9 files changed, 740 insertions, 0 deletions
diff --git a/examples/tour/src/iced_ggez/renderer.rs b/examples/tour/src/iced_ggez/renderer.rs
new file mode 100644
index 00000000..c0e6d559
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer.rs
@@ -0,0 +1,77 @@
+mod button;
+mod checkbox;
+mod debugger;
+mod image;
+mod radio;
+mod slider;
+mod text;
+
+use ggez::graphics::{
+    self, spritebatch::SpriteBatch, Font, Image, MeshBuilder,
+};
+use ggez::Context;
+
+pub use image::Cache;
+
+pub struct Renderer<'a> {
+    pub context: &'a mut Context,
+    pub images: &'a mut image::Cache,
+    pub sprites: SpriteBatch,
+    pub spritesheet: Image,
+    pub font: Font,
+    font_size: f32,
+    debug_mesh: Option<MeshBuilder>,
+}
+
+impl<'a> Renderer<'a> {
+    pub fn new(
+        context: &'a mut Context,
+        images: &'a mut image::Cache,
+        spritesheet: Image,
+        font: Font,
+    ) -> Renderer<'a> {
+        Renderer {
+            context,
+            images,
+            sprites: SpriteBatch::new(spritesheet.clone()),
+            spritesheet,
+            font,
+            font_size: 20.0,
+            debug_mesh: None,
+        }
+    }
+
+    pub fn flush(&mut self) {
+        graphics::draw(
+            self.context,
+            &self.sprites,
+            graphics::DrawParam::default(),
+        )
+        .expect("Draw sprites");
+
+        graphics::draw_queued_text(
+            self.context,
+            graphics::DrawParam::default(),
+            Default::default(),
+            graphics::FilterMode::Linear,
+        )
+        .expect("Draw text");
+
+        if let Some(debug_mesh) = self.debug_mesh.take() {
+            let mesh =
+                debug_mesh.build(self.context).expect("Build debug mesh");
+
+            graphics::draw(self.context, &mesh, graphics::DrawParam::default())
+                .expect("Draw debug mesh");
+        }
+    }
+}
+
+pub fn into_color(color: iced_native::Color) -> graphics::Color {
+    graphics::Color {
+        r: color.r,
+        g: color.g,
+        b: color.b,
+        a: color.a,
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/button.rs b/examples/tour/src/iced_ggez/renderer/button.rs
new file mode 100644
index 00000000..78a5de07
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/button.rs
@@ -0,0 +1,154 @@
+use super::Renderer;
+use ggez::graphics::{
+    self, Align, Color, DrawParam, Rect, Scale, Text, TextFragment, WHITE,
+};
+use iced_native::{button, Button, Layout, Length, MouseCursor, Node, Style};
+
+const LEFT: Rect = Rect {
+    x: 0.0,
+    y: 34.0,
+    w: 6.0,
+    h: 49.0,
+};
+
+const BACKGROUND: Rect = Rect {
+    x: LEFT.w,
+    y: LEFT.y,
+    w: 1.0,
+    h: LEFT.h,
+};
+
+const RIGHT: Rect = Rect {
+    x: LEFT.h - LEFT.w,
+    y: LEFT.y,
+    w: LEFT.w,
+    h: LEFT.h,
+};
+
+impl button::Renderer for Renderer<'_> {
+    fn node<Message>(&self, button: &Button<'_, Message>) -> Node {
+        let style = Style::default()
+            .width(button.width)
+            .height(Length::Units(LEFT.h as u16))
+            .min_width(Length::Units(100))
+            .align_self(button.align_self);
+
+        Node::new(style)
+    }
+
+    fn draw<Message>(
+        &mut self,
+        button: &Button<'_, Message>,
+        layout: Layout<'_>,
+        cursor_position: iced_native::Point,
+    ) -> MouseCursor {
+        let mut bounds = layout.bounds();
+        let mouse_over = bounds.contains(cursor_position);
+
+        let mut state_offset = 0.0;
+
+        if mouse_over {
+            if button.state.is_pressed() {
+                bounds.y += 4.0;
+                state_offset = RIGHT.x + RIGHT.w;
+            } else {
+                bounds.y -= 1.0;
+            }
+        }
+
+        let class_index = match button.class {
+            button::Class::Primary => 0,
+            button::Class::Secondary => 1,
+            button::Class::Positive => 2,
+        };
+
+        let width = self.spritesheet.width() as f32;
+        let height = self.spritesheet.height() as f32;
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (LEFT.x + state_offset) / width,
+                y: (LEFT.y + class_index as f32 * LEFT.h) / height,
