Implemented paint worklet arguments.

components/canvas/canvas_paint_thread.rs

@@ -548,10 +548,15 @@ impl<'a> CanvasPaintThread<'a> {
     }
 
     fn recreate(&mut self, size: Size2D<i32>) {
+        // TODO: clear the thread state. https://github.com/servo/servo/issues/17533
         self.drawtarget = CanvasPaintThread::create(size);
         self.state = CanvasPaintState::new(self.state.draw_options.antialias);
         self.saved_states.clear();
         // Webrender doesn't let images change size, so we clear the webrender image key.
+        // TODO: there is an annying race condition here: the display list builder
+        // might still be using the old image key. Really, we should be scheduling the image
+        // for later deletion, not deleting it immediately.
+        // https://github.com/servo/servo/issues/17534
         if let Some(image_key) = self.image_key.take() {
             // If this executes, then we are in a new epoch since we last recreated the canvas,
             // so `old_image_key` must be `None`.
@@ -582,13 +587,15 @@ impl<'a> CanvasPaintThread<'a> {
 
             match self.image_key {
                 Some(image_key) => {
+                    debug!("Updating image {:?}.", image_key);
                     self.webrender_api.update_image(image_key,
                                                     descriptor,
                                                     data,
                                                     None);
                 }
                 None => {
                     self.image_key = Some(self.webrender_api.generate_image_key());
+                    debug!("New image {:?}.", self.image_key);
                     self.webrender_api.add_image(self.image_key.unwrap(),
                                                  descriptor,
                                                  data,

components/layout/display_list_builder.rs

@@ -68,6 +68,7 @@ use style::values::generics::image::{Image, ShapeExtent};
 use style::values::generics::image::PaintWorklet;
 use style::values::specified::position::{X, Y};
 use style_traits::CSSPixel;
+use style_traits::ToCss;
 use style_traits::cursor::Cursor;
 use table_cell::CollapsedBordersForCell;
 use webrender_api::{ClipId, ColorF, ComplexClipRegion, GradientStop, LocalClip, RepeatMode};
@@ -1173,9 +1174,15 @@ impl FragmentDisplayListBuilding for Fragment {
         let device_pixel_ratio = state.layout_context.style_context.device_pixel_ratio();
         let size_in_au = unbordered_box.size.to_physical(style.writing_mode);
         let size_in_px = TypedSize2D::new(size_in_au.width.to_f32_px(), size_in_au.height.to_f32_px());
+
+        // TODO: less copying.
         let name = paint_worklet.name.clone();
+        let arguments = paint_worklet.arguments.iter()
+            .map(|argument| argument.to_css_string())
+            .collect();
 
         // Get the painter, and the computed values for its properties.
+        // TODO: less copying.
         let (properties, painter) = match state.layout_context.registered_painters.read().get(&name) {
             Some(registered_painter) => (
                 registered_painter.properties
@@ -1191,7 +1198,7 @@ impl FragmentDisplayListBuilding for Fragment {
         // TODO: add a one-place cache to avoid drawing the paint image every time.
         // https://github.com/servo/servo/issues/17369
         debug!("Drawing a paint image {}({},{}).", name, size_in_px.width, size_in_px.height);
-        let mut draw_result = painter.draw_a_paint_image(size_in_px, device_pixel_ratio, properties);
+        let mut draw_result = painter.draw_a_paint_image(size_in_px, device_pixel_ratio, properties, arguments);
         let webrender_image = WebRenderImageInfo {
             width: draw_result.width,
             height: draw_result.height,

components/script/dom/paintworkletglobalscope.rs

@@ -17,6 +17,7 @@ use dom::bindings::js::JS;
 use dom::bindings::js::Root;
 use dom::bindings::reflector::DomObject;
 use dom::bindings::str::DOMString;
+use dom::cssstylevalue::CSSStyleValue;
 use dom::paintrenderingcontext2d::PaintRenderingContext2D;
 use dom::paintsize::PaintSize;
 use dom::stylepropertymapreadonly::StylePropertyMapReadOnly;
@@ -38,6 +39,7 @@ use js::jsapi::IsConstructor;
 use js::jsapi::JSAutoCompartment;
 use js::jsapi::JS_ClearPendingException;
 use js::jsapi::JS_IsExceptionPending;
+use js::jsapi::JS_NewArrayObject;
 use js::jsval::JSVal;
 use js::jsval::ObjectValue;
 use js::jsval::UndefinedValue;
@@ -100,9 +102,9 @@ impl PaintWorkletGlobalScope {
 
