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"
+

[grt (UTC plus 2), 2010/11/25 18:00:13]

Include <algorithm> to explicitly pull in std::min/max

[erikwright (departed), 2010/12/01 20:05:52]

Awesome catch!

+#include "base/compiler_specific.h"
+#include "base/logging.h"
+
+#include "chrome_frame/infobars/content.h"
+
+namespace {
+const UINT_PTR kInfobarSlidingTimerId = 1U;
+const UINT kInfobarSlidingTimerIntervalMs = 50U;
+// The step when the infobar is sliding, in pixels.
+const int kInfobarSlideOpenStep = 2;
+const int kInfobarSlideCloseStep = 6;
+}  // namespace
+
+InfobarWindow::InfobarWindow(InfobarType type, InfobarHost* host)
+    : type_(type),
+      host_(host),
+      target_height_(0),
+      initial_height_(0),
+      content_(NULL),
+      frame_impl_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  DCHECK(type_ >= FIRST_INFOBAR_TYPE);
+  DCHECK(type_ < END_OF_INFOBAR_TYPE);
+  DCHECK(host_);
+}
+
+InfobarWindow::~InfobarWindow() {
+  ResetContent();
+}
+
+bool InfobarWindow::InitializeWindow() {
+  RECT dimensions = {0, 0, 0, 0};
+  if (!Create(host_->GetContainerWindow())) {
+    DPLOG(ERROR) << "Failure to create InfobarWindow.";
+    return false;
+  }
+
+  if (!::GetClientRect(host_->GetContainerWindow(), &dimensions)) {
+    DPLOG(ERROR) << "Failure in GetClientRect.";
+    DestroyWindow();
+    return false;
+  }
+
+  if (type_ == TOP_INFOBAR) {
+    dimensions.bottom = dimensions.top;
+  } else {
+    DCHECK(type_ == BOTTOM_INFOBAR);
+    dimensions.top = dimensions.bottom;
+  }
+
+  if (!MoveWindow(&dimensions, FALSE)) {
+    DPLOG(ERROR) << "Failure in MoveWindow.";
+    DestroyWindow();
+    return false;
+  }
+
+  return true;
+}
+
+bool InfobarWindow::Show(InfobarContent *content) {
+  ResetContent();
+
+  // Create the window if not created.
+  if (!IsWindow() && !InitializeWindow()) {
+    content->Reset();
+    return false;
+  }
+
+  if (!InstallContent(content))
+    return false;
+
+  return true;
+}
+
+void InfobarWindow::Hide() {
+  if (!IsWindow()) {
+    ResetContent();
+  } else if (!StartSlidingTowards(0)) {
+    // Failed to trigger a layout - seems our environment is going away or gone.
+    // Just hide immediately.
+    RECT empty = {0, 0, 0, 0};
+    MoveWindow(&empty, TRUE);
+    KillTimer(kInfobarSlidingTimerId);
+    ResetContent();
+  }
+}
+
+void InfobarWindow::ReserveSpace(RECT* rect) {
+  DCHECK(rect);
+  if (rect == NULL || !IsWindow())
+    return;
+
+  int 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);
+      break;
+    case BOTTOM_INFOBAR:
+      rect->bottom = std::max(rect->top,
+                              infobar_rect.top = rect->bottom - current_height);
+      break;
+    default:
+      NOTREACHED() << "Unknown InfobarType value.";
+      break;
+  }
+
+  if (!MoveWindow(&infobar_rect, TRUE))
+    DPLOG(ERROR) << "Failure in MoveWindow.";
+
+  if (!SetWindowPos(HWND_TOP,
+                    &infobar_rect,
+                    current_height != 0 ? SWP_SHOWWINDOW : SWP_HIDEWINDOW)) {
+    DPLOG(ERROR) << "Failure in SetWindowPos.";
+  }
+
+  if (content_ != NULL)
+    content_->SetDimensions(infobar_rect);
+
+  // Done sliding?
+  if (current_height == target_height_) {
+    KillTimer(kInfobarSlidingTimerId);
+    if (current_height == 0)
+      ResetContent();
+  }
+}
+
+bool InfobarWindow::StartSlidingTowards(int target_height) {
+  if (!IsWindow())
+    return false;
+
+  RECT dimensions = {0, 0, 0, 0};
+  if (!GetClientRect(&dimensions)) {
+    DPLOG(ERROR) << "Failure in GetClientRect.";
+    return false;
+  }
+
+  if (!SetTimer(kInfobarSlidingTimerId, kInfobarSlidingTimerIntervalMs, NULL)) {
+    DPLOG(ERROR) << "Failure in SetTimer.";
+    return false;
+  }
+
+  slide_start_ = base::Time::Now();
+  initial_height_ = dimensions.bottom - dimensions.top;
+  target_height_ = target_height;
+
+  // Trigger an immediate re-laying out. The timer will handle remaining steps.
+  host_->UpdateLayout();
+  return true;
+}
+
+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_;
+  }
+}
+
+bool InfobarWindow::InstallContent(InfobarContent* content) {
+  // Clear existing content, if any
+  ResetContent();
+
+  content_ = content;
+
+  if (!content_->InstallInFrame(&frame_impl_)) {
+    ResetContent();

[grt (UTC plus 2), 2010/11/25 18:00:13]

Multiple exits that require the same DoStuffBeforeExiting() calls can cause
trouble when others add new early exits but forget the magic cleanup.  Could you
refactor all occurrences of these in the CL so that there's (ideally) one
failure exit that does the proper cleanup?

[erikwright (departed), 2010/12/01 20:05:52]

Yeah, I didn't like it either.

Moved to Show(), BTW.

+    return false;
+  }
+
+  RECT dimensions = {0, 0, 0, 0};
+  if (!GetClientRect(&dimensions)) {
+    DPLOG(INFO) << "Failure in GetClientRect.";
+    ResetContent();
+    return false;
+  }
+
+  int infobar_width = dimensions.right - dimensions.left;
+  int content_height = content_->GetDesiredSize(infobar_width, 0);
+
+  if (!StartSlidingTowards(content_height)) {
+    ResetContent();
+    return false;
+  }
+
+  return true;
+}
+
+void InfobarWindow::ResetContent() {
+  if (content_ != NULL) {
+    content_->Reset();
+    content_ = NULL;
+  }
+}
+
+LRESULT InfobarWindow::OnTimer(UINT_PTR nIDEvent) {
+  DCHECK(nIDEvent == kInfobarSlidingTimerId);
+
+  // Might fail if the host is not able to update right now. Expect it to
+  // eventually succeed (on a future OnTimer invocation).
+  host_->UpdateLayout();
+  return S_OK;
+}