+                w: LEFT.w / width,
+                h: LEFT.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x,
+                y: bounds.y,
+            },
+            ..DrawParam::default()
+        });
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (BACKGROUND.x + state_offset) / width,
+                y: (BACKGROUND.y + class_index as f32 * BACKGROUND.h) / height,
+                w: BACKGROUND.w / width,
+                h: BACKGROUND.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x + LEFT.w,
+                y: bounds.y,
+            },
+            scale: ggez::mint::Vector2 {
+                x: bounds.width - LEFT.w - RIGHT.w,
+                y: 1.0,
+            },
+            ..DrawParam::default()
+        });
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (RIGHT.x + state_offset) / width,
+                y: (RIGHT.y + class_index as f32 * RIGHT.h) / height,
+                w: RIGHT.w / width,
+                h: RIGHT.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x + bounds.width - RIGHT.w,
+                y: bounds.y,
+            },
+            ..DrawParam::default()
+        });
+
+        let mut text = Text::new(TextFragment {
+            text: button.label.clone(),
+            font: Some(self.font),
+            scale: Some(Scale { x: 20.0, y: 20.0 }),
+            ..Default::default()
+        });
+
+        text.set_bounds(
+            ggez::mint::Point2 {
+                x: bounds.width,
+                y: bounds.height,
+            },
+            Align::Center,
+        );
+
+        graphics::queue_text(
+            self.context,
+            &text,
+            ggez::mint::Point2 {
+                x: bounds.x,
+                y: bounds.y + BACKGROUND.h / 4.0,
+            },
+            Some(if mouse_over {
+                WHITE
+            } else {
+                Color {
+                    r: 0.9,
+                    g: 0.9,
+                    b: 0.9,
+                    a: 1.0,
+                }
+            }),
+        );
+
+        if mouse_over {
+            MouseCursor::Pointer
+        } else {
+            MouseCursor::OutOfBounds
+        }
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/checkbox.rs b/examples/tour/src/iced_ggez/renderer/checkbox.rs
new file mode 100644
index 00000000..807185d9
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/checkbox.rs
@@ -0,0 +1,94 @@
+use super::Renderer;
+
+use ggez::graphics::{DrawParam, Rect};
+use iced_native::{
+    checkbox, text, Align, Checkbox, Column, Layout, Length, MouseCursor, Node,
+    Row, Text, Widget,
+};
+
+const SPRITE: Rect = Rect {
+    x: 98.0,
+    y: 0.0,
+    w: 28.0,
+    h: 28.0,
+};
+
+impl checkbox::Renderer for Renderer<'_>
+where
+    Self: text::Renderer,
+{
+    fn node<Message>(&mut self, checkbox: &Checkbox<Message>) -> Node {
+        Row::<(), Self>::new()
+            .spacing(15)
+            .align_items(Align::Center)
+            .push(
+                Column::new()
+                    .width(Length::Units(SPRITE.w as u16))
+                    .height(Length::Units(SPRITE.h as u16)),
+            )
+            .push(Text::new(&checkbox.label))
+            .node(self)
+    }
+
+    fn draw<Message>(
+        &mut self,
+        checkbox: &Checkbox<Message>,
+        layout: Layout<'_>,
+        cursor_position: iced_native::Point,
+    ) -> MouseCursor {
+        let bounds = layout.bounds();
+        let children: Vec<_> = layout.children().collect();
+        let text_bounds = children[1].bounds();
+
+        let mut text = Text::new(&checkbox.label);
+
+        if let Some(label_color) = checkbox.label_color {
+            text = text.color(label_color);
+        }
+
+        text::Renderer::draw(self, &text, children[1]);
+
+        let mouse_over = bounds.contains(cursor_position)
+            || text_bounds.contains(cursor_position);
+
+        let width = self.spritesheet.width() as f32;
+        let height = self.spritesheet.height() as f32;
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (SPRITE.x + (if mouse_over { SPRITE.w } else { 0.0 }))
+                    / width,
