Printing Techniques 2
|Column Tag:||Basic School
Printing Techniques for Basic
By Dave Kelly, Hybrids Engineer, MacTutor Editorial Board
Managing BASIC Font Printing
Sometimes when talking about the Macintosh, people have asked "How many columns does the Macintosh have?". My answer to them is that it depends. Many of you like myself started out on other computers such as the Apple //. Many of the early computers had only 40 columns of text display. This severely limited the usefulness of word processing software until the introduction of 80-col display plug in boards. Back in those days it was very important to ask how many columns there were because of the limitations that are imposed by the lack of 80 column display. The Macintosh is an entirely different animal though. Because of the ability of the Macintosh to display proportional spaced fonts on the screen just as it will look when printed, it is not applicable to refer to the Macintosh screen as an 80-col display. It is important in development of applications for the Macintosh that we realize the difference between the Macintosh and other computers when it comes to displaying and printing data. Some may have experienced some frustration in trying to format text when using proportional fonts. I'll try to discuss a few items to keep in mind when using proportional spacing. There are some advantages and disadvantages to be aware of. This month we will explore some of the ins and outs of printing in different size fonts.
First, lets take a look at the difference between proportional and monospaced fonts. The unit of measurement for the spacing is the size of the character "0" in the current font. For monospaced fonts the character "0" happens to be the same width as the rest of the characters in the font. For the proportional spaced font, the "0" is an average width but not necessarily the same width as the other characters. Notice that the spacing of all the uppercase characters for a monospaced font is the same as for the lower case characters. Also note that the proportional spaced "A" is wider than the "a".
The advantage of using the monspaced type of font is that you can always be sure of just where each character will be printed or displayed. In the proportional font each of the letters are a different width depending on how much spacing each character requires. Now that we have a feel for proportional characters, try the following lines of BASIC and compare the results of printing with monospacing and proportional spacing:
' Sample program #1
' Dave Kelly
' MACTUTOR ©1985
l1$="Name #1":r1$="Name #2"
l2$="123 Main St.":r2$="456 Central Ave."
l3$="Anyplace, USA":R3$="Anywhere, USA"
FOR i=1 TO 40
TEXTFONT(2):TEXTSIZE(12) 'New York
In the sample program it is clear that the spacing of "0" is different for the 2 fonts, which explains why the second column does not line up. RULE 1: Remember that when mixing fonts you can't expect them to line up. This program demonstrates the use of the BASIC WIDTH command. The syntax of the WIDTH command is defined on page 264 of the MSBASIC manual. In general the syntax is: WIDTH [size ] [,print-zone ] . The size is the number of standard characters that a line may contain. In other words, BASIC will force a carriage return after the line size is full. If the size is 255 then BASIC will not force any carriage returns. The print-zone assigns the width of the print zone. The print zones are similar to tab stops, and they are forced by comma delimiters in the PRINT or LPRINT statements. In the sample program you can see that by using TAB or by using WIDTH the same result can be achieved. Using WIDTH the position of the 2nd column is determined by the print-zone. By using TAB(I), print position moves to the position indicated by I. An understanding of how these commands may be used is helpful when you are trying to format your printed output. An example would be the printing of a multiple column roster or newsletter where different fields might be combined together to create an entire line. The traditional way to do this would be to combine the fields together as one string variable and then to print the variable. The spacing of each field is filled to the size of the print-zone before combining all the fields, so that the total width of all the fields will fit. This works fine with monospaced fonts but it quite difficult to accomplish with proportional spaced fonts. An alternative solution is to use TAB or WIDTH functions to specify where each field will be printed. It is still important to check the length of each field before printing to make sure that each field will fit into the specified print zone. If it won't fit then either the field must be truncated or the print-zone should be adjusted. If not, then the field will print past the assigned print-zone and into the next print-zone. The next field to be printed will be pushed over to the next available print-zone.
This can be demonstated by changing the sample program. In the program the print-zone is set at 20 characters wide. If fewer than 20 characters are printed then the next print field will begin 20 characters after the start of the first print field. Try changing the line: l1$="Name #1":r1$="Name #2" to a field that has more than 20 characters, for example: l1$="Name #1 is too long now":r1$="Name #2" to demonstate the problem. To fix the line change it to:
l1$=LEFT$("Name #1 is too long now",20):r1$="Name #2" or adjust the WIDTH statement to: WIDTH 40,25.
Another consideration when using fonts of different sizes and widths is that each font will use a different number of lines to print the same thing. Because there are so many different fonts and sizes available it is difficult to examine the effect of each one. So, before using any set of fonts you should test each one out to see how many lines will fit on a page and adjust your program to count the lines as they are printed. If you are printing in a 10 pt. font it is probable that you will have more lines than for a 12 pt. font. The Disk Labeler program is a quick sample of what might be done with the WIDTH statement. Keep in mind that this is just a sample and may or may not be a useful application, however it may be modified to meet your needs.
