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

chrome_frame/infobar_manager.cc

Index: chrome_frame/infobar_manager.cc
===================================================================
--- chrome_frame/infobar_manager.cc	(revision 0)
+++ chrome_frame/infobar_manager.cc	(revision 0)
@@ -0,0 +1,268 @@
+// 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.
+//
+// Implementation of the manager for infobar windows.
+
+#include "chrome_frame/infobar_manager.h"
+
+#include <atlbase.h>
+#include <atlapp.h>  // Must be included AFTER base.
+#include <atlcrack.h>
+#include <atlmisc.h>
+#include <atlwin.h>
+
+#include "base/logging.h"
+#include "base/task_queue.h"
+//#include "ceee/common/windows_constants.h"
+#include "chrome_frame/utils.h"
+
+namespace {
+
+const wchar_t kIeTabContentParentWindowClass[] = L"Shell DocObject View";
+
+}  // namespace
+
+DISABLE_RUNNABLE_METHOD_REFCOUNT(InfobarManager);
+DISABLE_RUNNABLE_METHOD_REFCOUNT(InfobarManager::DisplacedWindowManager);
+
+
+InfobarManager::InfobarHostImpl::InfobarHostImpl(InfobarManager *manager)
+    : manager_(manager) {
+}
+
+HWND InfobarManager::InfobarHostImpl::GetContainerWindow() {
+  return manager_->container_window_;
+}
+
+void InfobarManager::InfobarHostImpl::UpdateLayout() {
+  manager_->UpdateLayout();
+}
+
+// DisplacedWindowManager subclasses IE content window's container window,
+// handles WM_NCCALCSIZE to resize its client area. It also handles WM_SIZE and
+// WM_MOVE messages to make infobars consistent with IE content window's size
+// and position.
+//
+// Finally, allows delayed tasks to be scheduled on the window's event loop.
+class InfobarManager::DisplacedWindowManager
+    : public CWindowImpl<DisplacedWindowManager> {
+ public:
+  DisplacedWindowManager(InfobarManager* manager)
+      : infobar_manager_(manager) {
+  }
+
+  // Returns true if the window is successfully subclassed, in which case this
+  // instance will take responsibility for its own destruction when the window
+  // is destroyed. If this method returns false, the caller should delete the
+  // instance immediately.
+  bool Initialize(HWND displaced_hwnd) {
+    PinModule();
+    if (!SubclassWindow(displaced_hwnd)) {
+      LOG(DFATAL) << "Failed to subclass IE Renderer HWND for infobar "
+                  << "installation.";
+      return false;
+    }
+    return true;
+  }
+
+  virtual ~DisplacedWindowManager() {
+    if (IsWindow())
+      UnsubclassWindow();
+  }
+
+  // Triggers a deferred re-evaluation of the dimensions of the displaced
+  // window. InfobarManager::AdjustDisplacedWindowDimensions will be called
+  // with the natural dimensions of the displaced window.
+  virtual void UpdateLayout() {
+    PushTask(
+        NewRunnableMethod(this, &DisplacedWindowManager::DoUpdateLayout));
+  }
+
+  // Schedules a deferred task on the window message loop of this instance's
