exo: Implement minimal support for version 6 of XDG shell.

components/exo/shell_surface.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/shell_surface.h"
 
 #include <algorithm>
 
 #include "ash/common/frame/custom_frame_view_ash.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 666 matching lines @@
   return value;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // SurfaceDelegate overrides:
 
 void ShellSurface::OnSurfaceCommit() {
   surface_->CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces();
   surface_->CommitSurfaceHierarchy();
 
-  if (enabled() && !widget_)
-    CreateShellSurfaceWidget(ui::SHOW_STATE_NORMAL);
+  if (enabled() && !widget_) {
+    // Defer widget creation until surface contains some contents.
+    if (surface_->content_size().IsEmpty())
+      Configure();
+    else
+      CreateShellSurfaceWidget(ui::SHOW_STATE_NORMAL);
+  }
 
   // Apply the accumulated pending origin offset to reflect acknowledged
   // configure requests.
   origin_ += pending_origin_offset_;
   pending_origin_offset_ = gfx::Vector2d();
 
   // Update resize direction to reflect acknowledged configure requests.
   resize_component_ = pending_resize_component_;
 
   if (widget_) {
@@ skipping 442 matching lines @@
   }
 
   // Receive accessibility changes to update shadow underlay.
   WMHelper::GetInstance()->AddAccessibilityObserver(this);
 
   // Show widget next time Commit() is called.
   pending_show_widget_ = true;
 }
 
 void ShellSurface::Configure() {
-  DCHECK(widget_);
-
   // Delay configure callback if |scoped_configure_| is set.
   if (scoped_configure_) {
     scoped_configure_->set_needs_configure();
     return;
   }
 
   gfx::Vector2d origin_offset = pending_origin_config_offset_;
   pending_origin_config_offset_ = gfx::Vector2d();
 
-  ash::wm::WindowState* window_state =
-      ash::wm::GetWindowState(widget_->GetNativeWindow());
+  int resize_component = HTCAPTION;
+  if (widget_) {
+    ash::wm::WindowState* window_state =
+        ash::wm::GetWindowState(widget_->GetNativeWindow());
 
-  // If surface is being resized, save the resize direction.
-  int resize_component = window_state->is_dragged()
-                             ? window_state->drag_details()->window_component
-                             : HTCAPTION;
+    // If surface is being resized, save the resize direction.
+    if (window_state->is_dragged())
+      resize_component = window_state->drag_details()->window_component;
+  }
 
   uint32_t serial = 0;
   if (!configure_callback_.is_null()) {
-    const views::NonClientView* non_client_view = widget_->non_client_view();
-    serial = configure_callback_.Run(
-        non_client_view->frame_view()->GetBoundsForClientView().size(),
-        ash::wm::GetWindowState(widget_->GetNativeWindow())->GetStateType(),
-        IsResizing(), widget_->IsActive());
+    if (widget_) {
+      const views::NonClientView* non_client_view = widget_->non_client_view();
+      serial = configure_callback_.Run(
+          non_client_view->frame_view()->GetBoundsForClientView().size(),
+          ash::wm::GetWindowState(widget_->GetNativeWindow())->GetStateType(),
+          IsResizing(), widget_->IsActive());
+    } else {
+      serial = configure_callback_.Run(
+          gfx::Size(), ash::wm::WINDOW_STATE_TYPE_NORMAL, false, false);
+    }
   }
 
   if (!serial) {
     pending_origin_offset_ += origin_offset;
     pending_resize_component_ = resize_component;
     return;
   }
 
   // Apply origin offset and resize component at the first Commit() after this
   // configure request has been acknowledged.
@@ skipping 320 matching lines @@
     // small style shadow for them.
     if (!activatable_)
       shadow->SetElevation(wm::ShadowElevation::SMALL);
     // We don't have rounded corners unless frame is enabled.
     if (!frame_enabled_)
       shadow->SetRoundedCornerRadius(0);
   }
 }
 
 }  // namespace exo