Re: [racket-users] Problem when using horizontal pane
Yes, this is exactly what I want. Thank you a lot. -- Mianlai On Fri, Jul 17, 2015 at 4:36 PM, Matthew Flatt mfl...@cs.utah.edu wrote: At Fri, 17 Jul 2015 15:16:34 +0800, Mianlai Zhou wrote: I have the following code: #lang racket (require slideshow racket/class racket/gui/base) (define my-frame (new frame% [label My chess] [width 300] [height 391] [alignment '(center center)] )) (define my-canvas (new (class canvas% (super-new [parent my-frame]) [define/override (on-paint) (define my-dc (send my-canvas get-dc)) (send my-dc clear) ((make-pict-drawer (colorize (circle 225) red)) my-dc 20 20) ] [define/override (on-char ch) (define key (send ch get-key-code)) (if (eq? key 'release) (send my-canvas on-paint) null) ] ))) (new button% [parent my-frame] [label Replay] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) which runs perfectly with no error. However, I want to add two new bottons Play and Draw on the left and right of the button Replay. I tried to use horizontal-pane, changing the last several lines in the code as: (define my-pane (new horizontal-pane% [parent my-frame] [alignment '(center center)] )) (new button% [parent my-pane] [label Play] ) (new button% [parent my-pane] [label Replay] ) (new button% [parent my-pane] [label Draw] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) However, this is not what I wanted. The area of horizontal pane is obviously too large, and it makes the three buttons too distant from the two buttons below, also it shadows the main area above. Is there a way to minimize the width of the horizontal pane such that the outlook is the same as if not using it (the original code pasted above)? I think you want to make the panel have a non-stretchable height: (define my-pane (new horizontal-pane% [parent my-frame] [alignment '(center center)] [stretchable-height #f])) -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] set a timeout to tcp-connect
On Jul 17, 2015, at 9:31 AM, mazert rom...@elgeekador.net wrote: #lang racket (define (foo) (let* ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (kill-thread b] [b (thread (λ () (sleep 2) (printf I'll kill you !) (kill-thread a)))]) (void))) #lang racket (define (foo) (letrec ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (printf I will kill b\n) (kill-thread b] [b (thread (λ () (displayln `(hello world)) (sleep 2) (printf I'll kill a\n) (kill-thread a)))]) (void))) This actually works. But I am not sure why you'd want to do something like that. -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] set a timeout to tcp-connect
Hello, When i try to connect on smtp.google.com on port 587 (submission) through tcp-connect, it works perfectly ; but if instead of 587 i put 666 (for example) it stucks cause the server dont answer. So after reading fews hours the doc, I didn't found a native solution to implement this, so I programmed a thing like this : #lang racket (define (foo) (let* ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (kill-thread b] [b (thread (λ () (sleep 2) (printf I'll kill you !) (kill-thread a)))]) (void))) The only problem is that b have to be defined before killing him.. :p . Someone can help me to make it working ? Or have a better idea to do implement what i need ? Thanks in advance. -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Re: set a timeout to tcp-connect
Le 17/07/2015 16:16, Matthias Felleisen a écrit : This actually works. But I am not sure why you'd want to do something like that. Ah yes, letrec is what I was looking for :) . The goal was to test a port with a specific timeout (here I set it to two for dev purposes, but 10 is better). I rewrited foo with better comments below. Just to be sure, I cant have the prompt return without using a (thread-wait thd) function ? 1) The port is not good so b kills a, then b ends. The program continue. 2) But if I set (thread-wait a), b kills a, then b ends. As a was killed, it is considered as terminated so it is the same as 1) ? #lang racket (define (foo) (letrec ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect smtp.gmail.com 5887)]) (printf Server port is good) (kill-thread b] [b (thread (λ () (displayln `(hello world)) (sleep 2) (printf Server port is not good) (kill-thread a)))]) (thread-wait b))) -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] set a timeout to tcp-connect