+  // managed window. The task may not occur if the window is destroyed first.
+  virtual void PushTask(Task* task) {
+    task_queue_.Push(task);
+    if (IsWindow())
+      PostMessage(TM_RUN_TASK_QUEUE, 0, 0);
+  }
+
+  BEGIN_MSG_MAP_EX(DisplacedWindowManager)
+    MSG_WM_NCCALCSIZE(OnNcCalcSize)
+    MSG_WM_DESTROY(OnDestroy)
+    MESSAGE_HANDLER(TM_RUN_TASK_QUEUE, OnRunTaskQueue)
+  END_MSG_MAP()
+
+ private:
+  enum DisplacedWindowUserMessages {
+    TM_RUN_TASK_QUEUE = WM_USER + 600,
+  };
+
+  LRESULT OnRunTaskQueue(UINT message,
+                         WPARAM wparam,
+                         LPARAM lparam,
+                         BOOL& handled) {
+    task_queue_.Run();
+    handled = TRUE;
+    return 0;
+  }
+
+  void DoUpdateLayout() {
+    // Call SetWindowPos with SWP_FRAMECHANGED for IE window, then IE
+    // window would receive WM_NCCALCSIZE to recalculate its client size.
+    if (IsWindow())
+      ::SetWindowPos(m_hWnd,
+                     NULL, 0, 0, 0, 0,
+                     SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER |
+                     SWP_FRAMECHANGED);
+  }
+
+  // Handles WM_NCCALCSIZE message.
+  LRESULT OnNcCalcSize(BOOL calc_valid_rects, LPARAM lparam) {
+    // Adjust client area for infobar.
+    LRESULT ret = DefWindowProc(WM_NCCALCSIZE,
+                                static_cast<WPARAM>(calc_valid_rects), lparam);
+    // Whether calc_valid_rects is true or false, we could treat beginning of
+    // lparam as a RECT object.
+    RECT* rect = reinterpret_cast<RECT*>(lparam);
+    if (infobar_manager_ != NULL)
+      infobar_manager_->AdjustDisplacedWindowDimensions(rect);
+
+    // If infobars reserve all the space and rect becomes empty, the container
+    // window won't receive subsequent WM_SIZE and WM_MOVE messages.
+    // In this case, we have to explicitly notify infobars to update their
+    // position.
+    //if (rect->right - rect->left <= 0 || rect->bottom - rect->top <= 0)
+    //  PushTask(
+    //      NewRunnableMethod(infobar_manager_,
+    //                        &InfobarManager::OnDisplacedWindowPositionChange));
+    return ret;
+  }
+
+  // The displaced window has been destroyed. Inform the InfobarManager, who
+  // will orphan this instance. We will delete ourselves in OnFinalMessage.
+  void OnDestroy() {
+    infobar_manager_->OnDisplacedWindowDestroyed();
+  }
+
+  void OnFinalMessage(HWND) {
+    delete this;
+  }
+
+  InfobarManager* infobar_manager_;
+  TaskQueue task_queue_;
+  DISALLOW_COPY_AND_ASSIGN(DisplacedWindowManager);
+};
+
+InfobarManager::InfobarManager(HWND tab_window)
+    : container_window_(tab_window),
+      displaced_window_manager_(NULL),
+      infobar_host_impl_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  for (int index = 0; index < END_OF_INFOBAR_TYPE; ++index) {

