Switch primary display

ash/display/display_controller.cc

Index: ash/display/display_controller.cc
diff --git a/ash/display/display_controller.cc b/ash/display/display_controller.cc
index 11c76073eb2db87f056607ba0039c92537d0370f..0277844ecb24611875983d1c9e89957eb9ad9741 100644
--- a/ash/display/display_controller.cc
+++ b/ash/display/display_controller.cc
@@ -9,7 +9,6 @@
 #include "ash/ash_switches.h"
 #include "ash/display/multi_display_manager.h"
 #include "ash/root_window_controller.h"
-#include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/coordinate_conversion.h"
 #include "ash/wm/property_util.h"
@@ -17,6 +16,7 @@
 #include "base/command_line.h"
 #include "base/json/json_value_converter.h"
 #include "base/string_piece.h"
+#include "base/stringprintf.h"
 #include "base/values.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/env.h"
@@ -57,10 +57,28 @@ bool GetPositionFromString(const base::StringPiece& position,
     return true;
   }
   LOG(ERROR) << "Invalid position value: " << position;
-
   return false;
 }
 
+std::string GetStringFromPosition(DisplayLayout::Position position) {
+  switch (position) {
+    case DisplayLayout::TOP:
+      return std::string("top");
+    case DisplayLayout::BOTTOM:
+      return std::string("bottom");
+    case DisplayLayout::RIGHT:
+      return std::string("right");
+    case DisplayLayout::LEFT:
+      return std::string("left");
+  }
+  return std::string("unknown");
+}
+
+internal::MultiDisplayManager* GetDisplayManager() {
+  return static_cast<internal::MultiDisplayManager*>(
+      aura::Env::GetInstance()->display_manager());
+}
+
 }  // namespace
 
 DisplayLayout::DisplayLayout()
@@ -81,6 +99,25 @@ DisplayLayout::DisplayLayout(DisplayLayout::Position position, int offset)
   DCHECK_GE(kMaxValidOffset, abs(offset));
 }
 
+DisplayLayout DisplayLayout::Invert() const {
+  Position inverted_position = RIGHT;
+  switch (position) {
+    case TOP:
+      inverted_position = BOTTOM;
+      break;
+    case BOTTOM:
+      inverted_position = TOP;
+      break;
+    case RIGHT:
+      inverted_position = LEFT;
+      break;
+    case LEFT:
+      inverted_position = RIGHT;
+      break;
+  }
+  return DisplayLayout(inverted_position, -offset);
+}
+
 // static
 bool DisplayLayout::ConvertFromValue(const base::Value& value,
                                      DisplayLayout* layout) {
@@ -95,29 +132,17 @@ bool DisplayLayout::ConvertToValue(const DisplayLayout& layout,
   if (!value->GetAsDictionary(&dict_value) || dict_value == NULL)
     return false;
 
-  std::string position_value;
-  switch (layout.position) {
-    case TOP:
-      position_value = "top";
-      break;
-    case BOTTOM:
-      position_value = "bottom";
-      break;
-    case RIGHT:
-      position_value = "right";
-      break;
-    case LEFT:
-      position_value = "left";
-      break;
-    default:
-      return false;
-  }
-
-  dict_value->SetString("position", position_value);
+  const std::string position_str = GetStringFromPosition(layout.position);
+  dict_value->SetString("position", position_str);
   dict_value->SetInteger("offset", layout.offset);
   return true;
 }
 
+std::string DisplayLayout::ToString() const {
+  const std::string position_str = GetStringFromPosition(position);
+  return StringPrintf("%s, %d", position_str.c_str(), offset);
+}
+
 // static
 void DisplayLayout::RegisterJSONConverter(
     base::JSONValueConverter<DisplayLayout>* converter) {
@@ -127,11 +152,11 @@ void DisplayLayout::RegisterJSONConverter(
 }
 
 DisplayController::DisplayController() {
-  aura::Env::GetInstance()->display_manager()->AddObserver(this);
+  GetDisplayManager()->AddObserver(this);
 }
 
