auto merge of #3837 : pcwalton/servo/layout-formatting-cleanups, r=metajack

These should have no effect on functionality.

r? @metajack

components/layout/block.rs

@@ -436,7 +436,7 @@ impl<'a> PreorderFlowTraversal for AbsoluteAssignBSizesTraversal<'a> {
         }
 
         let AbsoluteAssignBSizesTraversal(ref ctx) = *self;
-        block_flow.calculate_abs_block_size_and_margins(*ctx);
+        block_flow.calculate_absolute_block_size_and_margins(*ctx);
     }
 }
 
@@ -631,7 +631,7 @@ impl BlockFlow {
         }
     }
 
-    /// Compute the used value of inline-size for this Block.
+    /// Compute the actual inline size and position for this block.
     pub fn compute_used_inline_size(&mut self,
                                     ctx: &LayoutContext,
                                     containing_block_inline_size: Au) {
@@ -686,7 +686,7 @@ impl BlockFlow {
     /// reference the CB.
     #[inline]
     pub fn containing_block_size(&mut self, viewport_size: Size2D<Au>) -> LogicalSize<Au> {
-        assert!(self.is_absolutely_positioned());
+        debug_assert!(self.is_absolutely_positioned());
         if self.is_fixed() {
             // Initial containing block is the CB for the root
             LogicalSize::from_physical(self.base.writing_mode, viewport_size)
@@ -1062,6 +1062,7 @@ impl BlockFlow {
         let margin_offset = LogicalPoint::new(writing_mode,
                                               Au(0),
                                               self.fragment.margin.block_start);
+
         self.base.position = self.base.position.translate(&float_offset).translate(&margin_offset);
     }
 
@@ -1071,9 +1072,9 @@ impl BlockFlow {
     /// The layout for its in-flow children has been done during normal layout.
     /// This is just the calculation of:
     /// + block-size for the flow
-    /// + y-coordinate of the flow wrt its Containing Block.
+    /// + position in the block direction of the flow with respect to its Containing Block.
     /// + block-size, vertical margins, and y-coordinate for the flow's box.
-    fn calculate_abs_block_size_and_margins(&mut self, ctx: &LayoutContext) {
+    fn calculate_absolute_block_size_and_margins(&mut self, ctx: &LayoutContext) {
         let containing_block_block_size = self.containing_block_size(ctx.shared.screen_size).block;
         let static_b_offset = self.static_b_offset;
 
@@ -1098,11 +1099,13 @@ impl BlockFlow {
             let block_end;
             {
                 let position = self.fragment.style().logical_position();
-                block_start = MaybeAuto::from_style(position.block_start, containing_block_block_size);
+                block_start = MaybeAuto::from_style(position.block_start,
+                                                    containing_block_block_size);
                 block_end = MaybeAuto::from_style(position.block_end, containing_block_block_size);
             }
 
-            let available_block_size = containing_block_block_size - self.fragment.border_padding.block_start_end();
+            let available_block_size = containing_block_block_size -
+                self.fragment.border_padding.block_start_end();
             if self.is_replaced_content() {
                 // Calculate used value of block-size just like we do for inline replaced elements.
                 // TODO: Pass in the containing block block-size when Fragment's
@@ -1348,6 +1351,8 @@ impl BlockFlow {
     /// on the floats we could see at the time of inline-size assignment. The job of this function,
     /// therefore, is not only to assign the final size but also to perform the layout again for
     /// this block formatting context if our speculation was wrong.
+    ///
+    /// FIXME(pcwalton): This code is not incremental-reflow-safe (i.e. not idempotent).
     fn assign_inline_position_for_formatting_context(&mut self) {
         debug_assert!(self.formatting_context_type() != NonformattingContext);
 
