zng_wgt_input/
misc.rs

1use std::sync::{
2    Arc,
3    atomic::{AtomicBool, Ordering},
4};
5
6use zng_ext_input::mouse::{ClickMode, MOUSE_HOVERED_EVENT, WidgetInfoBuilderMouseExt as _};
7use zng_ext_window::WINDOW_Ext as _;
8use zng_wgt::prelude::*;
9
10pub use zng_view_api::window::CursorIcon;
11
12pub use zng_ext_window::CursorSource;
13
14#[cfg(feature = "image")]
15pub use zng_ext_window::CursorImg;
16
17context_local! {
18    static CHILD_SETS_CURSOR: AtomicBool = AtomicBool::new(false);
19}
20
21/// Sets the mouse pointer cursor displayed when hovering the widget.
22///
23/// You can set this property to a [`CursorIcon`] for a named platform dependent icon, [`CursorImg`] for a custom image,
24/// or to `false` that converts to [`CursorSource::Hidden`].
25///
26/// [`CursorImg`]: zng_ext_window::CursorImg
27#[property(CONTEXT, default(CursorIcon::Default))]
28pub fn cursor(child: impl IntoUiNode, cursor: impl IntoVar<CursorSource>) -> UiNode {
29    let cursor = cursor.into_var();
30    let mut binding = None;
31    let mut child_sets_ctx = None::<Arc<AtomicBool>>;
32
33    match_node(child, move |c, op| {
34        let mut unbind_restore = false;
35        match op {
36            UiNodeOp::Init => {
37                WIDGET.sub_event(&MOUSE_HOVERED_EVENT);
38            }
39            UiNodeOp::Deinit => {
40                unbind_restore = true;
41                child_sets_ctx = None;
42            }
43            UiNodeOp::Event { update } => {
44                if let Some(args) = MOUSE_HOVERED_EVENT.on(update) {
45                    let mut bind = false;
46                    if args.is_over() {
47                        if child_sets_ctx.is_none() {
48                            child_sets_ctx = Some(Arc::new(AtomicBool::new(false)));
49                        }
50
51                        // if a child also sets cursor, it will flag our context.
52                        CHILD_SETS_CURSOR.with_context(&mut child_sets_ctx, || c.event(update));
53
54                        if !child_sets_ctx.as_ref().unwrap().swap(false, Ordering::Relaxed) {
55                            // no descendant sets cursor, it is ours.
56                            bind = true;
57                        }
58
59                        // flag parent context.
60                        CHILD_SETS_CURSOR.get().store(true, Ordering::Relaxed);
61                    }
62
63                    if bind {
64                        if binding.is_none() {
65                            // we are not already set, setup binding.
66                            binding = Some(cursor.set_bind(&WINDOW.vars().cursor()));
67                        }
68                    } else {
69                        unbind_restore = true;
70                    }
71                }
72            }
73            _ => {}
74        }
75
76        // restore to default, if not set to other value already
77        if unbind_restore && binding.is_some() {
78            binding = None;
79            let value = cursor.get();
80            WINDOW.vars().cursor().modify(move |c| {
81                if c.value() == &value {
82                    **c = CursorIcon::Default.into();
83                }
84            });
85        }
86    })
87}
88
89/// Defines how click events are generated for the widget.
90///
91/// Setting this to `None` will cause the widget to inherit the parent mode, or [`ClickMode::default`] if
92/// no parent sets the click mode.
93///
94/// [`ClickMode::default`]: zng_ext_input::mouse::ClickMode::default
95#[property(CONTEXT, default(None))]
96pub fn click_mode(child: impl IntoUiNode, mode: impl IntoVar<Option<ClickMode>>) -> UiNode {
97    let mode = mode.into_var();
98
99    match_node(child, move |_, op| match op {
100        UiNodeOp::Init => {
101            WIDGET.sub_var_info(&mode);
102        }
103        UiNodeOp::Info { info } => {
104            info.set_click_mode(mode.get());
105        }
106        _ => {}
107    })
108}
zng_wgt_input/misc.rs

zng_wgt_input/
misc.rs
