1use std::{any::TypeId, rc::Rc};
2
3use super::Padding;
4use crate::{
5 geometry::{
6 rect::RectF,
7 vector::{vec2f, Vector2F},
8 },
9 platform::CursorStyle,
10 scene::CursorRegion,
11 DebugContext, Element, ElementBox, Event, EventContext, LayoutContext, MouseRegion, MouseState,
12 PaintContext, RenderContext, SizeConstraint, View,
13};
14use serde_json::json;
15
16pub struct MouseEventHandler {
17 child: ElementBox,
18 tag: TypeId,
19 id: usize,
20 cursor_style: Option<CursorStyle>,
21 mouse_down_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
22 click_handler: Option<Rc<dyn Fn(Vector2F, usize, &mut EventContext)>>,
23 right_mouse_down_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
24 right_click_handler: Option<Rc<dyn Fn(Vector2F, usize, &mut EventContext)>>,
25 drag_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
26 padding: Padding,
27}
28
29impl MouseEventHandler {
30 pub fn new<Tag, V, F>(id: usize, cx: &mut RenderContext<V>, render_child: F) -> Self
31 where
32 Tag: 'static,
33 V: View,
34 F: FnOnce(MouseState, &mut RenderContext<V>) -> ElementBox,
35 {
36 Self {
37 id,
38 tag: TypeId::of::<Tag>(),
39 child: render_child(cx.mouse_state::<Tag>(id), cx),
40 cursor_style: None,
41 mouse_down_handler: None,
42 click_handler: None,
43 right_mouse_down_handler: None,
44 right_click_handler: None,
45 drag_handler: None,
46 padding: Default::default(),
47 }
48 }
49
50 pub fn with_cursor_style(mut self, cursor: CursorStyle) -> Self {
51 self.cursor_style = Some(cursor);
52 self
53 }
54
55 pub fn on_mouse_down(
56 mut self,
57 handler: impl Fn(Vector2F, &mut EventContext) + 'static,
58 ) -> Self {
59 self.mouse_down_handler = Some(Rc::new(handler));
60 self
61 }
62
63 pub fn on_click(
64 mut self,
65 handler: impl Fn(Vector2F, usize, &mut EventContext) + 'static,
66 ) -> Self {
67 self.click_handler = Some(Rc::new(handler));
68 self
69 }
70
71 pub fn on_right_mouse_down(
72 mut self,
73 handler: impl Fn(Vector2F, &mut EventContext) + 'static,
74 ) -> Self {
75 self.right_mouse_down_handler = Some(Rc::new(handler));
76 self
77 }
78
79 pub fn on_right_click(
80 mut self,
81 handler: impl Fn(Vector2F, usize, &mut EventContext) + 'static,
82 ) -> Self {
83 self.right_click_handler = Some(Rc::new(handler));
84 self
85 }
86
87 pub fn on_drag(mut self, handler: impl Fn(Vector2F, &mut EventContext) + 'static) -> Self {
88 self.drag_handler = Some(Rc::new(handler));
89 self
90 }
91
92 pub fn with_padding(mut self, padding: Padding) -> Self {
93 self.padding = padding;
94 self
95 }
96
97 fn hit_bounds(&self, bounds: RectF) -> RectF {
98 RectF::from_points(
99 bounds.origin() - vec2f(self.padding.left, self.padding.top),
100 bounds.lower_right() + vec2f(self.padding.right, self.padding.bottom),
101 )
102 .round_out()
103 }
104}
105
106impl Element for MouseEventHandler {
107 type LayoutState = ();
108 type PaintState = ();
109
110 fn layout(
111 &mut self,
112 constraint: SizeConstraint,
113 cx: &mut LayoutContext,
114 ) -> (Vector2F, Self::LayoutState) {
115 (self.child.layout(constraint, cx), ())
116 }
117
118 fn paint(
119 &mut self,
120 bounds: RectF,
121 visible_bounds: RectF,
122 _: &mut Self::LayoutState,
123 cx: &mut PaintContext,
124 ) -> Self::PaintState {
125 if let Some(style) = self.cursor_style {
126 cx.scene.push_cursor_region(CursorRegion {
127 bounds: self.hit_bounds(bounds),
128 style,
129 });
130 }
131
132 cx.scene.push_mouse_region(MouseRegion {
133 view_id: cx.current_view_id(),
134 tag: self.tag,
135 region_id: self.id,
136 bounds: self.hit_bounds(bounds),
137 hover: None,
138 click: self.click_handler.clone(),
139 mouse_down: self.mouse_down_handler.clone(),
140 right_click: self.right_click_handler.clone(),
141 right_mouse_down: self.right_mouse_down_handler.clone(),
142 drag: self.drag_handler.clone(),
143 });
144
145 self.child.paint(bounds.origin(), visible_bounds, cx);
146 }
147
148 fn dispatch_event(
149 &mut self,
150 event: &Event,
151 _: RectF,
152 _: RectF,
153 _: &mut Self::LayoutState,
154 _: &mut Self::PaintState,
155 cx: &mut EventContext,
156 ) -> bool {
157 self.child.dispatch_event(event, cx)
158 }
159
160 fn debug(
161 &self,
162 _: RectF,
163 _: &Self::LayoutState,
164 _: &Self::PaintState,
165 cx: &DebugContext,
166 ) -> serde_json::Value {
167 json!({
168 "type": "MouseEventHandler",
169 "child": self.child.debug(cx),
170 })
171 }
172}