@@ -1611,16 +1616,15 @@ impl Flow for BlockFlow {
         }
 
         if self.is_absolutely_positioned() {
-            let position_start = self.base.position.start.to_physical(
-                self.base.writing_mode, container_size);
-            self.base
-                .absolute_position_info
-                .absolute_containing_block_position = if self.is_fixed() {
+            let position_start = self.base.position.start.to_physical(self.base.writing_mode,
+                                                                      container_size);
+            self.base.absolute_position_info.absolute_containing_block_position =
+                if self.is_fixed() {
                     // The viewport is initially at (0, 0).
                     position_start
                 } else {
-                // Absolute position of the containing block + position of absolute flow w/r/t the
-                // containing block.
+                    // Absolute position of the containing block + position of absolute
+                    // flow w.r.t. the containing block.
                     self.base.absolute_position_info.absolute_containing_block_position
                         + position_start
                 };
@@ -1957,16 +1961,14 @@ pub trait ISizeAndMarginsComputer {
     /// CSS Section 10.4: Minimum and Maximum inline-sizes
     fn compute_used_inline_size(&self,
                                 block: &mut BlockFlow,
-                                ctx: &LayoutContext,
+                                layout_context: &LayoutContext,
                                 parent_flow_inline_size: Au) {
         let mut input = self.compute_inline_size_constraint_inputs(block,
                                                                    parent_flow_inline_size,
-                                                                   ctx);
+                                                                   layout_context);
 
-        let containing_block_inline_size = self.containing_block_inline_size(
-            block,
-            parent_flow_inline_size,
-            ctx);
+        let containing_block_inline_size =
+            self.containing_block_inline_size(block, parent_flow_inline_size, layout_context);
 
         let mut solution = self.solve_inline_size_constraints(block, &input);
 

components/layout/construct.rs

@@ -1192,11 +1192,11 @@ pub trait FlowConstructionUtils {
     fn add_new_child(&mut self, new_child: FlowRef);
 
     /// Finishes a flow. Once a flow is finished, no more child flows or boxes may be added to it.
-    /// This will normally run the bubble-inline-sizes (minimum and preferred -- i.e. intrinsic -- inline-size)
-    /// calculation, unless the global `bubble_inline-sizes_separately` flag is on.
+    /// This will normally run the bubble-inline-sizes (minimum and preferred -- i.e. intrinsic --
+    /// inline-size) calculation, unless the global `bubble_inline-sizes_separately` flag is on.
     ///
-    /// All flows must be finished at some point, or they will not have their intrinsic inline-sizes
-    /// properly computed. (This is not, however, a memory safety problem.)
+    /// All flows must be finished at some point, or they will not have their intrinsic inline-
+    /// sizes properly computed. (This is not, however, a memory safety problem.)
     fn finish(&mut self);
 }
 
@@ -1217,8 +1217,8 @@ impl FlowConstructionUtils for FlowRef {
     }
 
     /// Finishes a flow. Once a flow is finished, no more child flows or fragments may be added to
-    /// it. This will normally run the bubble-inline-sizes (minimum and preferred -- i.e. intrinsic --
-    /// inline-size) calculation, unless the global `bubble_inline-sizes_separately` flag is on.
+    /// it. This will normally run the bubble-inline-sizes (minimum and preferred -- i.e. intrinsic
+    /// -- inline-size) calculation, unless the global `bubble_inline-sizes_separately` flag is on.
     ///
     /// All flows must be finished at some point, or they will not have their intrinsic inline-sizes
     /// properly computed. (This is not, however, a memory safety problem.)

components/layout/css/matching.rs

@@ -2,7 +2,7 @@
  * 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/. */
 
-// High-level interface to CSS selector matching.
+//! High-level interface to CSS selector matching.
 
 use css::node_style::StyledNode;
 use util::{LayoutDataAccess, LayoutDataWrapper};

components/layout/css/node_util.rs

@@ -6,6 +6,7 @@ use incremental::RestyleDamage;
 use util::LayoutDataAccess;
 use wrapper::ThreadSafeLayoutNode;
 use wrapper::{After, Before, Normal};
+
 use std::mem;
 use style::ComputedValues;
 use sync::Arc;

components/layout/floats.rs

@@ -216,7 +216,7 @@ impl Floats {
         let mut r_block_start = None;
         let mut r_block_end = None;
 
-        // Find the float collisions for the given vertical range.
+        // Find the float collisions for the given range in the block direction.
         for float in list.floats.iter() {
             debug!("available_rect: Checking for collision against float");
             let float_pos = float.bounds.start;

components/layout/flow.rs

@@ -765,10 +765,11 @@ pub struct BaseFlow {
     /// Any layers that we're bubbling up, in a linked list.
     pub layers: DList<RenderLayer>,
 
