Support auto-hide taskbar for panels on Windows.

chrome/browser/ui/panels/panel_manager.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/ui/panels/panel_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/window_sizer.h"
 
 namespace {
 // Invalid panel index.
 const size_t kInvalidPanelIndex = static_cast<size_t>(-1);
 
 // Minimum width and height of a panel.
 const int kPanelMinWidthPixels = 64;
 const int kPanelMinHeightPixels = 24;
 
 // Default width and height of a panel.
 const int kPanelDefaultWidthPixels = 240;
 const int kPanelDefaultHeightPixels = 290;
 
 // Maxmium width and height of a panel based on the factor of the working
 // area.
 const double kPanelMaxWidthFactor = 1.0;
 const double kPanelMaxHeightFactor = 0.5;
 
 // Horizontal spacing between two panels.
 const int kPanelsHorizontalSpacing = 4;
 
+// Occasionally some system, like Windows, might not bring up or down the bottom
+// bar when the mouse enters or leaves the bottom screen area. This is the
+// maximum time we will wait for the bottom bar visibility change notification.
+// After the time expires, we bring up/down the titlebars as planned.
+const int kMaxTimeWaitForBottomBarVisibilityChange = 1000;

[jennb, 2011/08/23 20:28:34]

s/Time/<name of time unit>

[jianli, 2011/08/26 00:18:16]

Done.

+
 // Single instance of PanelManager.
-scoped_ptr<PanelManager> panel_instance;
+scoped_refptr<PanelManager> panel_instance;
 }  // namespace
 
 // static
 PanelManager* PanelManager::GetInstance() {
   if (!panel_instance.get()) {
-    panel_instance.reset(new PanelManager());
+    panel_instance = new PanelManager();
+    panel_instance->Init();
   }
   return panel_instance.get();
 }
 
+// static
+void PanelManager::CreateForTestingHelper(
+    const gfx::Rect& work_area, AutoHideBottomBar* auto_hide_bottom_bar) {
+  DCHECK(!panel_instance.get());
+  panel_instance = new PanelManager();
+  panel_instance->auto_hide_bottom_bar_ = auto_hide_bottom_bar;
+  panel_instance->SetWorkArea(work_area);
+}
+
 PanelManager::PanelManager()
     : max_width_(0),
       max_height_(0),
-      min_x_(0),
       current_x_(0),
-      bottom_edge_y_(0),
       dragging_panel_index_(kInvalidPanelIndex),
-      dragging_panel_original_x_(0) {
-  OnDisplayChanged();
+      dragging_panel_original_x_(0),
+      delayed_titlebar_action_(NO_ACTION),
+      ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {
 }
 
 PanelManager::~PanelManager() {
   DCHECK(panels_.empty());
   DCHECK(panels_pending_to_remove_.empty());
 }
 
+void PanelManager::Init() {
+  auto_hide_bottom_bar_ = AutoHideBottomBar::Create(this);
+  OnDisplayChanged();
+}
+
 void PanelManager::OnDisplayChanged() {
   scoped_ptr<WindowSizer::MonitorInfoProvider> info_provider(
       WindowSizer::CreateDefaultMonitorInfoProvider());
   SetWorkArea(info_provider->GetPrimaryMonitorWorkArea());
 }
 
 void PanelManager::SetWorkArea(const gfx::Rect& work_area) {
   if (work_area == work_area_)
     return;
   work_area_ = work_area;
 
-  min_x_ = work_area.x();
+  auto_hide_bottom_bar_->UpdateWorkArea(work_area);
+
   current_x_ = work_area.right();
-  bottom_edge_y_ = work_area.bottom();
   max_width_ = static_cast<int>(work_area.width() * kPanelMaxWidthFactor);
   max_height_ = static_cast<int>(work_area.height() * kPanelMaxHeightFactor);
 
   Rearrange(panels_.begin());
 }
 
 void PanelManager::FindAndClosePanelOnOverflow(const Extension* extension) {
   Panel* panel_to_close = NULL;
 
   // Try to find the left-most panel invoked from the same extension and close
@@ skipping 178 matching lines @@
   } else {
     panels_[dragging_panel_index_]->SetPanelBounds(
         dragging_panel_bounds_);
   }
 
   dragging_panel_index_ = kInvalidPanelIndex;
 
   DelayedRemove();
 }
 
-bool PanelManager::ShouldBringUpTitlebarForAllMinimizedPanels(
-    int mouse_x, int mouse_y) const {
+bool PanelManager::ShouldBringUpTitlebars(int mouse_x, int mouse_y) const {
+  // We should always bring up the title-bar if the mouse is over the auto-hide
+  // task-bar that becomes visible.
+  if (auto_hide_bottom_bar_->IsEnabled() &&
+      auto_hide_bottom_bar_->GetVisibility() == AutoHideBottomBar::VISIBLE &&
+      mouse_y >= work_area_.bottom() - auto_hide_bottom_bar_->GetHeight())
+    return true;
+
   for (Panels::const_iterator iter = panels_.begin();
        iter != panels_.end(); ++iter) {
     if ((*iter)->ShouldBringUpTitlebar(mouse_x, mouse_y))
       return true;
   }
   return false;
 }
 
