chiark - git - mdw - ssr/blob - StraySrc/Libraries/Sapphire/sh/drag

   1 ;
   2 ; drag.sh
   3 ;
   4 ; Support code for dragging operations
   5 ;
   6 ; © 1995-1998 Straylight
   7 ;
   8
   9 ;----- Licensing note -------------------------------------------------------
  10 ;
  11 ; This file is part of Straylight's Sapphire library.
  12 ;
  13 ; Sapphire is free software; you can redistribute it and/or modify
  14 ; it under the terms of the GNU General Public License as published by
  15 ; the Free Software Foundation; either version 2, or (at your option)
  16 ; any later version.
  17 ;
  18 ; Sapphire is distributed in the hope that it will be useful,
  19 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ; GNU General Public License for more details.
  22 ;
  23 ; You should have received a copy of the GNU General Public License
  24 ; along with Sapphire.  If not, write to the Free Software Foundation,
  25 ; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26
  27 ;----- Overview -------------------------------------------------------------
  28 ;
  29 ; Functions provided:
  30 ;
  31 ;  drag_start
  32 ;  drag_scroll
  33 ;  drag_setDash
  34 ;  drag_cancel
  35 ;  drag_redraw
  36 ;  drag_eorColour
  37
  38                 [       :LNOT::DEF:drag__dfn
  39                 GBLL    drag__dfn
  40
  41 ; --- drag_start ---
  42 ;
  43 ; On entry:     R0 == window containing the drag
  44 ;               R1 == flags word (see flags below)
  45 ;               R2 == pointer to drag routine
  46 ;               R3 == magic number to pass in R9
  47 ;               R4 == value to pass to routine in R10
  48 ;               R5 == value to pass to routine in R12
  49 ;
  50 ; On exit:      --
  51 ;
  52 ; Use:          Starts a drag operation.  Any outstanding drag operation
  53 ;               is cancelled on the assumption that someone stole our
  54 ;               UserDragBox event.
  55
  56                 IMPORT  drag_start
  57
  58 ; --- drag_scroll ---
  59 ;
  60 ; On entry:     R1 == pointer to window state block
  61 ;
  62 ; On exit:      R2,R3 == new scroll positions to set
  63 ;               R14 == R1+20 (pointer to scroll offsets)
  64 ;
  65 ; Use:          Works out the scroll positions which should be set to auto-
  66 ;               scroll the window.  The algorithm is simple: the window is
  67 ;               scrolled so that the point beneath the mouse pointer is
  68 ;               within the window's visible work area.
  69
  70                 IMPORT  drag_scroll
  71
  72 ; --- drag_setDash ---
  73 ;
  74 ; On entry:     R0 == dash pattern byte
  75 ;
  76 ; On exit:      --
  77 ;
  78 ; Use:          Sets the dash pattern to be the given value.
  79
  80                 IMPORT  drag_setDash
  81
  82 ; --- drag_cancel ---
  83 ;
  84 ; On entry:     --
  85 ;
  86 ; On exit:      --
  87 ;
  88 ; Use:          Cancels the current drag operation.
  89
  90                 IMPORT  drag_cancel
  91
  92 ; --- drag_redraw ---
  93 ;
  94 ; On entry:     R1 == pointer to redraw block
  95 ;
  96 ; On exit:      --
  97 ;
  98 ; Use:          Redraws the drag box, if the redraw takes place in the
  99 ;               currently dragging window.
 100
 101                 IMPORT  drag_redraw
 102
 103 ; --- drag_eorColour ---
 104 ;
 105 ; On entry:     R0 == colour A
 106 ;               R1 == colour B
 107 ;
 108 ; On exit:      --
 109 ;
 110 ; Use:          Sets the foreground colour to be an EOR colour such that
 111 ;               when painted over Wimp colour A, it appears as Wimp colour B.
 112
 113                 IMPORT  drag_eorColour
 114
 115 ;----- Flags ----------------------------------------------------------------
 116
 117 drFlag_noUpdate EQU     (1<<0)                  ;Don't generate update events
 118
 119 ;----- Drag handler events --------------------------------------------------
 120
 121 ; --- Note ---
 122 ;
 123 ; The events which request that you draw something are called for each
 124 ; rectangle of the draw operation -- i.e. do not call Wimp_GetRectangle
 125 ; because this is done for you.
 126
 127                 ^       0
 128 drEvent_draw    #       1                       ;Draw dragged object
 129                                                 ;R1 == pointer to redraw blk
 130                                                 ;R2,R3 == drag start posn
 131                                                 ;R4,R5 == drag current posn
 132                                                 ;R6,R7 == window origin
 133                                                 ;Dash pattern set up
 134
 135 drEvent_undraw  #       1                       ;Undraw dragged object
 136                                                 ;Regs as for drEvent_draw
 137                                                 ;Normally use the same code
 138
 139 drEvent_update  #       1                       ;Redraw dragged object in
 140                                                 ;place
 141                                                 ;Regs as for drEvent_draw
 142                                                 ;Dash pattern set up so that
 143                                                 ;single plot will rotate box,
 144                                                 ;so may share code with
 145                                                 ;drEvent_draw
 146
 147 drEvent_trans   #       1                       ;Translate coordinates
 148                                                 ;R1 == ptr to window state
 149                                                 ;R4,R5 == pointer position
 150                                                 ;R6,R7 == window origin
 151                                                 ;Translate pointer position
 152                                                 ;to internal coordinates if
 153                                                 ;this is useful to you.
 154                                                 ;Return new coords in R4,R5
 155
 156 drEvent_getPos  #       1                       ;Read pointer position
 157                                                 ;R1 == ptr to window state
 158                                                 ;R2,R3 == start position
 159                                                 ;R4,R5 == pointer position
 160                                                 ;R6,R7 == window origin
 161                                                 ;Used to read pointer posn.
 162                                                 ;Do any grid snapping here
 163                                                 ;and return with R4,R5 as
 164                                                 ;coords to use.
 165
 166 drEvent_done    #       1                       ;Drag operation completed
 167                                                 ;R1 == ptr to window state
 168                                                 ;R2,R3 == drag start posn
 169                                                 ;R4,R5 == drag current posn
 170
 171 drEvent_cancel  #       1                       ;Drag operation aborted
 172                                                 ;No other registers set up
 173
 174                 ]
 175
 176 ;----- That's all, folks ----------------------------------------------------
 177
 178                 END