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QPrinter Class Reference

The QPrinter class is a paint device that paints on a printer. More...

#include <qprinter.h>

Inherits QPaintDevice.

List of all member functions.

Public Members

Protected Members


Detailed Description

The QPrinter class is a paint device that paints on a printer.

On Windows it uses the built-in printer drivers. On X11 it generates postscript and sends that to lpr, lp, or another print command.

QPrinter is used much the same way as QWidget and QPixmap are used. The big difference is that you must keep track of the pages.

QPrinter supports a number of settable parameters, most of which can be changed by the end user when the application calls QPrinter::setup().

The most important parameters are:

Except where noted, you can only call the set functions before setup(), or between QPainter::end() and setup(). (Some may have effect between setup() and begin(), or between begin() and end(), but that's strictly undocumented and such behaviour may differ depending on platform.)

There are also some settings that the user sets (through the printer dialog) and that applications are expected to obey:

You can of course call these functions to establish defaults before you ask the user through QPrinter::setup().

Once you start printing, newPage() is essential. You will probably also need to look at the QPaintDeviceMetrics for the printer (see the simple print function in the Application walk-through). Note that the paint device metrics are valid only after the QPrinter has been set up, i.e., after setup() has returned successfully. If you want high-quality printing with accurate margins, setFullPage(TRUE) is a must.

If you want to abort the print job, abort() will make a best effort. It may cancel the entire job or just some of it.


Member Type Documentation

QPrinter::ColorMode

This enum type is used to indicate whether QPrinter should print in color or not. The possible values are:

QPrinter::Orientation

This enum type (not to be confused with Qt::Orientation) is used to decide how Qt should print on each sheet.

This type interacts with QPrinter::PageSize and QPrinter::setFullPage() to determine the final size of the page available to the application.

QPrinter::PageOrder

This enum type is used by QPrinter/QPrintDialog to tell the application program how to print. The possible values are

QPrinter::PageSize

This enum type decides what paper size QPrinter is to use. QPrinter does not check that the paper size is available; it just uses this information, together with Orientation and QPrinter::setFullPage(), to determine the printable area (see QPaintDeviceMetrics).

The defined sizes (with setFullPage( TRUE )) are

With setFullPage(FALSE) (the default), the metrics will be a bit smaller; how much depends on the printer in use.

QPrinter::PaperSource

This enum type decides what paper source QPrinter is to use. QPrinter does not check that the paper source is available; it just uses this information to try and set the paper source. Whether it will set the paper source depends on whether the printer has that particular source.

Note: It is currently only implemented for Windows.

QPrinter::PrinterMode

This enum describes the mode the printer should work in. It basically presets a certain resolution and working mode.


Member Function Documentation

QPrinter::QPrinter ( PrinterMode m = ScreenResolution )

Constructs a printer paint device.

QPrinter::~QPrinter ()

Destroys the printer paint device and cleans up.

bool QPrinter::abort ()

Aborts the print job. Returns TRUE if successful, otherwise FALSE.

See also aborted().

bool QPrinter::aborted () const

Returns TRUE is the printer job was aborted, otherwise FALSE.

See also abort().

ColorMode QPrinter::colorMode () const

Returns the current color mode. The default color mode is Color.

See also setColorMode().

QString QPrinter::creator () const

Returns the creator name.

See also setCreator().

QString QPrinter::docName () const

Returns the document name.

See also setDocName().

int QPrinter::fromPage () const

Returns the from-page setting. The default value is 0.

The programmer is responsible for reading this setting and printing accordingly.

See also setFromTo() and toPage().

bool QPrinter::fullPage () const

Returns TRUE if the origin of the printer's coordinate system is at the corner of the sheet and FALSE if it is at the edge of the printable area.

See setFullPage() for more detail and some warnings.

See also setFullPage(), PageSize and QPaintDeviceMetrics.

QSize QPrinter::margins () const

Returns the width of the left/right and top/bottom margins of the printer. This is a best-effort guess, not based on perfect knowledge.

If you have called setFullPage( TRUE ) (this is recommended for high-quality printing), margins().width() may be treated as the smallest sane left/right margin you can use, and margins().height() as the smallest sane top/bottom margins you can use.