[amit, 2010/11/12 00:04:49]

Feels like an overkill for our rudimentary infobar requirements.  We can
probably do away with the manager class and fold necessary 'manager'
functionality into a INFOBAR_TOP style infobar.

[erikwright (departed), 2010/11/24 06:24:56]

The TOP vs BOTTOM and sliding is unnecessary, but also not the tricky bit. I
prefer to keep it so that my implementation can easily replace the CEEE one. The
hard bit is the window lifecycle. For that, I don't think there is a working,
testable, and comprehensible solution that can be wrapped into a single-file /
single-class implementation.

+    infobars_[index].reset(
+        new InfobarWindow(static_cast<InfobarType>(index),
+                          &infobar_host_impl_));
+  }
+}
+
+HRESULT InfobarManager::Show(InfobarContent* content,
+                             InfobarType type,
+                             int max_height) {
+  if (type < FIRST_INFOBAR_TYPE || type >= END_OF_INFOBAR_TYPE ||

[grt (UTC plus 2), 2010/11/10 17:59:29]

This looks like programmer error.  Change to DCHECK if so.

[erikwright (departed), 2010/11/24 06:24:56]

Yes. A relic of the original code. Ideally, I'd like to get rid of this passing
of a type enum altogether in the final CL.

+      infobars_[type] == NULL) {

[grt (UTC plus 2), 2010/11/10 17:59:29]

How about this one, programmer error or something that could really happen?  If
the former, consider getting rid of return values for all functions that only
fail on programmer error (in which case use DCHECK).  If the latter, consider
adding VLOG or somesuch to make the condition(s) diagnosable.

[erikwright (departed), 2010/11/24 06:24:56]

Yes. I'm updating it to only return success or failure in cases where it can
unexpectedly fail (i.e., Windows returns a failure).

+    return E_INVALIDARG;
+  }
+
+  HRESULT hr = infobars_[type]->Show(content, max_height);
+  return hr;
+}
+
+bool InfobarManager::UpdateLayout() {
+  if (FindDisplacedWindow()) {
+    displaced_window_manager_->UpdateLayout();
+    return true;
+  } else {
+    return false;
+  }
+}
+
+HRESULT InfobarManager::Hide(InfobarType type) {
+  if (type < FIRST_INFOBAR_TYPE || type >= END_OF_INFOBAR_TYPE ||
+      infobars_[type] == NULL) {
+    return E_INVALIDARG;
+  }
+
+  infobars_[type]->Hide();
+  return S_OK;
+}
+
+void InfobarManager::HideAll() {
+  for (int index = 0; index < END_OF_INFOBAR_TYPE; ++index)
+    Hide(static_cast<InfobarType>(index));
+}
+
+// Callback function for EnumChildWindows. lParam should be the pointer to
+// HWND variable where the handle of the window which class is
+// kIeTabContentParentWindowClass will be written.
+static BOOL CALLBACK FindDisplacedWindowProc(HWND hwnd, LPARAM lparam) {
+  HWND* window_handle = reinterpret_cast<HWND*>(lparam);
+  if (NULL == window_handle) {

[grt (UTC plus 2), 2010/11/10 17:59:29]

I prefer this style of comparison.  For consistency, consider making a sweep for
(foo == NULL), (!foo) and other equivalent expressions and change them to this
style.  Likewise for the inverse (NULL != foo).

[erikwright (departed), 2010/11/24 06:24:56]

Agreed. Not the least because scoped_ptr does not allow evaluation as a boolean.
Although it will be the reverse (to meet coding style).

+    // It makes no sense to continue enumeration.
+    return FALSE;
+  }
+
+  // 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;
+}
+
+bool InfobarManager::FindDisplacedWindow() {
+  if (displaced_window_manager_ == NULL) {
+    if (::IsWindow(container_window_)) {
+      // Find the window which is the container for the HTML view (parent of
+      // the content).
+      HWND displaced_window = NULL;
+      ::EnumChildWindows(container_window_, FindDisplacedWindowProc,
+                         reinterpret_cast<LPARAM>(&displaced_window));
+
+      if (displaced_window == NULL) {
+        LOG(DFATAL) << "Failed to locate IE renderer HWND to displace for "
+                    << "Infobar installation.";
+      } else {
+        scoped_ptr<DisplacedWindowManager> displaced_window_manager(
+            new DisplacedWindowManager(this));
+        if (displaced_window_manager->Initialize(displaced_window)) {
+          displaced_window_manager_ = displaced_window_manager.release();
+        }
+      }
+    }
+  }
+
+  return displaced_window_manager_ != NULL;
+}
+
+void InfobarManager::AdjustDisplacedWindowDimensions(RECT* rect) {
+  if (rect == NULL)
+    return;
+
+  for (int index = 0; index < END_OF_INFOBAR_TYPE; ++index) {
+    if (infobars_[index] != NULL)
+      infobars_[index]->ReserveSpace(rect);
+  }
+}
+
+void InfobarManager::OnDisplacedWindowDestroyed() {
+  for (int index = 0; index < END_OF_INFOBAR_TYPE; ++index) {
+    if (infobars_[index] != NULL)
+      infobars_[index]->Hide();
+  }
+  // Will be deleted in its OnFinalMessage
+  displaced_window_manager_ = NULL;
+}