Allow printing directly to a non-default printer and convenience selector.

src/Typica.pro

     scale.h \
     draglabel.h \
     daterangeselector.h \
-    licensewindow.h
+    licensewindow.h \
+    printerselector.h
 SOURCES += typica.cpp \
     helpmenu.cpp \
     abouttypica.cpp \
     scale.cpp \
     draglabel.cpp \
     daterangeselector.cpp \
-    licensewindow.cpp
+    licensewindow.cpp \
+    printerselector.cpp
 
 RESOURCES += \
     resources.qrc

src/printerselector.w

+@* Saved Printers.
+
+\noindent In most cases it's best to handle printing in a way that is common
+across many applications. Put a Print menu option in a File menu, bring up the
+platform's standard print dialog, and allow people to take full advantage of
+the flexibility this provides.
+
+In more specialized use cases, however, it may make more sense to provide
+faster access to a printer that might not be the default printer for that
+computer. The first use in Typica where this makes sense is in printing tags
+that can follow the coffee and uniquely identify that batch. Using a full sheet
+of paper for this might be excessive and time consuming. Instead, it might make
+sense to get a small, inexpensive thermal receipt printer to keep at the
+roaster. If this were not the default printer, it would quickly become tedious
+to bring up the print dialog and change the selected printer after every batch.
+
+In cases like this, it would be better to provide a combo box in the window
+where a printer can be selected and remembered as the default printer just for
+that particular use, and allowing people to print directly to that printer
+without going through extra steps.
+
+@(printerselector.h@>=
+#include <QPrinterInfo>
+#include <QComboBox>
+
+#ifndef TypicaPrinterSelectorHeader
+#define TypicaPrinterSelectorHeader
+
+class PrinterSelector : public QComboBox@/
+{
+	@[Q_OBJECT@]@;
+	public:
+		PrinterSelector();
+};
+
+#endif
+
+@ The main file also requires this header.
+
+@<Header files to include@>=
+#include "printerselector.h"
+
+@ Implementation of this class is in a separate file.
+
+@(printerselector.cpp@>=
+#include "printerselector.h"
+
+@<PrinterSelector implementation@>@;
+
+@ The constructor looks at the list of available printers and populates itself
+with these.
+
+@<PrinterSelector implementation@>=
+PrinterSelector::PrinterSelector() : QComboBox(NULL)
+{
+	QList<QPrinterInfo> printers = QPrinterInfo::availablePrinters();
+	foreach(QPrinterInfo info, printers)
+	{
+		addItem(info.printerName());
+	}
+}
+
+@ The host environment is informed of this class in the usual way starting with
+a constructor function prototype.
+
+@<Function prototypes for scripting@>=
+QScriptValue constructPrinterSelector(QScriptContext *context,
+                                      QScriptEngine *engine);
+
+@ The engine is informed of this function.
+
+@<Set up the scripting engine@>=
+constructor = engine->newFunction(constructPrinterSelector);
+engine->globalObject().setProperty("PrinterSelector", constructor);
+
+@ There is nothing special about the constructor. If there were additional
+properties needed beyond those supplied by |setQComboBoxProperties()| it would
+make sense to add another function to the chain for setting script value
+properties.
+
+@<Functions for scripting@>=
+QScriptValue constructPrinterSelector(QScriptContext *, QScriptEngine *engine)
+{
+	QScriptValue object = engine->newQObject(new PrinterSelector);
+	setQComboBoxProperties(object, engine);
+	return object;
+}

src/typica.w

 
 @i webview.w
 
+@i printerselector.w
+
 @* The Application class.
 
 The |Application| class represents the \pn{} program. It is responsible for

src/webview.w

 	public:@/
 		TypicaWebView();
 		@[Q_INVOKABLE@,@, void@]@, load(const QString &url);@t\2\2@>@/
-		@[Q_INVOKABLE@,@, void@]@, print();@t\2\2@>@/
+		@[Q_INVOKABLE@,@, void@]@, print(const QString &printerName = QString());@t\2\2@>@/
 		@[Q_INVOKABLE@,@, void@]@, setHtml(const QString &html, const QUrl &baseUrl = QUrl());@t\2\2@>@/
 		@[Q_INVOKABLE@,@, void@]@, setContent(QIODevice *device);@t\2\2@>@/
 		@[Q_INVOKABLE@,@, QString@]@, saveXml();@t\2\2@>@/
 	QWebView::load(QUrl(url));
 }
 
-void TypicaWebView::print()
-{
-	QPrinter *printer = new QPrinter(QPrinter::HighResolution);
-	QPrintDialog printDialog(printer, NULL);
-	if(printDialog.exec() == QDialog::Accepted)
-	{
-		QWebView::print(printer);
-	}
-}
-
 void TypicaWebView::setHtml(const QString &html, const QUrl &baseUrl)
 {
 	QWebView::setHtml(html, baseUrl);
 	return page()->currentFrame()->documentElement().toOuterXml();
 }
 
+@ Print functionality has been extended to allow an optional argument. If the
+name of a printer is passed in, the print dialog will be bypassed.
+
+@<TypicaWebView implementation@>=
+void TypicaWebView::print(const QString &printerName)
+{
+	QPrinter *printer = new QPrinter(QPrinter::HighResolution);
+	if(!printerName.isEmpty())
+	{
+		printer->setPrinterName(printerName);
+		QWebView::print(printer);
+		return;
+	}
+	QPrintDialog printDialog(printer, NULL);
+	if(printDialog.exec() == QDialog::Accepted)
+	{
+		QWebView::print(printer);
+	}
+}
+
 @ Web views are exposed to the host environment in the usual manner.
 
 @<Set up the scripting engine@>=