move navigation_type from Pipeline to FrameChange

src/components/main/compositing/compositor_layer.rs

@@ -339,7 +339,8 @@ impl CompositorLayer {
 
         // Add new tiles.
         let quadtree = match self.quadtree {
-            NoTree(_, _) => fail!("CompositorLayer: cannot get buffer request, no quadtree initialized"),
+            NoTree(_, _) => fail!("CompositorLayer: cannot get buffer request for %?,
+                                   no quadtree initialized", self.pipeline.id),
             Tree(ref mut quadtree) => quadtree,
         };
 
@@ -384,7 +385,8 @@ impl CompositorLayer {
         if self.pipeline.id == pipeline_id {
             { // block here to prevent double mutable borrow of self
                 let quadtree = match self.quadtree {
-                    NoTree(_, _) => fail!("CompositorLayer: cannot get buffer request, no quadtree initialized"),
+                    NoTree(_, _) => fail!("CompositorLayer: cannot get buffer request for %?,
+                                           no quadtree initialized", self.pipeline.id),
                     Tree(ref mut quadtree) => quadtree,
                 };
 

src/components/main/compositing/mod.rs

@@ -299,6 +299,7 @@ impl CompositorTask {
                     }
 
                     SetLayerPageSize(id, new_size) => {
+                        println(fmt!("Compositor: id %? sent new layer of size %?", id, new_size));
                         match compositor_layer {
                             Some(ref mut layer) => {
                                 let page_window = Size2D(window_size.width as f32 / world_zoom,

src/components/main/constellation.rs

@@ -15,7 +15,7 @@ use gfx::opts::Opts;
 use pipeline::Pipeline;
 use servo_msg::constellation_msg::{ConstellationChan, ExitMsg, FrameRectMsg};
 use servo_msg::constellation_msg::{InitLoadUrlMsg, LoadIframeUrlMsg, LoadUrlMsg};
-use servo_msg::constellation_msg::{Msg, NavigateMsg};
+use servo_msg::constellation_msg::{Msg, NavigateMsg, NavigationType};
 use servo_msg::constellation_msg::{PipelineId, RendererReadyMsg, ResizedWindowMsg, SubpageId};
 use servo_msg::constellation_msg;
 use script::script_task::{SendEventMsg, ResizeInactiveMsg, ExecuteMsg};
@@ -157,6 +157,9 @@ impl ChildFrameTree {
     }
 }
 
+/// An iterator over a frame tree, returning nodes in depth-first order.
+/// Note that this iterator should _not_ be used to mutate nodes _during_
+/// iteration. Mutating nodes once the iterator is out of scope is OK.
 pub struct FrameTreeIterator {
     priv stack: ~[@mut FrameTree],
 }
@@ -165,7 +168,7 @@ impl Iterator<@mut FrameTree> for FrameTreeIterator {
     fn next(&mut self) -> Option<@mut FrameTree> {
         if !self.stack.is_empty() {
             let next = self.stack.pop();
-            for &ChildFrameTree { frame_tree, _ } in next.children.iter() {
+            for &ChildFrameTree { frame_tree, _ } in next.children.rev_iter() {
                 self.stack.push(frame_tree);
             }
             Some(next)
@@ -179,6 +182,7 @@ impl Iterator<@mut FrameTree> for FrameTreeIterator {
 struct FrameChange {
     before: Option<PipelineId>,
     after: @mut FrameTree,
+    navigation_type: NavigationType,
 }
 
 /// Stores the Id's of the pipelines previous and next in the browser's history
@@ -380,7 +384,7 @@ impl Constellation {
         if url.path.ends_with(".js") {
             pipeline.script_chan.send(ExecuteMsg(pipeline.id, url));
         } else {
-            pipeline.load(url, Some(constellation_msg::Load));
+            pipeline.load(url);
 
             self.pending_frames.push(FrameChange{
                 before: None,
@@ -389,6 +393,7 @@ impl Constellation {
                     parent: None,
                     children: ~[],
                 },
+                navigation_type: constellation_msg::Load,
             });
         }
         self.pipelines.insert(pipeline.id, pipeline);
@@ -518,7 +523,7 @@ impl Constellation {
         if url.path.ends_with(".js") {
             pipeline.execute(url);
         } else {
-            pipeline.load(url, None);
+            pipeline.load(url);
         }
         let rect = self.pending_sizes.pop(&(source_pipeline_id, subpage_id));
         for frame_tree in frame_trees.iter() {
@@ -574,7 +579,7 @@ impl Constellation {
         if url.path.ends_with(".js") {
             pipeline.script_chan.send(ExecuteMsg(pipeline.id, url));
         } else {
-            pipeline.load(url, Some(constellation_msg::Load));
+            pipeline.load(url);
 
             self.pending_frames.push(FrameChange{
                 before: Some(source_id),
@@ -583,6 +588,7 @@ impl Constellation {
                     parent: parent,
                     children: ~[],
                 },
+                navigation_type: constellation_msg::Load,
             });
         }
         self.pipelines.insert(pipeline.id, pipeline);
@@ -624,9 +630,9 @@ impl Constellation {
 
         for frame in destination_frame.iter() {
             let pipeline = &frame.pipeline;
-            pipeline.reload(Some(constellation_msg::Navigate));
+            pipeline.reload();
         }
-        self.grant_paint_permission(destination_frame);
+        self.grant_paint_permission(destination_frame, constellation_msg::Navigate);
 
