fltk/FL/Fl_Cairo.H

//
// Main header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2021 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

/* \file
    Handling transparently platform dependent cairo include files
*/

#ifndef FL_CAIRO_H
# define FL_CAIRO_H

# include <FL/fl_config.h> // build configuration

# ifdef FLTK_HAVE_CAIRO

// Cairo is currently supported for the following platforms:
// Win32, Apple Quartz, X11

# include <FL/Fl_Export.H>

# include <cairo.h>

/**
   \addtogroup group_cairo
   @{
*/

/**
   Contains all the necessary info on the current cairo context.
   A private internal & unique corresponding object is created to
   permit cairo context state handling while keeping it opaque.
   For internal use only.
   \note Only available when configure has the --enable-cairo or
        --enable-cairoext option or one or both of the CMake options
        OPTION_CAIRO or OPTION_CAIROEXT is set (ON)
*/
class FL_EXPORT Fl_Cairo_State {
public:
  Fl_Cairo_State() : cc_(0), own_cc_(false), autolink_(false), window_(0), gc_(0) {}

    // access attributes
    cairo_t* cc() const {return cc_;}            ///< Gets the current cairo context
    bool autolink() const {return autolink_;}    ///< Gets the autolink option. See Fl::cairo_autolink_context(bool)
    /** Sets the current cairo context.

        \p own == \e true (the default) indicates that the cairo context \p c
        will be deleted by FLTK internally when another cc is set later.

        \p own == \e false indicates cc deletion is handled externally
        by the user program.
    */
    void cc(cairo_t* c, bool own=true)  {
        if (cc_ && own_cc_) cairo_destroy(cc_);
        cc_=c;
        if (!cc_) window_=0;
        own_cc_=own;
    }
    void  autolink(bool b);                     ///< Sets the autolink option, only available with --enable-cairoext
    void  window(void* w)  {window_=w;}         ///< Sets the window \p w to keep track on
    void* window() const {return window_;}      ///< Gets the last window attached to a cc
    void  gc(void* c)  {gc_=c;}                 ///< Sets the gc \p c to keep track on
    void* gc() const {return gc_;}              ///< Gets the last gc attached to a cc

private:
    cairo_t * cc_;       // contains the unique autoupdated cairo context
    bool own_cc_;        // indicates whether we must delete the cc, useful for internal cleanup
    bool autolink_;      // false by default, prevents the automatic cairo mapping on fltk windows
                         // for custom cairo implementations.
    void* window_, *gc_; // for keeping track internally of last win+gc treated
};

/** @} */

# endif // FLTK_HAVE_CAIRO
#endif // FL_CAIRO_H