Programmer Reference : Common Printing : A complete example
A complete example
The following example prints two pages of text, diagonal lines, and filled circles. The printer where the pages are being sent is prompted for, and if there are no printers available or if no printer is chosen, no printing is done.
Object subclass: PrintingExample
instanceVariableNames: 'done gc fontStruct'
classVariableNames: ''
poolDictionaries: 'CwConstants CgConstants'
"Print two similar pages of text and graphics.
NOTE: This call must run in the UI process because it
runs its own event loop until printing is completed."
"To test, execute the following:
PrintingExample new print"
| prompter displayName display jobAttributes printerShell |
done := false.
CgDisplay allPrinterDisplayNames isEmpty
ifTrue: [^System errorMessage: 'There are no available printers.'].
prompter := CwPrinterPrompter new.
(displayName := prompter prompt) isNil
ifTrue: [^nil].
jobAttributes := prompter jobAttributes.
display := CwAppContext default
openDisplay: displayName.
display isNil
ifTrue: [^nil].
printerShell := CwPrinterShell
appCreateShell: self class name
applicationClass: nil
display: display
argBlock: [:w | w jobAttributes: jobAttributes].
addCallback: XmNmapCallback
receiver: self
selector: #printerShellMap:clientData:callData:
clientData: nil;
addCallback: XmNexposeCallback
receiver: self
selector: #printerShellExpose:clientData:callData:
clientData: nil;
addCallback: XmNdestroyCallback
receiver: self
selector: #printerShellDestroy:clientData:callData:
clientData: nil.
printerShell realizeWidget.
"Printing starts on return to the event loop - so force event loop here."
done] whileFalse: CwAppContext default readAndDispatch].
printerShellMap: printerShell clientData: clientData callData: callData
"Create a graphics context, load a font, begin the print job,
and start the first page."
| fontNames display |
gc isNil
ifTrue: [
"Create a graphics context."
gc := printerShell window
createGC: None
values: nil.
"Load a font (the first courier font) for use in drawing strings."
display := printerShell display.
fontNames := display
listFonts: '*courier*'
maxnames: 1.
fontStruct := fontNames isEmpty
ifTrue: display defaultFontStruct]
ifFalse: display loadQueryFont: fontNames first].
printerShellDestroy: printerShell clientData: aStream callData: callData
"Free resources allocated for printing."
done := true.
gc freeGC.
fontStruct = printerShell display defaultFontStruct
ifFalse: [fontStruct freeFont].
printerShell display close.
printerShellExpose: printerShell clientData: clientData callData: callData
"Process the current page. If all pages are processed, end the print job
and destroy the printer shell."
| pageNum |
gc setFont: fontStruct fid.
pageNum := callData pageNumber.
self printPage: pageNum on: printerShell.
printerShell endPage.
"This example only prints two pages."
pageNum < 2
ifTrue: [
printerShell startPage]
ifFalse: [
printPage: pageNum on: printerShell
"Print some text and graphics on a printerShell."
| halfWidth halfHeight fontHeight lineNumber |
halfWidth := printerShell extent x // 2.
halfHeight := printerShell extent y // 2.
lineNumber := 1.
fontHeight := fontStruct height.
0 to: halfHeight by: 100 do: [:y |
printerShell window
drawLine: gc
x1: 0
y1: 0
x2: halfWidth
y2: y].
printerShell y + fontHeight to: halfHeight + fontHeight
by: fontHeight do: [:y |
printerShell window
drawString: gc
x: 40
y: y
string: 'Line: ', lineNumber printString, ', page: ' ,
pageNum printString.
lineNumber := lineNumber + 1.
printerShell window
fillArc: gc
x: halfWidth
y: halfHeight
width: halfWidth // 2
height: halfHeight // 2
angle1: 0 * 64
angle2: 360 * 64.
Last modified date: 01/29/2015