BBC BASIC for Windows
Programming >> Graphics and Games >> Displaying a histogram in a dialog box
http://bb4w.conforums.com/index.cgi?board=graphics&action=display&num=1406624543
Displaying a histogram in a dialog box
Post by g3nrw on Jul 29th, 2014, 09:02am

Here is a very simple program that generates a histogram:

Code:
      MODE 8
      GCOL 131
      GCOL 12
      CLG
      MOVE 200,300

      FOR n% = 0 TO 18
  
        x% = n% * 50
        y% = n% * 20
        RECTANGLE FILL x%,30,35,y%
  
      NEXT


Can someone point me to reference(s) that explain how to plot this in a dialog box?

--
Ian
Re: Displaying a histogram in a dialog box
Post by rtr on Jul 29th, 2014, 12:00pm

on Jul 29th, 2014, 09:02am, g3nrw wrote:
Can someone point me to reference(s) that explain how to plot this in a dialog box?

There are various ways it might be done, but one simple method would be to save your plot to a BMP file (OSCLI "GSAVE....) and then display that bitmap in a 'picture box' (code to do that is in the BB4W docs). The best place to store the BMP would be the temporary folder @tmp$.

Beware DPI issues, and make sure you test your code at the common DPI values (96, 120, 144 at least).

This technique isn't ideal for a 'live' or 'animated' plot so if that is a requirement you might want to create a custom graphics control using the MULTIWIN library.

This would all be considerably easier in the other dialect of BASIC that I market (as it would have been using GUILIB, but if I keep mentioning that it will become annoying). wink

Richard.
Re: Displaying a histogram in a dialog box
Post by g3nrw on Jul 29th, 2014, 12:56pm

Richard

The histogram will be "animated", being updated each time each time the user opens the dialog box that displays the histogram.

I will investigate the MULTIWIN library.

--
Ian
Re: Displaying a histogram in a dialog box
Post by rtr on Jul 29th, 2014, 2:03pm

post removed
Re: Displaying a histogram in a dialog box
Post by g3nrw on Aug 4th, 2014, 9:37pm

on Jul 29th, 2014, 12:00pm, Richard Russell wrote:
There are various ways it might be done, but one simple method would be to save your plot to a BMP file (OSCLI "GSAVE....) and then display that bitmap in a 'picture box'


I'm getting ever closer. I have written code that creates a simple histogram, then saves the created image as a bitmap file (zzz.bmp), then displays the bitmap in a new dialog box (dlg2).

Code:
      REM +++++  A much emasculated DLGDEMO, modified to open a new dialog box
      REM to display a histogram


      INSTALL @lib$+"WINLIB2"


      BS_DEFPUSHBUTTON = &1
      CB_ADDSTRING = &143
      CB_SETCURSEL = &14E
      CBS_DROPDOWNLIST = &3
      ES_AUTOHSCROLL = &80
      ES_NUMBER = &2000
      ES_READ_ONLY = &880
      LB_ADDSTRING = &180
      LB_GETCURSEL = &188
      UDM_SETRANGE = &465
      UDS_ALIGNRIGHT = &4
      UDS_AUTOBUDDY = &10
      UDS_SETBUDDYINT = &2
      WS_CHILD = &40000000
      WS_GROUP = &20000
      WS_VISIBLE = &10000000

      dlg%=FN_newdialog("Dialogue box", 20, 20, 160, 128, 8, 32768)

      PROC_groupbox(dlg%, "Group box", 0, 4, 4, 152, 96, WS_GROUP)

      PROC_pushbutton(dlg%, "OK", 1, 12, 108, 56, 14, WS_GROUP OR BS_DEFPUSHBUTTON)
      PROC_pushbutton(dlg%, "Cancel", 2, 92, 108, 56, 14, 0)



      REM +++++++++++++++++++++++++++++++++++++++ new code:

      INSTALL @lib$+"WINLIB5A"
      WS_POPUP = &80000000

      dlg2%=FN_newdialog("MY HISTOGRAM", 20, 20, 500, 260, 10, 32768)

      PROC_static(dlg2%,"",700,100,100,500,500,&E)

      REM +++++++++++++++++++++++++++++++++++++++ end of new code


      PROC_showdialog(dlg%)
      ON CLOSE PROC_closedialog(dlg%):QUIT
      ON ERROR PROC_closedialog(dlg%):PRINT'REPORT$:END

      Click%=0
      ON SYS Click% = @wparam% : RETURN
      REPEAT
        WAIT 1
        click%=0
        SWAP Click%, click%
      UNTIL click%=1 OR click%=2 OR !dlg%=0

      IF click%=1 THEN
  
        REM +++++++++++++++++++++++++++++++++++++++ new code:
  
        PROC_showdialog(dlg2%)
  
        VDU 23,22,900;650;11,16,16,0
        GCOL 135
        GCOL 12
        CLG
  
        FOR n% = 0 TO 17
          x% = n% * 88
          y% = n% * 34
          RECTANGLE FILL x%+100,150,65,y%
        NEXT
  
        file$ = "zzz.bmp"
        OSCLI "GSAVE """+file$+""" 100,100,500,500"
  
        LR_LOADFROMFILE = 16
        STM_SETIMAGE = 370
        SYS "LoadImage", 0, file$, 0, 250, 250, LR_LOADFROMFILE TO hbitmap%
        SYS "SendDlgItemMessage", !dlg2%, 700, STM_SETIMAGE, 0, hbitmap%
  
      ELSE
        PROC_closedialog(dlg2%)
        SYS "DeleteObject", hbitmap%
      ENDIF

      REM +++++++++++++++++++++++++++++++++++++++  end of new code

      END


This works as expected, but the snag is that when I close the dialog box, the computed histogram is still visible in another window that was previously hidden.

