How to Dump Current Macintosh Screen or Window to Printer (32972)

SUMMARY

This article describes how a QuickBasic program can dump the entire Macintosh screen (Code Example 1) or dump just the current window contents (Code Example 2) to an Apple ImageWriter or LaserWriter printer.

When the examples below print color screens, the pixel colors are translated as follows:

White <= yellow, magenta, cyan, white

Black <= red, green, blue, black

For more information about color translation of the GET and PUT statements, query on the following words in the Microsoft Knowledge Base:

graphics and get and put and monochrome and macintosh

MORE INFORMATION

Both examples 1 and 2 require dynamic arrays; therefore, if you compile, you must compile WITHOUT the "Make All Arrays STATIC" option in QuickBasic. The interpreter in QuickBasic always uses dynamic arrays.

Code Example 1

The PrintScreen subprogram in the Utility Subprograms file in the "QB Demos" folder is very similar to the following example, and can be used in place of this example to save retyping.

The QuickBasic subprogram below enables you to dump the entire current Macintosh screen contents to the printer. Unlike the LCOPY statement, which also performs a screen dump, this subprogram also works for color screens and LaserWriters, although LaserWriter output will take a very long time. (LCOPY works only with a directly connected Apple ImageWriter and does not work over the AppleTalk network or to an Apple LaserWriter.)

PrintScreen 0,0,0   ' Prints whole screen without any scaling.
END
SUB PrintScreen(scale%,x%,y%) STATIC
' If scale% is true (nonzero) then the output is scaled to x% wide and
' y% high. If scale% is false (zero) then the screen is printed full
' size, and x% and y% are ignored.
    ' Calculate array size:
    max&=(4+(SYSTEM(6)+1)*2*INT((SYSTEM(5)+16)/16))/8+1
    ' Make sure there's enough memory and the array is within bounds.
    ' BEEP and EXIT if screen too big:
    IF FRE(0)<max&*8+26 OR max&>32767 THEN BEEP :EXIT SUB
    DIM origin%(1),screen#(max&)
    ' Get relative offset from current window(0,0):
    LocaltoGlobal origin%(0)
    x2 = SYSTEM(5)-origin%(1)
    y2 = SYSTEM(6)-origin%(0)
    GET (-origin%(1),-origin%(0))-(x2,y2),screen#
    OPEN "lpt1:prompt" FOR OUTPUT AS #10
    WINDOW OUTPUT #10
    IF scale% THEN PUT(0,0)-(x%,y%),screen# ELSE PUT(0,0),screen#
    CLOSE #10
    ERASE origin%,screen#
END SUB

Code Example 2

The following example sends just the contents of the current window to the printer:

FOR J=1 TO 10 : PRINT "This goes to printer" : NEXT
' Calling this SUBprogram prints just the contents of the current
' window:
CALL PrintWindow
END
SUB PrintWindow STATIC
    max&=FRE(-1)  ' Compacts memory to avoid heap memory fragmentation
    ' Calculate array size:
    wh=WINDOW(3)-1   ' Window height minus one pixel of border.
    ww=WINDOW(2)-1   ' Window width minus one pixel of border.
    max&=(4+(wh+1)*2*INT((ww+16)/16))/4 + 1
    ' Make sure there's enough memory and the array is within bounds.
    ' BEEP and EXIT if window image is too big:
    IF max&*4+26>FRE(0) OR max&>32767 THEN BEEP :EXIT SUB
    DIM win&(max&)
    GET (0,0)-(ww,wh),win&   ' GET current window contents into array.
    max&=FRE(-1)  ' Compacts memory before OPENing printer device name
    OPEN "lpt1:prompt" FOR OUTPUT AS #10
    WINDOW OUTPUT #10
    PUT(0,0),win&   ' PUT image to printer.
    CLOSE #10
    ERASE win&
END SUB