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

chrome_frame/infobars/internal/infobar_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.
+//
+// Implementation of the manager for infobar windows.
+
+#include "chrome_frame/infobars/internal/infobar_window.h"
+
+#include <algorithm>
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "chrome_frame/function_stub.h"
+
+namespace {
+
+// length of each step when opening or closing
+const UINT kInfobarSlidingTimerIntervalMs = 50U;
+// pixels per step, when opening or closing
+const int kInfobarSlideOpenStep = 2;
+const int kInfobarSlideCloseStep = 6;
+
+}  // namespace
+
+void OnSliderTimer(InfobarWindow::Host* host) {
+  host->UpdateLayout();
+}
+
+InfobarWindow::InfobarWindow(InfobarType type)
+    : type_(type),
+      host_(NULL),
+      target_height_(0),
+      initial_height_(0),
+      current_height_(0),
+      current_width_(0),
+      timer_id_(0),
+      timer_stub_(NULL),
+      frame_impl_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  DCHECK(type_ >= FIRST_INFOBAR_TYPE);
+  DCHECK(type_ < END_OF_INFOBAR_TYPE);
+}
+
+InfobarWindow::~InfobarWindow() {
+  StopTimer();
+  FunctionStub::Destroy(timer_stub_);

[tommi (sloooow) - chröme, 2010/12/01 21:51:28]

check for NULL?

+}
+
+void InfobarWindow::SetHost(Host* host) {
+  DCHECK(host_ == NULL);
+  DCHECK(host != NULL);
+  host_ = host;
+  timer_stub_ = FunctionStub::Create(reinterpret_cast<uintptr_t>(host),

[tommi (sloooow) - chröme, 2010/12/01 21:51:28]

maybe first DCHECK(timer_stub_ == NULL);

+                                     OnSliderTimer);
+}
+
+bool InfobarWindow::Show(InfobarContent *content) {

[grt (UTC plus 2), 2010/12/02 16:27:52]

InfobarContent* content

+  DCHECK(host_ != NULL);

[grt (UTC plus 2), 2010/12/02 16:27:52]

maybe instead do:
if (host_ == NULL) {
  NOTREACHED() << "some explanation";
  return false;
}

+  if (host_ == NULL)
+    return false;
+
+  scoped_ptr<InfobarContent> new_content(content);
+  content_.reset();
+
+  if (!new_content->InstallInFrame(&frame_impl_))
+    return false;
+
+  // Force a call to ReserveSpace, which will capture the width of the displaced
+  // window.
+  if (current_width_ == 0)
+    host_->UpdateLayout();
+  if (current_width_ == 0)
+    return false;  // Might not be any displaced window.. then we can't display.
+
+  content_.swap(new_content);
+  StartSlidingTowards(content_->GetDesiredSize(current_width_, 0));
+
+  return true;
+}
+
+void InfobarWindow::Hide() {
+  DCHECK(host_ != NULL);

[grt (UTC plus 2), 2010/12/02 16:27:52]

similar proposal as above

+  if (host_ == NULL)
+    return;
+
+  StartSlidingTowards(0);
+}
+
+void InfobarWindow::ReserveSpace(RECT* rect) {
+  DCHECK(rect);
+  DCHECK(host_ != NULL);
+  if (rect == NULL || host_ == NULL)
+    return;
+
+  current_width_ = rect->right - rect->left;
+  current_height_ = CalculateHeight();
+
+  RECT infobar_rect = *rect;
+
+  switch (type_) {
+    case TOP_INFOBAR:
+      rect->top = std::min(rect->bottom,
+                           infobar_rect.bottom = rect->top + current_height_);

[tommi (sloooow) - chröme, 2010/12/01 21:51:28]

this is a bit confusing because the assignment to infobar_rect.bottom is done on
the 2nd line but happens before the 1st line.  You're also using the current
value of rect->top on the second line which is newer than the value on the first
line.  Furthermore a reader might think that you meant to do == and not = :) 
So, I'd prefer:

infobar_rect.bottom = rect->top + current_height_;
rect->top = std::min(rect->bottom, infobar_rect.bottom);

+      break;
+    case BOTTOM_INFOBAR:
+      rect->bottom = std::max(

[tommi (sloooow) - chröme, 2010/12/01 21:51:28]

same here

+          rect->top, infobar_rect.top = rect->bottom - current_height_);
+      break;
+    default:
+      NOTREACHED() << "Unknown InfobarType value.";
+      break;
+  }
+
+  if (content_ != NULL)
+    content_->SetDimensions(infobar_rect);
+
+  // Done sliding?
+  if (current_height_ == target_height_) {
+    StopTimer();
+    if (current_height_ == 0)
+      content_.reset();
+  }
+}
+
+void InfobarWindow::StartSlidingTowards(int target_height) {
+  initial_height_ = current_height_;
+  target_height_ = target_height;
+
+  if (StartTimer())
+    slide_start_ = base::Time::Now();
+  else
+    slide_start_ = base::Time();  // NULL time means don't slide, resize now
+
+  // Trigger an immediate re-laying out. The timer will handle remaining steps.
+  host_->UpdateLayout();
+}
+
+bool InfobarWindow::StartTimer() {
+  timer_id_ = ::SetTimer(NULL,
+                         timer_id_,
+                         kInfobarSlidingTimerIntervalMs,
+                         reinterpret_cast<TIMERPROC>(timer_stub_->code()));
+
+  if (timer_id_ == 0)
+    DPLOG(ERROR) << "Failure in SetTimer.";

[grt (UTC plus 2), 2010/12/02 16:27:52]

DPLOG_IF(ERROR, timer_id_ == 0) << ...;

+
+  return timer_id_ != 0;
+}
+
+void InfobarWindow::StopTimer() {
+  ::KillTimer(NULL, timer_id_);
+}
+
+int InfobarWindow::CalculateHeight() {
+  if (slide_start_.is_null())
+    return target_height_;
+
+  base::TimeDelta elapsed = base::Time::Now() - slide_start_;
+  int elapsed_steps = static_cast<int>(elapsed.InMilliseconds()) /
+                      kInfobarSlidingTimerIntervalMs;
+
+  if (initial_height_ < target_height_) {
+    return std::min(initial_height_ + elapsed_steps * kInfobarSlideOpenStep,
+                    target_height_);
+  } else if (initial_height_ > target_height_) {
+    return std::max(initial_height_ - elapsed_steps * kInfobarSlideCloseStep,
+                    target_height_);
+  } else {
+    return target_height_;
+  }
+}
+
+InfobarWindow::FrameImpl::FrameImpl(InfobarWindow* infobar_window)
+    : infobar_window_(infobar_window) {
+}
+
+HWND InfobarWindow::FrameImpl::GetFrameWindow() {
+  return infobar_window_->host_->GetContainerWindow();
+}
+
+void InfobarWindow::FrameImpl::CloseInfobar() {
+  infobar_window_->Hide();
+}