feat(native): add Tooltip widget

Cargo.toml

@@ -83,6 +83,7 @@ members = [
     "examples/svg",
     "examples/todos",
     "examples/tour",
+    "examples/tooltip",
 ]
 
 [dependencies]

examples/tooltip/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "tooltip"
+version = "0.1.0"
+authors = ["Yusuf Bera Ertan <y.bera003.06@protonmail.com>"]
+edition = "2018"
+publish = false
+
+[dependencies]
+iced = { path = "../..", features = ["debug"] }

examples/tooltip/README.md

@@ -0,0 +1,14 @@
+## Tooltip
+
+A tooltip.
+
+It displays and positions a widget on another based on cursor position.
+
+The __[`main`]__ file contains all the code of the example.
+
+You can run it with `cargo run`:
+```
+cargo run --package tooltip
+```
+
+[`main`]: src/main.rs

examples/tooltip/src/main.rs

@@ -0,0 +1,123 @@
+use iced::{
+    button, tooltip::TooltipPosition, Button, Column, Container, Element,
+    Length, Row, Sandbox, Settings, Text, Tooltip,
+};
+
+pub fn main() {
+    Example::run(Settings::default()).unwrap()
+}
+
+#[derive(Default)]
+struct Example {
+    tooltip_top_button_state: button::State,
+    tooltip_bottom_button_state: button::State,
+    tooltip_right_button_state: button::State,
+    tooltip_left_button_state: button::State,
+    tooltip_cursor_button_state: button::State,
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Message;
+
+impl Sandbox for Example {
+    type Message = Message;
+
+    fn new() -> Self {
+        Self::default()
+    }
+
+    fn title(&self) -> String {
+        String::from("Tooltip - Iced")
+    }
+
+    fn update(&mut self, _message: Message) {}
+
+    fn view(&mut self) -> Element<Message> {
+        let tooltip_top = tooltip_builder(
+            "Tooltip at top",
+            &mut self.tooltip_top_button_state,
+            TooltipPosition::Top,
+        );
+        let tooltip_bottom = tooltip_builder(
+            "Tooltip at bottom",
+            &mut self.tooltip_bottom_button_state,
+            TooltipPosition::Bottom,
+        );
+        let tooltip_right = tooltip_builder(
+            "Tooltip at right",
+            &mut self.tooltip_right_button_state,
+            TooltipPosition::Right,
+        );
+        let tooltip_left = tooltip_builder(
+            "Tooltip at left",
+            &mut self.tooltip_left_button_state,
+            TooltipPosition::Left,
+        );
+
+        let fixed_tooltips = Row::with_children(vec![
+            tooltip_top.into(),
+            tooltip_bottom.into(),
+            tooltip_left.into(),
+            tooltip_right.into(),
+        ])
+        .width(Length::Fill)
+        .height(Length::Fill)
+        .align_items(iced::Align::Center)
+        .spacing(120);
+
+        let cursor_tooltip_area = Tooltip::new(
+            Button::new(
+                &mut self.tooltip_cursor_button_state,
+                Container::new(Text::new("Tooltip follows cursor").size(40))
+                    .center_y()
+                    .center_x()
+                    .width(Length::Fill)
+                    .height(Length::Fill),
+            )
+            .on_press(Message)
+            .width(Length::Fill)
+            .height(Length::Fill),
+            tooltip(),
+            TooltipPosition::FollowCursor,
+        );
+
+        let content = Column::with_children(vec![
+            Container::new(fixed_tooltips)
+                .width(Length::Fill)
+                .height(Length::Fill)
+                .center_x()
+                .center_y()
+                .into(),
+            cursor_tooltip_area.into(),
+        ])
+        .width(Length::Fill)
+        .height(Length::Fill);
+
+        Container::new(content)
+            .width(Length::Fill)
+            .height(Length::Fill)
+            .center_x()
+            .center_y()
+            .into()
+    }
+}
+
+fn tooltip_builder<'a>(
+    label: &str,
+    button_state: &'a mut button::State,
+    position: TooltipPosition,
+) -> Container<'a, Message> {
+    Container::new(Tooltip::new(
+        Button::new(button_state, Text::new(label).size(40)).on_press(Message),
+        tooltip(),
+        position,
+    ))
+    .center_x()
+    .center_y()
+    .width(Length::Fill)
+    .height(Length::Fill)
+}
+
+fn tooltip() -> Text {
+    Text::new("Tooltip").size(20)
+}

