zng_wgt_input/
misc.rs

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

zng_wgt_input/
misc.rs
