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

// Copyright 2019 The xi-editor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! A radio button widget.

use crate::kurbo::{Circle, Point, Rect, Size};
use crate::theme;
use crate::widget::{CrossAxisAlignment, Flex, Label, LabelText, Padding};
use crate::{
    BoxConstraints, Data, Env, Event, EventCtx, LayoutCtx, LifeCycle, LifeCycleCtx, LinearGradient,
    PaintCtx, RenderContext, UnitPoint, UpdateCtx, Widget, WidgetExt, WidgetPod,
};

/// A group of radio buttons
#[derive(Debug, Clone)]
pub struct RadioGroup;

impl RadioGroup {
    /// Given a vector of `(label_text, enum_variant)` tuples, create a group of Radio buttons
    pub fn new<T: Data + PartialEq>(
        variants: impl IntoIterator<Item = (impl Into<LabelText<T>> + 'static, T)>,
    ) -> impl Widget<T> {
        let mut col = Flex::column().cross_axis_alignment(CrossAxisAlignment::Start);
        for (label, variant) in variants.into_iter() {
            let radio = Radio::new(label, variant);
            col.add_child(Padding::new(5.0, radio));
        }
        col
    }
}

/// A single radio button
pub struct Radio<T> {
    variant: T,
    child_label: WidgetPod<T, Box<dyn Widget<T>>>,
}

impl<T: Data> Radio<T> {
    /// Create a lone Radio button from label text and an enum variant
    pub fn new(label: impl Into<LabelText<T>>, variant: T) -> Radio<T> {
        Radio {
            variant,
            child_label: WidgetPod::new(Label::new(label).boxed()),
        }
    }
}

impl<T: Data + PartialEq> Widget<T> for Radio<T> {
    fn event(&mut self, ctx: &mut EventCtx, event: &Event, data: &mut T, _env: &Env) {
        match event {
            Event::MouseDown(_) => {
                ctx.set_active(true);
                ctx.request_paint();
            }
            Event::MouseUp(_) => {
                if ctx.is_active() {
                    ctx.set_active(false);
                    if ctx.is_hot() {
                        *data = self.variant.clone();
                    }
                    ctx.request_paint();
                }
            }
            _ => (),
        }
    }

    fn lifecycle(&mut self, ctx: &mut LifeCycleCtx, event: &LifeCycle, _data: &T, _env: &Env) {
        if let LifeCycle::HotChanged(_) = event {
            ctx.request_paint();
        }
    }

    fn update(&mut self, ctx: &mut UpdateCtx, _old_data: &T, _data: &T, _env: &Env) {
        ctx.request_paint();
    }

    fn layout(&mut self, ctx: &mut LayoutCtx, bc: &BoxConstraints, data: &T, env: &Env) -> Size {
        bc.debug_check("Radio");

        let label_size = self.child_label.layout(ctx, &bc, data, env);
        let padding = 5.0;
        let label_x_offset = env.get(theme::BASIC_WIDGET_HEIGHT) + padding;
        let origin = Point::new(label_x_offset, 0.0);

        self.child_label.set_layout_rect(
            ctx,
            data,
            env,
            Rect::from_origin_size(origin, label_size),
        );

        bc.constrain(Size::new(
            label_x_offset + label_size.width,
            env.get(theme::BASIC_WIDGET_HEIGHT).max(label_size.height),
        ))
    }

    fn paint(&mut self, ctx: &mut PaintCtx, data: &T, env: &Env) {
        let size = env.get(theme::BASIC_WIDGET_HEIGHT);

        let circle = Circle::new((size / 2., size / 2.), 7.);

        // Paint the background
        let background_gradient = LinearGradient::new(
            UnitPoint::TOP,
            UnitPoint::BOTTOM,
            (
                env.get(theme::BACKGROUND_LIGHT),
                env.get(theme::BACKGROUND_DARK),
            ),
        );

        ctx.fill(circle, &background_gradient);

        let border_color = if ctx.is_hot() {
            env.get(theme::BORDER_LIGHT)
        } else {
            env.get(theme::BORDER_DARK)
        };

        ctx.stroke(circle, &border_color, 1.);

        // Check if data enum matches our variant
        if *data == self.variant {
            let inner_circle = Circle::new((size / 2., size / 2.), 2.);

            ctx.fill(inner_circle, &env.get(theme::LABEL_COLOR));
        }

        // Paint the text label
        self.child_label.paint(ctx, data, env);
    }
}