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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
use gpui::{div, prelude::*, Div, Element, ElementId, RenderOnce, Styled, WindowContext};

use theme2::ActiveTheme;

use crate::{Color, Icon, IconElement, Selection};

pub type CheckHandler = Box<dyn Fn(&Selection, &mut WindowContext) + 'static>;

/// # Checkbox
///
/// Checkboxes are used for multiple choices, not for mutually exclusive choices.
/// Each checkbox works independently from other checkboxes in the list,
/// therefore checking an additional box does not affect any other selections.
#[derive(RenderOnce)]
pub struct Checkbox {
    id: ElementId,
    checked: Selection,
    disabled: bool,
    on_click: Option<CheckHandler>,
}

impl Component for Checkbox {
    type Rendered = gpui::Stateful<Div>;

    fn render(self, cx: &mut WindowContext) -> Self::Rendered {
        let group_id = format!("checkbox_group_{:?}", self.id);

        let icon = match self.checked {
            // When selected, we show a checkmark.
            Selection::Selected => {
                Some(
                    IconElement::new(Icon::Check)
                        .size(crate::IconSize::Small)
                        .color(
                            // If the checkbox is disabled we change the color of the icon.
                            if self.disabled {
                                Color::Disabled
                            } else {
                                Color::Selected
                            },
                        ),
                )
            }
            // In an indeterminate state, we show a dash.
            Selection::Indeterminate => {
                Some(
                    IconElement::new(Icon::Dash)
                        .size(crate::IconSize::Small)
                        .color(
                            // If the checkbox is disabled we change the color of the icon.
                            if self.disabled {
                                Color::Disabled
                            } else {
                                Color::Selected
                            },
                        ),
                )
            }
            // When unselected, we show nothing.
            Selection::Unselected => None,
        };

        // A checkbox could be in an indeterminate state,
        // for example the indeterminate state could represent:
        //  - a group of options of which only some are selected
        //  - an enabled option that is no longer available
        //  - a previously agreed to license that has been updated
        //
        // For the sake of styles we treat the indeterminate state as selected,
        // but it's icon will be different.
        let selected =
            self.checked == Selection::Selected || self.checked == Selection::Indeterminate;

        // We could use something like this to make the checkbox background when selected:
        //
        // ~~~rust
        // ...
        // .when(selected, |this| {
        //     this.bg(cx.theme().colors().element_selected)
        // })
        // ~~~
        //
        // But we use a match instead here because the checkbox might be disabled,
        // and it could be disabled _while_ it is selected, as well as while it is not selected.
        let (bg_color, border_color) = match (self.disabled, selected) {
            (true, _) => (
                cx.theme().colors().ghost_element_disabled,
                cx.theme().colors().border_disabled,
            ),
            (false, true) => (
                cx.theme().colors().element_selected,
                cx.theme().colors().border,
            ),
            (false, false) => (
                cx.theme().colors().element_background,
                cx.theme().colors().border,
            ),
        };

        div()
            .id(self.id)
            // Rather than adding `px_1()` to add some space around the checkbox,
            // we use a larger parent element to create a slightly larger
            // click area for the checkbox.
            .size_5()
            // Because we've enlarged the click area, we need to create a
            // `group` to pass down interactivity events to the checkbox.
            .group(group_id.clone())
            .child(
                div()
                    .flex()
                    // This prevent the flex element from growing
                    // or shrinking in response to any size changes
                    .flex_none()
                    // The combo of `justify_center()` and `items_center()`
                    // is used frequently to center elements in a flex container.
                    //
                    // We use this to center the icon in the checkbox.
                    .justify_center()
                    .items_center()
                    .m_1()
                    .size_4()
                    .rounded_sm()
                    .bg(bg_color)
                    .border()
                    .border_color(border_color)
                    // We only want the interactivity states to fire when we
                    // are in a checkbox that isn't disabled.
                    .when(!self.disabled, |this| {
                        // Here instead of `hover()` we use `group_hover()`
                        // to pass it the group id.
                        this.group_hover(group_id.clone(), |el| {
                            el.bg(cx.theme().colors().element_hover)
                        })
                    })
                    .children(icon),
            )
            .when_some(
                self.on_click.filter(|_| !self.disabled),
                |this, on_click| this.on_click(move |_, cx| on_click(&self.checked.inverse(), cx)),
            )
    }
}
impl Checkbox {
    pub fn new(id: impl Into<ElementId>, checked: Selection) -> Self {
        Self {
            id: id.into(),
            checked,
            disabled: false,
            on_click: None,
        }
    }

