source: trunk/src/netlabs/macros/undo.e@ 2417

/****************************** Module Header *******************************
*
* Module Name: undo.e
*
* Copyright (c) Netlabs EPM Distribution Project 2002
*
* $Id: undo.e 2417 2011-05-15 23:32:51Z aschn $
*
* ===========================================================================
*
* This file is part of the Netlabs EPM Distribution package and is free
* software.  You can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* Netlabs EPM Distribution.  This library is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* General Public License for more details.
*
****************************************************************************/

; ---------------------------------------------------------------------------
; Moved from STDCTRL.E
defc ProcessUndo
   --undoaction 1, PresentState;
   --undoaction 2, OldestState;
   CurrentUndoState = arg(1)
   --
   --if CurrentUndoState<OldestState then
   --  return
   --endif
   --sayerror 'Undoing State ' CurrentUndoState ' old='OldestState ' new='PresentState
   undoaction 7, CurrentUndoState;
   --refresh;

; ---------------------------------------------------------------------------
; Restore standard undo recording. Some commands have to disable that
; in order to not clutter the record list, e.g. when a command is used
; repeatedly.
; Values for action:
;    0: at every keystroke (not default)
;    1: at every command (not default)
;    2: when moving the cursor from a modified line (default)
; This is used by following key defcs and events, e.g.:
; Space, Return, defselect, ProcessOtherKeys
defproc EnableUndoRec
   --action = 0  -- action, the 2nd param of undoaction, must be a var
   --undoaction 4, action  -- 4: disable undo recording at action

   --action = 1  -- action, the 2nd param of undoaction, must be a var
   --undoaction 5, action  -- 5: enable undo recording at action

   action = 2  -- action, the 2nd param of undoaction, must be a var
   undoaction 5, action  -- 5: enable undo recording at action
   return

; ---------------------------------------------------------------------------
; Disable undo recording. This is used by several key defcs, e.g.:
; Space, Tab, TypeTab, ShiftLeft, ShiftRight, DeleteChar, BackSpace
defproc DisableUndoRec
compile if 1
   universal curkey
   universal prevkey
   -- Only disable it if current key wasn't pressed before
   if curkey <> prevkey then
compile endif
      action = 0  -- action, the 2nd param of undoaction, must be a var
      undoaction 4, action  -- 4: disable undo recording at action
      action = 1  -- action, the 2nd param of undoaction, must be a var
      undoaction 4, action  -- 4: disable undo recording at action
      action = 2  -- action, the 2nd param of undoaction, must be a var
      undoaction 4, action  -- 4: disable undo recording at action
compile if 1
   endif
compile endif
   return

; ---------------------------------------------------------------------------
; Create a new undo record and restore standard undo behaviour
defproc NewUndoRec
   if .modify then
      undoaction 1, junk  -- 1: Create a new state
      call EnableUndoRec()
   endif
   return

; ---------------------------------------------------------------------------
; Commands for accessing undo procs from REXX and C
defc RestoreUndo, EnableUndoRec
   call EnableUndoRec()

defc DisableUndoRec
   call DisableUndoRec()

defc NewUndoRec
   call NewUndoRec()

; ---------------------------------------------------------------------------
; Moved from STDCTRL.E
defc RenderUndoInfo
    undoaction 1, PresentState        -- Do to fix range, not for value.
;   undoaction 2, OldestState;
;   statestr=PresentState OldestState \0
    undoaction 6, StateRange               -- query range
    parse value staterange with oldeststate neweststate
    statestr = newestState oldeststate\0
    action = 1
    undoaction 4, action
    -- sayerror '<'statestr'>'
    call windowmessage( 1, arg(1),   -- send message back to dialog
                        32,               -- WM_COMMAND - 0x0020
                        9999,
                        ltoa( offset( statestr) || selector( statestr), 10))

