fltk 0.8.7

Rust bindings for the FLTK GUI library
Documentation

fltk-rs

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Rust bindings for the FLTK Graphical User Interface library.

The FLTK crate is a crossplatform lightweight gui library which can be statically linked to produce small, self-contained (no dependencies) and fast gui applications.

Here is a list of software using FLTK.

  • Link to the official FLTK repository.
  • Link to the official documentation.

Usage

Just add the following to your project's Cargo.toml file:

[dependencies]
fltk = "^0.8"

The library offers prebuilt static cfltk and fltk libraries, which can be added using the "fltk-bundled" flag:

[dependencies]
fltk = { version = "^0.8", features = ["fltk-bundled"] }

Since these are pre-built libraries using the Github actions CI, the currently supported operating systems are:

  • Windows 10 x64 (msvc and gnu).
  • MacOS 10.15 x64.
  • Ubuntu 18.04 or later, x64. The library is automatically statically linked to your binary.

Since these are pre-built libraries using the Github actions CI, the currently supported operating systems are:

  • Windows 10 x64 (msvc and gnu).
  • MacOS 10.15 x64.
  • Ubuntu 18.04 or later, x64.

This also assumes you have curl and tar installed (for Windows, they're available in the Native Tools Command Prompt).

You can also enable ninja builds for a faster build of the C++ source using the "use-ninja" feature. Or if you have fltk already installed, you can use the fltk-system feature.

To use the master branch in your project, you can use:
```toml
[dependencies]
fltk = { git = "https://github.com/MoAlyousef/fltk-rs" }

An example hello world application:

use fltk::{app::*, window::*};

let app = App::default();
let mut wind = Window::new(100, 100, 400, 300, "Hello from rust");
wind.end();
wind.show();
app.run().unwrap();

Another example showing the basic callback functionality:

use fltk::{app::*, button::*, frame::*, window::*};

let app = App::default();
let mut wind = Window::new(100, 100, 400, 300, "Hello from rust");
let mut frame = Frame::new(0, 0, 400, 200, "");
let mut but = Button::new(160, 210, 80, 40, "Click me!");
wind.end();
wind.show();
but.set_callback(Box::new(move || frame.set_label("Hello World!")));
app.run().unwrap();

Please check the examples directory for more examples. You will notice that all widgets are instantiated with a new() method, taking the x and y coordinates, the width and height of the widget, as well as a label which can be left blank if needed. Another way to initialize a widget is using the builder pattern: (The following buttons are equivalent)

let but1 = Button::new(10, 10, 80, 40, "Button 1");

let but2 = Button::default()
.with_pos(10, 10)
.with_size(80, 40)
.with_label("Button 2");

An example of a counter showing use of the builder pattern:

let app = app::App::default();
let mut wind = Window::default()
.with_size(160, 200)
.center_screen()
.with_label("Counter");
let mut frame = Frame::default()
.with_size(100, 40)
.center_of(&wind)
.with_label("0");
let mut but_inc = Button::default()
.size_of(&frame)
.above_of(&frame, 0)
.with_label("+");
let mut but_dec = Button::default()
.size_of(&frame)
.below_of(&frame, 0)
.with_label("-");
wind.make_resizable(true);
wind.end();
wind.show();
/* Event handling */

Events

Events can be handled using the set_callback method (as above) or the available fltk::app::set_callback() free function, which will handle the default trigger of each widget(like clicks for buttons):

/* previous hello world code */
but.set_callback(Box::new(move || frame.set_label("Hello World!")));
app.run().unwrap();

Another way is to use message passing:

/* previous counter code */
let (s, r) = app::channel::<Message>();

but_inc.emit(s, Message::Increment);
but_dec.emit(s, Message::Decrement);

while app.wait().unwrap() {
let label: i32 = frame.label().parse().unwrap();
match r.recv() {
Some(Message::Increment) => frame.set_label(&(label + 1).to_string()),
Some(Message::Decrement) => frame.set_label(&(label - 1).to_string()),
None => (),
}
}

For the remainder of the code, check the full example here: https://github.com/MoAlyousef/fltk-rs/blob/master/examples/counter2.rs

For custom event handling, the handle() method can be used:

some_widget.handle(Box::new(move |ev: Event| {
match ev {
/* handle ev */
}
}));

Handled or ignored events using the handle method should return true, unhandled events should return false. More examples are available in the examples directory.

Theming

FLTK offers 4 application themes (called schemes):

  • Base
  • Gtk
  • Gleam
  • Plastic

These can be set using the App::with_scheme() function.

let app = App::default().with_scheme(AppScheme::Gleam);

Themes of individual widgets can be optionally modified using the provided methods in the WidgetExt trait, such as set_color(), set_label_font(), set_frame() etc:

some_button.set_color(Color::Light1); //! You can use one of the provided colors in the fltk enums
some_button.set_color(Color::from_rgb(255, 0, 0)); //! Or you can specify a color by rgb or hex/u32 value
some_button.set_color(Color::from_u32(0xffebee));
some_button.set_frame(FrameType::RoundUpBox);
some_button.set_font(Font::TimesItalic);

Features

The following are the features offered by the crate:

  • use-ninja: If you have ninja build installed, it builds faster than make or VS
  • system-libpng: Uses the system libpng
  • system-libjpeg: Uses the system libjpeg
  • system-zlib: Uses the system zlib
  • fltk-bundled: Support for bundled versions of cfltk and fltk on selected platforms (requires curl and tar)
  • enable-glwindow: Support for systems without OpenGL.

FAQ

please check the FAQ page for frequently asked questions, encountered issues, guides on deployment, and contribution.