rom/hyperlayers/movelayerinfrontof.c

   1 /*
   2     Copyright © 1995-2001, 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 #include "layers_intern.h"
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19 #include <proto/layers.h>
  20
  21         AROS_LH2(LONG, MoveLayerInFrontOf,
  22
  23 /*  SYNOPSIS */
  24         AROS_LHA(struct Layer *, layer_to_move, A0),
  25         AROS_LHA(struct Layer *, other_layer, A1),
  26
  27 /*  LOCATION */
  28         struct LayersBase *, LayersBase, 28, Layers)
  29
  30 /*  FUNCTION
  31         Moves layer directly in front of another layer. Other layers
  32         might become visible. You cannot move a backdrop layer in front
  33         of a non-backdrop layer. You can also not move a layer in front
  34         of a layer with different relationship to the root layer. Boot
  35         have to be children of grandchildren or grandgrandchildren etc.
  36         of the root layer. The root layer is not visible to you and
  37         should never be accessed.
  38         If parts of a simple layer become visible these areas are added
  39         to the damage list.
  40
  41     INPUTS
  42         layer_to_move - pointer to layer that is to be moved
  43         other_layer   - pointer to other layer that will be behind the
  44                         layer_to_move.
  45
  46     RESULT
  47         TRUE  - layer was moved
  48         FALSE - layer could not be moved. (probably out of memory)
  49
  50     NOTES
  51
  52     EXAMPLE
  53
  54     BUGS
  55
  56     SEE ALSO
  57
  58     INTERNALS
  59
  60     HISTORY
  61         27-11-96    digulla automatically created from
  62                             layers_lib.fd and clib/layers_protos.h
  63
  64 *****************************************************************************/
  65 {
  66   AROS_LIBFUNC_INIT
  67   AROS_LIBBASE_EXT_DECL(struct LayersBase *,LayersBase)
  68
  69   struct Layer * first, *_l;
  70   int toback = TRUE;
  71   LONG ret;
  72
  73   if (layer_to_move->parent  != other_layer->parent ||
  74       layer_to_move->priority < other_layer->priority)
  75     return FALSE;
  76
  77   LockLayers(layer_to_move->LayerInfo);
  78
  79   first = GetFirstFamilyMember(layer_to_move);
  80
  81   _l = layer_to_move->parent->front;
  82   while (1)
  83   {
  84     /*
  85      * If I run into the other layer before I find l
  86      * then I know I have to move it to the back.
  87      */
  88     if (_l == other_layer)
  89       break;
  90
  91     if (_l == layer_to_move)
  92     {
  93       toback = FALSE;
  94       break;
  95     }
  96     _l = _l->front;
  97     if (NULL == _l)
  98     {
  99       UnlockLayers(layer_to_move->LayerInfo);
 100       return FALSE;
 101     }
 102   }
 103
 104   _l = GetFirstFamilyMember(other_layer);
 105
 106   if (TRUE == toback)
 107   {
 108     /*
 109      * If the topmost child of the other layer is
 110      * behind my layer I don't have to do anything.
 111      */
 112     if (layer_to_move->back == _l)
 113     {
 114       UnlockLayers(layer_to_move->LayerInfo);
 115       return TRUE;
 116     }
 117     ret = _MoveLayerBehind(layer_to_move, _l, LayersBase);
 118   }
 119   else
 120   {
 121     ret = _MoveLayerToFront(layer_to_move, _l, LayersBase);
 122   }
 123
 124   UnlockLayers(layer_to_move->LayerInfo);
 125   return ret;
 126
 127   AROS_LIBFUNC_EXIT
 128 } /* MoveLayerInFrontOf */