; ---------------------------------------------------------------------------
; Moved from STDCTRL.E
defc UndoDlg
;   undoaction 1, PresentState        -- Do to fix range, not for value.
;   undoaction 6, StateRange               -- query range
;   parse value staterange with oldeststate neweststate
;   if oldeststate = neweststate  then
;      sayerror 'No other undo states recorded.'
;   else
       call windowmessage( 0,  getpminfo(APP_HANDLE),
                           5131,               -- EPM_POPUNDODLG
                           0,
                           0)
;   endif

; ---------------------------------------------------------------------------
; Moved from STDCTRL.E
defc Undo
   undo

; ---------------------------------------------------------------------------
; From EPMSMP\UNDOREDO.E
; Changed:
;    o  beep disabled

/* The following code defines a couple of keys that let you step backwards
and forwards through the undo states.  For the sake of example, I've
defined the Undo key as Ctrl+U and the Redo key as Ctrl+R.  You might
prefer to select other keys that don't conflict with standard EPM key
definitions.  One important note - the way that the keys determine if
you're still in an undo/redo sequence is checking if the previous key
pressed was also Ctrl+U or Ctrl+R.  Because of the way keys are handled,
you must press and hold the Ctrl key for as long as you're stepping back
and forth (by pressing U and R) - once you release the Ctrl key, the next
time you press Ctrl+U or Ctrl+R, they will see the previously-pressed key
as being the Ctrl key, not Ctrl+U or Ctrl+R.  The same is true if you
define the keys to be a Shift or Alt combination (which implies that they
both have to have the same shift state - both start with s_, both with c_,
both with a_, or both unshifted).

Note also that this assumes the user has not enabled undo-state recording
on *every* keystroke.  If you did, then you might have to add code here
to stop recording changes on keystrokes, and it's not clear how you'd
figure out when to turn it back on.
                                         by:  Larry Margolis  */

defc Undo1
   universal current_undo_state
   universal curkey
   universal prevkey
   parse value( prevkey) with Key''\1''Cmd
   UndoKeys = strip( GetAVar( 'keycmd.undo1')) strip( GetAVar( 'keycmd.redo1'))
   --dprintf( 'Key = 'Key', UndoKeys = 'UndoKeys)
   if wordpos( Key, UndoKeys) > 0 then  -- last key was undo or redo
      parse value current_undo_state with PresentState OldestState NewestState
      if PresentState > OldestState then
         PresentState = PresentState - 1
         undoaction 7, PresentState
         current_undo_State = PresentState OldestState NewestState
         'SayHint Now at state' PresentState 'of' NewestState
      else
         --call beep(800, 500)
         'SayHint Already at state' PresentState 'of' NewestState
      endif
   else
      -- Need to get new state information
      undoaction 1, starting_state  -- Do to fix range and for value.
      undoaction 6, StateRange               -- query range
      parse value StateRange with OldestState NewestState
      if NewestState = 1 then
         'SayHint No earlier undo states available'
      else
         PresentState = NewestState - 1
         undoaction 7, PresentState
         current_undo_state = PresentState OldestState NewestState
         'SayHint Initialized at state' PresentState 'of' NewestState
      endif
   endif

defc Redo1
   universal current_undo_state
   universal curkey
   universal prevkey
   parse value( prevkey) with Key''\1''Cmd
   UndoKeys = strip( GetAVar( 'keycmd.undo1')) strip( GetAVar( 'keycmd.redo1'))
   --dprintf( 'Key = 'Key', UndoKeys = 'UndoKeys)
   if wordpos( Key, UndoKeys) > 0 then  -- last key was undo or redo
      parse value current_undo_state with PresentState OldestState NewestState
      if PresentState < NewestState then
         PresentState = PresentState + 1
         undoaction 7, PresentState
         current_undo_state = PresentState OldestState NewestState
         'SayHint Now at state' PresentState 'of' NewestState
      else
         'SayHint Already at state' PresentState 'of' NewestState
      endif
   else
      --call beep(800, 500)
      -- Need to get new state information
      undoaction 1, starting_state  -- Do to fix range and for value.
      undoaction 6, StateRange               -- query range
      parse value StateRange with OldestState NewestState
      presentState = NewestState
      current_undo_state = PresentState OldestState NewestState
      'SayHint Initialized at state' PresentState 'of' NewestState
   endif