graphics/src/widget.rs

@@ -20,6 +20,7 @@ pub mod scrollable;
 pub mod slider;
 pub mod svg;
 pub mod text_input;
+pub mod tooltip;
 
 mod column;
 mod row;
@@ -48,6 +49,8 @@ pub use scrollable::Scrollable;
 pub use slider::Slider;
 #[doc(no_inline)]
 pub use text_input::TextInput;
+#[doc(no_inline)]
+pub use tooltip::Tooltip;
 
 pub use column::Column;
 pub use image::Image;

graphics/src/widget/tooltip.rs

@@ -0,0 +1,37 @@
+//! Decorate content and apply alignment.
+use crate::defaults::Defaults;
+use crate::{Backend, Renderer};
+use iced_native::{Element, Layout, Point, Rectangle};
+
+/// An element decorating some content.
+///
+/// This is an alias of an `iced_native` tooltip with a default
+/// `Renderer`.
+pub type Tooltip<'a, Message, Backend> =
+    iced_native::Tooltip<'a, Message, Renderer<Backend>>;
+
+impl<B> iced_native::tooltip::Renderer for Renderer<B>
+where
+    B: Backend,
+{
+    type Style = ();
+
+    fn draw<Message>(
+        &mut self,
+        defaults: &Defaults,
+        cursor_position: Point,
+        content: &Element<'_, Message, Self>,
+        content_layout: Layout<'_>,
+        viewport: &Rectangle,
+    ) -> Self::Output {
+        let (content, mouse_interaction) = content.draw(
+            self,
+            &defaults,
+            content_layout,
+            cursor_position,
+            viewport,
+        );
+
+        (content, mouse_interaction)
+    }
+}

native/src/element.rs

@@ -259,8 +259,11 @@ where
     pub fn overlay<'b>(
         &'b mut self,
         layout: Layout<'_>,
+        overlay_content_bounds: Option<Rectangle>,
+        cursor_position: Point,
     ) -> Option<overlay::Element<'b, Message, Renderer>> {
-        self.widget.overlay(layout)
+        self.widget
+            .overlay(layout, overlay_content_bounds, cursor_position)
     }
 }
 
@@ -352,11 +355,13 @@ where
     fn overlay(
         &mut self,
         layout: Layout<'_>,
+        overlay_content_bounds: Option<Rectangle>,
+        cursor_position: Point,
     ) -> Option<overlay::Element<'_, B, Renderer>> {
         let mapper = &self.mapper;
 
         self.widget
-            .overlay(layout)
+            .overlay(layout, overlay_content_bounds, cursor_position)
             .map(move |overlay| overlay.map(mapper))
     }
 }
@@ -440,7 +445,10 @@ where
     fn overlay(
         &mut self,
         layout: Layout<'_>,
+        overlay_content_bounds: Option<Rectangle>,
+        cursor_position: Point,
     ) -> Option<overlay::Element<'_, Message, Renderer>> {
-        self.element.overlay(layout)
+        self.element
+            .overlay(layout, overlay_content_bounds, cursor_position)
     }
 }

native/src/overlay.rs

@@ -4,6 +4,7 @@ mod element;
 pub mod menu;
 
 pub use element::Element;
+use iced_core::Rectangle;
 pub use menu::Menu;
 
 use crate::event::{self, Event};
@@ -35,6 +36,7 @@ where
         defaults: &Renderer::Defaults,
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
     ) -> Renderer::Output;
 
     /// Computes the _layout_ hash of the [`Overlay`].