On 7/17/2015 10:16 AM, Matthias Felleisen wrote: On Jul 17, 2015, at 9:31 AM, mazert rom...@elgeekador.net wrote: #lang racket (define (foo) (let* ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (kill-thread b] [b (thread (λ () (sleep 2) (printf I'll kill you !) (kill-thread a)))]) (void))) #lang racket (define (foo) (letrec ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect google.com 80)]) (printf I will kill b\n) (kill-thread b] [b (thread (λ () (displayln `(hello world)) (sleep 2) (printf I'll kill a\n) (kill-thread a)))]) (void))) This actually works. But I am not sure why you'd want to do something like that. Won't the connection attempt eventually time out and cause an exception when the TCP stack closes the socket? I know the default connect timeout is rather long though (150 seconds?). George -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Re: set a timeout to tcp-connect
At Fri, 17 Jul 2015 16:58:50 +0200, mazert wrote: Le 17/07/2015 16:16, Matthias Felleisen a écrit : This actually works. But I am not sure why you'd want to do something like that. Ah yes, letrec is what I was looking for :) . The goal was to test a port with a specific timeout (here I set it to two for dev purposes, but 10 is better). I rewrited foo with better comments below. Just to be sure, I cant have the prompt return without using a (thread-wait thd) function ? 1) The port is not good so b kills a, then b ends. The program continue. 2) But if I set (thread-wait a), b kills a, then b ends. As a was killed, it is considered as terminated so it is the same as 1) ? Yes. Beware, though, that there's a race condition here: #lang racket (define (foo) (letrec ([a (thread (λ () (let-values ([(p-in p-out) (tcp-connect smtp.gmail.com 5887)]) (printf Server port is good) (kill-thread b] [b (thread (λ () (displayln `(hello world)) (sleep 2) (printf Server port is not good) (kill-thread a)))]) (thread-wait b))) It's possible (but unlikely) for the thread bound to `a` to complete and try to kill `b` before the variable `b` is initialized. Here's what I'd do: * Create a custodian to manage the thread, and shut the custodian down instead of killing the thread. That way, in addition to killing the thread, any network resources are also released. * Instead of starting a timer thread, use `sync/timeout`. (define (foo) (define c (make-custodian)) (define t (parameterize ([current-custodian c]) (thread (λ () (let-values ([(p-in p-out) (tcp-connect smtp.gmail.com 5887)]) (printf Server port is good)) (displayln `(hello world)) (unless (sync/timeout 2 t) ; produces #f on timeout (printf Server port is not good) (custodian-shutdown-all c))) -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Problem when using horizontal pane
Hi all, I have the following code: #lang racket (require slideshow racket/class racket/gui/base) (define my-frame (new frame% [label My chess] [width 300] [height 391] [alignment '(center center)] )) (define my-canvas (new (class canvas% (super-new [parent my-frame]) [define/override (on-paint) (define my-dc (send my-canvas get-dc)) (send my-dc clear) ((make-pict-drawer (colorize (circle 225) red)) my-dc 20 20) ] [define/override (on-char ch) (define key (send ch get-key-code)) (if (eq? key 'release) (send my-canvas on-paint) null) ] ))) (new button% [parent my-frame] [label Replay] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) which runs perfectly with no error. However, I want to add two new bottons Play and Draw on the left and right of the button Replay. I tried to use horizontal-pane, changing the last several lines in the code as: (define my-pane (new horizontal-pane% [parent my-frame] [alignment '(center center)] )) (new button% [parent my-pane] [label Play] ) (new button% [parent my-pane] [label Replay] ) (new button% [parent my-pane] [label Draw] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) However, this is not what I wanted. The area of horizontal pane is obviously too large, and it makes the three buttons too distant from the two buttons below, also it shadows the main area above. Is there a way to minimize the width of the horizontal pane such that the outlook is the same as if not using it (the original code pasted above)? Thanks for your help in advance. Mianlai -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [racket-users] Problem when using horizontal pane