+    /// The writing mode for this flow.
+    pub writing_mode: WritingMode,
+
     /// Various flags for flows, tightly packed to save space.
     pub flags: FlowFlags,
-
-    pub writing_mode: WritingMode,
 }
 
 impl fmt::Show for BaseFlow {
@@ -824,9 +825,7 @@ impl BaseFlow {
             intrinsic_inline_sizes: IntrinsicISizes::new(),
             position: LogicalRect::zero(writing_mode),
             overflow: LogicalRect::zero(writing_mode),
-
             parallel: FlowParallelInfo::new(),
-
             floats: Floats::new(writing_mode),
             collapsible_margins: CollapsibleMargins::new(),
             abs_position: Zero::zero(),

components/layout/layout_task.rs

@@ -250,7 +250,8 @@ impl LayoutTask {
            font_cache_task: FontCacheTask,
            time_profiler_chan: TimeProfilerChan)
            -> LayoutTask {
-        let local_image_cache = Arc::new(Mutex::new(LocalImageCache::new(image_cache_task.clone())));
+        let local_image_cache =
+            Arc::new(Mutex::new(LocalImageCache::new(image_cache_task.clone())));
         let screen_size = Size2D(Au(0), Au(0));
         let device = Device::new(Screen, opts::get().initial_window_size.as_f32());
         let parallel_traversal = if opts::get().layout_threads != 1 {
@@ -297,8 +298,7 @@ impl LayoutTask {
     }
 
     // Create a layout context for use in building display lists, hit testing, &c.
-    fn build_shared_layout_context(
-      &self,
+    fn build_shared_layout_context(&self,
                                    rw_data: &LayoutTaskData,
                                    reflow_root: &LayoutNode,
                                    url: &Url)
@@ -318,7 +318,9 @@ impl LayoutTask {
     }
 
     /// Receives and dispatches messages from the script and constellation tasks
-    fn handle_request<'a>(&'a self, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) -> bool {
+    fn handle_request<'a>(&'a self,
+                          possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>)
+                          -> bool {
         enum PortToRead {
             Pipeline,
             Script,
@@ -343,8 +345,12 @@ impl LayoutTask {
         };
 
         match port_to_read {
-            Pipeline => match self.pipeline_port.recv() {
-                layout_traits::ExitNowMsg => self.handle_script_request(ExitNowMsg, possibly_locked_rw_data),
+            Pipeline => {
+                match self.pipeline_port.recv() {
+                    layout_traits::ExitNowMsg => {
+                        self.handle_script_request(ExitNowMsg, possibly_locked_rw_data)
+                    }
+                }
             },
             Script => {
                 let msg = self.port.recv();
@@ -359,17 +365,20 @@ impl LayoutTask {
     /// If you do not wish RPCs to remain blocked, just drop the `RWGuard`
     /// returned from this function. If you _do_ wish for them to remain blocked,
     /// use `return_rw_data`.
-    fn lock_rw_data<'a>(&'a self, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) -> RWGuard<'a> {
+    fn lock_rw_data<'a>(&'a self,
+                        possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>)
+                        -> RWGuard<'a> {
         match possibly_locked_rw_data.take() {
             None    => Used(self.rw_data.lock()),
             Some(x) => Held(x),
         }
     }
 
-    /// If no reflow has ever been trigger, this will keep the lock, locked
+    /// If no reflow has ever been triggered, this will keep the lock, locked
     /// (and saved in `possibly_locked_rw_data`). If it has been, the lock will
     /// be unlocked.
-    fn return_rw_data<'a>(possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>, rw_data: RWGuard<'a>) {
+    fn return_rw_data<'a>(possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>,
+                          rw_data: RWGuard<'a>) {
         match rw_data {
             Used(x) => drop(x),
             Held(x) => *possibly_locked_rw_data = Some(x),
@@ -377,20 +386,23 @@ impl LayoutTask {
     }
 
