Tooltips

Closes #37

examples/login.rs

@@ -3,29 +3,17 @@ use std::process::exit;
 use gooey::value::{Dynamic, Validations};
 use gooey::widget::MakeWidget;
 use gooey::widgets::input::{InputValue, MaskedString};
+use gooey::widgets::layers::OverlayLayer;
 use gooey::widgets::Expand;
 use gooey::Run;
 use kludgine::figures::units::Lp;
 
 fn main() -> gooey::Result {
+    let tooltips = OverlayLayer::default();
     let username = Dynamic::default();
     let password = Dynamic::default();
     let validations = Validations::default();
 
-    let username_valid = validations.validate(&username, |u: &String| {
-        if u.is_empty() {
-            Err("usernames must contain at least one character")
-        } else {
-            Ok(())
-        }
-    });
-
-    let password_valid = validations.validate(&password, |u: &MaskedString| match u.len() {
-        0..=7 => Err("passwords must be at least 8 characters long"),
-        _ => Ok(()),
-    });
-
-    // TODO this should be a grid layout to ensure proper visual alignment.
     let username_field = "Username"
         .align_left()
         .and(
@@ -33,8 +21,18 @@ fn main() -> gooey::Result {
                 .clone()
                 .into_input()
                 .placeholder("Username")
-                .validation(username_valid)
-                .hint("* required"),
+                .validation(validations.validate(&username, |u: &String| {
+                    if u.is_empty() {
+                        Err("usernames must contain at least one character")
+                    } else {
+                        Ok(())
+                    }
+                }))
+                .hint("* required")
+                .tooltip(
+                    &tooltips,
+                    "If you can't remember your username, that's because this is a demo.",
+                ),
         )
         .into_rows();
 
@@ -45,8 +43,14 @@ fn main() -> gooey::Result {
                 .clone()
                 .into_input()
                 .placeholder("Password")
-                .validation(password_valid)
-                .hint("* required, 8 characters min"),
+                .validation(
+                    validations.validate(&password, |u: &MaskedString| match u.len() {
+                        0..=7 => Err("passwords must be at least 8 characters long"),
+                        _ => Ok(()),
+                    }),
+                )
+                .hint("* required, 8 characters min")
+                .tooltip(&tooltips, "Passwords are always at least 8 bytes long."),
         )
         .into_rows();
 
@@ -57,6 +61,7 @@ fn main() -> gooey::Result {
             exit(0)
         })
         .into_escape()
+        .tooltip(&tooltips, "This button quits the program")
         .and(Expand::empty())
         .and(
             "Log In"
@@ -69,7 +74,7 @@ fn main() -> gooey::Result {
         )
         .into_columns();
 
-    username_field
+    let ui = username_field
         .and(password_field)
         .and(buttons)
         .into_rows()
@@ -77,6 +82,7 @@ fn main() -> gooey::Result {
         .width(Lp::inches(3)..Lp::inches(6))
         .pad()
         .scroll()
-        .centered()
-        .run()
+        .centered();
+
+    ui.and(tooltips).into_layers().run()
 }

src/widget.rs

@@ -39,6 +39,7 @@ use crate::tree::Tree;
 use crate::utils::IgnorePoison;
 use crate::value::{Dynamic, IntoDynamic, IntoValue, Validation, Value};
 use crate::widgets::checkbox::{Checkable, CheckboxState};
+use crate::widgets::layers::{OverlayLayer, Tooltipped};
 use crate::widgets::{
     Align, Button, Checkbox, Collapse, Container, Expand, Layers, Resize, Scroll, Space, Stack,
     Style, Themed, ThemedMode, Validated,
@@ -1077,6 +1078,11 @@ pub trait MakeWidget: Sized {
     fn validation(self, validation: impl IntoDynamic<Validation>) -> Validated {
         Validated::new(validation, self)
     }
+
+    /// Returns a widget that shows `tip` on `layer` when `self` is hovered.
+    fn tooltip(self, layer: &OverlayLayer, tip: impl MakeWidget) -> Tooltipped {
+        layer.new_tooltip(tip, self)
+    }
 }
 
 /// A type that can create a [`WidgetInstance`] with a preallocated

src/widgets/container.rs

@@ -1,5 +1,7 @@
 //! A visual container widget.
 
