org.ghost4j.display

Interface DisplayCallback

All Known Implementing Classes:

ImageWriterDisplayCallback, PageRasterDisplayCallback

public interface DisplayCallback

Interface representing a display callback. A display callback provides method to interract with the Ghostscript interpreter display. This can be usefull if you are interested in capturing PS or PDF page rasters. Important: in order to use a display callback, Ghostscript must be initialized with -sDEVICE=display -sDisplayHandle and -dDisplayFormat arguments. Usually set -sDisplayHandle to 0 and use -dDisplayFormat to define how display data will be sent to the displayPage method. -dDisplayFormat=16#804 sets a standard RGB ouput. Please refer to http://ghostscript.com/doc/8.54/Devices.htm to see how to set display parameters.

Author:

Gilles Grousset (gi.grousset@gmail.com)

Method Summary

Methods

Modifier and Type	Method and Description
void	displayClose() Method called when device has been closed.
void	displayOpen() Method called when new device has been opened.
void	displayPage(int width, int height, int raster, int format, int copies, int flush, byte[] imageData) Method called on show page.
void	displayPreClose() Method called when device is about to be closed.
void	displayPreSize(int width, int height, int raster, int format) Method called when device is about to be resized.
void	displaySize(int width, int height, int raster, int format) Method called when device has been resized.
void	displaySync() Method called on page flush.
void	displayUpdate(int x, int y, int width, int height) Method called to notify whenever a portion of the raster is updated.

Method Detail

displayOpen

void displayOpen()
                 throws GhostscriptException

Method called when new device has been opened. This is the first event from this device.

Throws:

GhostscriptException

displayPreClose

void displayPreClose()
                     throws GhostscriptException

Method called when device is about to be closed. Device will not be closed until this function returns.

Throws:

GhostscriptException

displayClose

void displayClose()
                  throws GhostscriptException

Method called when device has been closed. This is the last event from this device.

Throws:

GhostscriptException

displayPreSize

void displayPreSize(int width,
                  int height,
                  int raster,
                  int format)
                    throws GhostscriptException

Method called when device is about to be resized.

Parameters:

width - Width

height - Height

raster - Raster

format - Format

Throws:

GhostscriptException

displaySize

void displaySize(int width,
               int height,
               int raster,
               int format)
                 throws GhostscriptException

Method called when device has been resized.

Parameters:

width - Width

height - Height

raster - Raster

format - Format

Throws:

GhostscriptException

displaySync

void displaySync()
                 throws GhostscriptException

Method called on page flush.

Throws:

GhostscriptException

displayPage

void displayPage(int width,
               int height,
               int raster,
               int format,
               int copies,
               int flush,
               byte[] imageData)
                 throws GhostscriptException

Method called on show page.

Parameters:

width - Width

height - Height

raster - Raster

format - Format

copies - Copies

flush - Flush

imageData - Byte array representing image data. Data layout and order is controlled by the -dDisplayFormat argument.

Throws:

GhostscriptException

displayUpdate

void displayUpdate(int x,
                 int y,
                 int width,
                 int height)
                   throws GhostscriptException

Method called to notify whenever a portion of the raster is updated.

Parameters:

x - X coordinate

y - Y coordinate

width - Width

height - Height

Throws:

GhostscriptException