native/src/overlay/element.rs

@@ -1,3 +1,5 @@
+use iced_core::Rectangle;
+
 pub use crate::Overlay;
 
 use crate::event::{self, Event};
@@ -74,9 +76,10 @@ where
         defaults: &Renderer::Defaults,
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
     ) -> Renderer::Output {
         self.overlay
-            .draw(renderer, defaults, layout, cursor_position)
+            .draw(renderer, defaults, layout, cursor_position, viewport)
     }
 
     /// Computes the _layout_ hash of the [`Element`].
@@ -145,9 +148,10 @@ where
         defaults: &Renderer::Defaults,
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
     ) -> Renderer::Output {
         self.content
-            .draw(renderer, defaults, layout, cursor_position)
+            .draw(renderer, defaults, layout, cursor_position, viewport)
     }
 
     fn hash_layout(&self, state: &mut Hasher, position: Point) {

native/src/overlay/menu.rs

@@ -239,6 +239,7 @@ where
         defaults: &Renderer::Defaults,
         layout: Layout<'_>,
         cursor_position: Point,
+        _viewport: &Rectangle,
     ) -> Renderer::Output {
         let primitives = self.container.draw(
             renderer,

native/src/user_interface.rs

@@ -198,8 +198,11 @@ where
         messages: &mut Vec<Message>,
     ) -> Vec<event::Status> {
         let (base_cursor, overlay_statuses) = if let Some(mut overlay) =
-            self.root.overlay(Layout::new(&self.base.layout))
-        {
+            self.root.overlay(
+                Layout::new(&self.base.layout),
+                self.overlay.as_ref().map(|l| l.layout.bounds()),
+                cursor_position,
+            ) {
             let layer = Self::overlay_layer(
                 self.overlay.take(),
                 self.bounds,
@@ -334,9 +337,11 @@ where
     ) -> Renderer::Output {
         let viewport = Rectangle::with_size(self.bounds);
 
-        let overlay = if let Some(mut overlay) =
-            self.root.overlay(Layout::new(&self.base.layout))
-        {
+        let overlay = if let Some(mut overlay) = self.root.overlay(
+            Layout::new(&self.base.layout),
+            self.overlay.as_ref().map(|l| l.layout.bounds()),
+            cursor_position,
+        ) {
             let layer = Self::overlay_layer(
                 self.overlay.take(),
                 self.bounds,
@@ -351,6 +356,7 @@ where
                 &Renderer::Defaults::default(),
                 Layout::new(&layer.layout),
                 cursor_position,
+                &viewport,
             );
 
             self.overlay = Some(layer);

native/src/widget.rs

@@ -36,6 +36,7 @@ pub mod space;
 pub mod svg;
 pub mod text;
 pub mod text_input;
+pub mod tooltip;
 
 #[doc(no_inline)]
 pub use button::Button;
@@ -71,6 +72,8 @@ pub use svg::Svg;
 pub use text::Text;
 #[doc(no_inline)]
 pub use text_input::TextInput;
+#[doc(no_inline)]
+pub use tooltip::Tooltip;
 
 use crate::event::{self, Event};
 use crate::layout;
@@ -172,6 +175,8 @@ where
     fn overlay(
         &mut self,
         _layout: Layout<'_>,
+        _overlay_content_bounds: Option<Rectangle>,
+        _cursor_position: Point,
     ) -> Option<overlay::Element<'_, Message, Renderer>> {
         None
     }

native/src/widget/column.rs

@@ -198,11 +198,19 @@ where
     fn overlay(
         &mut self,
         layout: Layout<'_>,
+        overlay_content_bounds: Option<Rectangle>,
+        cursor_position: Point,
     ) -> Option<overlay::Element<'_, Message, Renderer>> {
         self.children
             .iter_mut()
             .zip(layout.children())
-            .filter_map(|(child, layout)| child.widget.overlay(layout))
+            .filter_map(|(child, layout)| {
+                child.widget.overlay(
+                    layout,
+                    overlay_content_bounds,
+                    cursor_position,
+                )
+            })
             .next()
     }
 }