ltk-user September 2012

ltk-user@common-lisp.net

2 participants
2 discussions

[ltk-user] two beginner questions (iterate over children / X_cursor)
by harven＠free.fr 26 Oct '12

26 Oct '12

Hi, I am working through the tk tutorial using ltk http://www.tkdocs.com/tutorial/firstexample.html One of the first examples is a feet-to-meter converter. At some point, the padding of the widgets is set by looping through the children of the mainframe. foreach w [winfo children .c] {grid configure $w -padx 5 -pady 5} Q1: How can I do this with ltk ? Is there a function that returns the list of the children of a widget ? Q2: The *cursor* variable lists "X_cursor" as its first element, but tk reports an error. (with-ltk nil (pack (make-instance 'button :text "some" :cursor "X_cursor" :width 15))) => Tcl/Tk error: bad cursor spec "x_cursor" This is the sole cursor in *cursor* that produces an error. I am using gnu/linux on debian squeeze stable and tk 8.5. Finally, here is my attempt at building the converter. It seems to work, I welcome any comments or advices. (defun calculate (arg) (let* ((*read-eval* nil) (num (read-from-string arg))) (if (numberp num) (format nil "~,4f" (* 0.3048 num)) "" ))) (defun converter-ltk () (with-ltk () (let* ((mainframe (make-instance 'frame :padding "\"3 3 12 12\"")) (feet-entry (make-instance 'entry :width 7 :master mainframe)) (label-1 (make-instance 'label :master mainframe)) (label-2 (make-instance 'label :text "feet" :master mainframe)) (label-3 (make-instance 'label :text "is equivalent to" :master mainframe)) (label-4 (make-instance 'label :text "meters" :master mainframe)) (calc (make-instance 'button :text "Calculate" :master mainframe :command (lambda () (setf (text label-1) (calculate (text feet-entry))))))) (bind feet-entry "<Return>" (lambda (evt) (declare (ignore evt)) (setf (text label-1) (calculate (text feet-entry))))) (wm-title *tk* "Feet to Meters") (grid mainframe 0 0 :sticky "nesw") (grid-columnconfigure mainframe 0 :weight 1) (grid-rowconfigure mainframe 0 :weight 1) (grid feet-entry 1 2 :sticky "we") (grid label-1 2 2 :sticky "we") (grid label-2 1 3 :sticky "w") (grid label-3 2 1 :sticky "e") (grid label-4 2 3 :sticky "w") (grid calc 3 3 :sticky "w") ; (loop for child in (children mainframe "winfo") ;; ?? ; do (configure child :padx 5 :pady 5)) ;; ?? (focus feet-entry))))

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[ltk-user] problem with the :background keyword
by harven＠free.fr 01 Sep '12

01 Sep '12

Hi, I am a beginner at both ltk and tk and I am trying to convert a small programme from Tk to LTk. Tk version: pack [button .b -text "Push Me" -background red -command {tk_messageBox -message "hello, world"}] LTk version: (with-ltk () (let ((my-button (make-instance 'text :text "Push Me" :background :red :command (lambda () (message-box "Hello, world!" "message" 'ok 'info))))) (pack my-button))) The Tk version works fine, whereas the LTk version gives the following error: Invalid initialization argument: :BACKGROUND in call for class #<STANDARD-CLASS BUTTON>. See also: The ANSI Standard, Section 7.1.2 [Condition of type INITARG-ERROR] On the other hand, there is no error if the :background line is removed. It's as if the :background keyword is only allowed for a few specific widgets, like the text widget. I also get errors if I try to set it with configure, as shown in the LTk manual, e.g. (configure my-button :background :blue) What am I doing wrong ? Any help is appreciated, I am using tk8.5 on debian squeeze, with sbcl 1.0.55, and the current release of ltk that ships with quicklisp. Sincerely, -- harven

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ltk-user September 2012