Change Tooltip to support Text only for now

graphics/src/widget/tooltip.rs

@@ -1,7 +1,10 @@
 //! Decorate content and apply alignment.
+use crate::backend::{self, Backend};
 use crate::defaults::Defaults;
-use crate::{Backend, Renderer};
-use iced_native::{Element, Layout, Point, Rectangle};
+use crate::{Primitive, Renderer, Vector};
+
+use iced_native::layout::{self, Layout};
+use iced_native::{Element, Point, Rectangle, Size, Text};
 
 /// An element decorating some content.
 ///
@@ -10,9 +13,11 @@ use iced_native::{Element, Layout, Point, Rectangle};
 pub type Tooltip<'a, Message, Backend> =
     iced_native::Tooltip<'a, Message, Renderer<Backend>>;
 
+pub use iced_native::tooltip::Position;
+
 impl<B> iced_native::tooltip::Renderer for Renderer<B>
 where
-    B: Backend,
+    B: Backend + backend::Text,
 {
     type Style = ();
 
@@ -20,10 +25,14 @@ where
         &mut self,
         defaults: &Defaults,
         cursor_position: Point,
-        content: &Element<'_, Message, Self>,
         content_layout: Layout<'_>,
         viewport: &Rectangle,
+        content: &Element<'_, Message, Self>,
+        tooltip: &Text<Self>,
+        position: Position,
     ) -> Self::Output {
+        let bounds = content_layout.bounds();
+
         let (content, mouse_interaction) = content.draw(
             self,
             &defaults,
@@ -32,6 +41,63 @@ where
             viewport,
         );
 
-        (content, mouse_interaction)
+        if bounds.contains(cursor_position) {
+            use iced_native::Widget;
+
+            let tooltip_layout = Widget::<(), Self>::layout(
+                tooltip,
+                self,
+                &layout::Limits::new(Size::ZERO, viewport.size()),
+            );
+
+            let tooltip_bounds = tooltip_layout.bounds();
+
+            let x_center =
+                bounds.x + (bounds.width - tooltip_bounds.width) / 2.0;
+
+            let y_center =
+                bounds.y + (bounds.height - tooltip_bounds.height) / 2.0;
+
+            let offset = match position {
+                Position::Top => {
+                    Vector::new(x_center, bounds.y - tooltip_bounds.height)
+                }
+                Position::Bottom => {
+                    Vector::new(x_center, bounds.y + bounds.height)
+                }
+                Position::Left => {
+                    Vector::new(bounds.x - tooltip_bounds.width, y_center)
+                }
+                Position::Right => {
+                    Vector::new(bounds.x + bounds.width, y_center)
+                }
+                Position::FollowCursor => Vector::new(
+                    cursor_position.x,
+                    cursor_position.y - tooltip_bounds.height,
+                ),
+            };
+
+            let (tooltip, _) = Widget::<(), Self>::draw(
+                tooltip,
+                self,
+                defaults,
+                Layout::with_offset(offset, &tooltip_layout),
+                cursor_position,
+                viewport,
+            );
+
+            (
+                Primitive::Clip {
+                    bounds: *viewport,
+                    offset: Vector::new(0, 0),
+                    content: Box::new(Primitive::Group {
+                        primitives: vec![content, tooltip],
+                    }),
+                },
+                mouse_interaction,
+            )
+        } else {
+            (content, mouse_interaction)
+        }
     }
 }