+                y: SPRITE.y / height,
+                w: SPRITE.w / width,
+                h: SPRITE.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x,
+                y: bounds.y,
+            },
+            ..DrawParam::default()
+        });
+
+        if checkbox.is_checked {
+            self.sprites.add(DrawParam {
+                src: Rect {
+                    x: (SPRITE.x + SPRITE.w * 2.0) / width,
+                    y: SPRITE.y / height,
+                    w: SPRITE.w / width,
+                    h: SPRITE.h / height,
+                },
+                dest: ggez::mint::Point2 {
+                    x: bounds.x,
+                    y: bounds.y,
+                },
+                ..DrawParam::default()
+            });
+        }
+
+        if mouse_over {
+            MouseCursor::Pointer
+        } else {
+            MouseCursor::OutOfBounds
+        }
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/debugger.rs b/examples/tour/src/iced_ggez/renderer/debugger.rs
new file mode 100644
index 00000000..ffb658af
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/debugger.rs
@@ -0,0 +1,32 @@
+use super::{into_color, Renderer};
+use ggez::graphics::{DrawMode, MeshBuilder, Rect};
+
+impl iced_native::renderer::Debugger for Renderer<'_> {
+    fn explain(
+        &mut self,
+        layout: &iced_native::Layout<'_>,
+        color: iced_native::Color,
+    ) {
+        let bounds = layout.bounds();
+
+        let mut debug_mesh =
+            self.debug_mesh.take().unwrap_or(MeshBuilder::new());
+
+        debug_mesh.rectangle(
+            DrawMode::stroke(1.0),
+            Rect {
+                x: bounds.x,
+                y: bounds.y,
+                w: bounds.width,
+                h: bounds.height,
+            },
+            into_color(color),
+        );
+
+        self.debug_mesh = Some(debug_mesh);
+
+        for child in layout.children() {
+            self.explain(&child, color);
+        }
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/image.rs b/examples/tour/src/iced_ggez/renderer/image.rs
new file mode 100644
index 00000000..b12b65c3
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/image.rs
@@ -0,0 +1,76 @@
+use super::Renderer;
+
+use ggez::{graphics, nalgebra};
+use iced_native::{image, Image, Layout, Length, Style};
+
+pub struct Cache {
+    images: std::collections::HashMap<String, graphics::Image>,
+}
+
+impl Cache {
+    pub fn new() -> Self {
+        Self {
+            images: std::collections::HashMap::new(),
+        }
+    }
+
+    fn get<'a>(
+        &mut self,
+        name: &'a str,
+        context: &mut ggez::Context,
+    ) -> graphics::Image {
+        if let Some(image) = self.images.get(name) {
+            return image.clone();
+        }
+
+        let mut image = graphics::Image::new(context, &format!("/{}", name))
+            .expect("Load ferris image");
+
+        image.set_filter(graphics::FilterMode::Linear);
+
+        self.images.insert(name.to_string(), image.clone());
+
+        image
+    }
+}
+
+impl<'a> image::Renderer<&'a str> for Renderer<'_> {
+    fn node(&mut self, image: &Image<&'a str>) -> iced_native::Node {
+        let ggez_image = self.images.get(image.handle, self.context);
+
+        let aspect_ratio =
+            ggez_image.width() as f32 / ggez_image.height() as f32;
+
+        let mut style = Style::default().align_self(image.align_self);
+
+        style = match (image.width, image.height) {
+            (Length::Units(width), _) => style.width(image.width).height(
+                Length::Units((width as f32 / aspect_ratio).round() as u16),
+            ),
+            (_, _) => style
+                .width(Length::Units(ggez_image.width()))
+                .height(Length::Units(ggez_image.height())),
+        };
+
+        iced_native::Node::new(style)
+    }
+
+    fn draw(&mut self, image: &Image<&'a str>, layout: Layout<'_>) {
+        let image = self.images.get(image.handle, self.context);
+        let bounds = layout.bounds();
+
+        // We should probably use batches to draw images efficiently and keep
+        // draw side-effect free, but this is good enough for the example.
