I don't know of a general way of stopping the timer. You can put a button on your window to stop the timer, but in my experience it's all-too-often better to restart J (and sometimes reboot the system) because of issues in the underlying subsystems. (An error will sometimes lead to a situation where something else isn't acting right).
This seems to be an issue for people working in other environments also. We're just spoiled a bit, in the J community. Thanks, -- Raul On Mon, Feb 13, 2017 at 12:37 PM, Louis de Forcrand <[email protected]> wrote: > Thanks for your replies. > > I looked at the pendulum example, and at first thought that isigraph is > better, but it doesn't support window size changes, and so settled with > isidraw. In addition it seems that ptimer is easier to use locale-wise than > sys_timer. > > One thing that was annoying was that if an error ever occured in the verb > called by the timer, I had to restart J (with the task manager) as I couldn't > change the focus off of the error pop-up window. JBRK didn't work either. Do > you know if there is any way to stop the timer without having access to the > JQT session? > > Thanks, > Louis > > PS: I noticed that there's no automatic shortcut creation for JBRK. I suggest > that it be added in the "shortcut" verb in installer.ijs, or that it be > mentioned on the wiki installation page for newcomers. > >> On 09 Feb 2017, at 01:02, bill lam <[email protected]> wrote: >> >> that depends on using isigraph or isidraw. isidraw is backup by bitmap so >> that you need to erase the previous scene. isigraph (in j8) is different, >> since it is not double buffered, it loses previous content in each paint >> event, so you need not erase the previous ball. >> >> opengl also works for 2d. >> >> >> >> On 9 Feb, 2017 12:42 am, "Louis de Forcrand" <[email protected]> wrote: >> >> Hi everyone, >> >> I've been looking into the Qt facilities available in J recently, and I >> read that 2D graphics are best done with gl2. >> >> I hacked together a simple program that displays a ball which bounces >> around the isidraw container. Having never really done any graphics-related >> programming, I used the window driver's timer function to call sys_timer at >> regular intervals, which erases the previous circle, draws the new one, and >> updates speed and position global vars. >> The advantage of using the wd timer is that I can create a button which >> calls "wd 'timer 0; pclose'" in order to exit the program in a clean >> fashion without having to break. >> >> I suspect there is a better way to do this; how would the seasoned J >> programmers on this forum go about creating such an animation? >> >> All help appreciated! >> Louis >> >> PS: I hardly have any web-related (html, css, php, etc.) programming >> skills, but any info about doing this in JHS is welcome as well. >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
