servo: Load images through the image cache

Source-Repo: https://github.com/servo/servo
Source-Revision: 38321d9b70c9822063d6f6c34f9efd9a573d2c65

servo/src/servo/content.rs

@@ -84,6 +84,7 @@ class Content<S:Sink send copy> {
     let jsrt: jsrt;
 
     let mut document: option<@Document>;
+    let mut doc_url: option<url>;
 
     let resource_task: ResourceTask;
 
@@ -97,6 +98,7 @@ class Content<S:Sink send copy> {
         self.jsrt = jsrt();
 
         self.document = none;
+        self.doc_url = none;
 
         self.sink.add_event_listener(self.event_port.chan());
 
@@ -135,8 +137,9 @@ class Content<S:Sink send copy> {
             #debug["%?", js_scripts];
 
             let document = Document(root, css_rules);
-            self.relayout(document);
+            self.relayout(document, &url);
             self.document = some(@document);
+            self.doc_url = some(copy url);
 
             //XXXjdm it was easier to duplicate the relevant ExecuteMsg code;
             //       they should be merged somehow in the future.
@@ -181,7 +184,7 @@ class Content<S:Sink send copy> {
         }
     }
 
-    fn relayout(document: Document) {
+    fn relayout(document: Document, doc_url: &url) {
         #debug("content: performing relayout");
 
         // Now, join the layout so that they will see the latest
@@ -190,7 +193,7 @@ class Content<S:Sink send copy> {
 
         // Send new document and relevant styles to layout
         // FIXME: Put CSS rules in an arc or something.
-        self.layout.send(BuildMsg(document.root, clone(&document.css_rules)));
+        self.layout.send(BuildMsg(document.root, clone(&document.css_rules), copy *doc_url));
 
         // Indicate that reader was forked so any further
         // changes will be isolated.
@@ -206,7 +209,8 @@ class Content<S:Sink send copy> {
                     // Nothing to do.
                 }
                 some(document) => {
-                    self.relayout(*document);
+                    assert self.doc_url.is_some();
+                    self.relayout(*document, &self.doc_url.get());
                 }
             }
             return true;

servo/src/servo/layout/base.rs

@@ -16,7 +16,10 @@ import text::TextBox;
 import traverse::extended_full_traversal;
 import style::style::{SpecifiedStyle};
 import vec::{push, push_all};
-
+import std::net::url::url;
+import resource::image_cache_task;
+import image_cache_task::ImageCacheTask;
+import core::to_str::to_str;
 import arc::{arc, clone};
 
 enum BoxKind {
@@ -51,7 +54,7 @@ class Appearance {
             let mut temp = none;
             temp <-> self.background_image;
             let holder <- option::unwrap(temp);
-            image = some(holder.get_image());
+            image = holder.get_image();
             self.background_image = some(holder);
         }
 
@@ -81,16 +84,21 @@ class Box {
 class ImageHolder {
     // Invariant: at least one of url and image is not none, except
     // occasionally while get_image is being called
-    let mut url : option<~str>;
+    let mut url : option<url>;
     let mut image : option<arc<~Image>>;
+    let image_cache_task: ImageCacheTask;
 
-    new(-url : ~str) {
-        self.url = some(url);
+    new(-url : url, image_cache_task: ImageCacheTask) {
+        self.url = some(copy url);
         self.image = none;
+        self.image_cache_task = image_cache_task;
+
+        // Tell the image cache we're going to be interested in this url
+        image_cache_task.send(image_cache_task::Prefetch(move url));
     }
 
     // This function should not be called by two tasks at the same time
-    fn get_image() -> ~arc<~Image> {
+    fn get_image() -> option<~arc<~Image>> {
         // If this is the first time we've called this function, load
         // the image and store it for the future
         if self.image.is_none() {
@@ -99,11 +107,20 @@ class ImageHolder {
             let mut temp = none;
             temp <-> self.url;
             let url = option::unwrap(temp);
-            let image = load(url);
 
-            self.image = some(arc(~image));
+            let response_port = port();
+            self.image_cache_task.send(image_cache_task::GetImage(copy url, response_port.chan()));
+            self.image = match response_port.recv() {
+              image_cache_task::ImageReady(image) => some(clone(&image)),
+              image_cache_task::ImageNotReady => {
+                #info("image was not ready for %s", url.to_str());
+                // FIXME: Need to schedule another layout when the image is ready
+                none
+              }
+            };
         }
 
+        if self.image.is_some() {
             // Temporarily swap out the arc of the image so we can clone
             // it without breaking purity, then put it back and return the
             // clone.  This is not threadsafe.
@@ -112,7 +129,10 @@ class ImageHolder {
             let im_arc = option::unwrap(temp);
             self.image = some(clone(&im_arc));
 