+        graphics::draw(
+            self.context,
+            &image,
+            graphics::DrawParam::new()
+                .dest(nalgebra::Point2::new(bounds.x, bounds.y))
+                .scale(nalgebra::Vector2::new(
+                    bounds.width / image.width() as f32,
+                    bounds.height / image.height() as f32,
+                )),
+        )
+        .expect("Draw image");
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/radio.rs b/examples/tour/src/iced_ggez/renderer/radio.rs
new file mode 100644
index 00000000..dbd29ecd
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/radio.rs
@@ -0,0 +1,92 @@
+use super::Renderer;
+
+use ggez::graphics::{DrawParam, Rect};
+use iced_native::{
+    radio, text, Align, Column, Layout, Length, MouseCursor, Node, Point,
+    Radio, Row, Text, Widget,
+};
+
+const SPRITE: Rect = Rect {
+    x: 98.0,
+    y: 28.0,
+    w: 28.0,
+    h: 28.0,
+};
+
+impl radio::Renderer for Renderer<'_>
+where
+    Self: text::Renderer,
+{
+    fn node<Message>(&mut self, radio: &Radio<Message>) -> Node {
+        Row::<(), Self>::new()
+            .spacing(15)
+            .align_items(Align::Center)
+            .push(
+                Column::new()
+                    .width(Length::Units(SPRITE.w as u16))
+                    .height(Length::Units(SPRITE.h as u16)),
+            )
+            .push(Text::new(&radio.label))
+            .node(self)
+    }
+
+    fn draw<Message>(
+        &mut self,
+        radio: &Radio<Message>,
+        layout: Layout<'_>,
+        cursor_position: Point,
+    ) -> MouseCursor {
+        let children: Vec<_> = layout.children().collect();
+
+        let mut text = Text::new(&radio.label);
+
+        if let Some(label_color) = radio.label_color {
+            text = text.color(label_color);
+        }
+
+        text::Renderer::draw(self, &text, children[1]);
+
+        let bounds = layout.bounds();
+        let mouse_over = bounds.contains(cursor_position);
+
+        let width = self.spritesheet.width() as f32;
+        let height = self.spritesheet.height() as f32;
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (SPRITE.x + (if mouse_over { SPRITE.w } else { 0.0 }))
+                    / width,
+                y: SPRITE.y / height,
+                w: SPRITE.w / width,
+                h: SPRITE.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x,
+                y: bounds.y,
+            },
+            ..DrawParam::default()
+        });
+
+        if radio.is_selected {
+            self.sprites.add(DrawParam {
+                src: Rect {
+                    x: (SPRITE.x + SPRITE.w * 2.0) / width,
+                    y: SPRITE.y / height,
+                    w: SPRITE.w / width,
+                    h: SPRITE.h / height,
+                },
+                dest: ggez::mint::Point2 {
+                    x: bounds.x,
+                    y: bounds.y,
+                },
+                ..DrawParam::default()
+            });
+        }
+
+        if mouse_over {
+            MouseCursor::Pointer
+        } else {
+            MouseCursor::OutOfBounds
+        }
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/slider.rs b/examples/tour/src/iced_ggez/renderer/slider.rs
new file mode 100644
index 00000000..60c40c55
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/slider.rs
@@ -0,0 +1,93 @@
+use super::Renderer;
+
+use ggez::graphics::{DrawParam, Rect};
+use iced_native::{
+    slider, Layout, Length, MouseCursor, Node, Point, Slider, Style,
+};
+
+const RAIL: Rect = Rect {
+    x: 98.0,
+    y: 56.0,
+    w: 1.0,
+    h: 4.0,
+};
+
+const MARKER: Rect = Rect {
+    x: RAIL.x + 28.0,
+    y: RAIL.y,
+    w: 16.0,
+    h: 24.0,
+};
+
+impl slider::Renderer for Renderer<'_> {
+    fn node<Message>(&self, slider: &Slider<'_, Message>) -> Node {
+        let style = Style::default()
+            .width(slider.width)
+            .height(Length::Units(25))
+            .min_width(Length::Units(100));
+
+        Node::new(style)
+    }
+
+    fn draw<Message>(
+        &mut self,
+        slider: &Slider<'_, Message>,
+        layout: Layout<'_>,
+        cursor_position: Point,
+    ) -> MouseCursor {
+        let bounds = layout.bounds();
+        let width = self.spritesheet.width() as f32;
+        let height = self.spritesheet.height() as f32;
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: RAIL.x / width,
+                y: RAIL.y / height,
+                w: RAIL.w / width,
+                h: RAIL.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x + MARKER.w as f32 / 2.0,
+                y: bounds.y + 12.5,
+            },
+            scale: ggez::mint::Vector2 {
+                x: bounds.width - MARKER.w as f32,
+                y: 1.0,
+            },
+            ..DrawParam::default()
+        });
+
+        let (range_start, range_end) = slider.range.clone().into_inner();
+
+        let marker_offset = (bounds.width - MARKER.w as f32)
+            * ((slider.value - range_start)
+                / (range_end - range_start).max(1.0));
+
+        let mouse_over = bounds.contains(cursor_position);
+        let is_active = slider.state.is_dragging() || mouse_over;
+
+        self.sprites.add(DrawParam {
+            src: Rect {
+                x: (MARKER.x + (if is_active { MARKER.w } else { 0.0 }))
+                    / width,
+                y: MARKER.y / height,
+                w: MARKER.w / width,
+                h: MARKER.h / height,
+            },
+            dest: ggez::mint::Point2 {
+                x: bounds.x + marker_offset.round(),
+                y: bounds.y
+                    + (if slider.state.is_dragging() { 2.0 } else { 0.0 }),
+            },
+            ..DrawParam::default()
+        });
+
+        if slider.state.is_dragging() {
+            MouseCursor::Grabbing
+        } else if mouse_over {
+            MouseCursor::Grab
+        } else {
+            MouseCursor::OutOfBounds
+        }
+    }
+}
diff --git a/examples/tour/src/iced_ggez/renderer/text.rs b/examples/tour/src/iced_ggez/renderer/text.rs
new file mode 100644
index 00000000..b51cc220
--- /dev/null
+++ b/examples/tour/src/iced_ggez/renderer/text.rs
@@ -0,0 +1,110 @@
+use super::{into_color, Renderer};
+use ggez::graphics::{self, mint, Align, Scale, Text, TextFragment};
+
+use iced_native::{text, Layout, Node, Style};
+use std::cell::RefCell;
+use std::f32;
+
+impl text::Renderer for Renderer<'_> {
+    fn node(&self, text: &iced_native::Text) -> Node {
+        let font = self.font;
+        let font_cache = graphics::font_cache(self.context);
+        let content = String::from(&text.content);
+
+        // TODO: Investigate why stretch tries to measure this MANY times
+        // with every ancestor's bounds.
