Gtk2Hs/Tutorials/TreeView
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I had much trouble with creating a simple selection from a list, lacking examples on the web i could find. Therefore i post here the solution I have working - it is not optimal and I would appreciate comments. I shows a simple list with four names and after clicking on one it says which one you selected. i hope it is useful for others!
module Main where
{- an example how to select from a list
not satisfactory yet:
- there should be a simpler way to render a simple list
- i could not convert the model i got back to a list
from which to get the value
- the interface offers a great number of functions
and it is very difficult to find which ones are
really needed for simple tasks
-}
import Graphics.UI.Gtk
import Graphics.UI.Gtk.ModelView as Model
main :: IO ()
main = do
initGUI -- is start
window <- windowNew
list <- listStoreNew ["Vince", "Jhen", "Chris", "Sharon"]
treeview <- Model.treeViewNewWithModel list
Model.treeViewSetHeadersVisible treeview True
-- there should be a simpler way to render a list as the following!
col <- Model.treeViewColumnNew
Model.treeViewColumnSetTitle col "colTitle"
renderer <- Model.cellRendererTextNew
Model.cellLayoutPackStart col renderer False
Model.cellLayoutSetAttributes col renderer list
$ \ind -> [Model.cellText := ind]
Model.treeViewAppendColumn treeview col
tree <- Model.treeViewGetSelection treeview
Model.treeSelectionSetMode tree SelectionSingle
Model.onSelectionChanged tree (oneSelection list tree)
set window [ windowDefaultWidth := 100
, windowDefaultHeight := 200
, containerChild := treeview
]
onDestroy window mainQuit
widgetShowAll window
mainGUI
return ()
oneSelection :: ListStore String -> Model.TreeSelection -> IO ()
oneSelection list tree = do
sel <- Model.treeSelectionGetSelectedRows tree
let s = head (head sel)
v <- Model.listStoreGetValue list s
putStrLn $ "selected " ++ v