examples: Add fill & stroke copy of the C gtk-demo

Author: bilelmoussaoui

examples/Cargo.toml

@@ -17,7 +17,7 @@ im-rc = { version = "15", optional = true }
 [dependencies.gtk]
 path = "../gtk4"
 package = "gtk4"
-features = ["v4_10"]
+features = ["v4_14"]
 
 # used by gif-paintable example
 [dependencies.image]
@@ -167,6 +167,10 @@ path = "squares/main.rs"
 name = "squeezer_bin"
 path = "squeezer_bin/main.rs"
 
+[[bin]]
+name = "fill_and_stroke"
+path = "fill_and_stroke/main.rs"
+
 [[bin]]
 name = "text_viewer"
 path = "text_viewer/main.rs"

examples/README.md

@@ -34,6 +34,7 @@ cargo run --bin basics
 - [Entry Undo](./entry_undo/)
 - [Expressions](./expressions/)
 - [FemtoVG Area](./femtovg_area/)
+- [Fill and Stroke](./fill_and_stroke/)
 - [FlowBox](./flow_box/)
 - [Glium GL-Area](./glium_gl_area/)
 - [Grid Packing](./grid_packing)

examples/fill_and_stroke/README.md

@@ -0,0 +1,5 @@
+# Fill and Stroke
+
+This example shows how to create a custom `gdk::Paintable` that uses the new Path APIs
+
+![Screenshot](screenshot.png)

examples/fill_and_stroke/main.rs

@@ -0,0 +1,28 @@
+mod paintable;
+
+use gtk::glib;
+use gtk::prelude::*;
+
+fn main() -> glib::ExitCode {
+    let application = gtk::Application::builder()
+        .application_id("com.github.gtk-rs.examples.fill_and_stroke")
+        .build();
+
+    application.connect_activate(|app| {
+        let win = gtk::ApplicationWindow::builder()
+            .application(app)
+            .title("Fill and Stroke")
+            .build();
+
+        let picture = gtk::Picture::builder()
+            .content_fit(gtk::ContentFit::ScaleDown)
+            .build();
+        let paintable = paintable::CustomPaintable::new();
+        picture.set_paintable(Some(&paintable));
+        win.set_child(Some(&picture));
+
+        win.present();
+    });
+
+    application.run()
+}

examples/fill_and_stroke/paintable/imp.rs

@@ -0,0 +1,99 @@
+use gtk::prelude::*;
+use gtk::subclass::prelude::*;
+use gtk::{gdk, glib, graphene, gsk};
+
+pub struct CustomPaintable {
+    pub(super) height: i32,
+    pub(super) width: i32,
+    pub(super) paths: Vec<gsk::Path>,
+    pub(super) colors: Vec<gdk::RGBA>,
+    pub(super) stroke_path: gsk::Path,
+    pub(super) stroke1: gsk::Stroke,
+    pub(super) stroke2: gsk::Stroke,
+    pub(super) stroke_color: gdk::RGBA,
+}
+
+impl Default for CustomPaintable {
+    fn default() -> Self {
+        /* Paths and colors extracted from gtk-logo.svg */
+        let paths = vec![
+            gsk::Path::parse("m3.12,66.17 -2.06,-51.46 32.93,24.7 v55.58 l-30.87,-28.82 z")
+                .unwrap(),
+            gsk::Path::parse("m34,95 49.4,-20.58 4.12,-51.46 -53.52,16.47 v55.58 z").unwrap(),
+            gsk::Path::parse("m1.06,14.71 32.93,24.7 53.52,-16.47 -36.75,-21.88 -49.7,13.65 z")
+                .unwrap(),
+        ];
+        let colors = vec![
+            gdk::RGBA::parse("#e40000").unwrap(),
+            gdk::RGBA::parse("#7fe719").unwrap(),
+            gdk::RGBA::parse("#729fcf").unwrap(),
+        ];
+        let stroke_path = gsk::Path::parse("m50.6,51.3 -47.3,14 z l33,23 z v-50").unwrap();
+        let stroke1 = gsk::Stroke::new(2.12);
+        let stroke2 = gsk::Stroke::new(1.25);
+        let stroke_color = gdk::RGBA::WHITE;
+
+        let mut bounds = paths[0].stroke_bounds(&stroke1).unwrap();
+        let bounds2 = paths[1].stroke_bounds(&stroke1).unwrap();
+        bounds = bounds.union(&bounds2);
+        let bounds3 = paths[2].stroke_bounds(&stroke1).unwrap();
+        bounds = bounds.union(&bounds3);
+        let bounds_path = stroke_path.stroke_bounds(&stroke2).unwrap();
+        bounds = bounds.union(&bounds_path);
+        let width = bounds.x() + bounds.width();
+        let height = bounds.y() + bounds.height();
+        Self {
+            height: height as i32,
+            width: width as i32,
+            paths,
+            colors,
+            stroke_path,
+            stroke1,
+            stroke2,
+            stroke_color,
+        }
+    }
+}
+
+#[glib::object_subclass]
+impl ObjectSubclass for CustomPaintable {
+    const NAME: &'static str = "CustomPaintable";
+    type Type = super::CustomPaintable;
+    type Interfaces = (gdk::Paintable,);
+}
+
+impl ObjectImpl for CustomPaintable {}
+
+impl PaintableImpl for CustomPaintable {
+    fn flags(&self) -> gdk::PaintableFlags {
+        // Fixed size and content
+        gdk::PaintableFlags::SIZE | gdk::PaintableFlags::CONTENTS
+    }
+
+    fn intrinsic_width(&self) -> i32 {
+        self.width
+    }
+
+    fn intrinsic_height(&self) -> i32 {
+        self.height
+    }
+
+    fn snapshot(&self, snapshot: &gdk::Snapshot, width: f64, height: f64) {
+        let bounds = graphene::Rect::new(0., 0., width as f32, height as f32);
+        for (i, path) in self.paths.iter().enumerate() {
+            snapshot.push_fill(path, gsk::FillRule::Winding);
+            snapshot.append_color(&self.colors[i], &bounds);
+            snapshot.pop();
+        }
+
+        for _ in 0..3 {
+            snapshot.push_stroke(&self.stroke_path, &self.stroke1);
+            snapshot.append_color(&self.stroke_color, &bounds);
+            snapshot.pop();
+        }
+
+        snapshot.push_stroke(&self.stroke_path, &self.stroke2);
+        snapshot.append_color(&self.stroke_color, &bounds);
+        snapshot.pop();
+    }
+}

examples/fill_and_stroke/paintable/mod.rs

@@ -0,0 +1,19 @@
+mod imp;
+
+use gtk::{gdk, glib};
+
+glib::wrapper! {
+    pub struct CustomPaintable(ObjectSubclass<imp::CustomPaintable>) @implements gdk::Paintable;
+}
+
+impl Default for CustomPaintable {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl CustomPaintable {
+    pub fn new() -> Self {
+        glib::Object::new()
+    }
+}