+        // Bug? Using the library wrong? I should probably open an issue on
+        // the stretch repository.
+        // I noticed that the first measure is the one that matters in
+        // practice. Here, we use a RefCell to store the cached measurement.
+        let measure = RefCell::new(None);
+        let size = text.size.map(f32::from).unwrap_or(self.font_size);
+
+        let style = Style::default().width(text.width);
+
+        iced_native::Node::with_measure(style, move |bounds| {
+            let mut measure = measure.borrow_mut();
+
+            if measure.is_none() {
+                let bounds = (
+                    match bounds.width {
+                        iced_native::Number::Undefined => f32::INFINITY,
+                        iced_native::Number::Defined(w) => w,
+                    },
+                    match bounds.height {
+                        iced_native::Number::Undefined => f32::INFINITY,
+                        iced_native::Number::Defined(h) => h,
+                    },
+                );
+
+                let mut text = Text::new(TextFragment {
+                    text: content.clone(),
+                    font: Some(font),
+                    scale: Some(Scale { x: size, y: size }),
+                    ..Default::default()
+                });
+
+                text.set_bounds(
+                    mint::Point2 {
+                        x: bounds.0,
+                        y: bounds.1,
+                    },
+                    Align::Left,
+                );
+
+                let (width, height) = font_cache.dimensions(&text);
+
+                let size = iced_native::Size {
+                    width: width as f32,
+                    height: height as f32,
+                };
+
+                // If the text has no width boundary we avoid caching as the
+                // layout engine may just be measuring text in a row.
+                if bounds.0 == f32::INFINITY {
+                    return size;
+                } else {
+                    *measure = Some(size);
+                }
+            }
+
+            measure.unwrap()
+        })
+    }
+
+    fn draw(&mut self, text: &iced_native::Text, layout: Layout<'_>) {
+        let size = text.size.map(f32::from).unwrap_or(self.font_size);
+        let bounds = layout.bounds();
+
+        let mut ggez_text = Text::new(TextFragment {
+            text: text.content.clone(),
+            font: Some(self.font),
+            scale: Some(Scale { x: size, y: size }),
+            ..Default::default()
+        });
+
+        ggez_text.set_bounds(
+            mint::Point2 {
+                x: bounds.width,
+                y: bounds.height,
+            },
+            match text.horizontal_alignment {
+                text::HorizontalAlignment::Left => graphics::Align::Left,
+                text::HorizontalAlignment::Center => graphics::Align::Center,
+                text::HorizontalAlignment::Right => graphics::Align::Right,
+            },
+        );
+
+        graphics::queue_text(
+            self.context,
+            &ggez_text,
+            mint::Point2 {
+                x: bounds.x,
+                y: bounds.y,
+            },
+            text.color
+                .or(Some(iced_native::Color::BLACK))
+                .map(into_color),
+        );
+    }
+}
diff --git a/examples/tour/src/iced_ggez/widget.rs b/examples/tour/src/iced_ggez/widget.rs
new file mode 100644
index 00000000..948f9fc6
--- /dev/null
+++ b/examples/tour/src/iced_ggez/widget.rs
@@ -0,0 +1,12 @@
+use super::Renderer;
+
+pub use iced_native::{
+    button, slider, text, Align, Button, Checkbox, Color, Length, Radio,
+    Slider, Text,
+};
+
+pub type Image<'a> = iced_native::Image<&'a str>;
+
+pub type Column<'a, Message> = iced_native::Column<'a, Message, Renderer<'a>>;
+pub type Row<'a, Message> = iced_native::Row<'a, Message, Renderer<'a>>;
+pub type Element<'a, Message> = iced_native::Element<'a, Message, Renderer<'a>>;