Implemented Tooltip as Pure

3 files changed, 323 insertions, 0 deletions

diff --git a/pure/src/helpers.rs b/pure/src/helpers.rs
index 24f6dbaa..2ddab3ae 100644
--- a/pure/src/helpers.rs
+++ b/pure/src/helpers.rs
@@ -38,6 +38,17 @@ pub fn button<'a, Message, Renderer>(
     widget::Button::new(content)
 }
 
+pub fn tooltip<'a, Message, Renderer>(
+    content: impl Into<Element<'a, Message, Renderer>>,
+    tooltip: impl ToString,
+    position: widget::tooltip::Position,
+) -> widget::Tooltip<'a, Message, Renderer>
+where
+    Renderer: iced_native::text::Renderer,
+{
+    widget::Tooltip::new(content, tooltip, position)
+}
+
 pub fn text<Renderer>(text: impl Into<String>) -> widget::Text<Renderer>
 where
     Renderer: iced_native::text::Renderer,
diff --git a/pure/src/widget.rs b/pure/src/widget.rs
index 8200f9a7..adce17ea 100644
--- a/pure/src/widget.rs
+++ b/pure/src/widget.rs
@@ -12,6 +12,7 @@ pub mod slider;
 pub mod svg;
 pub mod text_input;
 pub mod toggler;
+pub mod tooltip;
 pub mod tree;
 
 mod column;
@@ -37,6 +38,7 @@ pub use svg::Svg;
 pub use text::Text;
 pub use text_input::TextInput;
 pub use toggler::Toggler;
+pub use tooltip::{Position, Tooltip};
 pub use tree::Tree;
 
