ui/views/layout/layout_manager.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_VIEWS_LAYOUT_LAYOUT_MANAGER_H_
   6 #define UI_VIEWS_LAYOUT_LAYOUT_MANAGER_H_
   7
   8 #include "ui/views/views_export.h"
   9
  10 namespace gfx {
  11 class Size;
  12 }
  13
  14 namespace views {
  15
  16 class View;
  17
  18 /////////////////////////////////////////////////////////////////////////////
  19 //
  20 // LayoutManager interface
  21 //
  22 //   The LayoutManager interface provides methods to handle the sizing of
  23 //   the children of a View according to implementation-specific heuristics.
  24 //
  25 /////////////////////////////////////////////////////////////////////////////
  26 class VIEWS_EXPORT LayoutManager {
  27  public:
  28   virtual ~LayoutManager();
  29
  30   // Notification that this LayoutManager has been installed on a particular
  31   // host.
  32   virtual void Installed(View* host);
  33
  34   // Notification that this LayoutManager has been uninstalled on a particular
  35   // host.
  36   virtual void Uninstalled(View* host);
  37
  38   // Lay out the children of |host| according to implementation-specific
  39   // heuristics. The graphics used during painting is provided to allow for
  40   // string sizing.
  41   virtual void Layout(View* host) = 0;
  42
  43   // Return the preferred size which is the size required to give each
  44   // children their respective preferred size.
  45   virtual gfx::Size GetPreferredSize(const View* host) const = 0;
  46
  47   // Returns the preferred height for the specified width. The default
  48   // implementation returns the value from GetPreferredSize.
  49   virtual int GetPreferredHeightForWidth(const View* host, int width) const;
  50
  51   // Notification that a view has been added.
  52   virtual void ViewAdded(View* host, View* view);
  53
  54   // Notification that a view has been removed.
  55   virtual void ViewRemoved(View* host, View* view);
  56 };
  57
  58 }  // namespace views
  59
  60 #endif  // UI_VIEWS_LAYOUT_LAYOUT_MANAGER_H_