Preview CL for adding an Infobar facility to Google Chrome Frame....

chrome_frame/infobars/internal/host_window.cc

+// Copyright (c) 2010 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 "chrome_frame/infobars/internal/host_window.h"
+
+#include "chrome_frame/infobars/internal/displaced_window.h"
+
+namespace {
+
+const wchar_t kIeTabContentParentWindowClass[] = L"Shell DocObject View";
+
+}  // namespace
+
+// Receives notification when the displaced window is destroyed, and forwards
+// displaced window dimensions on to HostWindowManager::Delegate.
+class HostWindowManager::DisplacedWindowDelegate
+    : public DisplacedWindowManager::Delegate {
+ public:
+  explicit DisplacedWindowDelegate(HostWindowManager* manager);
+  virtual ~DisplacedWindowDelegate();
+
+  // DisplacedWindowManager::Delegate implementation
+  virtual void AdjustDisplacedWindowDimensions(RECT* rect);
+
+ private:
+  HostWindowManager* manager_;  // Not owned by this instance
+  DISALLOW_COPY_AND_ASSIGN(DisplacedWindowDelegate);
+};  // class HostWindowManager::DisplacedWindowDelegate
+
+HostWindowManager::DisplacedWindowDelegate::DisplacedWindowDelegate(
+    HostWindowManager* manager) : manager_(manager) {
+}
+
+// Called when the displaced window is destroyed. Try to find a new displaced
+// window.
+HostWindowManager::DisplacedWindowDelegate::~DisplacedWindowDelegate() {
+  HWND old_window = *manager_->displaced_window_manager_;
+  // Will be deleted in its OnFinalMessage
+  manager_->displaced_window_manager_ = NULL;
+
+  // Check to see if a new window has already been created.
+  if (manager_->FindDisplacedWindow(old_window))
+    manager_->UpdateLayout();
+}
+
+// Forward this on to our delegate
+void HostWindowManager::DisplacedWindowDelegate::
+    AdjustDisplacedWindowDimensions(RECT* rect) {
+  manager_->delegate()->AdjustDisplacedWindowDimensions(rect);
+}
+
+// Callback function for EnumChildWindows (looks for a window with class
+// kIeTabContentParentWindowClass).
+//
+// lparam must point to an HWND that is either NULL or the HWND of the displaced
+// window that is being destroyed. We will ignore that window if we come across
+// it, and update lparam to point to the new displaced window if it is found.
+static BOOL CALLBACK FindDisplacedWindowProc(HWND hwnd, LPARAM lparam) {
+  DCHECK(lparam != NULL);
+  HWND* window_handle = reinterpret_cast<HWND*>(lparam);
+
+  if (hwnd == *window_handle)
+    return TRUE;  // Skip this, it's the old displaced window.
+
+  // Variable to hold the class name. The size does not matter as long as it
+  // is at least can hold kIeTabContentParentWindowClass.
+  wchar_t class_name[100];
+  if (::GetClassName(hwnd, class_name, arraysize(class_name)) &&
+      lstrcmpi(kIeTabContentParentWindowClass, class_name) == 0) {
+    // We found the window. Return its handle and stop enumeration.
+    *window_handle = hwnd;
+    return FALSE;
+  }
+  return TRUE;
+}
+
+HostWindowManager::HostWindowManager() : displaced_window_manager_(NULL) {
+}
+
+HostWindowManager::~HostWindowManager() {
+  // If we are holding a displaced_window_manager_, it means that
+  // OnDisplacedWindowManagerDestroyed has not been called yet, and therefore
+  // our DisplacedWindowDelegate might still be around, ready to invoke us.
+  // Fail fast to prevent a call into lala-land.
+  CHECK(displaced_window_manager_ == NULL);
+}
+
+void HostWindowManager::UpdateLayout() {
+  if (FindDisplacedWindow(NULL))
+    displaced_window_manager_->UpdateLayout();
+}
+
+bool HostWindowManager::FindDisplacedWindow(HWND old_window) {
+  if (displaced_window_manager_ == NULL ||
+      *displaced_window_manager_ == old_window) {
+    // Find the window which is the container for the HTML view (parent of
+    // the content). When the displaced window is destroyed, the new one might
+    // already exist, so we say "find a displaced window that is not this
+    // (old) one".
+    HWND displaced_window = old_window;
+    ::EnumChildWindows(*this, FindDisplacedWindowProc,
+                       reinterpret_cast<LPARAM>(&displaced_window));
+
+    if (displaced_window == old_window) {
+      LOG(ERROR) << "Failed to locate IE renderer HWND to displace for "
+                 << "Infobar installation.";
+    } else {
+      scoped_ptr<DisplacedWindowManager> displaced_window_manager(
+          new DisplacedWindowManager());
+      if (displaced_window_manager->Initialize(
+              displaced_window, new DisplacedWindowDelegate(this))) {
+        displaced_window_manager_ = displaced_window_manager.release();
+      }
+    }
+  }
+
+  return displaced_window_manager_ != NULL;
+}