b4a00883f358625923365ca1560c96edec172a52sf{- |

b4a00883f358625923365ca1560c96edec172a52sfModule : $Header$

b4a00883f358625923365ca1560c96edec172a52sfDescription : description of undo and redo functions

b4a00883f358625923365ca1560c96edec172a52sfCopyright : uni-bremen and DFKI

b4a00883f358625923365ca1560c96edec172a52sfLicense : GPLv2 or higher, see LICENSE.txt

b4a00883f358625923365ca1560c96edec172a52sfMaintainer : r.pascanu@jacobs-university.de

b4a00883f358625923365ca1560c96edec172a52sfStability : provisional

b4a00883f358625923365ca1560c96edec172a52sfPortability : portable

b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sfCMDL.UnDoRedo contains the implementation of the undo and redo commads

0662ed52e814f8f08ef0e09956413a792584eddffuankg-}

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b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sfmodule CMDL.UndoRedo

b4a00883f358625923365ca1560c96edec172a52sf ( cUndo

b4a00883f358625923365ca1560c96edec172a52sf , cRedo

b4a00883f358625923365ca1560c96edec172a52sf ) where

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b4a00883f358625923365ca1560c96edec172a52sfimport Interfaces.History (redoOneStep, undoOneStep)

44f575c8cb19a7a5cd61664a7848be6bc197df02fuankgimport Interfaces.Command (showCmd)

b4a00883f358625923365ca1560c96edec172a52sfimport Interfaces.DataTypes

b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sfimport CMDL.DataTypesUtils (genMessage)

b4a00883f358625923365ca1560c96edec172a52sfimport CMDL.DataTypes (CmdlState (intState))

b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sf-- | Undoes the last command entered

b4a00883f358625923365ca1560c96edec172a52sfcUndo :: CmdlState -> IO CmdlState

b4a00883f358625923365ca1560c96edec172a52sfcUndo = cdo True

b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sf-- | Redoes the last undo command

b4a00883f358625923365ca1560c96edec172a52sfcRedo :: CmdlState -> IO CmdlState

b4a00883f358625923365ca1560c96edec172a52sfcRedo = cdo False

b4a00883f358625923365ca1560c96edec172a52sf

b4a00883f358625923365ca1560c96edec172a52sfcdo :: Bool -> CmdlState -> IO CmdlState

b4a00883f358625923365ca1560c96edec172a52sfcdo isUndo state =

b4a00883f358625923365ca1560c96edec172a52sf let msg = (if isUndo then "un" else "re") ++ "do"

b4a00883f358625923365ca1560c96edec172a52sf in case (if isUndo then undoList else redoList) . i_hist $ intState state of

b4a00883f358625923365ca1560c96edec172a52sf [] -> return $ genMessage [] ("Nothing to " ++ msg) state

b4a00883f358625923365ca1560c96edec172a52sf action : _ ->

b4a00883f358625923365ca1560c96edec172a52sf do

b4a00883f358625923365ca1560c96edec172a52sf nwIntState <- (if isUndo then undoOneStep else redoOneStep)

b4a00883f358625923365ca1560c96edec172a52sf $ intState state

b4a00883f358625923365ca1560c96edec172a52sf return . genMessage [] ("Action '" ++ showCmd (command action)

b4a00883f358625923365ca1560c96edec172a52sf ++ "' is now " ++ msg ++ "ne")

b4a00883f358625923365ca1560c96edec172a52sf $ state { intState = nwIntState }

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