Hi Alex, thanks for your reply. Are you on Slack? On Tue, Nov 24, 2020, 00:21 Alex Harsanyi <[email protected]> wrote:
> The snip selection and resize is handled by the pasteboard > on-default-event, and it looks like your code also handles events, > resulting in duplicate handling. There is no clear solution to this, as > the system does not know if you want to select snips or draw rectangles. > However, you could use Ctrl + drag to draw the rectangles. To do that, > move your own code into a new method, say "my-on-default-event" and call > that method for mouse events which have the control key set. > > (define/override (on-default-event event) > (if (send event get-control-down) > (on-default-event-1 event) > (super on-default-event event))) > > The disadvantage now, is that there is no visual feedback when you use > Ctrl + drag (previously, the selection rectangle was drawn). To draw an > intermediate selection rectangle, you can track mouse motion events in your > "my-on-default-event" and keep the intermediate rectangle, same as you do > for "start-pos", than override the "on-paint" method of the pasteboard to > draw the intermediate rectangle. Note that you cannot call on-paint > directly from on-default-event, and the pasteboard does not know it needs > to redraw itself unless you call "refresh". > > Alex. > > On Monday, November 23, 2020 at 7:49:00 PM UTC+8 [email protected] > wrote: > >> >> >> >> >> *please, disregard the previous email, there was a little bug. this is >> the correct code. the issue still exists. * >> >> I can click to drag in order to draw a rectangle, but when i drag the >> created rectangle (for position adjustment), a new rectangle is created >> from the said position. How do i constrain/fix the issue? i have been >> trying to use key-combination to draw a new rectangle on demand. How do i >> fix it ? >> >> ``` >> #lang racket/gui >> >> (define (maybe-set-box! b v) >> (when b >> (set-box! b v))) >> >> >> >> (define rect-snip-class% >> (class snip-class% >> (inherit set-classname) >> (super-new) >> >> (set-classname "rect-snip-class%") >> )) >> >> >> (define rect-snip-class (new rect-snip-class%)) >> >> (define rect-snip% >> (class snip% >> (inherit set-snipclass >> set-flags get-flags >> get-admin) >> (init w h) >> (super-new) >> (set-snipclass rect-snip-class) >> (define height h) >> (define width w) >> >> (define/override (get-extent dc x y [w #f] [h #f] . _) >> (maybe-set-box! w width) >> (maybe-set-box! h height)) >> >> (define/override (draw dc x y left top right bottom . _) >> (send dc draw-rectangle x y width height)) >> )) >> >> >> >> (define pb >> (new >> (class pasteboard% >> (super-new) >> (inherit insert) >> >> (define start-pos #f) >> >> (define/override (on-default-event event) >> (super on-default-event event) >> (define x (send event get-x)) >> (define y (send event get-y)) >> (cond >> [(and (equal? (send event get-event-type) 'left-down) >> (send event button-down? 'left) >> (not (send event dragging?))) >> (set! start-pos (cons x y))] >> [(and (equal? (send event get-event-type) 'left-up) >> start-pos) >> (let ([dx (- (car start-pos) x)] >> [dy (- (cdr start-pos) y)]) >> (define-values (nx nw) >> (if (> dx 0) >> (values x dx) >> (values (+ x dx) (abs dx)))) >> (define-values (ny nh) >> (if (> dy 0) >> (values y dy) >> (values (+ y dy) (abs dy)))) >> (define sn (new rect-snip% >> [w nw] >> [h nh])) >> (insert sn nx ny) >> (set! start-pos #f))])) >> >> >> ))) >> >> (define f-main (new frame% [label "wireframe"])) >> (define cnv-main (new editor-canvas% >> [editor pb] >> [parent f-main])) >> >> >> (send f-main show #t) >> ``` >> >> -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/c1da5a4e-730f-43ec-8d53-c6e223225b0an%40googlegroups.com > <https://groups.google.com/d/msgid/racket-users/c1da5a4e-730f-43ec-8d53-c6e223225b0an%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CAGcmBVWVW0qA_xcTFOLTPgTc4i_BKzjouFZSmMQVLKhG%2B9X4BQ%40mail.gmail.com.
