On Tue, Sep 13, 2011 at 10:42 AM, Andre RsFiveTwo <rs.andre@gmail.com> wrote:

Hi,
I'm trying to create an animation with words based on the (ltktest) function in the library (rotate).
For that I'm storing the words in a plist. The code to maintain the words is:

(defvar *initial-word-energy* 100)
(defvar *words* '()) ; list of words in the form (:text :x :y :energy)

(defun make-word (text x y display-item)
(list :text text :x x :y y :display-item display-item :energy *initial-word-energy*))

(defun add-word (word) (push word *words*))

Then I created a button that will add words to the plist and to the canvas:

           (enter-text-button (make-instance 'button
                                            :master controls
                                            :text "Enter text"
                                            :command (lambda ()
                                                        ;;store word in *words*
                                                        (let* ((text (text user-text-entry))
                                                                (x (random (read-from-string
                                                                           (cget drawing-canvas-reference
                                                                                            :width))))
                                                                (y (random (read-from-string
                                                                           (cget drawing-canvas-reference
                                                                                            :height))))
                                                                ;;put text in canvas
                                                                (display-item (create-text drawing-canvas-reference
                                                                                           x
                                                                                           y
                                                                                           text))
                                                                (word (make-word
                                                                       text
                                                                       x
                                                                       y
                                                                       display-item)))

                                                        ;;store new word
                                                        (add-word word)

                                                        ;;clear entry widget
                                                        (setf (text user-text-entry) "")
                                                        (focus user-text-entry)
                                                        (finish-output)))))

The idea is that a word will store the position, the text, other things and the visual representation of the text.

In the animation part (same code as rotate in the library) I move the words, and here is the problem.
If I try the move changing the coordinates of the updated values of x and y of the word the text apearing in the canvas 'jumps' in the first move, afterward it move normally.
The other alternative is to use itemmove, which works. but I would like to just manipulate x and y of the word and transpose it to the created text item in the canvas.

     ;;move display item
    [do not work] ---> (set-coords *drawing-canvas-reference* (getf word :display-item) (list (getf word :x) (getf word :y)))
    [works]         ----> (itemmove *drawing-canvas-reference* (getf word :display-item) atract-x atract-y)

So, I would like to understand better why there seems to be a difference in the values of x an y for the element stored and the element displayed, although they have been created with the same values.
If possible, I would like to know how can I query the created text element about it's x and y values.

Sorry for the long message.
Any help is appreciated.
Thanks,
André