If you have called setFullPage( FALSE ) (this is the default), margins() is automatically subtracted from the pageSize() by QPrinter.

See also setFullPage(), QPaintDeviceMetrics and PageSize.

int QPrinter::maxPage () const

Returns the max-page setting. A user can't choose a higher pagenumber than maxPage() when he or she selects a printrange. The default value is 0.

See also minPage() and setMinMax().

int QPrinter::minPage () const

Returns the min-page setting, i.e. the lowest pagenumber a user is allowed to choose. The default value is 0.

See also maxPage() and setMinMax().

bool QPrinter::newPage ()

Advances to a new page on the printer. Returns TRUE if successful, otherwise FALSE.

Examples: action/application.cpp, application/application.cpp, helpviewer/helpwindow.cpp and mdi/application.cpp.

int QPrinter::numCopies () const

Returns the number of copies to be printed. The default value is 1.

See also setNumCopies().

Orientation QPrinter::orientation () const

Returns the orientation setting. The default value is QPrinter::Portrait.

See also setOrientation().

QString QPrinter::outputFileName () const

Returns the name of the output file. There is no default file name.

See also setOutputFileName() and setOutputToFile().

bool QPrinter::outputToFile () const

Returns TRUE if the output should be written to a file, or FALSE if the output should be sent directly to the printer. The default setting is FALSE.

This function is currently supported only under X11.

See also setOutputToFile() and setOutputFileName().

PageOrder QPrinter::pageOrder () const

Returns the current page order.

The default page order is FirstPageFirst.

PageSize QPrinter::pageSize () const

Returns the printer page size. The default value is system-dependent.

See also setPageSize().

PaperSource QPrinter::paperSource () const

Returns the currently set paper source of the printer.

See also setPaperSource().

QString QPrinter::printProgram () const

Returns the name of the program that sends the print output to the printer.

The default is to return a null string; meaning that QPrinter will try to be smart in a system-dependent way. On X11 only, you can set it to something different to use a specific print program.

On Windows, this function returns the name of the printer device driver.

See also setPrintProgram() and setPrinterSelectionOption().

QString QPrinter::printerName () const

Returns the printer name. This value is initially set to the name of the default printer.

See also setPrinterName().

QString QPrinter::printerSelectionOption () const

Returns the printer options selection string. This is useful only if the print command has been explicitly set.

The default value (a null string) implies to select printer in a system-dependent manner.

Any other value implies to use that value.

See also setPrinterSelectionOption().

int QPrinter::resolution () const [virtual]

Returns the current assumed resolution of the printer, as set by setResolution() or the printer subsystem.

See also setResolution().

Reimplemented from QPaintDevice.

void QPrinter::setColorMode ( ColorMode newColorMode ) [virtual]

Sets the printer's color mode to newColorMode, which can be one of Color (the default) and GrayScale.

See also colorMode().

void QPrinter::setCreator ( const QString & creator ) [virtual]

Sets the creator name.

Calling this function has effect only for the X11 version of Qt. The creator name is the name of the application that created the document. If no creator name is specified, the creator will be set to "Qt" with some version number.

See also creator().

void QPrinter::setDocName ( const QString & name ) [virtual]

Sets the document name.

void QPrinter::setFromTo ( int fromPage, int toPage ) [virtual]

Sets the from-page and to-page settings.

The from-page and to-page settings specify what pages to print.

This function is useful mostly to set a default value that the user can override in the print dialog when you call setup().

See also fromPage(), toPage(), setMinMax() and setup().

void QPrinter::setFullPage ( bool fp ) [virtual]

Sets QPrinter to have the origin of the coordinate system at the top-left corner of the paper if fp is TRUE, or where it thinks the top-left corner of the printable area is if fp is FALSE.

The default is FALSE. You can (probably) print on (0,0), and QPaintDeviceMetrics will report something smaller than the size indicated by PageSize. (Note that QPrinter may be wrong - it does not have perfect knowledge of the physical printer.)

If you set it to TRUE, QPaintDeviceMetrics will report the exact same size as indicated by PageSize, but you cannot print on all of that - you have to take care of the output margins yourself.

See also PageSize, setPageSize(), QPaintDeviceMetrics and fullPage().

