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Diffstat (limited to 'kghostview/kpswidget.h')
| -rw-r--r-- | kghostview/kpswidget.h | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/kghostview/kpswidget.h b/kghostview/kpswidget.h new file mode 100644 index 00000000..66ef0b14 --- /dev/null +++ b/kghostview/kpswidget.h @@ -0,0 +1,387 @@ +/** + * Copyright (C) 2000-2003 the KGhostView authors. See file AUTHORS. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef __KPSWIDGET_H__ +#define __KPSWIDGET_H__ + +#include <queue> +#include <qstring.h> +#include <qstringlist.h> +#include <qwidget.h> +#include <qpixmap.h> + +#include "dscparse_adapter.h" +#include "configuration.h" + +#include <X11/X.h> + +class KProcess; + +class KGVConfigDialog; +class MessagesDialog; + +/** + * @class KPSWidget + * + * @brief KPSWidget is a widget on which Ghostscript can render. + * + * @ref ghostscript_interface + */ + +class KPSWidget : public QWidget +{ + Q_OBJECT + +public: + KPSWidget( QWidget* parent = 0, const char* name = 0 ); + ~KPSWidget(); + + /** + * Start up the Ghostscript interpreter. Returns true if Ghostscript + * could be started; otherwise false. + */ + bool startInterpreter(); + + /** + * Stop the interpreter process. + */ + void stopInterpreter(); + + /** + * Returns true if the interpreter is ready for new input. + */ + bool isInterpreterReady() const; + + bool isInterpreterBusy() const; + + /** + * Returns true if the interpreter is running; otherwise returns false. + */ + bool isInterpreterRunning() const; + + /** + * Tell ghostscript to start the next page. + * Returns false if ghostscript is not running, or not ready to start + * another page. If another page is started, sets the _interpreterReady + * flag and cursor. + */ + bool nextPage(); + + /** + * Queue a portion of a PostScript file for output to ghostscript and + * start processing the queue. + * + * fp: FILE* of the file in question. Should be seek()able. + * begin: position in file to start. + * len: number of bytes to write. + * + * If an interpreter is not running, nothing is queued and false is + * returned. + */ + bool sendPS( FILE*, unsigned int begin, unsigned int end ); + + /** + * Sets the filename of the ghostscript input. + * @p usePipe indicates whether we use a pipe for + * communication or let ghoscript read the file itself. + */ + void setFileName( const QString&, bool usePipe ); + + /** + * Set the bounding box of the drawable. See my comment in the source + * file. + */ + void setBoundingBox( const KDSCBBOX& ); + + /** + * Set the orientation of the page. + */ + void setOrientation( CDSC_ORIENTATION_ENUM ); + + /** + * Sets the resolution according to the physical resolution of the screen + * and the magnification value. + */ + void setMagnification( double magnification ); + + /** + * @return the boundingbox of the drawable. + */ + const KDSCBBOX& boundingBox() const; + + /** + * @return the current orientation. + */ + CDSC_ORIENTATION_ENUM orientation() const; + + /** + * Double buffering means that all the drawing is done outside the + * screen and the finished picture is then flashed to the screen. + * This reduces flicker ( to almost none ) at the price of speed. + * + * By default, KPSWidget is *not* double buffered. + */ + bool isDoubleBuffered() const { return _doubleBuffer; } + void setDoubleBuffering( bool n ); + + + void clear(); + +public slots: + /** + * Call this when the settings have changed. + */ + void readSettings(); +signals: + /** + * This signal gets emited whenever a page is finished, but contains a reference to the pixmap + * used to hold the image. + * + * Don't change the pixmap or bad things will happen. This is the backing pixmap of the display. + */ + void newPageImage( QPixmap image ); + + /** + * This signal is emitted whenever the ghostscript process has + * written data to stdout or stderr. + */ + void output( char* data, int len ); + + /** + * This means that gs exited uncleanly + * + * @param msg a <strong>translated</strong> error message to display the user which may be null if we cannot tell anything important + */ + void ghostscriptError( const QString& mgs ); + +protected: + struct Record + { + Record( FILE* fp_, long begin_, unsigned len_ ) + :fp( fp_ ), begin( begin_ ), len( len_ ) { } + + FILE* fp; + long begin; + unsigned int len; + }; + + // void resizeEvent( QResizeEvent* ); + bool x11Event( XEvent* ); + + /** + * Setup the widget according to the current settings for the + * boundingBox, the resolution and the orientation. This involves + * the following things: + * - Resize the widget + * - Resize and clear the background pixmap. + * - Setup the GHOSTVIEW and GHOSTVIEW_COLORS properties. + * + * Make sure ghostscript isn't running when calling this method. + */ + void setupWidget(); + + void setGhostscriptPath( const QString& ); + void setGhostscriptArguments( const QStringList& ); + void setPalette( Configuration::EnumPalette::type ); + +protected slots: + void gs_input( KProcess* ); + void gs_output( KProcess*, char* buffer, int len ); + void interpreterFailed(); + void slotProcessExited( KProcess* ); + +private: + Window _gsWindow; // Destination of ghostscript messages. + + enum AtomName { GHOSTVIEW = 0, GHOSTVIEW_COLORS, NEXT, PAGE, DONE }; + Atom _atoms[5]; + + QPixmap _backgroundPixmap; + + /** + * The following properties determine how Ghostscript is started. + * If any of these is changed, Ghostscript needs to be restarted. + */ + QString _ghostscriptPath; + QStringList _ghostscriptArguments; + QString _fileName; + bool _usePipe; + bool _doubleBuffer; + + /** + * Flag set