Improve Fl_Cairo_Window documentation (typos + indentation)

Also fix a doxygen warning in Fl_String.
This commit is contained in:
Albrecht Schlosser 2023-03-23 13:26:14 +01:00
parent b98aa7bee6
commit aebf2fec39
2 changed files with 45 additions and 41 deletions

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@ -1,5 +1,5 @@
//
// Cairo window header file for the Fast Light Tool Kit (FLTK).
// Fl_Cairo_Window header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2023 by Bill Spitzak and others.
//
@ -14,8 +14,8 @@
// https://www.fltk.org/bugs.php
//
/* \file
Fl_Cairo_Window, an FLTK window incorporating a Cairo draw callback.
/** \file FL/Fl_Cairo_Window.H
\brief Fl_Cairo_Window, an FLTK window incorporating a Cairo draw callback.
*/
#ifndef FL_CAIRO_WINDOW_H
@ -27,6 +27,7 @@
// Cairo is currently supported for the following platforms:
// Win32, Apple Quartz, X11, Wayland
# include <FL/Fl.H>
# include <FL/Fl_Double_Window.H>
@ -42,10 +43,11 @@
so that the only thing you have to do is to provide your Cairo code.
All Cairo context handling is achieved transparently.
The default coordinate system for cairo drawing commands within Fl_Cario_Window
is FLTK's coordinate system, where the `x,y,w,h` values are releative to the
The default coordinate system for Cairo drawing commands within Fl_Cairo_Window
is FLTK's coordinate system, where the `x,y,w,h` values are relative to the
top/left corner of the Fl_Cairo_Window, as one would expect with regular
FLTK drawing commands, e.g.: `(0&le;x&le;w-1),(0&le;y&le;h-1)`. \b Example:
FLTK drawing commands, e.g.: `(0 x w-1), (0 y h-1)`.
\b Example:
\code
static void my_cairo_draw_cb(Fl_Cairo_Window *window, cairo_t *cr) {
// Draw an "X"
@ -59,15 +61,15 @@
}
\endcode
The FLTK coordinate system differs from the default native cairo coordinate system
which uses normalized `(0.0&hellip;1.0)` values for x and y, e.g.: `(0&le;x&le;1.0),(0&le;y&le;1.0)`.
So beware of this when copy/pasting cairo example programs that assume normalized values.
If need be, you can revert to the cairo coordinate system by simply calling `cairo_scale()`
The FLTK coordinate system differs from the default native Cairo coordinate system
which uses normalized `(0.0 1.0)` values for x and y, e.g.: `(0 x 1.0), (0 y 1.0)`.
So beware of this when copy/pasting Cairo example programs that assume normalized values.
If need be, you can revert to the Cairo coordinate system by simply calling `cairo_scale()`
with the widget's `w()` and `h()` values. \b Example:
\code
static void my_cairo_draw_cb(Fl_Cairo_Window *window, cairo_t *cr) {
cairo_scale(cr, window->w(), window->h()); // use cairo's default coordinate system
cairo_scale(cr, window->w(), window->h()); // use Cairo's default coordinate system
[..use 0.0 to 1.0 values from here on..]
}
\endcode
@ -78,10 +80,10 @@
\note Class Fl_Cairo_Window requires the FLTK library to have been built with
CMake option OPTION_CAIRO or configure --enable-cairo.
\note You can alternatively define your custom cairo FLTK window,
\note You can alternatively define your custom Cairo FLTK window,
and thus at least override the draw() method to provide custom Cairo
support. In this case you will probably use Fl::cairo_make_current(Fl_Window*)
to attach a context to your window. You should do it only when your window is
to attach a context to your window. You should do this only when your window is
the current window. \see Fl_Window::current()
*/
class FL_EXPORT Fl_Cairo_Window : public Fl_Double_Window {
@ -93,7 +95,7 @@ public:
: Fl_Double_Window(X, Y, W, H, L), draw_cb_(0) {}
protected:
/** Overloaded to provide Cairo callback support */
/** Overloaded to provide Cairo callback support. */
void draw() FL_OVERRIDE {
Fl_Double_Window::draw();
if (draw_cb_) { // call the Cairo draw callback

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@ -301,8 +301,10 @@ char *Fl_String::data() {
/**
Return a pointer to the NUL terminated string.
\return reference to non-mutable string
\note same as `const char *Fl_String::data() const`
\note same as Fl_String::data() const
*/
const char *Fl_String::c_str() const {
return data();