1 files changed, 117 insertions, 0 deletions
diff --git a/graphics/src/overlay/menu.rs b/graphics/src/overlay/menu.rs
new file mode 100644
index 00000000..ffe998c5
--- /dev/null
+++ b/graphics/src/overlay/menu.rs
@@ -0,0 +1,117 @@
+//! Build and show dropdown menus.
+use crate::backend::{self, Backend};
+use crate::{Primitive, Renderer};
+use iced_native::{
+    mouse, overlay, Color, Font, HorizontalAlignment, Point, Rectangle,
+    VerticalAlignment,
+};
+
+pub use iced_style::menu::Style;
+
+impl<B> overlay::menu::Renderer for Renderer<B>
+where
+    B: Backend + backend::Text,
+{
+    type Style = Style;
+
+    fn decorate(
+        &mut self,
+        bounds: Rectangle,
+        _cursor_position: Point,
+        style: &Style,
+        (primitives, mouse_cursor): Self::Output,
+    ) -> Self::Output {
+        (
+            Primitive::Group {
+                primitives: vec![
+                    Primitive::Quad {
+                        bounds,
+                        background: style.background,
+                        border_color: style.border_color,
+                        border_width: style.border_width,
+                        border_radius: 0.0,
+                    },
+                    primitives,
+                ],
+            },
+            mouse_cursor,
+        )
+    }
+
+    fn draw<T: ToString>(
+        &mut self,
+        bounds: Rectangle,
+        cursor_position: Point,
+        viewport: &Rectangle,
+        options: &[T],
+        hovered_option: Option<usize>,
+        padding: u16,
+        text_size: u16,
+        font: Font,
+        style: &Style,
+    ) -> Self::Output {
+        use std::f32;
+
+        let is_mouse_over = bounds.contains(cursor_position);
+        let option_height = text_size as usize + padding as usize * 2;
+
+        let mut primitives = Vec::new();
+
+        let offset = viewport.y - bounds.y;
+        let start = (offset / option_height as f32) as usize;
+        let end =
+            ((offset + viewport.height) / option_height as f32).ceil() as usize;
+
+        let visible_options = &options[start..end.min(options.len())];
+
+        for (i, option) in visible_options.iter().enumerate() {
+            let i = start + i;
+            let is_selected = hovered_option == Some(i);
+
+            let bounds = Rectangle {
+                x: bounds.x,
+                y: bounds.y + (option_height * i) as f32,
+                width: bounds.width,
+                height: f32::from(text_size + padding * 2),
+            };
+
+            if is_selected {
+                primitives.push(Primitive::Quad {
+                    bounds,
+                    background: style.selected_background,
+                    border_color: Color::TRANSPARENT,
+                    border_width: 0.0,
+                    border_radius: 0.0,
+                });
+            }
+
+            primitives.push(Primitive::Text {
+                content: option.to_string(),
+                bounds: Rectangle {
+                    x: bounds.x + f32::from(padding),
+                    y: bounds.center_y(),
+                    width: f32::INFINITY,
+                    ..bounds
+                },
+                size: f32::from(text_size),
+                font,
+                color: if is_selected {
+                    style.selected_text_color
+                } else {
+                    style.text_color
+                },
+                horizontal_alignment: HorizontalAlignment::Left,
+                vertical_alignment: VerticalAlignment::Center,
+            });
+        }
+
+        (
+            Primitive::Group { primitives },
+            if is_mouse_over {
+                mouse::Interaction::Pointer
+            } else {
+                mouse::Interaction::default()
+            },
+        )
+    }
+}