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:
  • Field Details

    • handle

      public long 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.

      Restriction:
      This field is not intended to be referenced by clients.
  • Constructor Details

    • 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:
    • 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:
      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:
  • Method Details

    • 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
    • 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:
    • internal_new_GC

      public long 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
      Restriction:
      This method is not intended to be referenced by clients.
    • internal_dispose_GC

      public void internal_dispose_GC(long 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
      Restriction:
      This method is not intended to be referenced by clients.
    • isAutoScalable

      public boolean isAutoScalable()
      Description copied from interface: Drawable
      Returns true iff coordinates can be auto-scaled on this drawable and false if not. E.g. a GC method should not auto-scale the bounds of a figure drawn on a Printer device, but it may have to auto-scale when drawing on a high-DPI Display monitor.
      Returns:
      true if auto-scaling is enabled for this drawable
      Restriction:
      This method is not intended to be referenced by clients.
    • startJob

      public boolean startJob(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:
    • endJob

      public void endJob()
      Ends the current print job.
      Throws:
      SWTException -
      • ERROR_DEVICE_DISPOSED - if the receiver has been disposed
      See Also:
    • 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

      public void endPage()
      Ends the current page.
      Throws:
      SWTException -
      • ERROR_DEVICE_DISPOSED - if the receiver has been disposed
      See Also:
    • 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

      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:
    • 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:
    • 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:
    • 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: