fltk 0.2.21

Rust bindings for the FLTK GUI library
Documentation

fltk-rs

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.

This crate is still in active development and is not production ready. However, you can still try it out and give valuable feedback.

Here is a list of software using FLTK.

Usage

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

[dependencies]
fltk = "^0.2.21"

The library is automatically statically linked to your binary. If however you would prefer dynamic linking, you can use the fltk-shared feature:

[dependencies.fltk]
version = "^0.2.21"
features = ["fltk-shared"]

An example hello world application:

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

fn main() {
    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::*};

fn main() {
    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(|| 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, as well as the width and height of the widget. Most widgets, except the TextDisplay and TextEditor, also take 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:

fn main() {
    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();
    but_inc.set_callback(Box::new(|| {
        frame.set_label(&(frame.label().parse::<i32>().unwrap() + 1).to_string())
    }));
    but_dec.set_callback(Box::new(|| {
        frame.set_label(&(frame.label().parse::<i32>().unwrap() - 1).to_string())
    }));
    app.run().unwrap();
}

Events

Event handling must be done after the drawing is done and the main window shown.

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

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

Theming

FLTK offers 4 application themes (called schemes):

  • Base
  • Gtk
  • Gleam
  • Plastic

These can be set using the App::set_scheme() function. 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_type() 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);

Dependencies

CMake and a C++ compiler need to be installed and in your PATH for a crossplatform build.

  • Windows: No dependencies.
  • MacOs: No dependencies.
  • Linux: X11 development headers need to be installed for development.

For Debian-based distribution, that means running:

$ sudo apt-get install libx11-dev libxext-dev libxft-dev libxinerama-dev libxcursor-dev libxrender-dev libxfixes-dev

For RHEL-based distributions, that means running:

$ sudo yum groupinstall "X Software Development"

If you have ninja-build installed, you can enable it using the "use-ninja" feature. This should accelerate build times significantly.

Building

To build, just run:

$ git clone https://github.com/MoAlyousef/fltk-rs
$ cd fltk-rs
$ cargo build

Examples

To run the examples:

$ cargo run --example editor
$ cargo run --example calculator
$ cargo run --example gallery
$ cargo run --example button
$ cargo run --example terminal
$ cargo run --example counter
$ cargo run --example hello
$ cargo run --example hello_button
$ cargo run --example paint

alt_test

alt_test

Setting the scheme to Gtk.

alt_test

alt_test

Check the full code for the custom theming.

alt_test

Setting the scheme to Gtk

alt_test

Currently implemented widgets

Most common widgets are implemented:

  • Images (BMP, JPEG, GIF, PNG, SVG)
  • Button
  • RadioButton
  • ToggleButton
  • RoundButton
  • CheckButton
  • LightButton
  • RepeatButton
  • Native FileDialog
  • HelpDialog
  • Frame (Fl_Box)
  • Window
  • DoubleWindow
  • MenuWindow
  • Group
  • Pack
  • Tabs
  • Scroll
  • Tile
  • TextDisplay
  • TextEditor
  • SimpleTerminal
  • Input
  • IntInput
  • FloatInput
  • MultilineInput
  • SecretInput
  • FileInput
  • Output
  • MultilineOutput
  • MenuBar
  • MenuItem
  • Choice (dropdown list)
  • Slider
  • NiceSlider
  • ValueSlider
  • Dial
  • LineDial
  • Counter
  • Scrollbar
  • Roller
  • Adjuster
  • ValueInput
  • Browser
  • SelectBrowser
  • HoldBrowser
  • MultiBrowser
  • FileBrowser
  • Spinner
  • Clock
  • Chart
  • Progress (progress bar)
  • ColorChooser
  • Drawing primitives

Todo

  • Complete widget set
  • Better documentation
  • Better testing
  • Add tables

Contributions

Contributions are very welcome!

Regarding the wrapping code: I had issues with using Rust-Bindgen directly on C++ code. So wrapping must be in C/C++. The wrapping headers must be in C89 (no issues running bindgen on them). The wrapping code in .cpp files can be in C++98 or C++11, as not to impose on users having to install a new C++ compiler. Bindgen had a dependency on LLVM and libclang, so I prefer that it not be added as dependency to this project. However, I strongly advise installing it and using it for development. You can see the fltk-sys/bind.sh script on how bindgen is used with this project for development. C/C++ must be formatted using clang-format. Rust code must be formatted using rustfmt.

License

Code licensed under the MIT license!