+use std::ops::Div;
+
 use kludgine::figures::units::{Lp, Px, UPx};
 use kludgine::figures::{
     Abs, Angle, IntoSigned, IntoUnsigned, Point, Rect, ScreenScale, Size, Zero,
@@ -719,6 +721,18 @@ impl<Unit> ContainerShadow<Unit> {
         }
     }
 
+    /// Returns a drop shadow placed `distance` below with a combined
+    /// blur/spread radius of `blur`.
+    pub fn drop(distance: Unit, blur: Unit) -> Self
+    where
+        Unit: Zero + Div<i32, Output = Unit> + Default + Copy,
+    {
+        let half_blur = blur / 2;
+        Self::new(Point::new(Unit::ZERO, distance))
+            .blur_radius(half_blur)
+            .spread(half_blur)
+    }
+
     /// Sets the shadow color and returns self.
     #[must_use]
     pub fn color(mut self, color: Color) -> Self {

src/widgets/layers.rs

@@ -1,21 +1,24 @@
 //! Widgets that stack in the Z-direction.
 
-use std::fmt;
+use std::fmt::{self, Debug};
+use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 use alot::{LotId, OrderedLots};
 use gooey::widget::{RootBehavior, WidgetInstance};
 use intentional::Assert;
-use kludgine::figures::units::{Px, UPx};
+use kludgine::figures::units::{Lp, Px, UPx};
 use kludgine::figures::{IntoSigned, IntoUnsigned, Point, Rect, Size, Zero};
 
 use crate::animation::easings::EaseOutQuadradic;
-use crate::animation::{AnimationTarget, Spawn, ZeroToOne};
+use crate::animation::{AnimationHandle, AnimationTarget, IntoAnimate, Spawn, ZeroToOne};
 use crate::context::{AsEventContext, EventContext, GraphicsContext, LayoutContext};
+use crate::utils::IgnorePoison;
 use crate::value::{Dynamic, DynamicGuard, Generation, IntoValue, Value};
 use crate::widget::{
-    Children, MakeWidget, ManagedWidget, OnceCallback, Widget, WidgetId, WidgetRef,
+    Callback, Children, MakeWidget, ManagedWidget, Widget, WidgetId, WidgetRef, WrapperWidget,
 };
+use crate::widgets::container::ContainerShadow;
 use crate::ConstraintLimit;
 
 /// A Z-direction stack of widgets.
@@ -193,6 +196,20 @@ impl OverlayLayer {
             },
         }
     }
+
+    /// Returns a new wudget that shows a `tooltip` when `content` is hovered.
+    pub fn new_tooltip(&self, tooltip: impl MakeWidget, content: impl MakeWidget) -> Tooltipped {
+        Tooltipped {
+            child: WidgetRef::new(content),
+            data: TooltipData {
+                target_layer: self.clone(),
+                tooltip: tooltip.make_widget(),
+                direction: Direction::Down,
+                shown_tooltip: Dynamic::default(),
+            },
+            show_animation: None,
+        }
+    }
 }
 
 impl Widget for OverlayLayer {
@@ -562,6 +579,7 @@ impl OverlayState {
 }
 
 /// A builder for overlaying a widget on an [`OverlayLayer`].
+#[derive(Debug, Clone)]
 pub struct OverlayBuilder<'a> {
     overlay: &'a OverlayLayer,
     layout: OverlayLayout,
@@ -578,40 +596,40 @@ impl OverlayBuilder<'_> {
 
     /// Show this overlay to the left of the specified widget.
     #[must_use]
-    pub fn left_of(mut self, id: WidgetId) -> Self {
-        self.layout.relative_to = Some(id);
-        self.layout.direction = Direction::Left;
-        self
+    pub fn left_of(self, id: WidgetId) -> Self {
+        self.near(id, Direction::Left)
     }
 
     /// Show this overlay to the right of the specified widget.
     #[must_use]
-    pub fn right_of(mut self, id: WidgetId) -> Self {
-        self.layout.relative_to = Some(id);
-        self.layout.direction = Direction::Right;
-        self
+    pub fn right_of(self, id: WidgetId) -> Self {
+        self.near(id, Direction::Right)
     }
 
     /// Show this overlay to show below the specified widget.
     #[must_use]
-    pub fn below(mut self, id: WidgetId) -> Self {
-        self.layout.relative_to = Some(id);
-        self.layout.direction = Direction::Down;
-        self
+    pub fn below(self, id: WidgetId) -> Self {
+        self.near(id, Direction::Down)
     }
 
     /// Show this overlay to show above the specified widget.
     #[must_use]
-    pub fn above(mut self, id: WidgetId) -> Self {
+    pub fn above(self, id: WidgetId) -> Self {
+        self.near(id, Direction::Up)
+    }
+
+    /// Shows this overlay near `id` off to the `direction` side.
+    #[must_use]
+    pub fn near(mut self, id: WidgetId, direction: Direction) -> Self {
         self.layout.relative_to = Some(id);
-        self.layout.direction = Direction::Up;
+        self.layout.direction = direction;
         self
     }
 
