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.

• 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 = "^0.5"

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 = "^0.5", features = ["fltk-shared"] }

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 system-fltk feature, but note that this crate uses the latest FLTK (1.40).

To use the master branch in your project, you can use:

[dependencies]
fltk = { git = "https://github.com/MoAlyousef/fltk-rs" }

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(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, 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();
    /* Event handling */
}

Events

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

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

    some_widget.handle(Box::new(move |ev: app::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::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);

Features

The following are the features offered by the crate:

• fltk-shared: Builds a shared lib of fltk
• use-ninja: If you have ninja build installed, it builds faster than make or VS
• system-fltk: If you would like to use the installed fltk library, should be FLTK 1.4
• system-libpng: Uses the system libpng
• system-libjpeg: Uses the system libjpeg
• system-zlib: Uses the system zlib
• legacy-opengl: Support of Lagacy OpenGL, the crate uses GLVND by default
• fltk-bundled: Support for bundled versions of cfltk and fltk on selected platforms

Dependencies

Rust version > 1.38. CMake and a C++17 compiler need to be installed and in your PATH for a crossplatform build from source. This crate also offers a bundled form of fltk on selected platforms, this can be enabled using the fltk-bundled feature flag.

• Windows: No dependencies.
• MacOS: No dependencies.
• Linux: X11 and OpenGL development headers need to be installed for development.

For Debian-based GUI distributions, that means running:

$ sudo apt-get install libx11-dev libxext-dev libxft-dev libxinerama-dev libxcursor-dev libxrender-dev libxfixes-dev libgl1-mesa-dev libglu1-mesa-dev

For RHEL-based GUI distributions, that means running:

$ sudo yum groupinstall "X Software Development" 

For Arch-based GUI distributions, that means running:

$ sudo pacman -S libx11 libxext libxft libxinerama libxcursor libxrender libxfixes libgl mesa --needed

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

FAQ

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

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 terminal
$ cargo run --example counter
$ cargo run --example hello
$ cargo run --example hello_button
$ cargo run --example paint
$ cargo run --example glwindow

Setting the scheme to Gtk.

Check the full code for the custom theming.

Setting the scheme to Gtk

Currently implemented widgets

The most commonly widgets are implemented:

• Image widgets
  • SharedImage
  • BmpImage
  • JpegImage
  • GifImage
  • PngImage
  • SvgImage
  • RgbImage
• Buttons
  • Button
  • RadioButton
  • ToggleButton
  • RoundButton
  • CheckButton
  • LightButton
  • RepeatButton
  • RadioLightButton
  • RadioRoundButton
• Dialogs
  • Native FileDialog
  • HelpDialog
  • Message dialog
  • Alert dialog
  • Password dialog
  • Choice dialog
  • Input dialog
• Frame (Fl_Box)
• Windows
  • Window
  • DoubleWindow
  • MenuWindow
  • GlWindow
• Groups
  • Group
  • Pack
  • Tabs
  • Scroll
  • Tile
  • Wizard
  • ColorChooser
• Text display widgets
  • TextDisplay
  • TextEditor
  • SimpleTerminal
• Input widgets
  • Input
  • IntInput
  • FloatInput
  • MultilineInput
  • SecretInput
  • FileInput
• Output widgets
  • Output
  • MultilineOutput
• Menu widgets
  • MenuBar
  • MenuItem
  • Choice (dropdown list)
• Valuator widgets
  • Slider
  • NiceSlider
  • ValueSlider
  • Dial
  • LineDial
  • Counter
  • Scrollbar
  • Roller
  • Adjuster
  • ValueInput
  • ValueOutput
  • FillSlider
  • FillDial
  • HorSlider (Horizontal slider)
  • HorFillSlider
  • HorNiceSlider
  • HorValueSlider
• Browsing widgets
  • Browser
  • SelectBrowser
  • HoldBrowser
  • MultiBrowser
  • FileBrowser
• Miscelaneous widgets
  • Spinner
  • Clock
  • Chart
  • Progress (progress bar)
  • Tooltip
• Table widgets
  • Table
  • TableRow
• Trees
  • Tree
  • TreeItem
• Drawing primitives