At Fri, 17 Jul 2015 15:16:34 +0800, Mianlai Zhou wrote: I have the following code: #lang racket (require slideshow racket/class racket/gui/base) (define my-frame (new frame% [label My chess] [width 300] [height 391] [alignment '(center center)] )) (define my-canvas (new (class canvas% (super-new [parent my-frame]) [define/override (on-paint) (define my-dc (send my-canvas get-dc)) (send my-dc clear) ((make-pict-drawer (colorize (circle 225) red)) my-dc 20 20) ] [define/override (on-char ch) (define key (send ch get-key-code)) (if (eq? key 'release) (send my-canvas on-paint) null) ] ))) (new button% [parent my-frame] [label Replay] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) which runs perfectly with no error. However, I want to add two new bottons Play and Draw on the left and right of the button Replay. I tried to use horizontal-pane, changing the last several lines in the code as: (define my-pane (new horizontal-pane% [parent my-frame] [alignment '(center center)] )) (new button% [parent my-pane] [label Play] ) (new button% [parent my-pane] [label Replay] ) (new button% [parent my-pane] [label Draw] ) (new button% [parent my-frame] [label Save] ) (new button% [parent my-frame] [label Load] ) (send my-frame show #t) However, this is not what I wanted. The area of horizontal pane is obviously too large, and it makes the three buttons too distant from the two buttons below, also it shadows the main area above. Is there a way to minimize the width of the horizontal pane such that the outlook is the same as if not using it (the original code pasted above)? I think you want to make the panel have a non-stretchable height: (define my-pane (new horizontal-pane% [parent my-frame] [alignment '(center center)] [stretchable-height #f])) -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Re: set a timeout to tcp-connect
Le 17/07/2015 17:08, Matthew Flatt a écrit : It's possible (but unlikely) for the thread bound to `a` to complete and try to kill `b` before the variable `b` is initialized. Ah ok, yes that is risky in this case, plus we didn't close the tcp connection. Here's what I'd do: * Create a custodian to manage the thread, and shut the custodian down instead of killing the thread. That way, in addition to killing the thread, any network resources are also released. * Instead of starting a timer thread, use `sync/timeout`. (define (foo) (define c (make-custodian)) (define t (parameterize ([current-custodian c]) (thread (λ () (let-values ([(p-in p-out) (tcp-connect smtp.gmail.com 5887)]) (printf Server port is good)) (displayln `(hello world)) (unless (sync/timeout 2 t) ; produces #f on timeout (printf Server port is not good) (custodian-shutdown-all c))) That is an elegant solution :) . So I read the doc about custodian with parameterize to know more, but it is always a little mysterious for me. when : (parameterize ([current-custodian c]) We say that we run the code in the 'body' part with a c parameter that contain an empty custodian. But we never added something to c, how the connections are 'linked' to c, when we use custodian-shutdown-all ? It is automatic for all thread/network/streams etc... functions in the 'body' part of (parameterize) ? When we bind the (parameterize) to a variable, the type is the type of last result in the 'body' part in (parameterize) ? , So as a thread is an evt, we can use it in sync/timeout. -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[racket-users] Re: set a timeout to tcp-connect
Le 17/07/2015 17:06, George Neuner a écrit : Won't the connection attempt eventually time out and cause an exception when the TCP stack closes the socket? I know the default connect timeout is rather long though (150 seconds?). Yes it will close for sure but after a long time (maybe 150 sec as you said). Also it can server side maybe... I'm not a TCP/IP specialist so surely there is a better way to follow. One day I'll read a little the book mentionned in racket doc : TCP/IP Illustrated, Volume 1 by W. Richard Stevens http://www.jtbookyard.com/uploads/6/2/9/3/6293106/tcp_ip_illustrated_volume_1_the_protocols_2nd_edit.pdf -- 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 racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
