Redraw writes green X's

[Munksgaard]

I get a screen looking like the one below, when i try to run the following code:

(ns test.core
  (:use lanterna.screen))

(defn main-loop [scr x y]
  (redraw scr)
  (let [k (get-key-blocking scr)]))

(defn main []
  (let [scr (get-screen :swing)]
    (in-screen scr
               (main-loop scr 0 0))))

Any suggestions?

[sjl]

Did you resize the window at all? I sometimes saw that when I dragged the window to be bigger but Lanterna hadn't gotten around to updating its size...

[Munksgaard]

Not on purpose, but XMonad probably makes it a certain size when it is started. If I make the window smaller, the X's disappear and the screen is properly black when enlarged.

I just tried to record what happens, but when running an ffmpeg recording session, the X's don't appear.
Instead, here is an album that describes what is going on: http://imgur.com/a/3Q4Pz

Also, sometimes when i compile, i hardly get the behavior at all, other times only once in a while, and some times it happens all the time, even though the code is the same (like if i remove some comments or some other unrelated defns). Maybe some timing issues with XMonads resizing and lanternas detection of screen size?

[fhennig]

I had the same issue, runnig i3, also a tiling manager.

I found a workaround that seems to work:

(s/start-screen scr)
(s/get-key scr)
(s/redraw scr)

(after that, the correct screen size is determined.

[Martin-S-Weber]

Same problem here with awesome wm (yes, a tiling WM) - but my tests make me assume it's rather an issue in screen resizing in general. Will revisit / test / solve? for 0.10.0.

[postboy]

@fhennig, thank you very much for workaround, it was just what I needed, it worked for me! Much appreciated!

[UnchartedSystems]

For anyone stumbling onto this issue now, another workaround I've found for handling green Xs when resizing the screen with a resize listener

(defn clear-scr [cols rows]
  (let [blank (apply str (repeat cols " "))]
    (doseq [row (doall (range rows))]
      (s/put-string scr 0 row blank))))

(defn handle-resize [cols rows]
  (s/redraw scr)
  (clear-scr cols rows)
  ;; Rerender Screen Here
  (s/redraw scr))
  
  (s/add-resize-listener scr handle-resize)

redraw seems (?) to refresh the screen object's internal representation of it's size after being resized, so I've found it necessary to do it before clearing & rerendering.