De-duplicate shadow item code.

webrender/src/display_list_flattener.rs

@@ -1,4 +1,3 @@
-
 /* 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/. */
@@ -1791,42 +1790,10 @@ impl<'a> DisplayListFlattener<'a> {
                         match item {
                             // TODO(djg): ugh. de-duplicate this code.
                             ShadowItem::Primitive(ref pending_primitive) => {
-                                // Offset the local rect and clip rect by the shadow offset.
-                                let mut info = pending_primitive.info.clone();
-                                info.rect = info.rect.translate(&pending_shadow.shadow.offset);
-                                info.clip_rect = info.clip_rect.translate(&pending_shadow.shadow.offset);
-
-                                // Construct and add a primitive for the given shadow.
-                                let shadow_prim_instance = self.create_primitive(
-                                    &info,
-                                    pending_primitive.clip_and_scroll.clip_chain_id,
-                                    pending_primitive.clip_and_scroll.spatial_node_index,
-                                    pending_primitive.prim.create_shadow(
-                                        &pending_shadow.shadow,
-                                    ),
-                                );
-
-                                // Add the new primitive to the shadow picture.
-                                prims.push(shadow_prim_instance);
+                                self.add_shadow_prim(&pending_shadow, pending_primitive, &mut prims)
                             }
                             ShadowItem::TextRun(ref pending_text_run) => {
-                                // Offset the local rect and clip rect by the shadow offset.
-                                let mut info = pending_text_run.info.clone();
-                                info.rect = info.rect.translate(&pending_shadow.shadow.offset);
-                                info.clip_rect = info.clip_rect.translate(&pending_shadow.shadow.offset);
-
-                                // Construct and add a primitive for the given shadow.
-                                let shadow_prim_instance = self.create_primitive(
-                                        &info,
-                                        pending_text_run.clip_and_scroll.clip_chain_id,
-                                        pending_text_run.clip_and_scroll.spatial_node_index,
-                                        pending_text_run.prim.create_shadow(
-                                            &pending_shadow.shadow,
-                                        ),
-                                );
-
-                                // Add the new primitive to the shadow picture.
-                                prims.push(shadow_prim_instance);
+                                self.add_shadow_prim(&pending_shadow, pending_text_run, &mut prims)
                             }
                             _ => {}
                         }
@@ -1893,31 +1860,10 @@ impl<'a> DisplayListFlattener<'a> {
                     }
                 }
                 ShadowItem::Primitive(pending_primitive) => {
-                    // For a normal primitive, if it has alpha > 0, then we add this
-                    // as a normal primitive to the parent picture.
-                    if pending_primitive.prim.is_visible() {
-                        self.add_prim_to_draw_list(
-                            &pending_primitive.info,
-                            pending_primitive.clip_and_scroll.clip_chain_id,
-                            pending_primitive.clip_and_scroll,
-                            pending_primitive.prim,
-                        );
-                    }
+                    self.add_shadow_prim_to_draw_list(pending_primitive)
                 },
                 ShadowItem::TextRun(pending_text_run) => {
-                    // For a normal primitive, if it has alpha > 0, then we add this
-                    // as a normal primitive to the parent picture.
-                    //
-                    // TODO(djg): Can this be cleaned up?  It looks identical to
-                    // another piece of code.
-                    if pending_text_run.prim.is_visible() {
-                        self.add_prim_to_draw_list(
-                            &pending_text_run.info,
-                            pending_text_run.clip_and_scroll.clip_chain_id,
-                            pending_text_run.clip_and_scroll,
-                            pending_text_run.prim,
-                        );
-                    }
+                    self.add_shadow_prim_to_draw_list(pending_text_run)
                 },
             }
         }
@@ -1926,6 +1872,54 @@ impl<'a> DisplayListFlattener<'a> {
         self.pending_shadow_items = items;
     }
 
+    fn add_shadow_prim<P>(
+        &mut self,
+        pending_shadow: &PendingShadow,
+        pending_primitive: &PendingPrimitive<P>,
+        prims: &mut Vec<PrimitiveInstance>,
+    )
+    where
+        P: Internable<InternData=PrimitiveSceneData> + CreateShadow,
+        P::Source: AsInstanceKind<Handle<P::Marker>> + BuildKey<P>,
+        DocumentResources: InternerMut<P>,
+    {
+        // Offset the local rect and clip rect by the shadow offset.
+        let mut info = pending_primitive.info.clone();
+        info.rect = info.rect.translate(&pending_shadow.shadow.offset);
+        info.clip_rect = info.clip_rect.translate(&pending_shadow.shadow.offset);
+
+        // Construct and add a primitive for the given shadow.
+        let shadow_prim_instance = self.create_primitive(
+            &info,
+            pending_primitive.clip_and_scroll.clip_chain_id,
+            pending_primitive.clip_and_scroll.spatial_node_index,
+            pending_primitive.prim.create_shadow(
+                &pending_shadow.shadow,
+            ),
+        );
+
+        // Add the new primitive to the shadow picture.
+        prims.push(shadow_prim_instance);
+    }
+
+    fn add_shadow_prim_to_draw_list<P>(&mut self, pending_primitive: PendingPrimitive<P>)
+    where
+        P: Internable<InternData = PrimitiveSceneData> + IsVisible,
+        P::Source: AsInstanceKind<Handle<P::Marker>> + BuildKey<P>,
+        DocumentResources: InternerMut<P>,
+    {
+        // For a normal primitive, if it has alpha > 0, then we add this
+        // as a normal primitive to the parent picture.
+        if pending_primitive.prim.is_visible() {
+            self.add_prim_to_draw_list(
+                &pending_primitive.info,
+                pending_primitive.clip_and_scroll.clip_chain_id,
+                pending_primitive.clip_and_scroll,
+                pending_primitive.prim,
+            );
+        }
+    }
+
     #[cfg(debug_assertions)]
     fn register_chase_primitive_by_rect(
         &mut self,

webrender/src/prim_store/mod.rs

@@ -16,7 +16,7 @@ use border::{BorderSegmentCacheKey, NormalBorderAu};
 use clip::{ClipStore};
 use clip_scroll_tree::{ClipScrollTree, SpatialNodeIndex};
 use clip::{ClipDataStore, ClipNodeFlags, ClipChainId, ClipChainInstance, ClipItem, ClipNodeCollector};
-use display_list_flattener::{AsInstanceKind, BuildKey, IsVisible};
+use display_list_flattener::{AsInstanceKind, BuildKey, CreateShadow, IsVisible};
 use euclid::{SideOffsets2D, TypedTransform3D, TypedRect, TypedScale, TypedSize2D};
 use frame_builder::{FrameBuildingContext, FrameBuildingState, PictureContext, PictureState};
 use frame_builder::PrimitiveContext;
@@ -2122,11 +2122,11 @@ impl IsVisible for PrimitiveKeyKind {
     }
 }
 
-impl PrimitiveKeyKind {
+impl CreateShadow for PrimitiveKeyKind {
     // Create a clone of this PrimitiveContainer, applying whatever
     // changes are necessary to the primitive to support rendering
     // it as part of the supplied shadow.
-    pub fn create_shadow(
+    fn create_shadow(
         &self,
         shadow: &Shadow,
     ) -> PrimitiveKeyKind {