Refactor intra-strip panel drags by introducing PanelDragController.

chrome/browser/ui/panels/overflow_panel_strip.cc

 // Copyright (c) 2012 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/overflow_panel_strip.h"
 
 #include "base/logging.h"
 #include "chrome/browser/ui/panels/docked_panel_strip.h"
 #include "chrome/browser/ui/panels/panel_manager.h"
 #include "chrome/browser/ui/panels/panel_mouse_watcher.h"
@@ skipping 80 matching lines @@
     panel->set_has_temporary_layout(false);
     panels_.push_back(panel);
     DoRefresh(panels_.size() - 1, panels_.size() - 1);
   } else {
     panels_.insert(panels_.begin(), panel);
     RefreshLayout();
   }
 
   // Set panel properties for this strip.
   panel->SetAppIconVisibility(false);
-  panel->set_draggable(false);
   panel->ApplyVisualStyleForStrip();
 
   if (num_panels() == 1) {
     panel_manager_->mouse_watcher()->AddObserver(this);
     UpdateMaxVisiblePanelsOnHover();
   }
 
   // Update the overflow indicator only when the number of overflow panels go
   // beyond the maximum visible limit.
   if (num_panels() > max_visible_panels_) {
@@ skipping 63 matching lines @@
   // Overflow is already a minimized mode for a panel. Nothing more to do.
 }
 
 void OverflowPanelStrip::RestorePanel(Panel* panel) {
   DCHECK_EQ(this, panel->panel_strip());
   PanelStrip* docked_strip = panel_manager_->docked_strip();
   panel->MoveToStrip(docked_strip);
   docked_strip->RestorePanel(panel);
 }
 
+bool OverflowPanelStrip::CanDragPanel(const Panel* panel) const {
+  // All overflow panels are not draggable.
+  return false;
+}
+
+void OverflowPanelStrip::StartDraggingPanel(Panel* panel) {
+  NOTREACHED();
+}
+
+void OverflowPanelStrip::DragPanel(Panel* panel, int delta_x, int delta_y) {
+  NOTREACHED();
+}
+
+void OverflowPanelStrip::EndDraggingPanel(Panel* panel, bool cancelled) {
+  NOTREACHED();
+}
+
 void OverflowPanelStrip::RefreshLayout() {
   if (panels_.empty())
     return;
   DoRefresh(0, panels_.size() - 1);
 }
 
 void OverflowPanelStrip::DoRefresh(size_t start_index, size_t end_index) {
   if (panels_.empty() || start_index == panels_.size())
     return;
 
@@ skipping 169 matching lines @@
     bounds.set_width(current_display_width);
     overflow_indicator_->SetBounds(bounds);
     overflow_indicator_->SetCount(num_panels() - max_visible_panels);
   }
 }
 
 void OverflowPanelStrip::OnFullScreenModeChanged(bool is_full_screen) {
   for (size_t i = 0; i < panels_.size(); ++i)
     panels_[i]->FullScreenModeChanged(is_full_screen);
 }