 DisplayController::~DisplayController() {
-  aura::Env::GetInstance()->display_manager()->RemoveObserver(this);
+  GetDisplayManager()->RemoveObserver(this);
   // Delete all root window controllers, which deletes root window
   // from the last so that the primary root window gets deleted last.
   for (std::map<int64, aura::RootWindow*>::const_reverse_iterator it =
@@ -144,20 +169,40 @@ DisplayController::~DisplayController() {
 }
 
 void DisplayController::InitPrimaryDisplay() {
-  aura::DisplayManager* display_manager =
-      aura::Env::GetInstance()->display_manager();
-  const gfx::Display* display = display_manager->GetDisplayAt(0);
-  aura::RootWindow* root = AddRootWindowForDisplay(*display);
-  root->SetHostBounds(display->bounds_in_pixel());
+  const gfx::Display* primary_candidate = GetDisplayManager()->GetDisplayAt(0);
+#if defined(OS_CHROMEOS)
+  if (base::chromeos::IsRunningOnChromeOS()) {
+    internal::MultiDisplayManager* display_manager = GetDisplayManager();
+    // On ChromeOS device, root windows are stacked vertically, and
+    // default primary is the one on top.
+    int count = display_manager->GetNumDisplays();
+    int y = primary_candidate->bounds_in_pixel().y();
+    for (int i = 1; i < count; ++i) {
+      const gfx::Display* display = display_manager->GetDisplayAt(i);
+      if (display_manager->IsInternalDisplayId(display->id())) {
+        primary_candidate = display;
+        break;
+      } else if (display->bounds_in_pixel().y() < y) {
+        primary_candidate = display;
+        y = display->bounds_in_pixel().y();
+      }
+    }
+  }
+#endif
+  primary_display_ = *primary_candidate;
+  aura::RootWindow* root = AddRootWindowForDisplay(primary_display_);
+  root->SetHostBounds(primary_display_.bounds_in_pixel());
+  UpdateDisplayBoundsForLayout();
 }
 
 void DisplayController::InitSecondaryDisplays() {
-  aura::DisplayManager* display_manager =
-      aura::Env::GetInstance()->display_manager();
-  for (size_t i = 1; i < display_manager->GetNumDisplays(); ++i) {
+  internal::MultiDisplayManager* display_manager = GetDisplayManager();
+  for (size_t i = 0; i < display_manager->GetNumDisplays(); ++i) {
     const gfx::Display* display = display_manager->GetDisplayAt(i);
-    aura::RootWindow* root = AddRootWindowForDisplay(*display);
-    Shell::GetInstance()->InitRootWindowForSecondaryDisplay(root);
+    if (primary_display_.id() != display->id()) {
+      aura::RootWindow* root = AddRootWindowForDisplay(*display);
+      Shell::GetInstance()->InitRootWindowForSecondaryDisplay(root);
+    }
   }
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kAshSecondaryDisplayLayout)) {
@@ -190,9 +235,7 @@ void DisplayController::RemoveObserver(Observer* observer) {
 
 aura::RootWindow* DisplayController::GetPrimaryRootWindow() {
   DCHECK(!root_windows_.empty());
-  aura::DisplayManager* display_manager =
-      aura::Env::GetInstance()->display_manager();
-  return root_windows_[display_manager->GetDisplayAt(0)->id()];
+  return root_windows_[primary_display_.id()];
 }
 
 aura::RootWindow* DisplayController::GetRootWindowForDisplayId(int64 id) {
@@ -260,8 +303,9 @@ void DisplayController::SetLayoutForDisplayName(const std::string& name,
   }
 }
 
-const DisplayLayout& DisplayController::GetLayoutForDisplayName(
-    const std::string& name) {
+const DisplayLayout& DisplayController::GetLayoutForDisplay(
+    const gfx::Display& display) const {
+  const std::string& name = GetDisplayManager()->GetDisplayNameFor(display);
   std::map<std::string, DisplayLayout>::const_iterator it =
       secondary_layouts_.find(name);
 
@@ -270,10 +314,84 @@ const DisplayLayout& DisplayController::GetLayoutForDisplayName(
   return default_display_layout_;
 }
 
