fltk/FL/Fl_Cairo.H

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//
// Main Cairo support header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2023 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 Fl_Cairo.H
Cairo is currently supported for the following platforms:
Windows, macOS, Unix/Linux (X11 + Wayland).
\note In FLTK 1.3.x this header file (Fl_Cairo.H) included the platform
specific Cairo headers. This is no longer true since 1.4.0.
This header file is platform agnostic. If you need platform specific Cairo
headers you need to \#include them in your source file.
To use FLTK's builtin Cairo support you need to <tt>\#include \<FL/Fl.H></tt>
\b before you include any other FLTK header which is officially required anyway.
Since FLTK 1.4.0 the preprocessor constants \p FLTK_HAVE_CAIRO and/or
\p FLTK_HAVE_CAIROEXT are defined in \<FL/Fl.H> by including \<FL/fl_config.h>.
*/
#ifndef FL_CAIRO_H
#define FL_CAIRO_H
#include <FL/Fl.H>
# ifdef FLTK_HAVE_CAIRO
# 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