org.eclipse.swt.printing

Class Printer

java.lang.Object

org.eclipse.swt.graphics.Device

org.eclipse.swt.printing.Printer

All Implemented Interfaces:

Drawable

public final class Printer
extends Device

Instances of this class are used to print to a printer. Applications create a GC on a printer using new GC(printer) and then draw on the printer GC using the usual graphics calls.

A Printer object may be constructed by providing a PrinterData object which identifies the printer. A PrintDialog presents a print dialog to the user and returns an initialized instance of PrinterData. Alternatively, calling new Printer() will construct a printer object for the user's default printer.

Application code must explicitly invoke the Printer.dispose() method to release the operating system resources managed by each instance when those instances are no longer required.

See Also:

PrinterData, PrintDialog, Printing snippets, Sample code and further information

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static TCHAR	appName
(package private) PrinterData	data the printer data describing this printer
int	handle the handle to the printer DC (Warning: This field is platform dependent) IMPORTANT: This field is not part of the SWT public API.
(package private) boolean	isGCCreated whether or not a GC was created for this printer
(package private) static TCHAR	keyName
(package private) static TCHAR	profile strings used to access the Windows registry

Fields inherited from class org.eclipse.swt.graphics.Device

CurrentDevice, DEBUG, DeviceFinder, hPalette

Constructor Summary

Constructors

Constructor and Description
Printer() Constructs a new printer representing the default printer.
Printer(PrinterData data) Constructs a new printer given a PrinterData object representing the desired printer.

Method Summary

Methods

Modifier and Type	Method and Description
void	cancelJob() Cancels a print job in progress.
protected void	checkDevice() Checks the validity of this device.
(package private) static DeviceData	checkNull(PrinterData data)
Rectangle	computeTrim(int x, int y, int width, int height) Given a client area (as described by the arguments), returns a rectangle, relative to the client area's coordinates, that is the client area expanded by the printer's trim (or minimum margins).
protected void	create(DeviceData deviceData) Creates the printer handle.
protected void	destroy() Destroys the printer handle.
void	endJob() Ends the current print job.
void	endPage() Ends the current page.
Rectangle	getBounds() Returns a rectangle describing the receiver's size and location.
Rectangle	getClientArea() Returns a rectangle which describes the area of the receiver which is capable of displaying data.
static PrinterData	getDefaultPrinterData() Returns a PrinterData object representing the default printer or null if there is no default printer.
Point	getDPI() Returns a point whose x coordinate is the horizontal dots per inch of the printer, and whose y coordinate is the vertical dots per inch of the printer.
PrinterData	getPrinterData() Returns a PrinterData object representing the target printer for this print job.
static PrinterData[]	getPrinterList() Returns an array of PrinterData objects representing all available printers.
void	internal_dispose_GC(int hDC, GCData data) Invokes platform specific functionality to dispose a GC handle.
int	internal_new_GC(GCData data) Invokes platform specific functionality to allocate a new GC handle.
protected void	release() Releases any internal state prior to destroying this printer.
boolean	startJob(java.lang.String jobName) Starts a print job and returns true if the job started successfully and false otherwise.
boolean	startPage() Starts a page and returns true if the page started successfully and false otherwise.

Methods inherited from class org.eclipse.swt.graphics.Device

dispose, getDepth, getDeviceData, getFontList, getSystemColor, getSystemFont, getWarnings, init, isDisposed, loadFont, setWarnings

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

handle

public int handle

the handle to the printer DC (Warning: This field is platform dependent)

IMPORTANT: This field is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.

data

PrinterData data

the printer data describing this printer

isGCCreated

boolean isGCCreated

whether or not a GC was created for this printer

profile

static TCHAR profile

strings used to access the Windows registry

appName

static TCHAR appName

keyName

static TCHAR keyName

Constructor Detail

Printer

public Printer()

Constructs a new printer representing the default printer.

Note: You must dispose the printer when it is no longer required.

Throws:

SWTError -

• ERROR_NO_HANDLES - if there is no valid default printer

See Also:

Device.dispose()

Printer

public Printer(PrinterData data)

Constructs a new printer given a PrinterData object representing the desired printer. If the argument is null, then the default printer will be used.

Note: You must dispose the printer when it is no longer required.

Parameters:

data - the printer data for the specified printer, or null to use the default printer

Throws:

java.lang.IllegalArgumentException -

• ERROR_INVALID_ARGUMENT - if the specified printer data does not represent a valid printer

SWTError -

• ERROR_NO_HANDLES - if there are no valid printers

See Also:

Device.dispose()

Method Detail

getPrinterList

public static PrinterData[] getPrinterList()

Returns an array of PrinterData objects representing all available printers. If there are no printers, the array will be empty.

Returns:

an array of PrinterData objects representing the available printers

getDefaultPrinterData

public static PrinterData getDefaultPrinterData()

Returns a PrinterData object representing the default printer or null if there is no default printer.