-        return ~im_arc;
+            return some(~im_arc);
+        } else {
+            return none;
+        }
     }
 }
 

servo/src/servo/layout/layout_task.rs

@@ -10,6 +10,8 @@ import dom::style::Stylesheet;
 import gfx::geometry::px_to_au;
 import gfx::renderer::Renderer;
 import resource::image_cache_task::ImageCacheTask;
+import std::net::url::url;
+import style::apply::apply_style;
 
 import task::*;
 import comm::*;
@@ -17,12 +19,12 @@ import comm::*;
 type Layout = chan<Msg>;
 
 enum Msg {
-    BuildMsg(Node, arc<Stylesheet>),
+    BuildMsg(Node, arc<Stylesheet>, url),
     PingMsg(chan<content::PingMsg>),
     ExitMsg
 }
 
-fn Layout(renderer: Renderer, _image_cache_task: ImageCacheTask) -> Layout {
+fn Layout(renderer: Renderer, image_cache_task: ImageCacheTask) -> Layout {
     do spawn_listener::<Msg>|request| {
         loop {
             match request.recv() {
@@ -31,7 +33,7 @@ fn Layout(renderer: Renderer, _image_cache_task: ImageCacheTask) -> Layout {
                 #debug("layout: ExitMsg received");
                 break;
               }
-              BuildMsg(node, styles) => {
+              BuildMsg(node, styles, doc_url) => {
                 #debug("layout: received layout request for:");
                 node.dump();
 
@@ -42,7 +44,8 @@ fn Layout(renderer: Renderer, _image_cache_task: ImageCacheTask) -> Layout {
                     let this_box = node.construct_boxes();
                     this_box.dump();
 
-                    this_box.apply_css_style();
+                    apply_style(this_box, &doc_url, image_cache_task);
+
                     this_box.reflow_subtree(px_to_au(800));
 
                     let dlist = build_display_list(this_box);

servo/src/servo/layout/style/apply.rs

@@ -7,16 +7,34 @@ import image::base::load;
 import base::{Box, BTree, NTree, LayoutData, SpecifiedStyle, ImageHolder,
               BlockBox, InlineBox, IntrinsicBox, TextBox};
 import traverse::{top_down_traversal};
+import std::net::url::url;
+import resource::image_cache_task::ImageCacheTask;
 
-trait ApplyStyleBoxMethods {
-    fn apply_css_style();
-    fn apply_style();
+struct StyleApplicator {
+    box: @Box;
+    doc_url: &url;
+    image_cache_task: ImageCacheTask;
+}
+
+fn apply_style(box: @Box, doc_url: &url, image_cache_task: ImageCacheTask) {
+    let applicator = StyleApplicator {
+        box: box,
+        doc_url: doc_url,
+        image_cache_task: image_cache_task
+    };
+
+    applicator.apply_css_style();
 }
 
 #[doc="A wrapper around a set of functions that can be applied as a top-down traversal of layout
        boxes."]
-fn inheritance_wrapper(box : @Box) {
-    box.apply_style();
+fn inheritance_wrapper(box : @Box, doc_url: &url, image_cache_task: ImageCacheTask) {
+    let applicator = StyleApplicator {
+        box: box,
+        doc_url: doc_url,
+        image_cache_task: image_cache_task
+    };
+    applicator.apply_style();
     inhereit_height(box);
     inhereit_width(box);
 }
@@ -81,9 +99,13 @@ fn inhereit_width(box : @Box) {
     }
 }
 
-impl @Box : ApplyStyleBoxMethods {
+impl StyleApplicator {
     fn apply_css_style() {
-        top_down_traversal(self, inheritance_wrapper);
+        let doc_url = copy *self.doc_url;
+        let image_cache_task = self.image_cache_task;
+        do top_down_traversal(self.box) |box, move doc_url| {
+            inheritance_wrapper(box, &doc_url, image_cache_task);
+        }
     }
 
     #[doc="Applies CSS style to a layout box.
@@ -94,13 +116,14 @@ impl @Box : ApplyStyleBoxMethods {
 
      "]
     fn apply_style() {
+
         // Right now, we only handle images.
-        do self.node.read |node| {
+        do self.box.node.read |node| {
             match node.kind {
               ~Element(element) => {
-                let style = self.node.get_specified_style();
+                let style = self.box.node.get_specified_style();
 
-                self.appearance.background_color = match style.background_color {
+                self.box.appearance.background_color = match style.background_color {
                   some(col) => col,
                   none => node.kind.default_color()
                 };
@@ -112,7 +135,8 @@ impl @Box : ApplyStyleBoxMethods {
                     if url.is_some() {
                         // FIXME: Some sort of BASE HREF support!
                         // FIXME: Parse URLs!
-                        self.appearance.background_image = some(ImageHolder(option::unwrap(url)))
+                        let new_url = make_url(option::unwrap(url), some(copy *self.doc_url));
+                        self.box.appearance.background_image = some(ImageHolder(new_url, self.image_cache_task))
                     };
                   }
                   _ => { /* Ignore. */ }