 use iced_native::event::{self, Event};
diff --git a/pure/src/widget/tooltip.rs b/pure/src/widget/tooltip.rs
new file mode 100644
index 00000000..f0667e41
--- /dev/null
+++ b/pure/src/widget/tooltip.rs
@@ -0,0 +1,310 @@
+//! Display a widget over another.
+use crate::widget::Tree;
+use crate::{Element, Widget};
+use iced_native::event::{self, Event};
+use iced_native::widget::container;
+pub use iced_native::widget::Text;
+use iced_native::{layout, mouse, overlay};
+use iced_native::{renderer, Size};
+use iced_native::{text, Vector};
+use iced_native::{
+    Clipboard, Layout, Length, Padding, Point, Rectangle, Shell,
+};
+
+pub use iced_style::container::{Style, StyleSheet};
+
+/// An element to display a widget over another.
+#[allow(missing_debug_implementations)]
+pub struct Tooltip<'a, Message, Renderer: text::Renderer> {
+    content: Element<'a, Message, Renderer>,
+    tooltip: Text<Renderer>,
+    position: Position,
+    style_sheet: Box<dyn StyleSheet + 'a>,
+    gap: u16,
+    padding: u16,
+}
+
+impl<'a, Message, Renderer> Tooltip<'a, Message, Renderer>
+where
+    Renderer: text::Renderer,
+{
+    /// The default padding of a [`Tooltip`] drawn by this renderer.
+    const DEFAULT_PADDING: u16 = 5;
+
+    /// Creates an empty [`Tooltip`].
+    ///
+    /// [`Tooltip`]: struct.Tooltip.html
+    pub fn new(
+        content: impl Into<Element<'a, Message, Renderer>>,
+        tooltip: impl ToString,
+        position: Position,
+    ) -> Self {
+        Tooltip {
+            content: content.into(),
+            tooltip: Text::new(tooltip.to_string()),
+            position,
+            style_sheet: Default::default(),
+            gap: 0,
+            padding: Self::DEFAULT_PADDING,
+        }
+    }
+
+    /// Sets the size of the text of the [`Tooltip`].
+    pub fn size(mut self, size: u16) -> Self {
+        self.tooltip = self.tooltip.size(size);
+        self
+    }
+
+    /// Sets the font of the [`Tooltip`].
+    ///
+    /// [`Font`]: Renderer::Font
+    pub fn font(mut self, font: impl Into<Renderer::Font>) -> Self {
+        self.tooltip = self.tooltip.font(font);
+        self
+    }
+
+    /// Sets the gap between the content and its [`Tooltip`].
+    pub fn gap(mut self, gap: u16) -> Self {
+        self.gap = gap;
+        self
+    }
+
+    /// Sets the padding of the [`Tooltip`].
+    pub fn padding(mut self, padding: u16) -> Self {
+        self.padding = padding;
+        self
+    }
+
+    /// Sets the style of the [`Tooltip`].
+    pub fn style(
+        mut self,
+        style_sheet: impl Into<Box<dyn StyleSheet + 'a>>,
+    ) -> Self {
+        self.style_sheet = style_sheet.into();
+        self
+    }
+}
+
+/// The position of the tooltip. Defaults to following the cursor.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Position {
+    /// The tooltip will follow the cursor.
+    FollowCursor,
+    /// The tooltip will appear on the top of the widget.
+    Top,
+    /// The tooltip will appear on the bottom of the widget.
+    Bottom,
+    /// The tooltip will appear on the left of the widget.
+    Left,
+    /// The tooltip will appear on the right of the widget.
+    Right,
+}
+
+impl<'a, Message, Renderer> Widget<Message, Renderer>
+    for Tooltip<'a, Message, Renderer>
+where
+    Renderer: text::Renderer,
+{
+    fn children(&self) -> Vec<Tree> {
+        vec![Tree::new(&self.content)]
+    }
+
+    fn diff(&self, tree: &mut Tree) {
+        tree.diff_children(std::slice::from_ref(&self.content))
+    }
+
+    fn width(&self) -> Length {
+        self.content.as_widget().width()
+    }
+
+    fn height(&self) -> Length {
+        self.content.as_widget().height()
+    }
+
+    fn layout(
+        &self,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        self.content.as_widget().layout(renderer, limits)
+    }
+
+    fn on_event(
+        &mut self,
+        tree: &mut Tree,
+        event: Event,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+    ) -> event::Status {
+        self.content.as_widget_mut().on_event(
+            &mut tree.children[0],
+            event,
+            layout,
+            cursor_position,
+            renderer,
+            clipboard,
+            shell,
+        )
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout.children().next().unwrap(),
+            cursor_position,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        inherited_style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            inherited_style,
+            layout,
+            cursor_position,
+            viewport,
+        );
+
+        let bounds = layout.bounds();
+
+        if bounds.contains(cursor_position) {
+            let gap = f32::from(self.gap);
+            let style = self.style_sheet.style();
+
+            let defaults = renderer::Style {
+                text_color: style
+                    .text_color
+                    .unwrap_or(inherited_style.text_color),
+            };
+
+            let text_layout = Widget::<(), Renderer>::layout(
+                &self.tooltip,
+                renderer,
+                &layout::Limits::new(Size::ZERO, viewport.size())
+                    .pad(Padding::new(self.padding)),
+            );
+
+            let padding = f32::from(self.padding);
+            let text_bounds = text_layout.bounds();
+            let x_center = bounds.x + (bounds.width - text_bounds.width) / 2.0;
+            let y_center =
+                bounds.y + (bounds.height - text_bounds.height) / 2.0;
+
+            let mut tooltip_bounds = {
+                let offset = match self.position {
+                    Position::Top => Vector::new(
+                        x_center,
+                        bounds.y - text_bounds.height - gap - padding,
+                    ),
+                    Position::Bottom => Vector::new(
+                        x_center,
+                        bounds.y + bounds.height + gap + padding,
+                    ),
+                    Position::Left => Vector::new(
+                        bounds.x - text_bounds.width - gap - padding,
+                        y_center,
+                    ),
+                    Position::Right => Vector::new(
+                        bounds.x + bounds.width + gap + padding,
+                        y_center,
+                    ),
+                    Position::FollowCursor => Vector::new(
+                        cursor_position.x,
+                        cursor_position.y - text_bounds.height,
+                    ),
+                };
+
+                Rectangle {
+                    x: offset.x - padding,
+                    y: offset.y - padding,
+                    width: text_bounds.width + padding * 2.0,
+                    height: text_bounds.height + padding * 2.0,
+                }
+            };
+
+            if tooltip_bounds.x < viewport.x {
+                tooltip_bounds.x = viewport.x;
+            } else if viewport.x + viewport.width
+                < tooltip_bounds.x + tooltip_bounds.width
+            {
+                tooltip_bounds.x =
+                    viewport.x + viewport.width - tooltip_bounds.width;
+            }
+
+            if tooltip_bounds.y < viewport.y {
+                tooltip_bounds.y = viewport.y;
+            } else if viewport.y + viewport.height
+                < tooltip_bounds.y + tooltip_bounds.height
+            {
+                tooltip_bounds.y =
+                    viewport.y + viewport.height - tooltip_bounds.height;
+            }
+
+            renderer.with_layer(*viewport, |renderer| {
+                container::draw_background(renderer, &style, tooltip_bounds);
+
+                Widget::<(), Renderer>::draw(
+                    &self.tooltip,
+                    &tree.children[0],
+                    renderer,
+                    &defaults,
+                    Layout::with_offset(
+                        Vector::new(
+                            tooltip_bounds.x + padding,
+                            tooltip_bounds.y + padding,
+                        ),
+                        &text_layout,
+                    ),
+                    cursor_position,
+                    viewport,
+                );
+            });
+        }
+    }
+
+    fn overlay<'b>(
+        &'b self,
+        tree: &'b mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+    ) -> Option<overlay::Element<'b, Message, Renderer>> {
+        self.content.as_widget().overlay(
+            &mut tree.children[0],
+            layout,
+            renderer,
+        )
+    }
+}
+
+impl<'a, Message, Renderer> From<Tooltip<'a, Message, Renderer>>
+    for Element<'a, Message, Renderer>
+where
+    Renderer: 'a + text::Renderer,
+    Message: 'a,
+{
+    fn from(
+        tooltip: Tooltip<'a, Message, Renderer>,
+    ) -> Element<'a, Message, Renderer> {
+        Element::new(tooltip)
+    }
+}