Returns:

the default printer data or null

Since:

2.1

checkNull

static DeviceData checkNull(PrinterData data)

create

protected void create(DeviceData deviceData)

Creates the printer handle. This method is called internally by the instance creation mechanism of the Device class.

Overrides:

create in class Device

Parameters:

deviceData - the device data

See Also:

Device.init()

internal_new_GC

public int internal_new_GC(GCData data)

Invokes platform specific functionality to allocate a new GC handle.

IMPORTANT: This method is not part of the public API for Printer. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

Specified by:

internal_new_GC in interface Drawable

Specified by:

internal_new_GC in class Device

Parameters:

data - the platform specific GC data

Returns:

the platform specific GC handle

internal_dispose_GC

public void internal_dispose_GC(int hDC,
                       GCData data)

Invokes platform specific functionality to dispose a GC handle.

IMPORTANT: This method is not part of the public API for Printer. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

Specified by:

internal_dispose_GC in interface Drawable

Specified by:

internal_dispose_GC in class Device

Parameters:

hDC - the platform specific GC handle

data - the platform specific GC data

startJob

public boolean startJob(java.lang.String jobName)

Starts a print job and returns true if the job started successfully and false otherwise.

This must be the first method called to initiate a print job, followed by any number of startPage/endPage calls, followed by endJob. Calling startPage, endPage, or endJob before startJob will result in undefined behavior.

Parameters:

jobName - the name of the print job to start

Returns:

true if the job started successfully and false otherwise.

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

startPage(), endPage(), endJob()

endJob

public void endJob()

Ends the current print job.

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

startJob(java.lang.String), startPage(), endPage()

cancelJob

public void cancelJob()

Cancels a print job in progress.

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

startPage

public boolean startPage()

Starts a page and returns true if the page started successfully and false otherwise.

After calling startJob, this method may be called any number of times along with a matching endPage.

Returns:

true if the page started successfully and false otherwise.

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

endPage(), startJob(java.lang.String), endJob()

endPage

public void endPage()

Ends the current page.

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

startPage(), startJob(java.lang.String), endJob()

getDPI

public Point getDPI()

Returns a point whose x coordinate is the horizontal dots per inch of the printer, and whose y coordinate is the vertical dots per inch of the printer.

Overrides:

getDPI in class Device

Returns:

the horizontal and vertical DPI

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

getBounds

public Rectangle getBounds()

Returns a rectangle describing the receiver's size and location.

For a printer, this is the size of the physical page, in pixels.

Overrides:

getBounds in class Device

Returns:

the bounding rectangle

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

getClientArea(), computeTrim(int, int, int, int)

getClientArea

public Rectangle getClientArea()

Returns a rectangle which describes the area of the receiver which is capable of displaying data.

For a printer, this is the size of the printable area of the page, in pixels.

Overrides:

getClientArea in class Device

Returns:

the client area

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

getBounds(), computeTrim(int, int, int, int)

computeTrim

public Rectangle computeTrim(int x,
                    int y,
                    int width,
                    int height)

Given a client area (as described by the arguments), returns a rectangle, relative to the client area's coordinates, that is the client area expanded by the printer's trim (or minimum margins).

Most printers have a minimum margin on each edge of the paper where the printer device is unable to print. This margin is known as the "trim." This method can be used to calculate the printer's minimum margins by passing in a client area of 0, 0, 0, 0 and then using the resulting x and y coordinates (which will be <= 0) to determine the minimum margins for the top and left edges of the paper, and the resulting width and height (offset by the resulting x and y) to determine the minimum margins for the bottom and right edges of the paper, as follows:

• The left trim width is -x pixels
• The top trim height is -y pixels
• The right trim width is (x + width) pixels
• The bottom trim height is (y + height) pixels

Parameters:

x - the x coordinate of the client area

y - the y coordinate of the client area

width - the width of the client area

height - the height of the client area

Returns:

a rectangle, relative to the client area's coordinates, that is the client area expanded by the printer's trim (or minimum margins)

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

See Also:

getBounds(), getClientArea()

getPrinterData

public PrinterData getPrinterData()

Returns a PrinterData object representing the target printer for this print job.

Returns:

a PrinterData object describing the receiver

checkDevice

protected void checkDevice()

Checks the validity of this device.

Overrides:

checkDevice in class Device

Throws:

SWTException -

• ERROR_DEVICE_DISPOSED - if the receiver has been disposed

release

protected void release()

Releases any internal state prior to destroying this printer. This method is called internally by the dispose mechanism of the Device class.

Overrides:

release in class Device

See Also:

Device.dispose(), Device.destroy()

destroy

protected void destroy()

Destroys the printer handle. This method is called internally by the dispose mechanism of the Device class.

Overrides:

destroy in class Device

See Also:

Device.dispose(), Device.release()