Using Intel® Visual Fortran to Create and Build Windows*-Based Applications

ID 757211
Date 7/23/2021
Document Table of Contents

Creating Child Windows

The FILE='USER' option in the OPEN statement opens a child window. The child window defaults to a scrollable text window, 30 rows by 80 columns. You can open up to 40 child windows.

When a file OPEN that specifies " file='user' " is issued for a program built with /libs:qwin (or /MW), special processing takes place to handle this as a graphics window. The user can then write and or read to this window by issuing READ and WRITE statements with the same unit number.

There are some api's that manipulate the window via unit number (e.g., setwsizeqq(), and others that manipulate it because focus has been set to that window. The FRTL automatically sets focus to the last window accessed. Thus, after an open, read, or write to unit number - focus is set to that window, and subsequent api calls such as setbkcolorrgb(), which sets the background color, works for this window.

Running a QuickWin application displays the frame window, but not the child window. You must call SETWINDOWCONFIG or execute an I/O statement or a graphics statement to display the child window. The window receives output by its unit number, as in:

  OPEN (UNIT= 12, FILE= 'USER', TITLE= 'Product Matrix')
  WRITE (12, *) 'Enter matrix type: '

Child windows opened with FILE='USER' must be opened as sequential-access formatted files (the default). Other file specifications (direct-access, binary, or unformatted) result in run-time errors.

The following example creates three child windows. A frame window is automatically created. Text is written to each so the child windows are visible:

  program testch
  use ifqwin
  write(11,*) "Hello 11"
  write(12,*) "Hello 12"
  write(13,*) "Hello 13"
  write(13,*) "Windows 11, 12, and 13 can be read and written with normal"
  write(13,*) "Fortran I/O statements. The size of each window on the screen"
  write(13,*) "can be modified by SETWSIZEQQ. The size of the virtual window"
  write(13,*) "(i.e., a data buffer) can be modified by SETWINDOWCONFIG."

When this program is run, the output appears as follows:

To use the default graphics window, you should use units *, 5, or 6.

In the example below, if you comment out the " open(7, …" statement, and substitute the existing unit 7's with either *, or 6 for the WRITES and 5 for the READs, then the program should behave the same. API's such as " SETWSIZEQQ(7 , …" should specify either 5 or 6, because * is not a valid integer. One issue with using a default graphics window is that you cannot change the title of it from the default title.

ifort /threads /Qsave /traceback /libs:qwin simple_example.f90
      PROGRAM OneWindow
      USE DFMT

      type(windowconfig):: WIN_MainInput
      type(qwinfo)      :: FrameSize, Win1Size
      integer(2)        :: i2Status
      integer(4)        :: i4Status,i4NumQ, i4Columns, i4LetterX, i4LetterY
      logical(4)        :: L4Status
      character(1)      :: c1YesNo

      i4LetterX=8   ! Height and width of the text font
      ! Frame-Window as wide as screen but half the height
      FrameSize.H=FrameSize.H/2 !! set window height 1/2 of max height
      FrameSize.W=FrameSize.W/3 !! set window width 1/3 of max width
      i4Columns=FrameSize.W/i4LetterX -1  ! number of possible columns in each window
      ! Input-window for Main part
      open(7, file='user',title="Main Input"C)
      Win_MainInput.title="Main Input"C !! in addition to OPEN, title can also be specified by setwindowconfig()
      i4Status=setbkcolorrgb(#FFFFFF)   !! white background
      i4Status=settextcolorrgb(#000000) !! black text
      call clearscreen($GCLEARSCREEN)

      write(7,'("This is the Main Input window.",/)')
10    write(7,'("Type Y or y to Terminate this program: ",\)')
      read(7,'(Q,A)') i4NumQ, c1YesNo
      if (i4NumQ /= 1) goto 10
      if (c1YesNo == 'Y' .or. c1YesNo == 'y') goto 20
      goto 10

20    continue    
      END PROGRAM OneWindow