     pub fn perform_a_worklet_task(&self, task: PaintWorkletTask) {
         match task {
-            PaintWorkletTask::DrawAPaintImage(name, size_in_px, device_pixel_ratio, properties, sender) => {
+            PaintWorkletTask::DrawAPaintImage(name, size_in_px, device_pixel_ratio, properties, arguments, sender) => {
                 let properties = StylePropertyMapReadOnly::from_iter(self.upcast(), properties);
-                let result = self.draw_a_paint_image(name, size_in_px, device_pixel_ratio, &*properties);
+                let result = self.draw_a_paint_image(name, size_in_px, device_pixel_ratio, &*properties, arguments);
                 let _ = sender.send(result);
             }
         }
@@ -113,24 +115,30 @@ impl PaintWorkletGlobalScope {
                           name: Atom,
                           size_in_px: TypedSize2D<f32, CSSPixel>,
                           device_pixel_ratio: ScaleFactor<f32, CSSPixel, DevicePixel>,
-                          properties: &StylePropertyMapReadOnly)
+                          properties: &StylePropertyMapReadOnly,
+                          arguments: Vec<String>)
                           -> DrawAPaintImageResult
     {
+        let size_in_dpx = size_in_px * device_pixel_ratio;
+        let size_in_dpx = TypedSize2D::new(size_in_dpx.width.abs() as u32, size_in_dpx.height.abs() as u32);
+
+        // TODO: Steps 1-5.
+
         // TODO: document paint definitions.
-        self.invoke_a_paint_callback(name, size_in_px, device_pixel_ratio, properties)
+        self.invoke_a_paint_callback(name, size_in_px, size_in_dpx, device_pixel_ratio, properties, arguments)
     }
 
     /// https://drafts.css-houdini.org/css-paint-api/#invoke-a-paint-callback
     #[allow(unsafe_code)]
     fn invoke_a_paint_callback(&self,
                                name: Atom,
                                size_in_px: TypedSize2D<f32, CSSPixel>,
+                               size_in_dpx: TypedSize2D<u32, DevicePixel>,
                                device_pixel_ratio: ScaleFactor<f32, CSSPixel, DevicePixel>,
-                               properties: &StylePropertyMapReadOnly)
+                               properties: &StylePropertyMapReadOnly,
+                               mut arguments: Vec<String>)
                                -> DrawAPaintImageResult
     {
-        let size_in_dpx = size_in_px * device_pixel_ratio;
-        let size_in_dpx = TypedSize2D::new(size_in_dpx.width.abs() as u32, size_in_dpx.height.abs() as u32);
         debug!("Invoking a paint callback {}({},{}) at {}.",
                name, size_in_px.width, size_in_px.height, device_pixel_ratio);
 
@@ -198,10 +206,19 @@ impl PaintWorkletGlobalScope {
         // TODO: Step 10
         // Steps 11-12
         debug!("Invoking paint function {}.", name);
+        rooted_vec!(let arguments_values <- arguments.drain(..)
+                    .map(|argument| CSSStyleValue::new(self.upcast(), argument)));
+        let arguments_value_vec: Vec<JSVal> = arguments_values.iter()
+            .map(|argument| ObjectValue(argument.reflector().get_jsobject().get()))
+            .collect();
+        let arguments_value_array = unsafe { HandleValueArray::from_rooted_slice(&*arguments_value_vec) };
+        rooted!(in(cx) let argument_object = unsafe { JS_NewArrayObject(cx, &arguments_value_array) });
+
         let args_slice = [
             ObjectValue(rendering_context.reflector().get_jsobject().get()),
             ObjectValue(paint_size.reflector().get_jsobject().get()),
             ObjectValue(properties.reflector().get_jsobject().get()),
+            ObjectValue(argument_object.get()),
         ];
         let args = unsafe { HandleValueArray::from_rooted_slice(&args_slice) };
 
@@ -252,12 +269,17 @@ impl PaintWorkletGlobalScope {
             fn draw_a_paint_image(&self,
                                   size: TypedSize2D<f32, CSSPixel>,
                                   device_pixel_ratio: ScaleFactor<f32, CSSPixel, DevicePixel>,
-                                  properties: Vec<(Atom, String)>)
-                                  -> DrawAPaintImageResult
-            {
+                                  properties: Vec<(Atom, String)>,
+                                  arguments: Vec<String>)
+                                  -> DrawAPaintImageResult {
                 let name = self.0.clone();
                 let (sender, receiver) = mpsc::channel();
-                let task = PaintWorkletTask::DrawAPaintImage(name, size, device_pixel_ratio, properties, sender);
+                let task = PaintWorkletTask::DrawAPaintImage(name,
+                                                             size,
+                                                             device_pixel_ratio,
+                                                             properties,
+                                                             arguments,
+                                                             sender);
                 self.1.lock().expect("Locking a painter.")
                     .schedule_a_worklet_task(WorkletTask::Paint(task));
                 receiver.recv().expect("Worklet thread died?")
@@ -296,7 +318,7 @@ impl PaintWorkletGlobalScopeMethods for PaintWorkletGlobalScope {
         let properties = property_names.drain(..).map(Atom::from).collect();
 
