rom/hyperlayers/movelayerinfrontof.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <aros/libcall.h>
  10 #include <proto/layers.h>
  11 #include <proto/graphics.h>
  12 #include <graphics/clip.h>
  13 #include <graphics/layers.h>
  14
  15 #include "basicfuncs.h"
  16 #include "layers_intern.h"
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21 #include <proto/layers.h>
  22
  23         AROS_LH2(LONG, MoveLayerInFrontOf,
  24
  25 /*  SYNOPSIS */
  26         AROS_LHA(struct Layer *, layer_to_move, A0),
  27         AROS_LHA(struct Layer *, other_layer, A1),
  28
  29 /*  LOCATION */
  30         struct LayersBase *, LayersBase, 28, Layers)
  31
  32 /*  FUNCTION
  33         Moves layer directly in front of another layer. Other layers
  34         might become visible. You cannot move a backdrop layer in front
  35         of a non-backdrop layer. You can also not move a layer in front
  36         of a layer with different relationship to the root layer. Boot
  37         have to be children of grandchildren or grandgrandchildren etc.
  38         of the root layer. The root layer is not visible to you and
  39         should never be accessed.
  40         If parts of a simple layer become visible these areas are added
  41         to the damage list.
  42
  43     INPUTS
  44         layer_to_move - pointer to layer that is to be moved
  45         other_layer   - pointer to other layer that will be behind the
  46                         layer_to_move.
  47
  48     RESULT
  49         TRUE  - layer was moved
  50         FALSE - layer could not be moved. (probably out of memory)
  51
  52     NOTES
  53
  54     EXAMPLE
  55
  56     BUGS
  57
  58     SEE ALSO
  59
  60     INTERNALS
  61
  62     HISTORY
  63         27-11-96    digulla automatically created from
  64                             layers_lib.fd and clib/layers_protos.h
  65
  66 *****************************************************************************/
  67 {
  68   AROS_LIBFUNC_INIT
  69
  70   struct Layer *_l;
  71   int toback = TRUE;
  72   LONG ret;
  73
  74   if (layer_to_move->parent  != other_layer->parent ||
  75       layer_to_move->priority < other_layer->priority)
  76     return FALSE;
  77
  78   LockLayers(layer_to_move->LayerInfo);
  79
  80   _l = layer_to_move->parent->front;
  81   while (1)
  82   {
  83     /*
  84      * If I run into the other layer before I find l
  85      * then I know I have to move it to the back.
  86      */
  87     if (_l == other_layer)
  88       break;
  89
  90     if (_l == layer_to_move)
  91     {
  92       toback = FALSE;
  93       break;
  94     }
  95     _l = _l->front;
  96     if (NULL == _l)
  97     {
  98       UnlockLayers(layer_to_move->LayerInfo);
  99       return FALSE;
 100     }
 101   }
 102
 103   _l = GetFirstFamilyMember(other_layer);
 104
 105   if (TRUE == toback)
 106   {
 107     /*
 108      * If the topmost child of the other layer is
 109      * behind my layer I don't have to do anything.
 110      */
 111     if (layer_to_move->back == _l)
 112     {
 113       UnlockLayers(layer_to_move->LayerInfo);
 114       return TRUE;
 115     }
 116     ret = _MoveLayerBehind(layer_to_move, _l, LayersBase);
 117   }
 118   else
 119   {
 120     ret = _MoveLayerToFront(layer_to_move, _l, LayersBase);
 121   }
 122
 123   UnlockLayers(layer_to_move->LayerInfo);
 124   return ret;
 125
 126   AROS_LIBFUNC_EXIT
 127 } /* MoveLayerInFrontOf */