Will Donnelly <will.donnelly@gmail.com> writes: HI Will, First, thanks for your detail explain.

Hi Andy,

Your program didn't compile as given, so I cut out some of the event handling fanciness you were doing. Also, my modified version restarts whenever the 'r' key is pressed. I figure those changes aren't important to the problem at hand.

Anyway, I don't think it's ever going to be possible to define a Binary instance for a TextView, since all of the functions which can yield information about it are impure. I would recommend extracting the relevant data beforehand, and then persisting it in a tuple. You could use some 'marshal<WIDGET>' and 'recreate<WIDGET>' functions if you need to persist many different widget types. Saving just the text can be done as follows: Before your mail, i thinking long time to integrate dyre with gtk2hs program.

I have three need to dynamic reconfigure gtk2hs program. 1-> Entry new version master binary if recompile successful. (dyre have implement this with relaunchMaster) 2-> Recompile new module dynamic for update algorithms. (dyre have implement this) 3-> Keep gtk2hs object state through reboot. Now just point (3) need solve. To keep GTK widget state, it's un-necessary to define a Binary instance for Gtk2hs object (and not possible), we just need extract relevant data from widget ( for TextView, we can extract text, iter, etc. ), then recreate widget with states after we relaunch master binary. Then we can keep gtk2hs state through reboot. Below is my analysis that how to keep gtk2hs object state: gtk2hs use c2hs binding Haskell to C, c2hs will use Ptr point to C struct address when it found current type is C struct. So we can't save pointer address for restore, because pointer address will not valid after relaunch master binary. Second solution, we can use Haskell define pure state model, then use gtk2hs rendering data. Example, we can use Haskell define "data HaskellTextBuffer" for keep Buffer information for TextView. But this solution have it's disadvantage, we need do duplicate work in HaskellTextBuffer that TextBuffer have do. And between TextBuffer and TextView have many relevant C functions need handle, and this solution is not neat. Third solution, we just need define new type that store necessary information to recreate widget, example like below: data TextViewState ---------------------- | TextBuffer -> Text | | TextBuffer -> Iter | ---------------------- Save TextViewState => Dyre recompile => Restore TextViewState => Recreate widget with TextViewState

<code> module DyreExample where

import Graphics.UI.Gtk hiding (get) import qualified Graphics.UI.Gtk.Gdk.Events as E

import qualified Config.Dyre as Dyre import Config.Dyre.Relaunch

import System.IO import Data.Binary

data Config = Config { message :: String, errorMsg :: Maybe String }

defaultConfig :: Config defaultConfig = Config "Dyre Example v0.1" Nothing

showError :: Config -> String -> Config showError cfg msg = cfg { errorMsg = Just msg }

realMain Config{message = message, errorMsg = errorMsg } = do initGUI

textView <- textViewNew textBuffer <- textViewGetBuffer textView text <- restoreBinaryState "" putStrLn $ "Restored state: " ++ text textBufferSetText textBuffer text

rootWindow <- windowNew rootWindow `onDestroy` mainQuit windowFullscreen rootWindow

rootWindow `containerAdd` textView

widgetShowAll rootWindow

rootWindow `onKeyPress` (\event -> dyreKeyTest event textView)

mainGUI

dyreExample = Dyre.wrapMain $ Dyre.defaultParams { Dyre.projectName = "Main" , Dyre.realMain = realMain , Dyre.showError = showError }

dyreKeyTest :: E.Event -> TextView -> IO Bool dyreKeyTest ev textView = do case E.eventKeyName ev of "r" -> do textBuffer <- textViewGetBuffer textView sI <- textBufferGetStartIter textBuffer eI <- textBufferGetEndIter textBuffer text <- textBufferGetText textBuffer sI eI True putStrLn $ "Relaunching with state: " ++ text relaunchWithBinaryState text Nothing return True _ -> return False </code>

Other comments: 1. It isn't necessary to explicitly tell Dyre to do a custom compile. It will take care of figuring that out once you restart it. 2. Instead of manually setting paths in the code, you can use the '--dyre-debug' command-line flag, which will cause Dyre to look for configurations in the current directory, and store temporary files in a 'cache' subdirectory. 3. Giving a project name of 'Main' causes Dyre to see the file 'Main.hs' as a custom configuration. I'm not sure if that's what you intended, but it will make testing custom configurations harder than it needs to be. 4. Good luck with the rest of your project!

Thanks for your suggestions! :) -- Andy

- Will Donnelly

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