ltk-user April 2012

ltk-user@common-lisp.net

5 participants
4 discussions

[ltk-user] Add an event in the ltk event queue
by Syll 05 Jun '12

05 Jun '12

Hello Is it possible to add an event in the ltk event queue from another thread ? I can put events in a queue and use (after ...) to read it periodically in the ltk thread, but it would be easier and more efficient to use the ltk event queue directly. Thank you Syll

2 2

[ltk-user] Selection in listbox
by Syll 28 Apr '12

28 Apr '12

Hello I have a few problems/questions with listbox selection (especially multiple selection). * If the listbox does'nt have the focus and I select items with Ctrl+click (including the first one), events from keys are not triggered for this listbox. Is it because the listbox has'nt get the focus at all ? How do i give the focus to the listbox (but not to any item) ? * If I understand this well, there are two special states that can be applied to list items : say "selected" (zero, one or several items) and "focused" (zero or one item). * I can select an item with listbox-select. How can I give the focus to an item ? * I catch selection events with <<ListboxSelect>>. How can I catch "item focus" events ? How can I get the focused item ? Thank you Syll

1 1

[ltk-user] resizing canvas, exiting main loop, fullscreen
by Tamas K Papp 28 Apr '12

28 Apr '12

Hi, I am trying to write a small program that would do the following: 1. create a full screen window with no decorations 2. when the left mouse button is pressed, change the color of the window according to the relative position (ie the color is calculated from the position), 3. when the right mouse button is pressed, exit. BTW, the application is for testing LCD screens. I came up with the following: (in-package :cl-user) (require :ltk) (use-package :ltk) (defun hex-color (r g b) "Return a hexadecimal color string. R G B should be in [0,1]." (flet ((normalize (x) (assert (<= 0 x 1)) (round (* x 255)))) (format nil "#~2,0x~2,0x~2,0x" (normalize r) (normalize g) (normalize b)))) (defun lcd-test () (with-ltk () (let* ((canvas (make-instance 'canvas)) (down nil)) (flet ((set-color (x-rel y-rel) (configure canvas "background" (hex-color x-rel y-rel 0.5)))) (pack canvas) (bind canvas "<ButtonPress-1>" (lambda (evt) (set-color (/ (event-x evt) (window-width canvas)) (/ (event-y evt) (window-height canvas))) (setf down t))) (bind canvas "<ButtonPress-2>" (lambda (evt) (declare (ignore evt)) (setf *exit-mainloop* t))))))) However, a. the application does not exit (maybe I am doing it wrong, I found *exit-mainloop* in some examples), b. I could not figure out how to make a full screen window, c. when the window is resized, the canvas isn't (but of course with a fullscreen window this would not be an issue). Any help would be appreciated. Tamas

3 6

[ltk-user] unpack frame?
by Christy 27 Apr '12

27 Apr '12

I'm trying to program a little computer game for my sons, and I'm wondering if there is a way to have some of the buttons on it disappear for a while and then return. I have them in a frame, and I was wondering if there is a command I could use to remove that frame temporarily. Any suggestions? Christy

2 1

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ltk-user April 2012