Is there a way to run the histogram computation in a "virtual" window without displaying it, or, alternatively, forcing the previously hidden window to close when closing dlg2 ?

--
Ian

Re: Displaying a histogram in a dialog box
Post by rtr on Aug 4th, 2014, 11:09pm

on Aug 4th, 2014, 9:37pm, g3nrw wrote:
This works as expected, but the snag is that when I close the dialog box, the computed histogram is still visible in another window that was previously hidden

See my earlier post (although it's not clear from your example why you need the histogram to be displayed in a dialogue box at all; an ordinary non-dialogue window looks as if it would suit just as well):

User Image

Richard.
Re: Displaying a histogram in a dialog box
Post by g3nrw on Aug 5th, 2014, 05:44am

Richard

I don't understand your reply:

on Aug 4th, 2014, 11:09pm, Richard Russell wrote:
See my earlier post


Which "earlier post"?

Quote:
an ordinary non-dialogue window looks as if it would suit just as well):


Don't understand: your 4-window "Hello world"/graphics example *is* in a dialog box.

--
Ian


Re: Displaying a histogram in a dialog box
Post by rtr on Aug 5th, 2014, 08:34am

on Aug 5th, 2014, 05:44am, g3nrw wrote:
Which "earlier post"?

The one in which I announced support for drawing graphics in a custom dialogue control, which I posted yesterday only a few hours before yours. wink

This thread triggered me to re-visit that functionality, which was intended to have been provided in GUILIB but, in the absence of that library, has never been supported in BB4W until now.

Quote:
Don't understand: your 4-window "Hello world"/graphics example *is* in a dialog box.

The subject line of this thread is "Displaying a histogram in a dialog box". That is exactly the sort of thing the newly-supported functionality, as illustrated by that graphic, allows!

My 'aside' stemmed from the fact that you accompanied your most recent message with a code listing. When I run that program, and click on the OK button, it displays your histogram graphics in what appears to be a regular window - it has no 'dialogue-style' features such as multiple controls or OK/cancel buttons.

Looking at the detail of your code, that window consists of a dialogue box containing a static 'picture box' and nothing else. Therefore it begs the question of why you are using a dialogue box at all, when you could achieve something almost identical with an ordinary 'BBC' window, and in so doing avoid all the complications of drawing graphics and dealing with DPI variation.

Having spent considerable time and effort in providing support for drawing graphics in a dialogue control, it was a bit disconcerting to see that - at least superficially - you don't actually require that functionality at all. sad

So do you actually need to "display a histogram in a dialog box" as the thread title implies, or would an ordinary graphics-capable window (created most easily using the MULTIWIN library) suffice?

Richard.
Re: Displaying a histogram in a dialog box
Post by sveinioslo on Aug 5th, 2014, 11:54pm

Well Ian, if you want to animate graphics in a dialog, here is one way of doing it.
But it so much easier with the new Multiwin library Richard so kindly provided.

Svein

Code:
      STM_SETIMAGE = 370
      SS_BITMAP = &E
      BS_DEFPUSHBUTTON = 1

      INSTALL @lib$+"WINLIB2"
      dlg%=FN_newdialog("Displaying animated histogram in a dialog box", 20, 20, 400, 200, 8, 500)
      cx%=380 : cy%=160
      PROC_static(dlg%,"",123,10,10,cx%,cy%,SS_BITMAP)
      PROC_pushbutton(dlg%, "Start", 1, 240, 180, 56, 14, BS_DEFPUSHBUTTON)
      PROC_pushbutton(dlg%, "Cancel", 2, 310, 180, 56, 14, 0)
      PROC_showdialog(dlg%)

      ON CLOSE PROC_close:QUIT
      ON ERROR PROC_close:PRINT'REPORT$:END

      DIM rc{l%,t%,r%,b%}
      rc.r%=cx% : rc.b%=cy%
      SYS "MapDialogRect", !dlg%, rc{}
      cx%=rc.r% : cy%=rc.b%
      SYS "CreateCompatibleBitmap", @memhdc%, cx%, cy% TO hbitmap%

      *REFRESH OFF
      Click%=0 : start%=0
      ON SYS Click% = @wparam% : RETURN

      REPEAT
        IF start%=1 THEN
          a%+=1 : IF a%>30 THEN a%=1
          FOR n% = 0 TO 17
            SYS "SelectObject", @memhdc%, hbitmap% TO C%
      
            REM do your graphics here
            x% = n% * 64
            y% = n% * a%
            GCOL RND(15): RECTANGLE FILL x%, 2*@vdu%!212-2*cy%, 32, y%
            REM .....................
      
            SYS "SelectObject", @memhdc%, C%
            SYS "SendDlgItemMessage", !dlg%, 123, STM_SETIMAGE, 0, hbitmap%
            *REFRESH
            WAIT 2
          NEXT n%
        ENDIF
  
        click%=0
        SWAP Click%, click%
        IF click%=1 THEN start%=1
  
      UNTIL click%=2 OR !dlg%=0
      PROC_close : QUIT

      DEF PROC_close
      PROC_closedialog(dlg%) : SYS "DeleteObject", hbitmap%
      ENDPROC