     /// Receives and dispatches messages from the script task.
-    fn handle_script_request<'a>(&'a self, request: Msg, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) -> bool {
+    fn handle_script_request<'a>(&'a self,
+                                 request: Msg,
+                                 possibly_locked_rw_data: &mut Option<MutexGuard<'a,
+                                                                                 LayoutTaskData>>)
+                                 -> bool {
         match request {
             AddStylesheetMsg(sheet) => self.handle_add_stylesheet(sheet, possibly_locked_rw_data),
             LoadStylesheetMsg(url) => self.handle_load_stylesheet(url, possibly_locked_rw_data),
             GetRPCMsg(response_chan) => {
-                response_chan.send(
-                    box LayoutRPCImpl(
-                        self.rw_data.clone()) as Box<LayoutRPC + Send>);
+                response_chan.send(box LayoutRPCImpl(self.rw_data.clone()) as
+                                   Box<LayoutRPC + Send>);
             },
             ReflowMsg(data) => {
-                profile(time::LayoutPerformCategory, Some((&data.url, data.iframe, self.first_reflow.get())),
-                self.time_profiler_chan.clone(), || {
-                    self.handle_reflow(&*data, possibly_locked_rw_data);
-                });
+                profile(time::LayoutPerformCategory,
+                        Some((&data.url, data.iframe, self.first_reflow.get())),
+                        self.time_profiler_chan.clone(),
+                        || self.handle_reflow(&*data, possibly_locked_rw_data));
             },
             ReapLayoutDataMsg(dead_layout_data) => {
                 unsafe {
@@ -415,7 +427,9 @@ impl LayoutTask {
     /// Enters a quiescent state in which no new messages except for `ReapLayoutDataMsg` will be
     /// processed until an `ExitNowMsg` is received. A pong is immediately sent on the given
     /// response channel.
-    fn prepare_to_exit<'a>(&'a self, response_chan: Sender<()>, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
+    fn prepare_to_exit<'a>(&'a self,
+                           response_chan: Sender<()>,
+                           possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
         response_chan.send(());
         loop {
             match self.port.recv() {
@@ -455,7 +469,10 @@ impl LayoutTask {
         response_port.recv()
     }
 
-    fn handle_load_stylesheet<'a>(&'a self, url: Url, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
+    fn handle_load_stylesheet<'a>(&'a self,
+                                  url: Url,
+                                  possibly_locked_rw_data:
+                                    &mut Option<MutexGuard<'a, LayoutTaskData>>) {
         // TODO: Get the actual value. http://dev.w3.org/csswg/css-syntax/#environment-encoding
         let environment_encoding = UTF_8 as EncodingRef;
 
@@ -463,11 +480,17 @@ impl LayoutTask {
         let protocol_encoding_label = metadata.charset.as_ref().map(|s| s.as_slice());
         let final_url = metadata.final_url;
 
-        let sheet = Stylesheet::from_bytes_iter(iter, final_url, protocol_encoding_label, Some(environment_encoding));
+        let sheet = Stylesheet::from_bytes_iter(iter,
+                                                final_url,
+                                                protocol_encoding_label,
+                                                Some(environment_encoding));
         self.handle_add_stylesheet(sheet, possibly_locked_rw_data);
     }
 
-    fn handle_add_stylesheet<'a>(&'a self, sheet: Stylesheet, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
+    fn handle_add_stylesheet<'a>(&'a self,
+                                 sheet: Stylesheet,
+                                 possibly_locked_rw_data:
+                                    &mut Option<MutexGuard<'a, LayoutTaskData>>) {
         // Find all font-face rules and notify the font cache of them.
         // GWTODO: Need to handle unloading web fonts (when we handle unloading stylesheets!)
         iter_font_face_rules(&sheet, &self.device, |family, src| {
@@ -566,11 +589,15 @@ impl LayoutTask {
     }
 
     /// The high-level routine that performs layout tasks.
-    fn handle_reflow<'a>(&'a self, data: &Reflow, possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
+    fn handle_reflow<'a>(&'a self,
+                         data: &Reflow,
+                         possibly_locked_rw_data: &mut Option<MutexGuard<'a, LayoutTaskData>>) {
         // FIXME: Isolate this transmutation into a "bridge" module.
         // FIXME(rust#16366): The following line had to be moved because of a
         // rustc bug. It should be in the next unsafe block.
-        let mut node: JS<Node> = unsafe { JS::from_trusted_node_address(data.document_root) };
+        let mut node: JS<Node> = unsafe {
+            JS::from_trusted_node_address(data.document_root)
+        };
         let node: &mut LayoutNode = unsafe {
             mem::transmute(&mut node)
         };
@@ -599,9 +626,7 @@ impl LayoutTask {
         rw_data.screen_size = current_screen_size;
 
         // Create a layout context for use throughout the following passes.
-        let mut shared_layout_ctx =
-            self.build_shared_layout_context(
-                rw_data.deref(),
+        let mut shared_layout_ctx = self.build_shared_layout_context(rw_data.deref(),
                                                                      node,
                                                                      &data.url);
 
