example

/*
 * Copyright (c) 2017 Boucher, Antoni <bouanto@zoho.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#![feature(proc_macro)]

extern crate gtk;
#[macro_use]
extern crate relm;
extern crate relm_attributes;
#[macro_use]
extern crate relm_derive;

use gtk::{
    ButtonExt,
    EntryExt,
    Inhibit,
    OrientableExt,
    WidgetExt,
    WindowExt,
};
use gtk::Orientation::*;
use relm::Widget;
use relm_attributes::widget;

use self::Msg::*;

#[derive(Clone)]
pub struct Model {
    content: Wrapper,
}

#[derive(Msg)]
pub enum Msg {
    Add(String),
    Remove(usize),
    Quit,
}

#[derive(Clone)]
struct Wrapper(gtk::TextBuffer);

unsafe impl Send for Wrapper {}

#[widget]
impl Widget for Win {
    fn model() -> Model {
        Model {
            content: Wrapper(gtk::TextBuffer::new(None)),
        }
    }

    fn update(&mut self, event: Msg, model: &mut Model) {
        match event {
            Add(text) => {
                let buffer = model.content.0.clone();
                if let Some(mark) = buffer.clone().get_insert() {
                    let mut iter = buffer.get_iter_at_mark(&mark);
                    buffer.insert(&mut iter, &text);
                }
            }
            Remove(count) => {
                let buffer = model.content.0.clone();
                let start =  buffer.get_start_iter();
                let end =  buffer.get_end_iter();
                if let Some(content) = buffer.get_text(&start, &end, true) {
                    if content.len() >= count {
                        let limit = content.len() - count;
                        buffer.set_text(&content[..limit]);
                    } else {
                        buffer.set_text("");
                    }
                }
            }
            Quit => gtk::main_quit(),
        }
    }

    view! {
        gtk::Window {
            property_default_width: 400,
            property_default_height: 600,
            gtk::Box {
                orientation: Vertical,
                gtk::TextView {
                    buffer: Some(&model.content.0),
                    editable: false,
                    vexpand: true,
                },
                gtk::Box {
                    orientation: Horizontal,
                    gtk::Entry {
                        activate(entry) => {
                            let text = entry.get_text().unwrap();
                            entry.set_text("");
                            Msg::Add(text)
                        },
                        placeholder_text: "Text to add",
                        hexpand: true,
                    },
                    gtk::Button {
                        clicked => Msg::Remove(4),
                        label: "Remove some string...",
                    },
                    hexpand: true,
                },
            },
            title: "fooooo",
            delete_event(_, _) => (Quit, Inhibit(false)),
        }
    }
}

fn main() {
    relm::run::<Win>().unwrap();
}