veloren_voxygen/ui/ice/widget/
overlay.rs

1use iced::{
2    Align, Clipboard, Element, Event, Hasher, Layout, Length, Padding, Point, Rectangle, Size,
3    Widget, layout, mouse,
4};
5use std::hash::Hash;
6
7/// A widget used to overlay one widget on top of another
8/// Layout behaves similar to the iced::Container widget
9/// Manages filtering out mouse input for the back widget if the mouse is over
10/// the front widget
11/// Alignment and padding is used for the front widget
12pub struct Overlay<'a, M, R: Renderer> {
13    padding: Padding,
14    width: Length,
15    height: Length,
16    max_width: u32,
17    max_height: u32,
18    horizontal_alignment: Align,
19    vertical_alignment: Align,
20    over: Element<'a, M, R>,
21    under: Element<'a, M, R>,
22    pos: Option<Point>,
23    // add style etc as needed
24}
25
26impl<'a, M, R> Overlay<'a, M, R>
27where
28    R: Renderer,
29{
30    pub fn new<O, U>(over: O, under: U) -> Self
31    where
32        O: Into<Element<'a, M, R>>,
33        U: Into<Element<'a, M, R>>,
34    {
35        Self {
36            padding: Padding::ZERO,
37            width: Length::Shrink,
38            height: Length::Shrink,
39            max_width: u32::MAX,
40            max_height: u32::MAX,
41            horizontal_alignment: Align::Start,
42            vertical_alignment: Align::Start,
43            over: over.into(),
44            under: under.into(),
45            pos: None,
46        }
47    }
48
49    #[must_use]
50    pub fn over_position(mut self, pos: Point) -> Self {
51        self.pos = Some(pos);
52        self
53    }
54
55    #[must_use]
56    pub fn padding<P: Into<Padding>>(mut self, pad: P) -> Self {
57        self.padding = pad.into();
58        self
59    }
60
61    #[must_use]
62    pub fn width(mut self, width: Length) -> Self {
63        self.width = width;
64        self
65    }
66
67    #[must_use]
68    pub fn height(mut self, height: Length) -> Self {
69        self.height = height;
70        self
71    }
72
73    #[must_use]
74    pub fn max_width(mut self, max_width: u32) -> Self {
75        self.max_width = max_width;
76        self
77    }
78
79    #[must_use]
80    pub fn max_height(mut self, max_height: u32) -> Self {
81        self.max_height = max_height;
82        self
83    }
84
85    #[must_use]
86    pub fn align_x(mut self, align_x: Align) -> Self {
87        self.horizontal_alignment = align_x;
88        self
89    }
90
91    #[must_use]
92    pub fn align_y(mut self, align_y: Align) -> Self {
93        self.vertical_alignment = align_y;
94        self
95    }
96
97    #[must_use]
98    pub fn center_x(mut self) -> Self {
99        self.horizontal_alignment = Align::Center;
100        self
101    }
102
103    #[must_use]
104    pub fn center_y(mut self) -> Self {
105        self.vertical_alignment = Align::Center;
106        self
107    }
108}
109
110impl<M, R> Widget<M, R> for Overlay<'_, M, R>
111where
112    R: Renderer,
113{
114    fn width(&self) -> Length { self.width }
115
116    fn height(&self) -> Length { self.height }
117
118    fn layout(&self, renderer: &R, limits: &layout::Limits) -> layout::Node {
119        let limits = limits
120            .loose()
121            .max_width(self.max_width)
122            .max_height(self.max_height)
123            .width(self.width)
124            .height(self.height);
125
126        let under = self.under.layout(renderer, &limits.loose());
127        let under_size = under.size();
128
129        let limits = limits.pad(self.padding);
130        let mut over = self.over.layout(renderer, &limits.loose());
131        let over_size = over.size();
132
133        let size = limits.resolve(
134            Size {
135                width: under_size.width.max(over_size.width),
136                height: under_size.height.max(over_size.height),
137            }
138            .pad(self.padding),
139        );
140
141        over.move_to(
142            self.pos
143                .unwrap_or_else(|| Point::new(self.padding.left.into(), self.padding.top.into())),
144        );
145        over.align(self.horizontal_alignment, self.vertical_alignment, size);
146
147        layout::Node::with_children(size, vec![over, under])
148    }
149
150    fn draw(
151        &self,
152        renderer: &mut R,
153        defaults: &R::Defaults,
154        layout: Layout<'_>,
155        cursor_position: Point,
156        viewport: &Rectangle,
157    ) -> R::Output {
158        let mut children = layout.children();
159        renderer.draw(
160            defaults,
161            layout.bounds(),
162            cursor_position,
163            viewport,
164            &self.over,
165            children.next().unwrap(),
166            &self.under,
167            children.next().unwrap(),
168        )
169    }
170
171    fn hash_layout(&self, state: &mut Hasher) {
172        struct Marker;
173        std::any::TypeId::of::<Marker>().hash(state);
174
175        self.padding.hash(state);
176        self.width.hash(state);
177        self.height.hash(state);
178        self.max_width.hash(state);
179        self.max_height.hash(state);
180
181        self.over.hash_layout(state);
182        self.under.hash_layout(state);
183    }
184
185    fn on_event(
186        &mut self,
187        event: Event,
188        layout: Layout<'_>,
189        cursor_position: Point,
190        renderer: &R,
191        clipboard: &mut dyn Clipboard,
192        messages: &mut Vec<M>,
193    ) -> iced::event::Status {
194        let mut children = layout.children();
195        let over_layout = children.next().unwrap();
196
197        // TODO: consider passing to under if ignored?
198        let status = self.over.on_event(
199            event.clone(),
200            over_layout,
201            cursor_position,
202            renderer,
203            clipboard,
204            messages,
205        );
206
207        // If mouse press check if over the overlay widget before sending to under
208        // widget
209        if !matches!(&event, Event::Mouse(mouse::Event::ButtonPressed(_)))
210            || !over_layout.bounds().contains(cursor_position)
211        {
212            self.under
213                .on_event(
214                    event,
215                    children.next().unwrap(),
216                    cursor_position,
217                    renderer,
218                    clipboard,
219                    messages,
220                )
221                .merge(status)
222        } else {
223            status
224        }
225    }
226
227    fn overlay(&mut self, layout: Layout<'_>) -> Option<iced::overlay::Element<'_, M, R>> {
228        let mut children = layout.children();
229        let (over, under) = (&mut self.over, &mut self.under);
230        over.overlay(children.next().unwrap())
231            .or_else(move || under.overlay(children.next().unwrap()))
232    }
233}
234
235pub trait Renderer: iced::Renderer {
236    fn draw<M>(
237        &mut self,
238        defaults: &Self::Defaults,
239        bounds: Rectangle,
240        cursor_position: Point,
241        viewport: &Rectangle,
242        over: &Element<'_, M, Self>,
243        over_layout: Layout<'_>,
244        under: &Element<'_, M, Self>,
245        under_layout: Layout<'_>,
246    ) -> Self::Output;
247}
248
249impl<'a, M, R> From<Overlay<'a, M, R>> for Element<'a, M, R>
250where
251    R: 'a + Renderer,
252    M: 'a,
253{
254    fn from(overlay: Overlay<'a, M, R>) -> Element<'a, M, R> { Element::new(overlay) }
255}