Make code path for bounds changes getting to renderer less brittle

content/browser/web_contents/web_contents_view_aura.cc

Index: content/browser/web_contents/web_contents_view_aura.cc
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index 3f520db8d6efc07e5558fa6a1d2e21adfa794c28..4a824c76a7ef7bdf916efd9523804c978ed3a0e8 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -4,6 +4,8 @@
 
 #include "content/browser/web_contents/web_contents_view_aura.h"
 
+#include <algorithm>
+
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ -43,9 +45,7 @@
 #include "ui/aura/client/window_tree_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
-#include "ui/aura/root_window_observer.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_observer.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/custom_data_helper.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
@@ -417,6 +417,111 @@ class ImageLayerDelegate : public ui::LayerDelegate {
 
 }  // namespace
 
+WebContentsViewAuraWindowObserver::WebContentsViewAuraWindowObserver(
+    WebContentsViewAuraWindowObserverDelegate* delegate)
+    : delegate_(delegate) {
+  DCHECK(delegate);
+  delegate_->AddDelegateWindowObserver(this);
+  std::set<aura::Window*> ancestors = GenerateAncestors(
+      delegate_->GetDelegateWindow());
+  AddToObserved(ancestors);
+}
+
+WebContentsViewAuraWindowObserver::~WebContentsViewAuraWindowObserver() {
+  RemoveFromObserved(observed_);
+  delegate_->RemoveRootWindowObserver(this);
+  delegate_->RemoveDelegateWindowObserver(this);
+}
+
+void WebContentsViewAuraWindowObserver::OnWindowParentChanged(
+    aura::Window* window,
+    aura::Window* parent) {
+  std::set<aura::Window*> ancestors = GenerateAncestors(
+      delegate_->GetDelegateWindow());
+  std::set<aura::Window*> difference;
+  std::set_difference(
+      observed_.begin(),
+      observed_.end(),
+      ancestors.begin(),
+      ancestors.end(),
+      std::inserter(difference, difference.end()));
+  RemoveFromObserved(difference);
+
+  difference.clear();
+  std::set_difference(
+      ancestors.begin(),
+      ancestors.end(),
+      observed_.begin(),
+      observed_.end(),
+      std::inserter(difference, difference.end()));
+  AddToObserved(difference);
+}
+
+void WebContentsViewAuraWindowObserver::OnWindowBoundsChanged
+(aura::Window* window,
+ const gfx::Rect& old_bounds,
+ const gfx::Rect& new_bounds) {
+  delegate_->SendScreenRects();
+  delegate_->UpdateEditingController();
+}
+
+void WebContentsViewAuraWindowObserver::OnWindowAddedToRootWindow(
+    aura::Window* window) {
+  if (window == delegate_->GetDelegateWindow())
+    delegate_->AddRootWindowObserver(this);
+}
+
+void WebContentsViewAuraWindowObserver::OnWindowRemovingFromRootWindow(
+    aura::Window* window) {
+  if (window == delegate_->GetDelegateWindow())
+    delegate_->RemoveRootWindowObserver(this);
+}
+
+void WebContentsViewAuraWindowObserver::OnRootWindowHostMoved(
+    const aura::RootWindow* root,
+    const gfx::Point& new_origin) {
+  // This is for the desktop case (i.e. Aura desktop).
+  delegate_->SendScreenRects();
+}
+
+std::set<aura::Window*> WebContentsViewAuraWindowObserver::GenerateAncestors(
+    aura::Window* window) {
+  std::set<aura::Window*> ret_val;
+  while (window->parent()) {
+    ret_val.insert(window->parent());
+    window = window->parent();
+  }
+  return ret_val;
+}
+
+void WebContentsViewAuraWindowObserver::AddToObserved(
+    const std::set<aura::Window*>& windows) {
+  for (std::set<aura::Window*>::iterator iter = windows.begin();
+       iter != windows.end();
+       ++iter) {
+    if (observed_.end() == observed_.find(*iter)) {
+      (*iter)->AddObserver(this);
+      observed_.insert(*iter);
+    }
+  }
+}
+
+void WebContentsViewAuraWindowObserver::RemoveFromObserved(
+    const std::set<aura::Window*>& windows) {
+  // Since windows can possibly be observer_ we cannot blindly iterate and
+  // delete, since that breaks the iterators.
+  for (std::set<aura::Window*>::iterator iter = windows.begin();
+       iter != windows.end();) {
+    std::set<aura::Window*>::iterator next = iter;
+    next++;
+    if (observed_.end() != observed_.find(*iter)) {
+      (*iter)->RemoveObserver(this);
+      observed_.erase(*iter);
+    }
+    iter = next;
+  }
+}
+
 // When a history navigation is triggered at the end of an overscroll
 // navigation, it is necessary to show the history-screenshot until the page is
 // done navigating and painting. This class accomplishes this by showing the
@@ -648,75 +753,6 @@ class OverscrollNavigationOverlay :
   DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
 };
 
