Always position the gaia dialog in the center of the screen.

We should re-position the dialog when tablet mode is changed, and when
display metrics is changed.

Bug: 841074, 837005
Change-Id: I11299070a947e2fc4f4f494d2bbac4c94c27746e
Reviewed-on: https://chromium-review.googlesource.com/1110487Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Xiaoyin Hu <xiaoyinh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569404}

chrome/browser/chromeos/login/ui/login_display_host_mojo.cc

@@ -254,7 +254,7 @@ void LoginDisplayHostMojo::UpdateGaiaDialogVisibility(
 
 void LoginDisplayHostMojo::UpdateGaiaDialogSize(int width, int height) {
   if (dialog_)
-    dialog_->SetSize(width, height);
+    dialog_->UpdateSizeAndPosition(width, height);
 }
 
 const user_manager::UserList LoginDisplayHostMojo::GetUsers() {

chrome/browser/chromeos/login/ui/oobe_ui_dialog_delegate.cc

@@ -9,6 +9,7 @@
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
 #include "chrome/browser/ui/ash/ash_util.h"
+#include "chrome/browser/ui/ash/tablet_mode_client.h"
 #include "chrome/browser/ui/webui/chrome_web_contents_handler.h"
 #include "chrome/browser/ui/webui/chromeos/login/oobe_ui.h"
 #include "content/public/browser/web_contents.h"
@@ -31,7 +32,12 @@ constexpr int kGaiaDialogWidth = 768;
 OobeUIDialogDelegate::OobeUIDialogDelegate(
     base::WeakPtr<LoginDisplayHostMojo> controller)
     : controller_(controller),
-      size_(gfx::Size(kGaiaDialogWidth, kGaiaDialogHeight)) {}
+      size_(gfx::Size(kGaiaDialogWidth, kGaiaDialogHeight)),
+      display_observer_(this),
+      tablet_mode_observer_(this) {
+  display_observer_.Add(display::Screen::GetScreen());
+  tablet_mode_observer_.Add(TabletModeClient::Get());
+}
 
 OobeUIDialogDelegate::~OobeUIDialogDelegate() {
   if (controller_)
@@ -71,7 +77,7 @@ void OobeUIDialogDelegate::Show(bool closable_by_esc) {
 void OobeUIDialogDelegate::ShowFullScreen() {
   const gfx::Size& size =
       display::Screen::GetScreen()->GetPrimaryDisplay().size();
-  SetSize(size.width(), size.height());
+  UpdateSizeAndPosition(size.width(), size.height());
   Show(false /*closable_by_esc*/);
 }
 
@@ -85,10 +91,7 @@ void OobeUIDialogDelegate::Close() {
     dialog_widget_->Close();
 }
 
-void OobeUIDialogDelegate::SetSize(int width, int height) {
-  if (size_ == gfx::Size(width, height))
-    return;
-
+void OobeUIDialogDelegate::UpdateSizeAndPosition(int width, int height) {
   size_.SetSize(width, height);
   if (!dialog_widget_)
     return;
@@ -118,6 +121,26 @@ gfx::NativeWindow OobeUIDialogDelegate::GetNativeWindow() const {
   return dialog_widget_ ? dialog_widget_->GetNativeWindow() : nullptr;
 }
 
+void OobeUIDialogDelegate::OnDisplayMetricsChanged(
+    const display::Display& display,
+    uint32_t changed_metrics) {
+  if (!dialog_widget_)
+    return;
+
+  const display::Display this_display =
+      display::Screen::GetScreen()->GetDisplayNearestWindow(
+          dialog_widget_->GetNativeWindow());
+  if (this_display.id() == display.id())
+    UpdateSizeAndPosition(size_.width(), size_.height());
+}
+
+void OobeUIDialogDelegate::OnTabletModeToggled(bool enabled) {
+  if (!dialog_widget_)
+    return;
+
+  UpdateSizeAndPosition(size_.width(), size_.height());
+}
+
 ui::ModalType OobeUIDialogDelegate::GetDialogModalType() const {
   return ui::MODAL_TYPE_SYSTEM;
 }

chrome/browser/chromeos/login/ui/oobe_ui_dialog_delegate.h

@@ -9,13 +9,22 @@
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
 #include "base/strings/string16.h"
+#include "chrome/browser/ui/ash/tablet_mode_client_observer.h"
+#include "ui/display/display_observer.h"
 #include "ui/web_dialogs/web_dialog_delegate.h"
 
+class TabletModeClient;
+
 namespace content {
 class WebContents;
 }
 
+namespace display {
+class Screen;
+}
+
 namespace ui {
 class Accelerator;
 }
@@ -37,7 +46,9 @@ class OobeUI;
 //         |
 //         V
 //   clientView---->Widget's view hierarchy
-class OobeUIDialogDelegate : public ui::WebDialogDelegate {
+class OobeUIDialogDelegate : public display::DisplayObserver,
+                             public TabletModeClientObserver,
+                             public ui::WebDialogDelegate {
  public:
   explicit OobeUIDialogDelegate(base::WeakPtr<LoginDisplayHostMojo> controller);
   ~OobeUIDialogDelegate() override;
@@ -61,11 +72,17 @@ class OobeUIDialogDelegate : public ui::WebDialogDelegate {
 
   content::WebContents* GetWebContents();
 
-  void SetSize(int width, int height);
+  void UpdateSizeAndPosition(int width, int height);
   OobeUI* GetOobeUI() const;
   gfx::NativeWindow GetNativeWindow() const;
 
  private:
+  // display::DisplayObserver:
+  void OnDisplayMetricsChanged(const display::Display& display,
+                               uint32_t changed_metrics) override;
+  // TabletModeClientObserver:
+  void OnTabletModeToggled(bool enabled) override;
+
   // ui::WebDialogDelegate:
   ui::ModalType GetDialogModalType() const override;
   base::string16 GetDialogTitle() const override;
@@ -93,6 +110,10 @@ class OobeUIDialogDelegate : public ui::WebDialogDelegate {
   gfx::Size size_;
   bool closable_by_esc_ = true;
 
+  ScopedObserver<display::Screen, display::DisplayObserver> display_observer_;
+  ScopedObserver<TabletModeClient, TabletModeClientObserver>
+      tablet_mode_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(OobeUIDialogDelegate);
 };
 

ui/login/display_manager.js

@@ -786,7 +786,9 @@ cr.define('cr.ui.login', function() {
       if (this.showingViewsLogin) {
         chrome.send('updateGaiaDialogSize', [width, height]);
         $('scroll-container').classList.toggle('disable-scroll', true);
-        $('scroll-container').scrollTop = $('inner-container').offsetTop;
+        $('inner-container').classList.toggle('disable-scroll', true);
+        $('inner-container').style.top =
+            cr.ui.toCssPx($('scroll-container').scrollTop);
       }
     },