+const DisplayLayout& DisplayController::GetCurrentDisplayLayout() const {
+  DCHECK_EQ(2U, GetDisplayManager()->GetNumDisplays());
+  if (GetDisplayManager()->GetNumDisplays() > 1) {
+    DisplayController* non_const = const_cast<DisplayController*>(this);
+    return GetLayoutForDisplay(*(non_const->GetSecondaryDisplay()));
+  }
+  // On release build, just fallback to default instead of blowing up.
+  return default_display_layout_;
+}
+
+void DisplayController::SetPrimaryDisplay(
+    const gfx::Display& new_primary_display) {
+  internal::MultiDisplayManager* display_manager = GetDisplayManager();
+  DCHECK(new_primary_display.is_valid());
+  DCHECK(display_manager->IsActiveDisplay(new_primary_display));
+
+  if (!new_primary_display.is_valid() ||
+      !display_manager->IsActiveDisplay(new_primary_display)) {
+    LOG(ERROR) << "Invalid or non-existent display is requested:"
+               << new_primary_display.ToString();
+    return;
+  }
+
+  if (primary_display_.id() == new_primary_display.id() ||
+      root_windows_.size() < 2) {
+    return;
+  }
+
+  aura::RootWindow* non_primary_root = root_windows_[new_primary_display.id()];
+  LOG_IF(ERROR, !non_primary_root)
+      << "Unknown display is requested in SetPrimaryDisplay: id="
+      << new_primary_display.id();
+  if (!non_primary_root)
+    return;
+
+  gfx::Display old_primary_display = primary_display_;
+
+  // Swap root windows between current and new primary display.
+  aura::RootWindow* primary_root = root_windows_[primary_display_.id()];
+  DCHECK(primary_root);
+  DCHECK_NE(primary_root, non_primary_root);
+
+  root_windows_[new_primary_display.id()] = primary_root;
+  primary_root->SetProperty(internal::kDisplayIdKey, new_primary_display.id());
+
+  root_windows_[old_primary_display.id()] = non_primary_root;
+  non_primary_root->SetProperty(internal::kDisplayIdKey,
+                                old_primary_display.id());
+
+  primary_display_ = new_primary_display;
+
+  // Update the layout.
+  SetLayoutForDisplayName(
+      display_manager->GetDisplayNameFor(old_primary_display),
+      GetLayoutForDisplay(new_primary_display).Invert());
+
+  // Update the dispay manager with new display info.
+  std::vector<gfx::Display> displays;
+  displays.push_back(primary_display_);
+  displays.push_back(*GetSecondaryDisplay());
+  GetDisplayManager()->set_force_bounds_changed(true);
+  GetDisplayManager()->OnNativeDisplaysChanged(displays);
+  GetDisplayManager()->set_force_bounds_changed(false);
+}
+
+gfx::Display* DisplayController::GetSecondaryDisplay() {
+  internal::MultiDisplayManager* display_manager = GetDisplayManager();
+  CHECK_EQ(2U, display_manager->GetNumDisplays());
+  return display_manager->GetDisplayAt(0)->id() == primary_display_.id() ?
+      display_manager->GetDisplayAt(1) : display_manager->GetDisplayAt(0);
+}
+
 void DisplayController::OnDisplayBoundsChanged(const gfx::Display& display) {
+  if (display.id() == primary_display_.id())
+    primary_display_ = display;
   NotifyDisplayConfigurationChanging();
-  root_windows_[display.id()]->SetHostBounds(display.bounds_in_pixel());
   UpdateDisplayBoundsForLayout();
+  root_windows_[display.id()]->SetHostBounds(display.bounds_in_pixel());
 }
 
 void DisplayController::OnDisplayAdded(const gfx::Display& display) {
@@ -285,30 +403,45 @@ void DisplayController::OnDisplayAdded(const gfx::Display& display) {
 }
 
