utils/framelayout/src/gcupdatesmgr.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        No names yet.
   3 // Purpose:     Contrib. demo
   4 // Author:      Aleksandras Gluchovas
   5 // Modified by:
   6 // Created:     19/10/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Aleksandras Gluchovas
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef __GCUPDATESMGR_G__
  13 #define __GCUPDATESMGR_G__
  14
  15 #include "controlbar.h"
  16 #include "updatesmgr.h"
  17
  18 #include "garbagec.h"
  19
  20 /*
  21  * class implements optimized logic for refreshing
  22  * areas of frame layout - which actually need to be updated.
  23  * Is used as default updates-manager by wxFrameLayout.
  24  *
  25  * it is called "Garbage Collecting" u.mgr for it's impelmentation
  26  * tries to find out dependencies between bars, and to order
  27  * them ito "hierarchy", this hierarchical sorting resembles
  28  * impelmenation of heap-garbage collectors, which resolve
  29  * dependencies between referencs.
  30  *
  31  * Example: there are situations where the order of moving
  32  *          the windows does matter:
  33  *
  34  *   case 1)
  35  *      ------              ---
  36  *      | A      |                  |B|
  37  *              ------   --->   | |
  38  *                      ---                     --- ------
  39  *                      |B|                             | A  |
  40  *                      | |                             ------
  41  *                      ---
  42  *                                              (future)
  43  *         (past)
  44  *
  45  *  past/future positions of A and B windows completely overlapp, i.e.
  46  *  depend on each other, and there is not solution for
  47  *  moving the windows witout refereshing both of them,
  48  *  -- we have cyclic dependency here. The gc. alg will
  49  *  find this cyclic dependecy and will force "refresh"
  50  *  after movement.
  51  *
  52  *   case 2)
  53  *
  54  *      ------
  55  *      | A      |
  56  *              ------   --->
  57  *                      ---
  58  *                      |B|                                        ------
  59  *                      | |                                        | A  |
  60  *                      ---                                        ------
  61  *                                               ---
  62  *                                               |B|
  63  *                                               | |
  64  *                                           ---
  65  *
  66  *                                              (future)
  67  *         (past)
  68  *
  69  *  in this case past/future positions do not overlapp, thus
  70  *  it's enough only to move windows, without refreshing them.
  71  *  GC will "notice" it.
  72  *
  73  *  there is also third case, when overlapping is partial
  74  *  in this case the refershing can be also avoided by
  75  *  moving windows in the order of "most-dependant" towards the
  76  *  "least-dependent". GC handles this automatically, by
  77  *  sorting windows by their dependency-level (or "hierarchy")
  78  *
  79  *  See garbagec.h for more details of this method, garbagec.h/cpp
  80  *  implement sorting of generic-depenencies (does not deal
  81  *  with graphical objects directly)
  82  *
  83  *  Summary: improves performance when complex/large windows are
  84  *           moved around, by reducing number of repaints. Also helps
  85  *           to avoid dirty non-client areas of moved windows
  86  *           in some sepcal cases of "overlapping anomalies"
  87  */
  88
  89 class cbGCUpdatesMgr : public cbSimpleUpdatesMgr
  90 {
  91         DECLARE_DYNAMIC_CLASS( cbGCUpdatesMgr )
  92 protected:
  93
  94         GarbageCollector mGC;
  95
  96         void DoRepositionItems( wxList& items );
  97
  98         void AddItem( wxList&     itemList,
  99                                   cbBarInfo*  pBar,
 100                           cbDockPane* pPane,
 101                                   wxRect&     curBounds,
 102                                   wxRect&     prevBounds );
 103
 104 public:
 105
 106         cbGCUpdatesMgr(void) {}
 107
 108         cbGCUpdatesMgr( wxFrameLayout* pPanel );
 109
 110         // notificiactions received from Frame Layout :
 111
 112         virtual void OnStartChanges();
 113
 114         // refreshes parts of the frame layout, which need an update
 115         virtual void UpdateNow();
 116 };
 117
 118 #endif