Created new PanelStrip base class and make DockedPanelStrip and OverflowPanelStrip its subclasses.

chrome/browser/ui/panels/panel_strip.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_
+#define CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_
+#pragma once
+
+#include "ui/gfx/rect.h"
+
+class Panel;
+
+// Common base class for a collection of panels. Subclasses manage
+// various layouts for displaying panels in the collection.
+class PanelStrip {
+ public:
+  // Types of layout for the panel collections.
+  enum Type {
+    DETACHED,  // free-floating panels
+    DOCKED,    // panels are 'docked' along the window's edge
+    IN_OVERFLOW,  // panels that cannot fit in the 'docked' panels area
+  };
+
+  Type type() const { return type_; }
+
+  // Sets the bounds of the panel strip.
+  // |display_area| is in screen coordinates.
+  virtual void SetDisplayArea(const gfx::Rect& display_area) = 0;
+
+  // Updates the positioning of all panels in the collection, usually as
+  // a result of removing or resizing a panel in collection.
+  virtual void RefreshLayout() = 0;
+
+  // Adds |panel| to the collection of panels.
+  virtual void AddPanel(Panel* panel) = 0;
+
+  // Removes |panel| from the collection of panels. Invoked asynchronously
+  // after a panel has been closed.
+  // Returns |false| if the panel is not in the strip.
+  virtual bool RemovePanel(Panel* panel) = 0;
+
+  // Closes all panels in the collection. Panels will be removed after closing.
+  virtual void CloseAll() = 0;
+
+  // Resizes the |panel| to the |preferred_window_size|.
+  // |preferred_window_size| is the outer dimensions of the window, not
+  // the content area, and is in screen coordinates.
+  // The preferred size may be adjusted to fit layout constraints.
+  virtual void ResizePanelWindow(Panel* panel,
+                                 const gfx::Size& preferred_window_size) = 0;
+
+  // Invoked when the draw attention state of the panel has changed.
+  // Subclass should update the display of the panel to match the new
+  // draw attention state.
+  virtual void OnPanelAttentionStateChanged(Panel* panel) = 0;
+
+ protected:
+  explicit PanelStrip(Type type);
+  virtual ~PanelStrip();
+
+  const Type type_;  // Type of this panel strip.
+};
+
+#endif  // CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_