Basic display management for mus

components/mus/ws/platform_screen_impl_ozone.cc

+// Copyright 2016 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/mus/ws/platform_screen_impl_ozone.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/memory/ptr_util.h"
+#include "base/sys_info.h"
+#include "base/thread_task_runner_handle.h"
+#include "ui/display/types/display_snapshot.h"
+#include "ui/display/types/native_display_delegate.h"
+#include "ui/ozone/public/ozone_platform.h"
+
+namespace mus {
+
+namespace ws {
+namespace {
+
+// TODO(rjkroege): Remove this code once ozone oxygen has the same
+// display creation semantics as ozone drm.
+// Some ozone platforms do not configure physical displays and so do not
+// callback into this class via the implementation of NativeDisplayObserver.
+// FixedSizeScreenConfiguration() short-circuits the implementation of display
+// configuration in this case by calling the |callback| provided to
+// ConfigurePhysicalDisplay() with a hard-coded |id| and |bounds|.
+void FixedSizeScreenConfiguration(
+    const PlatformScreen::ConfiguredDisplayCallback& callback) {
+  callback.Run(1, gfx::Rect(1024, 768));
+}
+
+// The display subsystem calls |OnDisplayConfigured| for each display that has
+// been successfully configured. This in turn calls |callback_| with the
+// identity and bounds of each physical display.
+void OnDisplayConfigured(
+    const PlatformScreen::ConfiguredDisplayCallback& callback,
+    int64_t id,
+    const gfx::Rect& bounds,
+    bool success) {
+  if (success)
+    callback.Run(id, bounds);
+  else
+    LOG(FATAL) << "Failed to configure display at " << bounds.ToString();
+}
+
+}  // namespace
+
+// static
+std::unique_ptr<PlatformScreen> PlatformScreen::Create() {
+  return base::WrapUnique(new PlatformScreenImplOzone);
+}
+
+PlatformScreenImplOzone::PlatformScreenImplOzone() : weak_ptr_factory_(this) {}
+
+PlatformScreenImplOzone::~PlatformScreenImplOzone() {}
+
+void PlatformScreenImplOzone::Init() {
+  native_display_delegate_ =
+      ui::OzonePlatform::GetInstance()->CreateNativeDisplayDelegate();
+  native_display_delegate_->AddObserver(this);
+  native_display_delegate_->Initialize();
+}
+
+void PlatformScreenImplOzone::ConfigurePhysicalDisplay(
+    const PlatformScreen::ConfiguredDisplayCallback& callback) {
+  if (base::SysInfo::IsRunningOnChromeOS()) {
+    // Kick off the configuration of the physical displays comprising the
+    // |PlatformScreenImplOzone|
+
+    DCHECK(native_display_delegate_) << "DefaultDisplayManager::"
+                                        "OnConfigurationChanged requires a "
+                                        "native_display_delegate_ to work.";
+
+    native_display_delegate_->GrabServer();
+    native_display_delegate_->GetDisplays(
+        base::Bind(&PlatformScreenImplOzone::OnDisplaysAquired,
+                   weak_ptr_factory_.GetWeakPtr(), callback));
+
+  } else {
+    // PostTask()ed to maximize control flow similarity with the ChromeOS case.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&FixedSizeScreenConfiguration, callback));
+  }
+}
+
+void PlatformScreenImplOzone::OnConfigurationChanged() {}
+
+// The display subsystem calls |OnDisplaysAquired| to deliver |displays|
+// describing the attached displays.
+void PlatformScreenImplOzone::OnDisplaysAquired(
+    const ConfiguredDisplayCallback& callback,
+    const std::vector<ui::DisplaySnapshot*>& displays) {
+  DCHECK(native_display_delegate_) << "DefaultDisplayManager::"
+                                      "OnConfigurationChanged requires a "
+                                      "native_display_delegate_ to work.";
+  CHECK(displays.size() == 1) << "Mus only supports one 1 display\n";
+  gfx::Point origin;
+  for (auto display : displays) {
+    if (!display->native_mode()) {
+      LOG(ERROR) << "Display " << display->display_id()
+                 << " doesn't have a native mode";
+      continue;
+    }
+    // Setup each native display. This places a task on the DRM thread's
+    // runqueue that configures the window size correctly before the call to
+    // Configure.
+    native_display_delegate_->Configure(
+        *display, display->native_mode(), origin,
+        base::Bind(&OnDisplayConfigured, callback, display->display_id(),
+                   gfx::Rect(origin, display->native_mode()->size())));
+    origin.Offset(display->native_mode()->size().width(), 0);
+  }
+  native_display_delegate_->UngrabServer();

[sky, 2016/05/04 23:48:07]

If this is destroyed between ConfigurePhysicalDisplay and OnDisplaysAquired do
you need to UngrabServer?

[rjkroege, 2016/05/05 00:55:43]

Probably not. I should have removed the cals to Grab/Ungrab. Fixed.

+}
+
+}  // namespace ws
+}  // namespace mus