1 files changed, 138 insertions, 0 deletions
diff --git a/gfx/wr/examples/document.rs b/gfx/wr/examples/document.rs
new file mode 100644
index 0000000000..6579189c81
--- /dev/null
+++ b/gfx/wr/examples/document.rs
@@ -0,0 +1,138 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+extern crate euclid;
+extern crate gleam;
+extern crate glutin;
+extern crate webrender;
+extern crate winit;
+
+#[path = "common/boilerplate.rs"]
+mod boilerplate;
+
+use crate::boilerplate::Example;
+use euclid::Scale;
+use webrender::api::*;
+use webrender::render_api::*;
+use webrender::api::units::*;
+
+// This example creates multiple documents overlapping each other with
+// specified layer indices.
+
+struct Document {
+    id: DocumentId,
+    pipeline_id: PipelineId,
+    content_rect: LayoutRect,
+    color: ColorF,
+}
+
+struct App {
+    documents: Vec<Document>,
+}
+
+impl App {
+    fn init(
+        &mut self,
+        api: &mut RenderApi,
+        device_pixel_ratio: f32,
+    ) {
+        let init_data = vec![
+            (
+                PipelineId(1, 0),
+                ColorF::new(0.0, 1.0, 0.0, 1.0),
+                DeviceIntPoint::new(0, 0),
+            ),
+            (
+                PipelineId(2, 0),
+                ColorF::new(1.0, 1.0, 0.0, 1.0),
+                DeviceIntPoint::new(200, 0),
+            ),
+            (
+                PipelineId(3, 0),
+                ColorF::new(1.0, 0.0, 0.0, 1.0),
+                DeviceIntPoint::new(200, 200),
+            ),
+            (
+                PipelineId(4, 0),
+                ColorF::new(1.0, 0.0, 1.0, 1.0),
+                DeviceIntPoint::new(0, 200),
+            ),
+        ];
+
+        for (pipeline_id, color, offset) in init_data {
+            let size = DeviceIntSize::new(250, 250);
+            let bounds = DeviceIntRect::from_origin_and_size(offset, size);
+
+            let document_id = api.add_document(size);
+            let mut txn = Transaction::new();
+            txn.set_root_pipeline(pipeline_id);
+            api.send_transaction(document_id, txn);
+
+            self.documents.push(Document {
+                id: document_id,
+                pipeline_id,
+                content_rect: LayoutRect::from_size(
+                    bounds.size().to_f32() / Scale::new(device_pixel_ratio),
+                ),
+                color,
+            });
+        }
+    }
+}
+
+impl Example for App {
+    fn render(
+        &mut self,
+        api: &mut RenderApi,
+        _base_builder: &mut DisplayListBuilder,
+        _txn: &mut Transaction,
+        _device_size: DeviceIntSize,
+        _pipeline_id: PipelineId,
+        _: DocumentId,
+    ) {
+        if self.documents.is_empty() {
+            // this is the first run, hack around the boilerplate,
+            // which assumes an example only needs one document
+            self.init(api, 1.0);
+        }
+
+        for doc in &self.documents {
+            let space_and_clip = SpaceAndClipInfo::root_scroll(doc.pipeline_id);
+            let mut builder = DisplayListBuilder::new(
+                doc.pipeline_id,
+            );
+            builder.begin();
+            let local_rect = LayoutRect::from_size(doc.content_rect.size());
+
+            builder.push_simple_stacking_context(
+                doc.content_rect.min,
+                space_and_clip.spatial_id,
+                PrimitiveFlags::IS_BACKFACE_VISIBLE,
+            );
+            builder.push_rect(
+                &CommonItemProperties::new(local_rect, space_and_clip),
+                local_rect,
+                doc.color,
+            );
+            builder.pop_stacking_context();
+
+            let mut txn = Transaction::new();
+            txn.set_display_list(
+                Epoch(0),
+                None,
+                doc.content_rect.size(),
+                builder.end(),
+            );
+            txn.generate_frame(0, RenderReasons::empty());
+            api.send_transaction(doc.id, txn);
+        }
+    }
+}
+
+fn main() {
+    let mut app = App {
+        documents: Vec::new(),
+    };
+    boilerplate::main_wrapper(&mut app, None);
+}