| Re: Question about selecting images from Draw Widgets [message #53047 is a reply to message #53046] |
Sat, 17 March 2007 05:49   |
gearoid.k
Messages: 6
Registered: March 2007
|
Junior Member |
|
|
On Mar 17, 3:49 am, David Fanning <n...@dfanning.com> wrote:
> gearoi...@gmail.com writes:
>> This program takes in 10 images and displays the first 4 (image0 to
>> image3) in the GUI. For the final function 'viewNext', I would like
>> all the images (which are saved in the array 'images_array' which is
>> defined in the OpenFile function) to shift up by one place, such that
>> image1 to image4 are displayed.
>
>> Could you tell me how to do this?
>
> Well, to start with, I wouldn't be using the GUI Builder
> to build your widget program. The possibility that you might
> actually understand how the program works is slim, to say
> the least. :-)
>
> Typically, what we do is store ALL the information we
> need to run our program in an "info" structure. Suppose
> we need the four drawIDs, the window index numbers that go
> with the draw widgets, and the 10 images themselves. And
> suppose we have stored these in the variables drawIDs,
> wIDs, and theImages. (The array containing the images
> is probably a pointer array, because we don't really
> want to carry around 10 images.) We probably need some
> kind of counter, so we know which image is first in the
> image display. Let's call this imgCounter and suppose it
> starts off at 0, so the first 4 of 10 images are displayed
> in our windows.
>
> info = {drawIDs:drawIDs, wIDs:wIDs, theImages:theImages, $
> imgCounter:imgCounter, numImages:numImages)
>
> Usually, we make info a pointer, then we store it in
> the user value of the top-level base, so it is accessible
> to all the even handlers:
>
> info = Ptr_New(info, /No_Copy)
> Widget_Control, tlb, Set_UValue=info
>
> This is typically done just before you call XMANAGER
> to start your program running in the widget definition
> module (or sometimes called the command module).
>
> Ok, so somewhere you have created a couple of buttons
> named NEXT and PREVIOUS, and you have assigned an event
> handler to them. Maybe you did something like this:
>
> buttonID = Widget_Button(baseID, Value='Next', $
> Event_Pro='MyProgram_ButtonEvents')
> buttonID = Widget_Button(baseID, Value='Next', $
> Event_Pro='MyProgram_ButtonEvents')
>
> So when the user hits either the NEXT or PREVIOUS
> button, the event will go to this event handler.
> Here is how you write it:
>
> PRO MyProgram_ButtonEvents, event
>
> ; Get the information you need to run the program.
> Widget_Control, event.top, Get_UValue=info
>
> ; Which button is this?
> Widget_Control, event.ID, Get_Value=buttonValue
>
> ; Set the image counter.
> CASE buttonValue OF
> 'Next': (*info).imgCounter = 0 > ((*info).imgCounter) + 1 < $
> ((*info).numImages-4)
> 'Previous': (*info).imgCounter = 0 > ((*info).imgCounter) - 1 < $
> ((*info).numImages-4)
> ENDCASE
>
> ; Display the four images in the four draw widget windows.
> cnt = Indgen(4) + (*info).imgCounter
> FOR j=0,3 DO BEGIN
> WSet, (*info).wIDs[j]
> TV, *((*info).theImages[cnt[j]])
> ENDFOR
> END
>
> That's it. Pretty simple. :-)
>
> Cheers,
>
> David
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.dfanning.com/
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
Thanks again David.
So do you suggest that I work solely on the .pro file? And to forget
about the prc file?
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