Example: helpviewer/helpwindow.cpp.

void QPrinter::setMinMax ( int minPage, int maxPage ) [virtual]

Sets the min-page and max-page settings.

The min-page and max-page restrict the from-page and to-page settings. When the printer setup dialog comes up, the user cannot select from and to that are outside the range specified by min and max pages.

See also minPage(), maxPage(), setFromTo() and setup().

void QPrinter::setNumCopies ( int numCopies ) [virtual]

Sets the number of pages to be printed.

The printer driver reads this setting and prints the specified number of copies.

See also numCopies() and setup().

void QPrinter::setOrientation ( Orientation orientation ) [virtual]

Sets the print orientation.

The orientation can be either QPrinter::Portrait or QPrinter::Landscape.

The printer driver reads this setting and prints using the specified orientation. On Windows however, this setting won't take effect until the printer dialog is shown (using QPrinter::setup() ).

See also orientation().

void QPrinter::setOutputFileName ( const QString & fileName ) [virtual]

Sets the name of the output file.

Setting a null name (0 or "") disables output to a file, i.e., calls setOutputToFile(FALSE). Setting a non-null name enables output to a file, i.e. calls setOutputToFile(TRUE).

This function is currently supported only under X11.

See also outputFileName() and setOutputToFile().

void QPrinter::setOutputToFile ( bool enable ) [virtual]

Specifies whether the output should be written to a file or sent directly to the printer.

Will output to a file if enable is TRUE, or will output directly to the printer if enable is FALSE.

This function is currently supported only under X11.

See also outputToFile() and setOutputFileName().

void QPrinter::setPageOrder ( PageOrder newPageOrder ) [virtual]

Sets the page order to newPageOrder.

The page order can be QPrinter::FirstPageFirst or QPrinter::LastPageFirst. The application programmer is responsible for reading the page order and printing accordingly.

This function is useful mostly for setting a default value that the user can override in the print dialog when you call setup().

void QPrinter::setPageSize ( PageSize newPageSize ) [virtual]

Sets the printer page size to newPageSize if that size is supported. The result if undefined if newPageSize is not supported.

The default page size is system-dependent.

This function is useful mostly for setting a default value that the user can override in the print dialog when you call setup().

See also pageSize(), PageSize, setFullPage() and setResolution().

void QPrinter::setPaperSource ( PaperSource source ) [virtual]

Sets the paper source setting.

See also paperSource().

void QPrinter::setPrintProgram ( const QString & printProg ) [virtual]

Sets the name of the program that should do the print job.

On X11, this function sets the program to call with the PostScript output. On other platforms, it has no effect.

See also printProgram().

void QPrinter::setPrinterName ( const QString & name ) [virtual]

Sets the printer name.

The default printer will be used if no printer name is set.

Under X11, the PRINTER environment variable defines the default printer. Under any other window system, the window system defines the default printer.

See also printerName().

void QPrinter::setPrinterSelectionOption ( const QString & option ) [virtual]

Sets the printer to use option to select printer. option is null by default (meaning to be a little smart), but it can be set to other values to use a specific printer selection option.

If the printer selection option is changed while the printer is active, the current print job may or may not be affected.

void QPrinter::setResolution ( int dpi ) [virtual]

Requests the printer to operate at dpi if possible, or do the best it can.

This setting affects the coordinate system as returned by e.g. QPaintDeviceMetrics and QPainter::viewport().

The value depends on the PrintingMode used in the QPrinter constructor. By default, the dpi value of the screen is used.

This function must be called before setup() to have an effect on all platforms.

See also resolution() and setPageSize().

Reimplemented from QPaintDevice.

bool QPrinter::setup ( QWidget * parent = 0 )

Opens a printer setup dialog and asks the user to specify what printer to use and miscellaneous printer settings.

Returns TRUE if the user pressed "OK" to print, or FALSE if the user cancelled the operation.

Examples: action/application.cpp, application/application.cpp, drawdemo/drawdemo.cpp, helpviewer/helpwindow.cpp and mdi/application.cpp.

int QPrinter::toPage () const

Returns the to-page setting. The default value is 0.

The programmer is responsible for reading this setting and printing accordingly.

See also setFromTo() and fromPage().


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