comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Keyboard events
items: Re: Keyboard events

Keyboard events
type: item
description: I'm in the process of writing a new application, and several of the likely users have requested that I allow various keyboard "shortcuts", as an alternative to clicking on various controls with the mouse. For example, we will need to define a region in an image that will be zoomed in a separate draw window, and it would be nice to be able to use arrow keys to position and resize the zoom region. I've never tried to do this before in IDL (previously I've been content to handle mouse events), so I went looking through the manuals to figure out how to do it. Unfortunately, the event handling routines seem to be limited to mouse and focus events. The closest thing I could find was the get_kbrd function; someone here suggested putting a call to get_kbrd in the event handling function. However, it would seem that this would cause keyboard events to queue up, unprocessed, until the user wiggled the mouse. In other words, it doesn't seem to be quite what I need. Is there something in the documentation that I have overlooked? Any ideas would be most appreciated. Doug
creator: dsreyn
date: 2000-07-28T07:00:00-00:00

Re: Keyboard events
type: item
description: By the way, are people aware that you can trap control keys with the hack (either version). At least for me, Control+a-z map to keys 1B-26B. C-p for print anyone? Haven't tried this one on anything but Unix. Just in case people couldn't find the post I've reattached the latest hack with this modification. Just run tt and try various keys, including control+letter and arrows. If people want to experiment along these lines on other platforms/os's, I'd be willing to collect the results and bundle the routine into something generically useable and distributeable. Maybe then RSI would take notice and work to include a less hackish alternative. JD -- J.D. Smith /*\ WORK: (607) 255-6263 Cornell University Dept. of Astronomy \*/ (607) 255-5842 304 Space Sciences Bldg. /*\ FAX: (607) 255-5875 Ithaca, NY 14853 \*/ pro catch_text,ev type=tag_names(ev,/STRUCTURE_NAME) erase case type of 'WIDGET_TEXT_SEL': begin widget_control, ev.id, get_uvalue=ulrdo widget_control, ev.id,SET_TEXT_SELECT=ulrdo[4],SENSITIVE=0 case ev.offset of ulrdo[0]: xyouts,.5,.5,/NORMAL,'Up', CHARSIZE=2.,ALIGNMENT=.5 ulrdo[1]: xyouts,.5,.5,/NORMAL,'Left', CHARSIZE=2.,ALIGNMENT=.5 ulrdo[2]: xyouts,.5,.5,/NORMAL,'Right',CHARSIZE=2.,ALIGNMENT=.5 ulrdo[3]: xyouts,.5,.5,/NORMAL,'Down', CHARSIZE=2.,ALIGNMENT=.5 else: endcase widget_control, ev.id,/SENSITIVE,/INPUT_FOCUS end 'WIDGET_TEXT_CH': begin if ev.ch le 26 then $ xyouts,.5,.5,/NORMAL,'C-'+strtrim(ev.ch+96b,2),CHARSIZE=2., $ ALIGNMENT=.5 $ else $ xyouts,.5,.5,/NORMAL,string(ev.ch),CHARSIZE=2.,ALIGNMENT=.5 end endcase end pro tt_event,ev type=tag_names(ev,/STRUCTURE_NAME) widget_control, ev.top,GET_UVALUE=info if type eq 'WIDGET_TRACKING' then begin widget_control, info.key,/INPUT_FOCUS return endif if ev.type le 1 then widget_control, info.key,/INPUT_FOCUS str=string(format='(2(I2.2,:,":"))',ev.X,ev.Y) case ev.type of 0:str='P'+str 1:str='R'+str 2:str='M'+str else:str='*' endcase erase xyouts,.5,.5,/NORMAL,str, CHARSIZE=1.,ALIGNMENT=.5 end pro tt base=widget_…
creator: John-David T. Smith
date: 2000-08-03T07:00:00-00:00

Re: Keyboard events
type: item
description: Doug Reynolds wrote: > > I'm in the process of writing a new application, and several of the likely > users have requested that I allow various keyboard "shortcuts", as an > alternative to clicking on various controls with the mouse. For example, > we will need to define a region in an image that will be zoomed in a > separate draw window, and it would be nice to be able to use arrow keys > to position and resize the zoom region. > > I've never tried to do this before in IDL (previously I've been content > to handle mouse events), so I went looking through the manuals to figure > out how to do it. Unfortunately, the event handling routines seem to be > limited to mouse and focus events. The closest thing I could find was the > get_kbrd function; someone here suggested putting a call to get_kbrd in > the event handling function. However, it would seem that this would cause > keyboard events to queue up, unprocessed, until the user wiggled the mouse. > In other words, it doesn't seem to be quite what I need. > > Is there something in the documentation that I have overlooked? Any ideas > would be most appreciated. > > Doug I think I recently posted a follow-on entitled "More keyboard events" to my hack of many years ago which allows cursor key widget events. It increases the hackery to some degree and has cross-platform issues, but sometimes, you just need them. An example program is included in the post. My original hack is widely used in a variety of programs, including popular ones such as atv, so it's stability is probably pretty good. The new hack has undergone limited testing, so beware. I've been using it with success under Unix, but your mileage may vary. Good luck, JD -- J.D. Smith /*\ WORK: (607) 255-6263 Cornell University Dept. of Astronomy \*/ (607) 255-5842 304 Space Sciences Bldg. /*\ FAX: (607) 255-5875 Ithaca, NY 14853 \*/
creator: John-David T. Smith
date: 2000-08-03T07:00:00-00:00