Crate fltk[−][src]

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.

Tutorials:

Here is a list of software using FLTK. For software using fltk-rs, check here.

  • 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 = "^1"

To use the latest changes in the repo:

[dependencies]
fltk = { version = "^1", git = "https://github.com/MoAlyousef/fltk-rs" }

The library is automatically built and statically linked to your binary.

For faster builds you can enable ninja builds for the C++ source using the “use-ninja” feature.

An example hello world application:

use fltk::{app, prelude::*, window::Window};
let app = 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::Button, frame::Frame, prelude::*, window::Window};
let app = 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(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)

use fltk::{button::*, prelude::*};
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:

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

Alternatively, you can use packs to layout your widgets:

use fltk::{button::*, frame::*, group::*, prelude::*, window::*};
let mut wind = Window::default().with_size(160, 200).with_label("Counter");
// Vertical is default. You can choose horizontal using pack.set_type(PackType::Horizontal);
let mut pack = Pack::default().with_size(120, 140).center_of(&wind);
pack.set_spacing(10);
let mut but_inc = Button::default().with_size(0, 40).with_label("+");
let mut frame = Frame::default().with_size(0, 40).with_label("0");
let mut but_dec = Button::default().with_size(0, 40).with_label("-");
pack.end();

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(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() {
        let label: i32 = frame.label().parse().unwrap();
        if let Some(msg) = r.recv() {
            match msg {
                Message::Increment => frame.set_label(&(label + 1).to_string()),
                Message::Decrement => frame.set_label(&(label - 1).to_string()),
            }
        }
    }

For the remainder of the code, check the full example here.

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

ⓘ
    some_widget.handle(move |widget, 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::App::default().with_scheme(app::Scheme::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)
  • no-pango: Build without pango support on Linux/BSD.
  • enable-glwindow: Support for drawing using OpenGL functions.

Dependencies

Rust (version > 1.38), CMake (version > 3.0), Git and a C++11 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 (which requires curl and tar to download and unpack the bundled libraries).

  • Windows: No dependencies.
  • MacOS: No dependencies.
  • Linux/BSD: X11 and OpenGL development headers need to be installed for development. The libraries themselves are available on linux distros with a graphical user interface.

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 libpango1.0-dev libpng-dev libgl1-mesa-dev libglu1-mesa-dev

For RHEL-based GUI distributions, that means running:

ⓘ
$ sudo yum groupinstall "X Software Development" && yum install pango-devel libXinerama-devel libpng-devel

For Arch-based GUI distributions, that means running:

ⓘ
$ sudo pacman -S libx11 libxext libxft libxinerama libxcursor libxrender libxfixes libpng pango cairo libgl mesa --needed

For Alpine linux:

ⓘ
$ apk add pango-dev fontconfig-dev libxinerama-dev libxfixes-dev libxcursor-dev libpng-dev mesa-gl

For NixOS (Linux distribution) this nix-shell environment can be used:

ⓘ
$ nix-shell --packages rustc cmake git gcc xorg.libXext xorg.libXft xorg.libXinerama xorg.libXcursor xorg.libXrender xorg.libXfixes libpng libcerf pango cairo libGL mesa pkg-config
  • Android(experimental): Android Studio, Android Sdk, Android Ndk.

FAQ

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

Modules

app

Application related methods and functions

browser

Browser widgets

button

Button widgets

dialog

Dialog widgets

draw

Drawing primitives

enums

Fltk defined enums: Color, Font, CallbackTrigger etc

frame

Basic fltk box/frame widget

group

Group widgets

image

Image types supported by fltk

input

Input widgets

menu

Menu widgets

misc

Miscellaneous widgets not fitting a certain group

output

Output widgets

prelude

All fltk widget traits and flt error types

printer

Printing related functions

surface

Widget surface to image functions

table

Table widgets

text

Text display widgets

tree

Tree widgets

utils

General utility functions

valuator

Valuator widgets

widget

Basic empty widget

window

Window widgets