 void DisplayController::OnDisplayRemoved(const gfx::Display& display) {
-  aura::RootWindow* root = root_windows_[display.id()];
-  DCHECK(root);
-  // Primary display should never be removed by DisplayManager.
-  DCHECK(root != GetPrimaryRootWindow());
+  aura::RootWindow* root_to_delete = root_windows_[display.id()];
+  DCHECK(root_to_delete) << display.ToString();
   NotifyDisplayConfigurationChanging();
+
   // Display for root window will be deleted when the Primary RootWindow
   // is deleted by the Shell.
-  if (root != GetPrimaryRootWindow()) {
-    root_windows_.erase(display.id());
-    internal::RootWindowController* controller =
-        GetRootWindowController(root);
-    DCHECK(controller);
-    controller->MoveWindowsTo(GetPrimaryRootWindow());
-    // Delete most of root window related objects, but don't delete
-    // root window itself yet because the stak may be using it.
-    controller->Shutdown();
-    MessageLoop::current()->DeleteSoon(FROM_HERE, controller);
+  root_windows_.erase(display.id());
+
+  // When the primary root window's display is removed, move the primary
+  // root to the other display.
+  if (primary_display_.id() == display.id()) {
+    DCHECK_EQ(1U, root_windows_.size());
+    primary_display_ = *GetSecondaryDisplay();
+    aura::RootWindow* primary_root = root_to_delete;
+
+    // Delete the other root instead.
+    root_to_delete = root_windows_[primary_display_.id()];
+    root_to_delete->SetProperty(internal::kDisplayIdKey, display.id());
+
+    // Setup primary root.
+    root_windows_[primary_display_.id()] = primary_root;
+    primary_root->SetProperty(internal::kDisplayIdKey, primary_display_.id());
+
+    OnDisplayBoundsChanged(primary_display_);
   }
+  internal::RootWindowController* controller =
+      GetRootWindowController(root_to_delete);
+  DCHECK(controller);
+  controller->MoveWindowsTo(GetPrimaryRootWindow());
+  // Delete most of root window related objects, but don't delete
+  // root window itself yet because the stak may be using it.
+  controller->Shutdown();
+  MessageLoop::current()->DeleteSoon(FROM_HERE, controller);
 }
 
 aura::RootWindow* DisplayController::AddRootWindowForDisplay(
     const gfx::Display& display) {
-  aura::RootWindow* root = aura::Env::GetInstance()->display_manager()->
-      CreateRootWindowForDisplay(display);
+  aura::RootWindow* root =
+      GetDisplayManager()->CreateRootWindowForDisplay(display);
   root_windows_[display.id()] = root;
 
 #if defined(OS_CHROMEOS)
@@ -326,25 +459,18 @@ void DisplayController::UpdateDisplayBoundsForLayout() {
     return;
 
   DCHECK_EQ(2, gfx::Screen::GetNumDisplays());
-  aura::DisplayManager* display_manager =
-      aura::Env::GetInstance()->display_manager();
-  const gfx::Rect& primary_bounds = display_manager->GetDisplayAt(0)->bounds();
-  gfx::Display* secondary_display = display_manager->GetDisplayAt(1);
-  const std::string& secondary_name = display_manager->GetDisplayNameAt(1);
+  const gfx::Rect& primary_bounds = primary_display_.bounds();
+
+  gfx::Display* secondary_display = GetSecondaryDisplay();
   const gfx::Rect& secondary_bounds = secondary_display->bounds();
   gfx::Point new_secondary_origin = primary_bounds.origin();
 
-  const DisplayLayout* layout = &default_display_layout_;
-  std::map<std::string, DisplayLayout>::const_iterator iter =
-      secondary_layouts_.find(secondary_name);
-  if (iter != secondary_layouts_.end())
-    layout = &iter->second;
-
-  DisplayLayout::Position position = layout->position;
+  const DisplayLayout& layout = GetLayoutForDisplay(*secondary_display);
+  DisplayLayout::Position position = layout.position;
 
   // Ignore the offset in case the secondary display doesn't share edges with
   // the primary display.
-  int offset = layout->offset;
+  int offset = layout.offset;
   if (position == DisplayLayout::TOP || position == DisplayLayout::BOTTOM) {
     offset = std::min(
         offset, primary_bounds.width() - kMinimumOverlapForInvalidOffset);