-void PanelManager::BringUpOrDownTitlebarForAllMinimizedPanels(bool bring_up) {
+void PanelManager::BringUpOrDownTitlebars(bool bring_up) {
+  // If the auto-hide bottom bar exists, delay the action until the bottom
+  // bar is fully visible or hidden. We do not want both bottom bar and panel
+  // titlebar to move at the same time but with different speeds.
+  if (auto_hide_bottom_bar_->IsEnabled()) {
+    AutoHideBottomBar::Visibility visibility =
+        auto_hide_bottom_bar_->GetVisibility();
+    if (visibility != (bring_up ? AutoHideBottomBar::VISIBLE
+                                : AutoHideBottomBar::HIDDEN)) {
+      // OnAutoHideBottomBarVisibilityChanged will handle this.
+      delayed_titlebar_action_ = bring_up ? BRING_UP : BRING_DOWN;
+
+      // Occasionally some system, like Windows, might not bring up or down the
+      // bottom bar when the mouse enters or leaves the bottom screen area.
+      // Thus, we schedule a delayed task to do the work if we do not receive
+      // the bottom bar visibility change notification within a certain period
+      // of time.
+      MessageLoop::current()->PostDelayedTask(
+          FROM_HERE,
+          method_factory_.NewRunnableMethod(
+              &PanelManager::DelayedBringUpOrDownTitlebarsCheck),
+          kMaxTimeWaitForBottomBarVisibilityChange);
+
+      return;
+    }
+  }
+
+  DoBringUpOrDownTitlebars(bring_up);
+}
+
+void PanelManager::DelayedBringUpOrDownTitlebarsCheck() {

[jennb, 2011/08/23 20:28:34]

Seems like this could be coded more compactly:

if (delayed_titlebar_action_ == NO_ACTION)
  return;

DoBringUpOrDownTitlebars(delayed_titlebar_action_ == BRING_UP);
delayed_titlebar_action_ = NO_ACTION_;
return;

[jianli, 2011/08/26 00:18:16]

Done.

+  switch (delayed_titlebar_action_) {
+    case NO_ACTION:
+      break;
+    case BRING_UP:
+      delayed_titlebar_action_ = NO_ACTION;
+      DoBringUpOrDownTitlebars(true);
+      break;
+    case BRING_DOWN:
+      delayed_titlebar_action_ = NO_ACTION;
+      DoBringUpOrDownTitlebars(false);
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+void PanelManager::DoBringUpOrDownTitlebars(bool bring_up) {
   for (Panels::const_iterator iter = panels_.begin();
        iter != panels_.end(); ++iter) {
     Panel* panel = *iter;
 
     // Skip any panel that is drawing the attention.
     if (panel->IsDrawingAttention())
       continue;
 
     if (bring_up) {
       if (panel->expansion_state() == Panel::MINIMIZED)
         panel->SetExpansionState(Panel::TITLE_ONLY);
     } else {
       if (panel->expansion_state() == Panel::TITLE_ONLY)
         panel->SetExpansionState(Panel::MINIMIZED);
     }
   }
 }
 
+int PanelManager::GetBottomPositionForExpansionState(

[jennb, 2011/08/23 20:28:34]

As discussed, some logic error computing bottom here...

[jianli, 2011/08/26 00:18:16]

Done.

+    Panel::ExpansionState expansion_state) const {
+  int bottom = work_area_.bottom();
+  if (expansion_state != Panel::MINIMIZED)
+    bottom -= auto_hide_bottom_bar_->GetHeight();
+  return bottom;
+}
+
+void PanelManager::OnAutoHideBottomBarVisibilityChanged(
+    AutoHideBottomBar::Visibility visibility) {
+  switch (delayed_titlebar_action_) {

[jennb, 2011/08/23 20:28:34]

Feels like this method can be coded more compactly as well.

[jianli, 2011/08/26 00:18:16]

Done.

+    case NO_ACTION:
+      break;
+    case BRING_UP:
+      if (visibility == AutoHideBottomBar::VISIBLE) {
+        delayed_titlebar_action_ = NO_ACTION;
+        DoBringUpOrDownTitlebars(true);
+      }
+      break;
+    case BRING_DOWN:
+      if (visibility == AutoHideBottomBar::HIDDEN) {
+        delayed_titlebar_action_ = NO_ACTION;
+        DoBringUpOrDownTitlebars(false);
+      }
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+void PanelManager::OnAutoHideBottomBarHeightChanged(int height) {
+  current_x_ = work_area_.right();

[jennb, 2011/08/23 20:28:34]

Why does current_x_ get updated when height changed?

[jianli, 2011/08/26 00:18:16]

Changed the logic such that current_x_ is removed.

+  Rearrange(panels_.begin());
+}
+
 void PanelManager::Rearrange(Panels::iterator iter_to_start) {
   if (iter_to_start == panels_.end())
     return;
 
   for (Panels::iterator iter = iter_to_start; iter != panels_.end(); ++iter) {
     gfx::Rect new_bounds((*iter)->GetBounds());
     ComputeBoundsForNextPanel(&new_bounds, false);
     if (new_bounds != (*iter)->GetBounds())
       (*iter)->SetPanelBounds(new_bounds);
   }
@@ skipping 16 matching lines @@
     else if (width > max_width_)
       width = max_width_;
 
     if (height < kPanelMinHeightPixels)
       height = kPanelMinHeightPixels;
     else if (height > max_height_)
       height = max_height_;
   }
 
   int x = current_x_ - width;
-  int y = bottom_edge_y_ - height;
+  int y = work_area_.bottom() - auto_hide_bottom_bar_->GetHeight() - height;
 
-  if (x < min_x_)
+  if (x < work_area_.x())
     return false;
 
   current_x_ -= width + kPanelsHorizontalSpacing;
 
   bounds->SetRect(x, y, width, height);
   return true;
 }
 
 void PanelManager::RemoveAll() {
   // This should not be called when we're in the process of dragging.
   DCHECK(dragging_panel_index_ == kInvalidPanelIndex);
 
   // Start from the bottom to avoid reshuffling.
   for (Panels::reverse_iterator iter = panels_.rbegin();
        iter != panels_.rend(); ++iter)
     (*iter)->Close();
 }
 
 bool PanelManager::is_dragging_panel() const {
   return dragging_panel_index_ != kInvalidPanelIndex;
 }