1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

use gtk::prelude::{BoxExt, ButtonExt, GtkWindowExt, OrientableExt};
use relm4::{
    gtk, ComponentParts, ComponentSender, RelmApp, RelmWidgetExt, SimpleComponent, WidgetTemplate,
};

#[relm4::widget_template]
impl WidgetTemplate for MyBox {
    view! {
        gtk::Box {
            set_margin_all: 10,
            // Make the boxes visible
            inline_css: "border: 2px solid blue",
        }
    }
}

#[relm4::widget_template]
impl WidgetTemplate for MySpinner {
    view! {
        gtk::Spinner {
            set_spinning: true,
        }
    }
}

#[relm4::widget_template]
impl WidgetTemplate for CustomBox {
    view! {
        gtk::Box {
            set_orientation: gtk::Orientation::Vertical,
            set_margin_all: 5,
            set_spacing: 5,

            #[template]
            MyBox {
                #[template]
                MySpinner,

                #[template]
                MyBox {
                    #[template]
                    MySpinner,

                    #[template]
                    MyBox {
                        #[template]
                        MySpinner,

                        // Deeply nested!
                        #[name = "child_label"]
                        gtk::Label {
                            set_label: "This is a test",
                        }
                    }
                }
            }
        }
    }
}

#[derive(Default)]
struct AppModel {
    counter: u8,
}

#[derive(Debug)]
enum AppMsg {
    Increment,
    Decrement,
}

#[relm4::component]
impl SimpleComponent for AppModel {
    type Init = u8;
    type Input = AppMsg;
    type Output = ();

    view! {
        gtk::Window {
            set_title: Some("Widget template"),
            set_default_width: 300,
            set_default_height: 100,

            #[template]
            CustomBox {
                #[template_child]
                child_label {
                    #[watch]
                    set_label: &format!("Counter: {}", model.counter),
                },
                gtk::Button {
                    set_label: "Increment",
                    connect_clicked[sender] => move |_| {
                        sender.input(AppMsg::Increment);
                    },
                },
                gtk::Button {
                    set_label: "Decrement",
                    connect_clicked[sender] => move |_| {
                        sender.input(AppMsg::Decrement);
                    },
                },
            },
        }
    }

    fn init(
        counter: Self::Init,
        root: &Self::Root,
        sender: ComponentSender<Self>,
    ) -> ComponentParts<Self> {
        let model = Self { counter };

        let widgets = view_output!();

        ComponentParts { model, widgets }
    }

    fn update(&mut self, msg: AppMsg, _sender: ComponentSender<Self>) {
        match msg {
            AppMsg::Increment => {
                self.counter = self.counter.wrapping_add(1);
            }
            AppMsg::Decrement => {
                self.counter = self.counter.wrapping_sub(1);
            }
        }
    }
}

fn main() {
    let app = RelmApp::new("relm4.example.widget_template");
    app.run::<AppModel>(0);
}