Disk Labeler Program Sample
The program will read filenames one at a time from the disk and place them in an array called filename$(i). I have limited the size to 10 files to simplify the program. Choose Add/Remove from the files menu to add or remove a file. The selected files are printed in window 1. The second menu lets you select the font info. This illustrates a method of changing the fonts and sizes that will be used. This could be expanded to select various attributes such as Bold or Italics. Keep in mind that the different attributes will also change the width of each character. The printlabel routine demonstrates printing different fonts to the printer. If you have had trouble changing fonts when printing to the printer you may want to take a closer look at this routine. The key is the WINDOW OUTPUT #1 statement. This statement is necessary to direct all graphics commands, including those which change the fonts, to the printer. The Set Disk Label item of the files menu will let you set the number of lines and the number of columns that will be printed. The columns are formatted with the WIDTH statement. Disk labels may be printed in any desired font by adding additional fonts to the menu. I recommend printing labels in a small font (9 point) in order to fit more on a label. Have any useful printing tips? Send your best suggestions to me care of MacTutor!
' Disk Labeler
' By Dave Kelly
' MACTUTOR ©1985
' Watch line breaks. A few Basic lines are longer than
' this Journals column width, but the breaks are
' obviously placed so that it is clear the Basic line
' continues from the previous line.
number.of.files=0:DEFINT i-m:maxfiles=10 number.of.lines=5:number.of.col=2
chicago=0: Appl=1: Newyork=2: Geneva=3: Monaco=4
FOR i=1 TO 5:MENU i,0,0,"":NEXT i
'set new menus
MENU 1,1,1,"Add/Remove a file"
MENU 1,2,1,"Clear all files"
MENU 1,4,1,"Print Disk Label"
MENU 1,5,1,"Set Disk Label"
MENU 2,0,1,"Font Info"
MENU 2,6,1,"9 point"
MENU 2,7,1,"10 point"
MENU 2,8,2,"12 point"
ON MENU GOSUB Menucheck:MENU ON
idle: GOTO idle
ON Menunumber GOSUB Filemenu, Fontmenu
ON Menuitem GOSUB Add, Clearfiles,Blank,Printlabel, Setlabel, Quit
IF x$="" THEN GOSUB display:RETURN 'x$=MID$(x$,INSTR(x$,":")+1)
'optional line:use to strip volume name
FOR i= 1 TO number.of.files
IF x$=filename$(i) THEN filename$(i)="zzzzz": i=number.of.files+2:
CALL Sort(filename$(), number.of.files): number.of.files= number.of.files-1
IF number.of.files>=maxfiles THEN GOSUB display: RETURN
IF i=number.of.files+1 THEN filename$(i)=x$: number.of.files=i
CALL Sort (filename$(),number.of.files )
CLS:PRINT number.of.files;"files have been selected." TEXTFONT(activefont):TEXTSIZE(activesize)
FOR i=1 TO number.of.files
IF activesize<=10 THEN maxlength=40
IF number.of.files=maxfiles THEN
IF number.of.files=0 THEN RETURN
OPEN "LPT1:PROMPT" FOR OUTPUT AS #1
WINDOW OUTPUT #1 TEXTFONT(activefont):TEXTSIZE(activesize)
colwid=30:IF number.of.col=2 THEN colwid=20
ON ERROR GOTO Error.handle 'check for printing abort
IF number.of.col=1 THEN onecol
IF number.of.lines<number.of.files/2 THEN items=number.of.lines*2
FOR i= 1 TO items STEP 2
PRINT #1,LEFT$(filename$(i),colwid), LEFT$(filename$(i+1),colwid)
WINDOW OUTPUT 1
IF number.of.lines<number.of.files THEN items=number.of.lines
FOR i= 1 TO items
LOCATE 1,1:PRINT"Lines per label:"
LOCATE 3,1:PRINT "# of columns:" lines$=STR$(number.of.lines)
EDIT FIELD 2,cwid$,(125,31)-(155,46),1,2
EDIT FIELD 1,lines$,(125,1)-(145,16),1,2
IF d=1 THEN Done ' got OK button
IF d=2 THEN i=DIALOG(2):EDIT FIELD i 'got field
IF d=6 THEN Done 'got return key
IF d=7 THEN i=(i MOD 2)+1:EDIT FIELD i 'got TAB key GOTO loop
IF number.of.lines<1 OR number.of.lines>9 THEN loop cwid$=EDIT$(2)
IF number.of.col<1 OR number.of.col>2 THEN loop
EDIT FIELD CLOSE 1:EDIT FIELD CLOSE 2
BUTTON CLOSE 1
WINDOW 1,"Disk Labeler",(2,40)-(510,250),1
ON Menuitem GOSUB Blank,NY,Geneva,Monaco, Blank,Pt09,Pt10,Pt12
MENU 2,2,2: MENU 2,3,1: MENU 2,4,1
MENU 2,2,1: MENU 2,3,2: MENU 2,4,1
MENU 2,2,1: MENU 2,3,1: MENU 2,4,2
MENU 2,6,2: MENU 2,7,1: MENU 2,8,1
MENU 2,6,1: MENU 2,7,2: MENU 2,8,1
MENU 2,6,1: MENU 2,7,1: MENU 2,8,2
SUB Sort (item$(maxfiles),N) STATIC
FOR i=1 TO N-1
FOR j=i+1 TO N
IF item$(i)> item$(j) THEN SWAP item$(i),item$(j)