     /// Sets `callback` to be invoked once this overlay is dismissed.
     #[must_use]
-    pub fn on_dismiss(mut self, callback: OnceCallback) -> Self {
-        self.layout.on_dismiss = Some(callback);
+    pub fn on_dismiss(mut self, callback: Callback) -> Self {
+        self.layout.on_dismiss = Some(Arc::new(Mutex::new(callback)));
         self
     }
 
@@ -639,7 +657,7 @@ impl OverlayBuilder<'_> {
     }
 }
 
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Debug, Clone)]
 struct OverlayLayout {
     widget: WidgetRef,
     opacity: Dynamic<ZeroToOne>,
@@ -647,17 +665,36 @@ struct OverlayLayout {
     direction: Direction,
     requires_hover: bool,
     layout: Option<Rect<Px>>,
-    on_dismiss: Option<OnceCallback>,
+    on_dismiss: Option<Arc<Mutex<Callback>>>,
 }
 
 impl Drop for OverlayLayout {
     fn drop(&mut self) {
-        if let Some(on_dismiss) = self.on_dismiss.take() {
+        if let Some(on_dismiss) = &self.on_dismiss {
+            let mut on_dismiss = on_dismiss.lock().ignore_poison();
             on_dismiss.invoke(());
         }
     }
 }
 
+impl Eq for OverlayLayout {}
+
+impl PartialEq for OverlayLayout {
+    fn eq(&self, other: &Self) -> bool {
+        self.widget == other.widget
+            && self.opacity == other.opacity
+            && self.relative_to == other.relative_to
+            && self.direction == other.direction
+            && self.requires_hover == other.requires_hover
+            && self.layout == other.layout
+            && match (&self.on_dismiss, &other.on_dismiss) {
+                (Some(this), Some(other)) => Arc::ptr_eq(this, other),
+                (None, None) => true,
+                _ => false,
+            }
+    }
+}
+
 /// A relative direction.
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub enum Direction {
@@ -685,6 +722,7 @@ impl Direction {
 }
 
 /// A handle to an overlay that was shown in an [`OverlayLayer`].
+#[derive(PartialEq, Eq)]
 pub struct OverlayHandle {
     state: Dynamic<OverlayState>,
     id: LotId,
@@ -719,3 +757,74 @@ impl Drop for OverlayHandle {
         }
     }
 }
+
+impl Debug for OverlayHandle {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("OverlayHandle")
+            .field("id", &self.id)
+            .field("dismiss_on_drop", &self.dismiss_on_drop)
+            .finish_non_exhaustive()
+    }
+}
+
+/// A widget that shows a tooltip when hovered.
+#[derive(Debug)]
+pub struct Tooltipped {
+    child: WidgetRef,
+    show_animation: Option<AnimationHandle>,
+    data: TooltipData,
+}
+
+#[derive(Debug, Clone)]
+struct TooltipData {
+    target_layer: OverlayLayer,
+    tooltip: WidgetInstance,
+    direction: Direction,
+    shown_tooltip: Dynamic<Option<OverlayHandle>>,
+}
+
+impl WrapperWidget for Tooltipped {
+    fn child_mut(&mut self) -> &mut WidgetRef {
+        &mut self.child
+    }
+
+    fn hover(
+        &mut self,
+        _location: Point<Px>,
+        context: &mut EventContext<'_, '_>,
+    ) -> Option<kludgine::app::winit::window::CursorIcon> {
+        let background_color = context.theme().surface.highest_container;
+
+        let data = self.data.clone();
+        let my_id = self.child.widget().id();
+
+        self.show_animation = Some(
+            Duration::from_millis(500)
+                .on_complete(move || {
+                    let mut shown_tooltip = data.shown_tooltip.lock();
+                    if shown_tooltip.is_none() {
+                        *shown_tooltip = Some(
+                            data.target_layer
+                                .build_overlay(
+                                    data.tooltip
+                                        .clone()
+                                        .contain()
+                                        .background_color(background_color)
+                                        .shadow(ContainerShadow::drop(Lp::mm(1), Lp::mm(2))),
+                                )
+                                .hide_on_unhover()
+                                .near(my_id, data.direction)
+                                .show(),
+                        );
+                    }
+                })
+                .spawn(),
+        );
+        None
+    }
+
+    fn unhover(&mut self, _context: &mut EventContext<'_, '_>) {
+        self.show_animation = None;
+        self.data.shown_tooltip.set(None);
+    }
+}