when one of the properties _ghostscriptPath, + * _ghostscriptArguments or _fileName has been changed. + */ + bool _ghostscriptDirty; + + /** + * The following properties determine how Ghostscript renders its + * pages. If any of these is changed, the widget needs to be setup, + * and Ghostscript needs to be restarted. + */ + CDSC_ORIENTATION_ENUM _orientation; + KDSCBBOX _boundingBox; + float _magnification; + Configuration::EnumPalette::type _palette; + + /** + * Flag set when one of the properties _orientation, _boundingBox, + * _dpi[X|Y] or _palette has been changed. + */ + bool _widgetDirty; + + KProcess* _process; + char* _buffer; + + std::queue<Record> _inputQueue; + + bool _stdinReady; + bool _interpreterBusy; + bool _interpreterReady; +}; + +inline const KDSCBBOX& KPSWidget::boundingBox() const +{ + return _boundingBox; +} + +inline CDSC_ORIENTATION_ENUM KPSWidget::orientation() const +{ + return _orientation; +} + +/** + * @page ghostview_interface Ghostview interface to Ghostscript + * + * When the GHOSTVIEW environment variable is set, Ghostscript draws on + * an existing drawable rather than creating its own window. Ghostscript + * can be directed to draw on either a window or a pixmap. + * + * + * @section window Drawing on a Window + * + * The GHOSTVIEW environment variable contains the window id of the target + * window. The window id is an integer. Ghostscript will use the attributes + * of the window to obtain the width, height, colormap, screen, and visual of + * the window. The remainder of the information is gotten from the GHOSTVIEW + * property on that window. + * + * + * @section pixmap Drawing on a Pixmap + * + * The GHOSTVIEW environment variable contains a window id and a pixmap id. + * They are integers separated by white space. Ghostscript will use the + * attributes of the window to obtain the colormap, screen, and visual to use. + * The width and height will be obtained from the pixmap. The remainder of the + * information, is gotten from the GHOSTVIEW property on the window. In this + * case, the property is deleted when read. + * + * + * @section gv_variable The GHOSTVIEW environment variable + * + * @par parameters: + * <tt> window-id [pixmap-id] </tt> + * + * @par scanf format: + * @code "%d %d" @endcode + * + * @par Explanation of the parameters + * @li @e window-id: + * tells Ghostscript where to: + * - read the GHOSTVIEW property + * - send events + * If pixmap-id is not present, Ghostscript will draw on this window. + * + * @li @e pixmap-id: + * If present, tells Ghostscript that a pixmap will be used as the + * final destination for drawing. The window will not be touched for + * drawing purposes. + * + * + * @section gv_property The GHOSTVIEW property + * + * @par type: + * STRING + * + * @par parameters: + * <tt> bpixmap orient llx lly urx ury xdpi ydpi [left bottom top right] + * </tt> + * + * @par scanf format: + * @code "%d %d %d %d %d %d %f %f %d %d %d %d" @endcode + * + * @par Explanation of the parameters + * @li @e bpixmap: + * pixmap id of the backing pixmap for the window. If no pixmap is to + * be used, this parameter should be zero. This parameter must be zero + * when drawing on a pixmap. + * + * @li <em>orient:</em> + * orientation of the page. The number represents clockwise rotation + * of the paper in degrees. Permitted values are 0, 90, 180, 270. + * + * @li <em>llx, lly, urx, ury:</em> + * Bounding box of the drawable. The bounding box is specified in + * PostScript points in default user coordinates. (Note the word + * @e drawable. This means that this bounding box is generally not + * the same as the BoundingBox specified in the DSC. In case + * DocumentMedia is specified, it is equal to the Media's bounding + * box.) + * + * @li <em>xdpi, ydpi:</em> + * Resolution of window. (This can be derived from the other + * parameters, but not without roundoff error. These values are + * included to avoid this error.) + * + * @li <em>left, bottom, top, right (optional):</em> + * Margins around the window. The margins extend the imageable area + * beyond the boundaries of the window. This is primarily used for + * popup zoom windows. I have encountered several instances of + * PostScript programs that position themselves with respect to the + * imageable area. The margins are specified in PostScript points. + * If omitted, the margins are assumed to be 0. + * + * + * @section events Events from Ghostscript + * + * If the final destination is a pixmap, the client will get a property + * notify event when Ghostscript reads the GHOSTVIEW property causing it to + * be deleted. + * + * Ghostscript sends events to the window where it read the GHOSTVIEW + * property. These events are of type ClientMessage. The message_type is set + * to either PAGE or DONE. The first long data value gives the window to be + * used to send replies to Ghostscript. The second long data value gives the + * primary drawable. If rendering to a pixmap, it is the primary drawable. + * If rendering to a window, the backing pixmap is the primary drawable. If + * no backing pixmap is employed, then the window is the primary drawable. + * This field is necessary to distinguish multiple Ghostscripts rendering to + * separate pixmaps where the GHOSTVIEW property was placed on the same + * window. + * + * The PAGE message indicates that a "page" has completed. Ghostscript will + * wait until it receives a ClientMessage whose message_type is NEXT before + * continuing. + * + * The DONE message indicates that Ghostscript has finished processing. + */ + +#endif // __KPSWIDGET_H__ + + +// vim:sw=4:sts=4:ts=8:noet |