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

chrome_frame/infobar_window.cc

Index: chrome_frame/infobar_window.cc
===================================================================
--- chrome_frame/infobar_window.cc	(revision 0)
+++ chrome_frame/infobar_window.cc	(revision 0)
@@ -0,0 +1,197 @@
+// 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_window.h"
+
+#include "base/logging.h"
+#include "base/scoped_ptr.h"
+
+namespace {
+
+const UINT_PTR kInfobarSlidingTimerId = 1U;
+// In milliseconds.
+const UINT kInfobarSlidingTimerInterval = 50U;

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

Consider putting "ms" in the constant name so that it's obvious everywhere that
it's in ms?

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

Agreed.

+// The step when the infobar is sliding, in pixels.
+const int kInfobarSlidingStep = 1;
+// The default height of the infobar.
+const int kInfobarDefaultHeight = 39;
+
+}  // namespace
+
+InfobarWindow::InfobarWindow(InfobarType type, InfobarHost* host)
+    : type_(type),

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

Although I like spreading the initializer list out like this, I think the style
guide prefers to not have so much vertical space taken up.

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

It does prefer to avoid unnecessary whitespace, but it also specifically
mandates that, when a list of parameters or initializers must be split on more
than one line, each element appears on its own line (with an exception if sets
of elements are clearly related, i.e., width and height).

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Constr...

+      host_(host),
+      show_(false),
+      target_height_(1),
+      initial_height_(1),
+      content_(NULL),
+      frame_impl_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  DCHECK(host_);
+}
+
+InfobarWindow::~InfobarWindow() {
+  Reset();
+
+  if (IsWindow()) {
+    DestroyWindow();
+  }
+}
+
+HRESULT InfobarWindow::Show(InfobarContent *content,
+                            int max_height) {
+  if (content_) {
+    content_->Reset();
+    content_ = NULL;
+  }
+
+  // Create the window if not created.
+  if (!IsWindow()) {
+    Create(host_->GetContainerWindow());
+    RECT dimensions = {0, 0, 0, 0};
+    GetClientRect(&dimensions);
+    dimensions.bottom = 1;
+    MoveWindow(&dimensions, TRUE);
+  }
+  if (!IsWindow())
+    return E_UNEXPECTED;
+
+  HRESULT hr = content->InstallInFrame(&frame_impl_);
+  if (FAILED(hr)) {
+    return hr;
+  }
+
+  StartUpdatingLayout(true, max_height, true);
+
+  // We only keep the pointer in case of success. At this point, we promise to
+  // call Reset at some future point on the content.
+  content_ = content;
+  return S_OK;
+}
+
+HRESULT InfobarWindow::Hide() {
+  StartUpdatingLayout(false, 0, false);
+
+  return S_OK;
+}
+
+void InfobarWindow::ReserveSpace(RECT* rect) {
+  DCHECK(rect);
+  if (rect == NULL || !show_ || !IsWindow())
+    return;
+
+  RECT infobar_rect = *rect;
+
+  int height = CalculateHeight();
+
+  switch (type_) {
+    case TOP_INFOBAR:
+      infobar_rect.bottom = rect->top = std::min(rect->bottom,
+                                                 rect->top + height);
+      break;
+    case BOTTOM_INFOBAR:
+      infobar_rect.top = rect->bottom = std::max(rect->top,
+                                                 rect->bottom - height);
+      break;
+    default:
+      NOTREACHED() << "Unknown InfobarType value.";
+      break;
+  }
+  
+
+  MoveWindow(&infobar_rect, TRUE);
+
+  SetWindowPos(HWND_TOP,
+               &infobar_rect,
+               show_ || height != target_height_ ?
+                   SWP_SHOWWINDOW : SWP_HIDEWINDOW);
+
+  if (content_ != NULL) {
+    content_->SetDimensions(infobar_rect);
+  }
+
+  if (height == target_height_) {
+    KillTimer(kInfobarSlidingTimerId);
+    if (!show_ && content_) {
+      // Content is responsible for freeing itself.
+      content_->Reset();
+      content_ = NULL;
+    }
+  }
+}
+
+void InfobarWindow::StartUpdatingLayout(bool show, int max_height, bool slide) {
+  if (!IsWindow()) {
+    return;
+  }
+
+  show_ = show;
+  if (show) {
+    // TODO(erikwright): ask our widget for its height
+    target_height_ = (max_height == 0 || kInfobarDefaultHeight < max_height) ?
+        kInfobarDefaultHeight : max_height;
+    if (target_height_ <= 0) {
+      target_height_ = 1;
+    }
+  } else {
+    target_height_ = 1;
+  }
+
+  // Trigger an deferred call to ReserveSpace, in which we will do the actual
+  // MoveWindow
+  if (!host_->UpdateLayout()) {
+    // Failed to trigger a layout - seems our environment is going away or gone.
+    // Let's get out of here.
+    RECT empty = {0, 0, 0, 0};
+    MoveWindow(&empty, TRUE);
+    KillTimer(kInfobarSlidingTimerId);
+    if (content_) {
+      // Content is responsible for freeing itself.
+      content_->Reset();
+      content_ = NULL;
+    }
+    return;
+  }
+
+  if (!slide || !show) {
+    slide_start_ = base::Time();
+    KillTimer(kInfobarSlidingTimerId);
+  } else {
+    RECT dimensions = {0, 0, 0, 0};
+    GetClientRect(&dimensions);
+    slide_start_ = base::Time::Now();
+    initial_height_ = dimensions.bottom;
+    SetTimer(kInfobarSlidingTimerId, kInfobarSlidingTimerInterval, NULL);
+  }
+
+}
+
+int InfobarWindow::CalculateHeight() {
+  RECT dimensions;
+  int current_height = GetClientRect(&dimensions) ? dimensions.bottom : 0;
+
+  if (slide_start_.is_null()) {
+    return target_height_;
+  }
+
+  base::TimeDelta elapsed = base::Time::Now() - slide_start_;
+  int travel = (static_cast<int>(elapsed.InMilliseconds()) /
+                kInfobarSlidingTimerInterval) * kInfobarSlidingStep;
+
+  if (current_height < target_height_) {
+    return std::min(current_height + travel, target_height_);
+  } else if (current_height > target_height_) {
+    return std::max(current_height - travel, target_height_);
+  } else {
+    return current_height;
+  }
+}
+
+LRESULT InfobarWindow::OnTimer(UINT_PTR nIDEvent) {
+  DCHECK(nIDEvent == kInfobarSlidingTimerId);
+
+  host_->UpdateLayout();
+  return S_OK;
+}