     }
 
@@ -640,8 +646,6 @@ impl Constellation {
             // TODO(tkuehn): In fact, this kind of message might be provably
             // impossible to occur.
             if current_frame.contains(pipeline_id) {
-                debug!("updating compositor frame tree with %?", current_frame);
-                self.set_ids(current_frame);
                 return;
             }
         }
@@ -701,7 +705,7 @@ impl Constellation {
                     }
                 }
             }
-        self.grant_paint_permission(next_frame_tree);
+        self.grant_paint_permission(next_frame_tree, frame_change.navigation_type);
         }
     }
 
@@ -713,8 +717,9 @@ impl Constellation {
                                                    ResizeEvent(width, height)));
             already_seen.insert(pipeline.id.clone());
         }
-        for &@FrameTree { pipeline: ref pipeline, _ } in self.navigation_context.previous.iter()
+        for frame_tree in self.navigation_context.previous.iter()
             .chain(self.navigation_context.next.iter()) {
+            let pipeline = &frame_tree.pipeline;
             if !already_seen.contains(&pipeline.id) {
                 pipeline.script_chan.send(ResizeInactiveMsg(pipeline.id.clone(), new_size));
                 already_seen.insert(pipeline.id.clone());
@@ -723,14 +728,14 @@ impl Constellation {
     }
 
     // Grants a frame tree permission to paint; optionally updates navigation to reflect a new page
-    fn grant_paint_permission(&mut self, frame_tree: @mut FrameTree) {
+    fn grant_paint_permission(&mut self, frame_tree: @mut FrameTree, navigation_type: NavigationType) {
         // Give permission to paint to the new frame and all child frames
         self.set_ids(frame_tree);
 
         // Don't call navigation_context.load() on a Navigate type (or None, as in the case of
         // parsed iframes that finish loading)
-        match frame_tree.pipeline.navigation_type {
-            Some(constellation_msg::Load) => {
+        match navigation_type {
+            constellation_msg::Load => {
                 let evicted = self.navigation_context.load(frame_tree);
                 for frame_tree in evicted.iter() {
                     // exit any pipelines that don't exist outside the evicted frame trees

src/components/main/pipeline.rs

@@ -11,7 +11,7 @@ use gfx::opts::Opts;
 use layout::layout_task::LayoutTask;
 use script::layout_interface::LayoutChan;
 use script::script_task::{ExecuteMsg, LoadMsg};
-use servo_msg::constellation_msg::{ConstellationChan, NavigationType, PipelineId, SubpageId};
+use servo_msg::constellation_msg::{ConstellationChan, PipelineId, SubpageId};
 use script::script_task::{AttachLayoutMsg, NewLayoutInfo, ScriptTask, ScriptChan};
 use script::script_task;
 use servo_net::image_cache_task::ImageCacheTask;
@@ -31,7 +31,6 @@ pub struct Pipeline {
     render_chan: RenderChan,
     /// The most recently loaded url
     url: Option<Url>,
-    navigation_type: Option<NavigationType>,
 }
 
 impl Pipeline {
@@ -140,13 +139,11 @@ impl Pipeline {
             layout_chan: layout_chan,
             render_chan: render_chan,
             url: None,
-            navigation_type: None,
         }
     }
 
-    pub fn load(&mut self, url: Url, navigation_type: Option<NavigationType>) {
+    pub fn load(&mut self, url: Url) {
         self.url = Some(url.clone());
-        self.navigation_type = navigation_type;
         self.script_chan.send(LoadMsg(self.id, url));
     }
 
@@ -163,11 +160,10 @@ impl Pipeline {
         self.render_chan.send(PaintPermissionRevoked);
     }
 
-    pub fn reload(&mut self, navigation_type: Option<NavigationType>) {
-        if self.url.is_some() {
-            let url = self.url.get_ref().clone();
-            self.load(url, navigation_type);
-        }
+    pub fn reload(&mut self) {
+        do self.url.clone().map_consume() |url| {
+            self.load(url);
+        };
     }
 
     pub fn exit(&self) {