@@ -664,8 +689,10 @@ impl LayoutTask {
 
         // Perform the primary layout passes over the flow tree to compute the locations of all
         // the boxes.
-        profile(time::LayoutMainCategory, Some((&data.url, data.iframe, self.first_reflow.get())),
-                self.time_profiler_chan.clone(), || {
+        profile(time::LayoutMainCategory,
+                Some((&data.url, data.iframe, self.first_reflow.get())),
+                self.time_profiler_chan.clone(),
+                || {
             let rw_data = rw_data.deref_mut();
             match rw_data.parallel_traversal {
                 None => {
@@ -674,7 +701,10 @@ impl LayoutTask {
                 }
                 Some(_) => {
                     // Parallel mode.
-                    self.solve_constraints_parallel(data, rw_data, &mut layout_root, &mut shared_layout_ctx)
+                    self.solve_constraints_parallel(data,
+                                                    rw_data,
+                                                    &mut layout_root,
+                                                    &mut shared_layout_ctx);
                 }
             }
         });
@@ -682,22 +712,25 @@ impl LayoutTask {
         // Build the display list if necessary, and send it to the renderer.
         if data.goal == ReflowForDisplay {
             let writing_mode = flow::base(layout_root.deref()).writing_mode;
-            profile(time::LayoutDispListBuildCategory, Some((&data.url, data.iframe, self.first_reflow.get())), self.time_profiler_chan.clone(), || {
-                shared_layout_ctx.dirty = flow::base(layout_root.deref()).position.to_physical(
-                    writing_mode, rw_data.screen_size);
+            profile(time::LayoutDispListBuildCategory,
+                    Some((&data.url, data.iframe, self.first_reflow.get())),
+                         self.time_profiler_chan.clone(),
+                         || {
+                shared_layout_ctx.dirty =
+                    flow::base(layout_root.deref()).position.to_physical(writing_mode,
+                                                                         rw_data.screen_size);
                 flow::mut_base(layout_root.deref_mut()).abs_position =
-                    LogicalPoint::zero(writing_mode).to_physical(writing_mode, rw_data.screen_size);
+                    LogicalPoint::zero(writing_mode).to_physical(writing_mode,
+                                                                 rw_data.screen_size);
 
                 let rw_data = rw_data.deref_mut();
                 match rw_data.parallel_traversal {
                     None => {
-                        sequential::build_display_list_for_subtree(
-                            &mut layout_root,
+                        sequential::build_display_list_for_subtree(&mut layout_root,
                                                                    &shared_layout_ctx);
                     }
                     Some(ref mut traversal) => {
-                        parallel::build_display_list_for_subtree(
-                            &mut layout_root,
+                        parallel::build_display_list_for_subtree(&mut layout_root,
                                                                  &data.url,
                                                                  data.iframe,
                                                                  self.first_reflow.get(),

components/layout/sequential.rs

@@ -37,7 +37,9 @@ pub fn traverse_dom_preorder(root: LayoutNode,
 
 pub fn traverse_flow_tree_preorder(root: &mut FlowRef,
                                    shared_layout_context: &SharedLayoutContext) {
-    fn doit(flow: &mut Flow, assign_inline_sizes: AssignISizes, assign_block_sizes: AssignBSizesAndStoreOverflow) {
+    fn doit(flow: &mut Flow,
+            assign_inline_sizes: AssignISizes,
+            assign_block_sizes: AssignBSizesAndStoreOverflow) {
         if assign_inline_sizes.should_process(flow) {
             assign_inline_sizes.process(flow);
         }
@@ -68,7 +70,9 @@ pub fn traverse_flow_tree_preorder(root: &mut FlowRef,
 
 pub fn build_display_list_for_subtree(root: &mut FlowRef,
                                       shared_layout_context: &SharedLayoutContext) {
-    fn doit(flow: &mut Flow, compute_absolute_positions: ComputeAbsolutePositions, build_display_list: BuildDisplayList) {
+    fn doit(flow: &mut Flow,
+            compute_absolute_positions: ComputeAbsolutePositions,
+            build_display_list: BuildDisplayList) {
         if compute_absolute_positions.should_process(flow) {
             compute_absolute_positions.process(flow);
         }