::string& new_workspace);
 
+  // Called when display changes between conventional and tablet mode.
+  virtual void OnDisplayTabletStateChanged(TabletState state);
+
  protected:
   ~DisplayObserver() override;
 };

ui/ozone/platform/wayland/host/wayland_connection.cc

@@ -65,7 +65,7 @@ constexpr uint32_t kMaxWpPresentationVersion = 1;
 constexpr uint32_t kMaxWpViewporterVersion = 1;
 constexpr uint32_t kMaxTextInputManagerVersion = 1;
 constexpr uint32_t kMaxExplicitSyncVersion = 2;
-constexpr uint32_t kMinAuraShellVersion = 10;
+constexpr uint32_t kMinAuraShellVersion = 11;
 constexpr uint32_t kMinWlDrmVersion = 2;
 constexpr uint32_t kMinWlOutputVersion = 2;
 constexpr uint32_t kMaxXdgDecorationVersion = 1;

ui/ozone/platform/wayland/host/wayland_screen.cc

@@ -13,7 +13,6 @@
 #include "ui/display/display.h"
 #include "ui/display/display_finder.h"
 #include "ui/display/display_list.h"
-#include "ui/display/display_observer.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/display_color_spaces.h"
 #include "ui/gfx/geometry/point.h"
@@ -133,6 +132,13 @@ void WaylandScreen::AddOrUpdateDisplay(uint32_t output_id,
     window->UpdateBufferScale(true);
 }
 
+void WaylandScreen::OnTabletStateChanged(display::TabletState tablet_state) {
+  auto* observer_list = display_list_.observers();
+  for (auto& observer : *observer_list) {
+    observer.OnDisplayTabletStateChanged(tablet_state);
+  }
+}
+
 base::WeakPtr<WaylandScreen> WaylandScreen::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }

ui/ozone/platform/wayland/host/wayland_screen.h

@@ -12,6 +12,8 @@
 #include "base/observer_list.h"
 #include "base/optional.h"
 #include "ui/display/display_list.h"
+#include "ui/display/display_observer.h"
+#include "ui/display/tablet_state.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/ozone/public/platform_screen.h"
@@ -37,6 +39,8 @@ class WaylandScreen : public PlatformScreen {
                               int32_t output_scale);
   void OnOutputRemoved(uint32_t output_id);
 
+  void OnTabletStateChanged(display::TabletState tablet_state);
+
   base::WeakPtr<WaylandScreen> GetWeakPtr();
 
   // PlatformScreen overrides:

ui/ozone/platform/wayland/host/wayland_zaura_shell.cc

@@ -4,7 +4,12 @@
 
 #include "ui/ozone/platform/wayland/host/wayland_zaura_shell.h"
 
+#include <components/exo/wayland/protocol/aura-shell-client-protocol.h>
+
 #include "base/check.h"
+#include "ui/ozone/platform/wayland/host/wayland_connection.h"
+#include "ui/ozone/platform/wayland/host/wayland_output_manager.h"
+#include "ui/ozone/platform/wayland/host/wayland_screen.h"
 
 namespace ui {
 
@@ -13,8 +18,33 @@ WaylandZAuraShell::WaylandZAuraShell(zaura_shell* aura_shell,
     : obj_(aura_shell), connection_(connection) {
   DCHECK(obj_);
   DCHECK(connection_);
+
+  static const zaura_shell_listener zaura_shell_listener = {
+      &WaylandZAuraShell::OnLayoutMode,
+  };
+  zaura_shell_add_listener(obj_.get(), &zaura_shell_listener, this);
 }
 
 WaylandZAuraShell::~WaylandZAuraShell() = default;
 
+// static
+void WaylandZAuraShell::OnLayoutMode(void* data,
+                                     struct zaura_shell* zaura_shell,
+                                     uint32_t layout_mode) {
+  auto* self = static_cast<WaylandZAuraShell*>(data);
+  auto* screen = self->connection_->wayland_output_manager()->wayland_screen();
+  // |screen| is null in some unit test suites.
+  if (!screen)
+    return;
+
+  switch (layout_mode) {
+    case ZAURA_SHELL_LAYOUT_MODE_WINDOWED:
+      screen->OnTabletStateChanged(display::TabletState::kInClamshellMode);
+      return;
+    case ZAURA_SHELL_LAYOUT_MODE_TABLET:
+      screen->OnTabletStateChanged(display::TabletState::kInTabletMode);
+      return;
+  }
+}
+
 }  // namespace ui

ui/ozone/platform/wayland/host/wayland_zaura_shell.h

@@ -22,6 +22,11 @@ class WaylandZAuraShell {
   zaura_shell* wl_object() const { return obj_.get(); }
 
  private:
+  // zaura_shell_listener
+  static void OnLayoutMode(void* data,
+                           struct zaura_shell* zaura_shell,
+                           uint32_t layout_mode);
+
   wl::Object<zaura_shell> obj_;
   WaylandConnection* const connection_;
 };