exo: Send DSF of internal display to ARC

components/exo/wayland/server.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/exo/wayland/server.h"
 
 #include <alpha-compositing-unstable-v1-server-protocol.h>
 #include <gaming-input-unstable-v1-server-protocol.h>
 #include <gaming-input-unstable-v2-server-protocol.h>
 #include <grp.h>
@@ skipping 2109 matching lines @@
                               weak_ptr_factory_.GetWeakPtr()),
         base::TimeDelta::FromMilliseconds(delay_ms));
   }
 
   void SendDisplayMetrics() {
     if (!needs_send_display_metrics_)
       return;
     needs_send_display_metrics_ = false;
 
     const display::Screen* screen = display::Screen::GetScreen();
+    display::Display primary_display = screen->GetPrimaryDisplay();
 
     if (IsMultiDisplaySupported()) {
+      // TODO(domlaskowski): Send real DSFs once client selects DPI using DSF.

[reveman, 2017/03/28 07:12:21]

I don't understand this TODO. Can you link to a bug or better explain what the
plan is?

[Dominik Laskowski, 2017/03/30 01:21:43]

Updated comment.

+      double device_scale_factor =
+          WMHelper::GetInstance()
+              ->GetDisplayInfo(display::Display::HasInternalDisplay()
+                                   ? display::Display::InternalDisplayId()
+                                   : primary_display.id())
+              .device_scale_factor();

[oshima, 2017/03/28 12:46:55]

This value may change (as primary display may change), but Android need to keep
using the same value correct? Is it the above comment?

[Dominik Laskowski, 2017/03/30 01:21:44]

On a device without an internal display, the cursor scale might be wrong if the
primary DSF does not match the density configured at build time. The density
should be selected at run time based on the primary DSF.

+
       for (const auto& display : screen->GetAllDisplays()) {
         const gfx::Rect& bounds = display.bounds();
         const gfx::Insets& insets = display.GetWorkAreaInsets();
 
         zcr_remote_shell_v1_send_workspace(
             remote_shell_resource_,
             static_cast<uint32_t>(display.id() >> 32),
             static_cast<uint32_t>(display.id()),
             bounds.x(), bounds.y(), bounds.width(), bounds.height(),
             insets.left(), insets.top(), insets.right(), insets.bottom(),
             OutputTransform(display.rotation()),
-            wl_fixed_from_double(display.device_scale_factor()));
+            wl_fixed_from_double(device_scale_factor));
       }
 
       zcr_remote_shell_v1_send_configure(remote_shell_resource_, layout_mode_);
     }
 
-    display::Display primary_display = screen->GetPrimaryDisplay();
     const gfx::Insets& insets = primary_display.GetWorkAreaInsets();
 
     zcr_remote_shell_v1_send_configuration_changed(
         remote_shell_resource_,
         primary_display.size().width(),
         primary_display.size().height(),
         OutputTransform(primary_display.rotation()),
         wl_fixed_from_double(primary_display.device_scale_factor()),
         insets.left(), insets.top(), insets.right(), insets.bottom(),
         layout_mode_);
@@ skipping 1754 matching lines @@
   DCHECK(event_loop);
   wl_event_loop_dispatch(event_loop, timeout.InMilliseconds());
 }
 
 void Server::Flush() {
   wl_display_flush_clients(wl_display_.get());
 }
 
 }  // namespace wayland
 }  // namespace exo