Wayland event for dpi scaling change

Send a wayland event to Android when user requests
a density change (CTRL +/CTRL -/CTRL 0) on ARC++
application.
BUG=b:142100473
TEST=`adb shell logcat -s libwayland-client:*'

Change-Id: I550557eeb017fb24eef83cc09a7b0d809462d7b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1846629
Commit-Queue: Mikolaj Walczak <walczakm@google.com>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#704993}

components/exo/client_controlled_shell_surface.cc

@@ -626,7 +626,8 @@ void ClientControlledShellSurface::OnBoundsChangeEvent(
 }
 
 void ClientControlledShellSurface::ChangeZoomLevel(ZoomChange change) {
-  // TODO(walczakm): Send wayland event.
+  if (change_zoom_level_callback_)
+    change_zoom_level_callback_.Run(change);
 }
 
 void ClientControlledShellSurface::OnDragStarted(int component) {

components/exo/client_controlled_shell_surface.h

@@ -122,6 +122,12 @@ class ClientControlledShellSurface : public ShellSurfaceBase,
     drag_finished_callback_ = callback;
   }
 
+  // Set callback to run when user requests to change a zoom level.
+  using ChangeZoomLevelCallback = base::RepeatingCallback<void(ZoomChange)>;
+  void set_change_zoom_level_callback(const ChangeZoomLevelCallback& callback) {
+    change_zoom_level_callback_ = callback;
+  }
+
   // Returns true if this shell surface is currently being dragged.
   bool IsDragging();
 
@@ -298,6 +304,7 @@ class ClientControlledShellSurface : public ShellSurfaceBase,
   BoundsChangedCallback bounds_changed_callback_;
   DragStartedCallback drag_started_callback_;
   DragFinishedCallback drag_finished_callback_;
+  ChangeZoomLevelCallback change_zoom_level_callback_;
 
   // TODO(reveman): Use configure callbacks for orientation. crbug.com/765954
   Orientation pending_orientation_ = Orientation::LANDSCAPE;

components/exo/wayland/zcr_remote_shell.cc

@@ -689,6 +689,13 @@ class WaylandRemoteShell : public ash::TabletModeObserver,
         weak_ptr_factory_.GetWeakPtr(), base::Unretained(resource));
   }
 
+  ClientControlledShellSurface::ChangeZoomLevelCallback
+  CreateChangeZoomLevelCallback(wl_resource* resource) {
+    return base::BindRepeating(
+        &WaylandRemoteShell::HandleRemoteSurfaceChangeZoomLevelCallback,
+        weak_ptr_factory_.GetWeakPtr(), base::Unretained(resource));
+  }
+
   ClientControlledShellSurface::StateChangedCallback CreateStateChangedCallback(
       wl_resource* resource) {
     return base::BindRepeating(
@@ -1019,6 +1026,23 @@ class WaylandRemoteShell : public ash::TabletModeObserver,
     wl_client_flush(wl_resource_get_client(resource));
   }
 
+  void HandleRemoteSurfaceChangeZoomLevelCallback(wl_resource* resource,
+                                                  ZoomChange change) {
+    int32_t value = 0;
+    switch (change) {
+      case ZoomChange::IN:
+        value = ZCR_REMOTE_SURFACE_V1_ZOOM_CHANGE_IN;
+        break;
+      case ZoomChange::OUT:
+        value = ZCR_REMOTE_SURFACE_V1_ZOOM_CHANGE_OUT;
+        break;
+      case ZoomChange::RESET:
+        value = ZCR_REMOTE_SURFACE_V1_ZOOM_CHANGE_RESET;
+        break;
+    }
+    zcr_remote_surface_v1_send_change_zoom_level(resource, value);
+  }
+
   void HandleRemoteSurfaceGeometryChangedCallback(wl_resource* resource,
                                                   const gfx::Rect& geometry) {
     LOG_IF(ERROR, pending_bounds_changes_.count(resource) > 0)
@@ -1139,6 +1163,10 @@ void remote_shell_get_remote_surface(wl_client* client,
       base::BindRepeating(&HandleRemoteSurfaceDragFinishedCallback,
                           base::Unretained(remote_surface_resource)));
 
+  DCHECK(wl_resource_get_version(remote_surface_resource) >= 23);
+  shell_surface->set_change_zoom_level_callback(
+      shell->CreateChangeZoomLevelCallback(remote_surface_resource));
+
   SetImplementation(remote_surface_resource, &remote_surface_implementation,
                     std::move(shell_surface));
 }

components/exo/wayland/zcr_remote_shell.h

@@ -22,7 +22,7 @@ class Display;
 namespace exo {
 namespace wayland {
 
-constexpr uint32_t kZcrRemoteShellVersion = 22;
+constexpr uint32_t kZcrRemoteShellVersion = 23;
 
 void bind_remote_shell(wl_client* client,
                        void* data,

third_party/wayland-protocols/unstable/remote-shell/remote-shell-unstable-v1.xml

@@ -38,7 +38,7 @@
     reset.
   </description>
 
-  <interface name="zcr_remote_shell_v1" version="22">
+  <interface name="zcr_remote_shell_v1" version="23">
     <description summary="remote_shell">
       The global interface that allows clients to turn a wl_surface into a
       "real window" which is remotely managed but can be stacked, activated
@@ -237,7 +237,7 @@
 
   </interface>
 
-  <interface name="zcr_remote_surface_v1" version="20">
+  <interface name="zcr_remote_surface_v1" version="23">
     <description summary="A desktop window">
       An interface that may be implemented by a wl_surface, for
       implementations that provide a desktop-style user interface
@@ -1016,6 +1016,23 @@
 	description of set_ime_blocked for detail.
       </description>
     </request>
+
+    <!-- Version 23 additions -->
+    <enum name="zoom_change">
+      <description summary="zoom level change">
+	Zoom level change.
+      </description>
+      <entry name="in" value="0" summary="zoom in"/>
+      <entry name="out" value="1" summary="zoom out"/>
+      <entry name="reset" value="2" summary="reset zoom level"/>
+    </enum>
+
+    <event name="change_zoom_level" since="23">
+      <description summary="change zoom level">
+	Request application zoom level change.
+      </description>
+      <arg name="change" type="int" summary="zoom_change"/>
+    </event>
   </interface>
 
   <interface name="zcr_notification_surface_v1" version="16">