    pub fn disabled(mut self, disabled: bool) -> Self {
        self.disabled = disabled;
        self
    }

    pub fn on_click(
        mut self,
        handler: impl 'static + Fn(&Selection, &mut WindowContext) + Send + Sync,
    ) -> Self {
        self.on_click = Some(Box::new(handler));
        self
    }

    pub fn render(self, cx: &mut WindowContext) -> impl Element {
        let group_id = format!("checkbox_group_{:?}", self.id);

        let icon = match self.checked {
            // When selected, we show a checkmark.
            Selection::Selected => {
                Some(
                    IconElement::new(Icon::Check)
                        .size(crate::IconSize::Small)
                        .color(
                            // If the checkbox is disabled we change the color of the icon.
                            if self.disabled {
                                Color::Disabled
                            } else {
                                Color::Selected
                            },
                        ),
                )
            }
            // In an indeterminate state, we show a dash.
            Selection::Indeterminate => {
                Some(
                    IconElement::new(Icon::Dash)
                        .size(crate::IconSize::Small)
                        .color(
                            // If the checkbox is disabled we change the color of the icon.
                            if self.disabled {
                                Color::Disabled
                            } else {
                                Color::Selected
                            },
                        ),
                )
            }
            // When unselected, we show nothing.
            Selection::Unselected => None,
        };

        // A checkbox could be in an indeterminate state,
        // for example the indeterminate state could represent:
        //  - a group of options of which only some are selected
        //  - an enabled option that is no longer available
        //  - a previously agreed to license that has been updated
        //
        // For the sake of styles we treat the indeterminate state as selected,
        // but it's icon will be different.
        let selected =
            self.checked == Selection::Selected || self.checked == Selection::Indeterminate;

        // We could use something like this to make the checkbox background when selected:
        //
        // ~~~rust
        // ...
        // .when(selected, |this| {
        //     this.bg(cx.theme().colors().element_selected)
        // })
        // ~~~
        //
        // But we use a match instead here because the checkbox might be disabled,
        // and it could be disabled _while_ it is selected, as well as while it is not selected.
        let (bg_color, border_color) = match (self.disabled, selected) {
            (true, _) => (
                cx.theme().colors().ghost_element_disabled,
                cx.theme().colors().border_disabled,
            ),
            (false, true) => (
                cx.theme().colors().element_selected,
                cx.theme().colors().border,
            ),
            (false, false) => (
                cx.theme().colors().element_background,
                cx.theme().colors().border,
            ),
        };

        div()
            .id(self.id)
            // Rather than adding `px_1()` to add some space around the checkbox,
            // we use a larger parent element to create a slightly larger
            // click area for the checkbox.
            .size_5()
            // Because we've enlarged the click area, we need to create a
            // `group` to pass down interactivity events to the checkbox.
            .group(group_id.clone())
            .child(
                div()
                    .flex()
                    // This prevent the flex element from growing
                    // or shrinking in response to any size changes
                    .flex_none()
                    // The combo of `justify_center()` and `items_center()`
                    // is used frequently to center elements in a flex container.
                    //
                    // We use this to center the icon in the checkbox.
                    .justify_center()
                    .items_center()
                    .m_1()
                    .size_4()
                    .rounded_sm()
                    .bg(bg_color)
                    .border()
                    .border_color(border_color)
                    // We only want the interactivity states to fire when we
                    // are in a checkbox that isn't disabled.
                    .when(!self.disabled, |this| {
                        // Here instead of `hover()` we use `group_hover()`
                        // to pass it the group id.
                        this.group_hover(group_id.clone(), |el| {
                            el.bg(cx.theme().colors().element_hover)
                        })
                    })
                    .children(icon),
            )
            .when_some(
                self.on_click.filter(|_| !self.disabled),
                |this, on_click| this.on_click(move |_, cx| on_click(&self.checked.inverse(), cx)),
            )
    }
}