chrome_frame/infobars/internal/host_window_manager.cc

   1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome_frame/infobars/internal/host_window_manager.h"
   6
   7 #include "chrome_frame/infobars/internal/displaced_window_manager.h"
   8
   9 namespace {
  10
  11 const wchar_t kIeTabContentParentWindowClass[] = L"Shell DocObject View";
  12
  13 }  // namespace
  14
  15 // Receives notification when the displaced window is destroyed, and forwards
  16 // displaced window dimensions on to HostWindowManager::Delegate.
  17 class HostWindowManager::DisplacedWindowDelegate
  18     : public DisplacedWindowManager::Delegate {
  19  public:
  20   explicit DisplacedWindowDelegate(HostWindowManager* manager);
  21   virtual ~DisplacedWindowDelegate();
  22
  23   // DisplacedWindowManager::Delegate implementation
  24   virtual void AdjustDisplacedWindowDimensions(RECT* rect);
  25
  26  private:
  27   HostWindowManager* manager_;  // Not owned by this instance
  28   DISALLOW_COPY_AND_ASSIGN(DisplacedWindowDelegate);
  29 };  // class HostWindowManager::DisplacedWindowDelegate
  30
  31 HostWindowManager::DisplacedWindowDelegate::DisplacedWindowDelegate(
  32     HostWindowManager* manager) : manager_(manager) {
  33 }
  34
  35 // Called when the displaced window is destroyed. Try to find a new displaced
  36 // window.
  37 HostWindowManager::DisplacedWindowDelegate::~DisplacedWindowDelegate() {
  38   HWND old_window = *manager_->displaced_window_manager_;
  39   // Will be deleted in its OnFinalMessage
  40   manager_->displaced_window_manager_ = NULL;
  41
  42   // Check to see if a new window has already been created.
  43   if (manager_->FindDisplacedWindow(old_window))
  44     manager_->UpdateLayout();
  45 }
  46
  47 // Forward this on to our delegate
  48 void HostWindowManager::DisplacedWindowDelegate::
  49     AdjustDisplacedWindowDimensions(RECT* rect) {
  50   manager_->delegate()->AdjustDisplacedWindowDimensions(rect);
  51 }
  52
  53 // Callback function for EnumChildWindows (looks for a window with class
  54 // kIeTabContentParentWindowClass).
  55 //
  56 // lparam must point to an HWND that is either NULL or the HWND of the displaced
  57 // window that is being destroyed. We will ignore that window if we come across
  58 // it, and update lparam to point to the new displaced window if it is found.
  59 static BOOL CALLBACK FindDisplacedWindowProc(HWND hwnd, LPARAM lparam) {
  60   DCHECK(lparam != NULL);
  61   HWND* window_handle = reinterpret_cast<HWND*>(lparam);
  62
  63   if (hwnd == *window_handle)
  64     return TRUE;  // Skip this, it's the old displaced window.
  65
  66   // Variable to hold the class name. The size does not matter as long as it
  67   // is at least can hold kIeTabContentParentWindowClass.
  68   wchar_t class_name[100];
  69   if (::GetClassName(hwnd, class_name, arraysize(class_name)) &&
  70       lstrcmpi(kIeTabContentParentWindowClass, class_name) == 0) {
  71     // We found the window. Return its handle and stop enumeration.
  72     *window_handle = hwnd;
  73     return FALSE;
  74   }
  75   return TRUE;
  76 }
  77
  78 HostWindowManager::HostWindowManager() : displaced_window_manager_(NULL) {
  79 }
  80
  81 HostWindowManager::~HostWindowManager() {
  82   // If we are holding a displaced_window_manager_, it means that
  83   // OnDisplacedWindowManagerDestroyed has not been called yet, and therefore
  84   // our DisplacedWindowDelegate might still be around, ready to invoke us.
  85   // Fail fast to prevent a call into lala-land.
  86   CHECK(displaced_window_manager_ == NULL);
  87 }
  88
  89 void HostWindowManager::UpdateLayout() {
  90   if (FindDisplacedWindow(NULL))
  91     displaced_window_manager_->UpdateLayout();
  92 }
  93
  94 bool HostWindowManager::FindDisplacedWindow(HWND old_window) {
  95   if (displaced_window_manager_ == NULL ||
  96       *displaced_window_manager_ == old_window) {
  97     // Find the window which is the container for the HTML view (parent of
  98     // the content). When the displaced window is destroyed, the new one might
  99     // already exist, so we say "find a displaced window that is not this
 100     // (old) one".
 101     HWND displaced_window = old_window;
 102     ::EnumChildWindows(*this, FindDisplacedWindowProc,
 103                        reinterpret_cast<LPARAM>(&displaced_window));
 104
 105     if (displaced_window == old_window) {
 106       LOG(ERROR) << "Failed to locate IE renderer HWND to displace for "
 107                  << "Infobar installation.";
 108     } else {
 109       scoped_ptr<DisplacedWindowManager> displaced_window_manager(
 110           new DisplacedWindowManager());
 111       if (displaced_window_manager->Initialize(
 112               displaced_window, new DisplacedWindowDelegate(this))) {
 113         displaced_window_manager_ = displaced_window_manager.release();
 114       }
 115     }
 116   }
 117
 118   return displaced_window_manager_ != NULL;
 119 }