         // Step 7-9.
-        let _argument_names: Vec<String> =
+        let input_arguments: Vec<String> =
             unsafe { get_property(cx, paint_obj.handle(), "inputArguments", ()) }?
             .unwrap_or_default();
 
@@ -332,6 +354,7 @@ impl PaintWorkletGlobalScopeMethods for PaintWorkletGlobalScope {
         let definition = PaintDefinition::new(paint_val.handle(),
                                               paint_function.handle(),
                                               alpha,
+                                              input_arguments.len(),
                                               &*context);
 
         // Step 20.
@@ -356,6 +379,7 @@ pub enum PaintWorkletTask {
                     TypedSize2D<f32, CSSPixel>,
                     ScaleFactor<f32, CSSPixel, DevicePixel>,
                     Vec<(Atom, String)>,
+                    Vec<String>,
                     Sender<DrawAPaintImageResult>)
 }
 
@@ -370,6 +394,8 @@ struct PaintDefinition {
     paint_function: Heap<JSVal>,
     constructor_valid_flag: Cell<bool>,
     context_alpha_flag: bool,
+    // TODO: this should be a list of CSS syntaxes.
+    input_arguments_len: usize,
     // TODO: the spec calls for fresh rendering contexts each time a paint image is drawn,
     // but to avoid having the primary worklet thread create a new renering context,
     // we recycle them.
@@ -380,6 +406,7 @@ impl PaintDefinition {
     fn new(class_constructor: HandleValue,
            paint_function: HandleValue,
            alpha: bool,
+           input_arguments_len: usize,
            context: &PaintRenderingContext2D)
            -> Box<PaintDefinition>
     {
@@ -388,6 +415,7 @@ impl PaintDefinition {
             paint_function: Heap::default(),
             constructor_valid_flag: Cell::new(true),
             context_alpha_flag: alpha,
+            input_arguments_len: input_arguments_len,
             context: JS::from_ref(context),
         });
         result.class_constructor.set(class_constructor.get());

components/script_traits/lib.rs

@@ -822,7 +822,8 @@ pub trait Painter: Sync + Send {
     fn draw_a_paint_image(&self,
                           size: TypedSize2D<f32, CSSPixel>,
                           zoom: ScaleFactor<f32, CSSPixel, DevicePixel>,
-                          properties: Vec<(Atom, String)>)
+                          properties: Vec<(Atom, String)>,
+                          arguments: Vec<String>)
                           -> DrawAPaintImageResult;
 }
 

components/style/values/generics/image.rs

@@ -8,6 +8,7 @@
 
 use Atom;
 use cssparser::serialize_identifier;
+use custom_properties::SpecifiedValue;
 use std::fmt;
 use style_traits::{HasViewportPercentage, ToCss};
 use values::computed::ComputedValueAsSpecified;
@@ -136,17 +137,26 @@ pub struct ColorStop<Color, LengthOrPercentage> {
 
 /// Specified values for a paint worklet.
 /// https://drafts.css-houdini.org/css-paint-api/
-#[derive(Clone, Debug, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct PaintWorklet {
     /// The name the worklet was registered with.
     pub name: Atom,
+    /// The arguments for the worklet.
+    /// TODO: store a parsed representation of the arguments.
+    pub arguments: Vec<SpecifiedValue>,
 }
 
+impl ComputedValueAsSpecified for PaintWorklet {}
+
 impl ToCss for PaintWorklet {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
         dest.write_str("paint(")?;
         serialize_identifier(&*self.name.to_string(), dest)?;
+        for argument in &self.arguments {
+            dest.write_str(", ")?;
+            argument.to_css(dest)?;
+        }
         dest.write_str(")")
     }
 }

components/style/values/specified/image.rs

@@ -9,6 +9,7 @@
 
 use Atom;
 use cssparser::{Parser, Token, BasicParseError};
+use custom_properties::SpecifiedValue;
 use parser::{Parse, ParserContext};
 use selectors::parser::SelectorParseError;
 #[cfg(feature = "servo")]
@@ -874,12 +875,17 @@ impl Parse for ColorStop {
 }
 
 impl Parse for PaintWorklet {
-    fn parse<'i, 't>(_context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
+    fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         input.expect_function_matching("paint")?;
-        input.parse_nested_block(|i| {
-            let name = i.expect_ident()?;
+        input.parse_nested_block(|input| {
+            let name = Atom::from(&**input.expect_ident()?);
+            let arguments = input.try(|input| {
+                input.expect_comma()?;
+                input.parse_comma_separated(|input| Ok(*SpecifiedValue::parse(context, input)?))
+            }).unwrap_or(vec![]);
             Ok(PaintWorklet {
-                name: Atom::from(name.as_ref()),
+                name: name,
+                arguments: arguments,
             })
         })
     }