-class WebContentsViewAura::WindowObserver
-    : public aura::WindowObserver, public aura::RootWindowObserver {
- public:
-  explicit WindowObserver(WebContentsViewAura* view)
-      : view_(view),
-        parent_(NULL) {
-    view_->window_->AddObserver(this);
-  }
-
-  virtual ~WindowObserver() {
-    view_->window_->RemoveObserver(this);
-    if (view_->window_->GetDispatcher())
-      view_->window_->GetDispatcher()->RemoveRootWindowObserver(this);
-    if (parent_)
-      parent_->RemoveObserver(this);
-  }
-
-  // Overridden from aura::WindowObserver:
-  virtual void OnWindowParentChanged(aura::Window* window,
-                                     aura::Window* parent) OVERRIDE {
-    if (window == parent_)
-      return;
-    if (parent_)
-      parent_->RemoveObserver(this);
-    parent_ = parent;
-    if (parent)
-      parent->AddObserver(this);
-  }
-
-  virtual void OnWindowBoundsChanged(aura::Window* window,
-                                     const gfx::Rect& old_bounds,
-                                     const gfx::Rect& new_bounds) OVERRIDE {
-    SendScreenRects();
-    if (view_->touch_editable_)
-      view_->touch_editable_->UpdateEditingController();
-  }
-
-  virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE {
-    if (window != parent_)
-      window->GetDispatcher()->AddRootWindowObserver(this);
-  }
-
-  virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
-    if (window != parent_)
-      window->GetDispatcher()->RemoveRootWindowObserver(this);
-  }
-
-  // Overridden RootWindowObserver:
-  virtual void OnRootWindowHostMoved(const aura::RootWindow* root,
-                                     const gfx::Point& new_origin) OVERRIDE {
-    // This is for the desktop case (i.e. Aura desktop).
-    SendScreenRects();
-  }
-
- private:
-  void SendScreenRects() {
-    RenderWidgetHostImpl::From(view_->web_contents_->GetRenderViewHost())->
-        SendScreenRects();
-  }
-
-  WebContentsViewAura* view_;
-
-  // We cache the old parent so that we can unregister when it's not the parent
-  // anymore.
-  aura::Window* parent_;
-
-  DISALLOW_COPY_AND_ASSIGN(WindowObserver);
-};
-
 #if defined(OS_WIN)
 // Constrained windows are added as children of the WebContent's view which may
 // overlap with windowed NPAPI plugins. In that case, tell the RWHV so that it
@@ -1164,7 +1200,7 @@ void WebContentsViewAura::CreateView(
   window_->layer()->SetMasksToBounds(true);
   window_->SetName("WebContentsViewAura");
 
-  window_observer_.reset(new WindowObserver(this));
+  window_observer_.reset(new WebContentsViewAuraWindowObserver(this));

[sadrul, 2013/11/06 20:24:06]

I was thinking of something more like a NativeViewScreenBoundsObserver. So,

  NativeViewSreenBoundsObserver:
    NativeViewScreenBoundsObserver(WebContentsView*)

    void OnScreenPositionChanged();
    void OnScreenBoundsChanged();

The NVSBO installs itself as a WindowObserver to the WCV::window_ and its
ancestor windows, and calls into OnScreenPositionChanged/OnScreenBoundsChanged
from the relevant callbacks. OnScreenPoisitionChanged() calls into
SendScreenRects(), and OnScreenBoundsChanged() calls into both SendScreenRects()
and touch-editable.

This NVSBO can live in web_contents/aura/, with its own _unittest.cc

WCVA simply creates this NVSBO here, and does not need to care about anything
else (so no delegate implementation etc.).

 #if defined(OS_WIN)
   child_window_observer_.reset(new ChildWindowObserver(this));
 #endif
@@ -1652,4 +1688,43 @@ int WebContentsViewAura::OnPerformDrop(const ui::DropTargetEvent& event) {
   return current_drag_op_;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// WebContentsViewAura, WebContentsViewAuraWindowObserverDelgate implementation:
+
+aura::Window* WebContentsViewAura::GetDelegateWindow() {
+  return window_.get();
+}
+
+void WebContentsViewAura::AddDelegateWindowObserver(
+    aura::WindowObserver* observer) {
+  window_->AddObserver(observer);
+}
+
+void WebContentsViewAura::RemoveDelegateWindowObserver(
+    aura::WindowObserver* observer) {
+    window_->RemoveObserver(observer);
+}
+
+void WebContentsViewAura::RemoveRootWindowObserver(
+    aura::RootWindowObserver* observer) {
+  if (window_->GetDispatcher())
+    window_->GetDispatcher()->RemoveRootWindowObserver(observer);
+}
+
+void WebContentsViewAura::AddRootWindowObserver(
+    aura::RootWindowObserver* observer) {
+  if (window_->GetDispatcher())
+    window_->GetDispatcher()->AddRootWindowObserver(observer);
+}
+
+void WebContentsViewAura::UpdateEditingController() {
+  if (touch_editable_)
+    touch_editable_->UpdateEditingController();
+}
+
+void WebContentsViewAura::SendScreenRects() {
+  RenderWidgetHostImpl::From(web_contents_->GetRenderViewHost())->
+      SendScreenRects();
+}
+
 }  // namespace content