Re: Looking for a wait until x or timeout design pattern..
Here's the basic idea of the code I needed. the touchMove event arrives in no particular order, and in no particular time. If you absolutely have to have a timeout, you can't just test for a timestamp on the next run of touchMove, because there might not be another touchMove. I'm not quite clear on what the wait 50 milliseconds with messages command does. Is that a more succinct way of putting it? -Ken ---8--- -- Semaphore handling for touch movements -- -- This code is meant to be used to group random events that -- happen in a timeframe, group them together, and take action -- on those events as a whole. -- -- User input is pseudo-random, and we therefore cannot count on -- events coming in a particular order, or even coming at all. -- -- I use code similar to this to group several distinct user inputs and -- deal with several at a time. If no more events come within the -- delay period, we fire the handler. -- -- This isn't perfect, as there doesn't seem to be a way to cancel a -- pending send...so we guard against the send happening in -- performAction. -- -- What this means is that the delay (50 milliseconds below) must -- be chosen carefully so that there's only one group of data waiting -- to be processed. -- -- If the touchMove event happens but is delayed, and another -- touchMove event with immediate execution happens within the -- timeout period, the second touchMove event clears the sSemaphore, -- so then the delayed performAction from the first touchMove event -- is ignored. -- local sDetails,sSemaphore on touchMove pID,pX,pY -- check to see if we've dealt with pID before if pID is in the keys of sSemaphore then -- have seen it before so take action immediately put (pXcommapY) into sSemaphore[pID] send performAction pID,pX,pY else -- haven't seen it, only do it after a delay put (pXcommapY) into sSemaphore[pID] send performAction pID,pX,pY to me in 50 milliseconds end if end touchMove on performAction -- check to see if it's already been handled. if the number of lines in the keys of sSemaphore 0 then -- nope, let's get busy -- code to deal with the data delete variable sSemaphore end if end performAction ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: Looking for a wait until x or timeout design pattern..
you should check out Dar Scott's primers on Message Mechanics. Visually and technically informative. http://pages.swcp.com/dsc/revstacks.html On 29 January 2012 11:38, Ken Corey k...@kencorey.com wrote: Here's the basic idea of the code I needed. the touchMove event arrives in no particular order, and in no particular time. If you absolutely have to have a timeout, you can't just test for a timestamp on the next run of touchMove, because there might not be another touchMove. I'm not quite clear on what the wait 50 milliseconds with messages command does. Is that a more succinct way of putting it? -Ken ---8-**-- -- Semaphore handling for touch movements -- -- This code is meant to be used to group random events that -- happen in a timeframe, group them together, and take action -- on those events as a whole. -- -- User input is pseudo-random, and we therefore cannot count on -- events coming in a particular order, or even coming at all. -- -- I use code similar to this to group several distinct user inputs and -- deal with several at a time. If no more events come within the -- delay period, we fire the handler. -- -- This isn't perfect, as there doesn't seem to be a way to cancel a -- pending send...so we guard against the send happening in -- performAction. -- -- What this means is that the delay (50 milliseconds below) must -- be chosen carefully so that there's only one group of data waiting -- to be processed. -- -- If the touchMove event happens but is delayed, and another -- touchMove event with immediate execution happens within the -- timeout period, the second touchMove event clears the sSemaphore, -- so then the delayed performAction from the first touchMove event -- is ignored. -- local sDetails,sSemaphore on touchMove pID,pX,pY -- check to see if we've dealt with pID before if pID is in the keys of sSemaphore then -- have seen it before so take action immediately put (pXcommapY) into sSemaphore[pID] send performAction pID,pX,pY else -- haven't seen it, only do it after a delay put (pXcommapY) into sSemaphore[pID] send performAction pID,pX,pY to me in 50 milliseconds end if end touchMove on performAction -- check to see if it's already been handled. if the number of lines in the keys of sSemaphore 0 then -- nope, let's get busy -- code to deal with the data delete variable sSemaphore end if end performAction __**_ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/**mailman/listinfo/use-livecodehttp://lists.runrev.com/mailman/listinfo/use-livecode -- Stephen Barncard San Francisco Ca. USA more about sqb http://www.google.com/profiles/sbarncar ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: Looking for a wait until x or timeout design pattern..
Now *that* is exactly what I needed. Should be required reading. Why didn't runrev hire this guy to write more of their manuals in this style? Thanks muchly! -Ken On 29/01/2012 19:51, stephen barncard wrote: you should check out Dar Scott's primers on Message Mechanics. Visually and technically informative. http://pages.swcp.com/dsc/revstacks.html ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Looking for a wait until x or timeout design pattern..
I've been working on a pinch library for a week or so, and I have complained about the jerkiness. I am thinking that the problem is that it's /too/ repsonsive. The instant one touch moves, it's causing the pinchMove event to be generated. This is fine if nothing else truly has moved, but if the two move events are sent back to back, they should both be handled before sending a pinchMove message...not two different pinchMove events. The pinchMove event should only be sent once the status of all the touches have been updated...but of course, we have no guarantee that there's a touchMove coming for each point, nor the order in which they will come... So, in pseudo code, what I'd like to do is: on touchMove i,x,y store x,y into positionArray[i] -- update the postition for a touch wait until (got touch events from all touches) or \ (30 milliseconds have passed) pinchMove blah,blah,blah end touchMove But the wait command seems to either wait 100 milliseconds or wait until cond, but not both. Then I thought to provide a timeout with a 'send timeout in xx milliseconds', but cancel it if we got events on all touches first. Couldn't see how to cancel a pending send. I guess I could break my timeout period down and do a series of shorter waits (sort of slow polling), with a fall-through at the end of the timeout. Also, all other events still need to be handled in the normal way...can't lock the application for those 30 seconds. Thoughts? -Ken ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: Looking for a wait until x or timeout design pattern..
You might try: wait 30 millisecs with messages Regards, Scott Rossi Creative Director Tactile Media, UX Design Recently, Ken Corey wrote: I've been working on a pinch library for a week or so, and I have complained about the jerkiness. I am thinking that the problem is that it's /too/ repsonsive. The instant one touch moves, it's causing the pinchMove event to be generated. This is fine if nothing else truly has moved, but if the two move events are sent back to back, they should both be handled before sending a pinchMove message...not two different pinchMove events. The pinchMove event should only be sent once the status of all the touches have been updated...but of course, we have no guarantee that there's a touchMove coming for each point, nor the order in which they will come... So, in pseudo code, what I'd like to do is: on touchMove i,x,y store x,y into positionArray[i] -- update the postition for a touch wait until (got touch events from all touches) or \ (30 milliseconds have passed) pinchMove blah,blah,blah end touchMove But the wait command seems to either wait 100 milliseconds or wait until cond, but not both. Then I thought to provide a timeout with a 'send timeout in xx milliseconds', but cancel it if we got events on all touches first. Couldn't see how to cancel a pending send. I guess I could break my timeout period down and do a series of shorter waits (sort of slow polling), with a fall-through at the end of the timeout. Also, all other events still need to be handled in the normal way...can't lock the application for those 30 seconds. Thoughts? -Ken ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
