Implement element.innerText getter

components/layout/query.rs

@@ -10,11 +10,13 @@ use context::LayoutContext;
 use euclid::{Point2D, Vector2D, Rect, Size2D};
 use flow::{Flow, GetBaseFlow};
 use fragment::{Fragment, FragmentBorderBoxIterator, SpecificFragmentInfo};
-use gfx::display_list::{DisplayList, OpaqueNode, ScrollOffsetMap};
+use gfx::display_list::{DisplayItem, DisplayList, OpaqueNode, ScrollOffsetMap};
 use inline::InlineFragmentNodeFlags;
 use ipc_channel::ipc::IpcSender;
 use msg::constellation_msg::PipelineId;
 use opaque_node::OpaqueNodeMethods;
+use script_layout_interface::{LayoutElementType, LayoutNodeType};
+use script_layout_interface::StyleData;
 use script_layout_interface::rpc::{ContentBoxResponse, ContentBoxesResponse, LayoutRPC};
 use script_layout_interface::rpc::{NodeGeometryResponse, NodeScrollIdResponse};
 use script_layout_interface::rpc::{OffsetParentResponse, ResolvedStyleResponse, StyleResponse};
@@ -24,10 +26,12 @@ use script_traits::LayoutMsg as ConstellationMsg;
 use script_traits::UntrustedNodeAddress;
 use sequential;
 use std::cmp::{min, max};
+use std::collections::HashMap;
 use std::ops::Deref;
 use std::sync::{Arc, Mutex};
 use style::computed_values::display::T as Display;
 use style::computed_values::position::T as Position;
+use style::computed_values::visibility::T as Visibility;
 use style::context::{StyleContext, ThreadLocalStyleContext};
 use style::dom::TElement;
 use style::logical_geometry::{WritingMode, BlockFlowDirection, InlineBaseDirection};
@@ -79,6 +83,9 @@ pub struct LayoutThreadData {
 
     /// A queued response for the list of nodes at a given point.
     pub nodes_from_point_response: Vec<UntrustedNodeAddress>,
+
+    /// A queued response for the inner text of a given element.
+    pub element_inner_text_response: String,
 }
 
 pub struct LayoutRPCImpl(pub Arc<Mutex<LayoutThreadData>>);
@@ -161,6 +168,12 @@ impl LayoutRPC for LayoutRPCImpl {
         let rw_data = rw_data.lock().unwrap();
         rw_data.text_index_response.clone()
     }
+
+    fn element_inner_text(&self) -> String {
+        let &LayoutRPCImpl(ref rw_data) = self;
+        let rw_data = rw_data.lock().unwrap();
+        rw_data.element_inner_text_response.clone()
+    }
 }
 
 struct UnioningFragmentBorderBoxIterator {
@@ -864,3 +877,167 @@ pub fn process_style_query<N: LayoutNode>(requested_node: N)
 
     StyleResponse(data.map(|d| d.styles.primary().clone()))
 }
+
+enum InnerTextItem {
+    Text(String),
+    RequiredLineBreakCount(u32),
+}
+
+// https://html.spec.whatwg.org/multipage/#the-innertext-idl-attribute
+pub fn process_element_inner_text_query<N: LayoutNode>(node: N,
+                                                       display_list: &Option<Arc<DisplayList>>) -> String {
+    if !display_list.is_some() {
+        warn!("We should have a display list at this point. Cannot get inner text");
+        return String::new();
+    }
+
+    // Step 1.
+    let mut results = Vec::new();
+    // Step 2.
+    inner_text_collection_steps(node, display_list.as_ref().unwrap(), &mut results);
+    let mut max_req_line_break_count = 0;
+    let mut inner_text = Vec::new();
+    for item in results {
+        match item {
+            InnerTextItem::Text(s) => {
+                if max_req_line_break_count > 0 {
+                    // Step 5.
+                    for _ in 0..max_req_line_break_count {
+                        inner_text.push("\u{000A}".to_owned());
+                    }
+                    max_req_line_break_count = 0;
+                }
+                // Step 3.
+                if !s.is_empty() {
+                    inner_text.push(s.to_owned());
+                }
+            },
+            InnerTextItem::RequiredLineBreakCount(count) => {
+                // Step 4.
+                if inner_text.len() == 0 {
+                    // Remove required line break count at the start.
+                    continue;
+                }
+                // Store the count if it's the max of this run,
+                // but it may be ignored if no text item is found afterwards,
+                // which means that these are consecutive line breaks at the end.
+                if count > max_req_line_break_count {
+                    max_req_line_break_count = count;
+                }
+            }
+        }
+    }
+    inner_text.into_iter().collect()
+}
+
+// https://html.spec.whatwg.org/multipage/#inner-text-collection-steps
+#[allow(unsafe_code)]
+fn inner_text_collection_steps<N: LayoutNode>(node: N,
+                                              display_list: &Arc<DisplayList>,
+                                              results: &mut Vec<InnerTextItem>) {
+    // Extracts the text nodes from the display list to avoid traversing it
+    // for each child node.
+    let mut text = HashMap::new();
+    for item in &display_list.as_ref().list {
+        if let &DisplayItem::Text(ref text_content) = item {
+            let entries = text.entry(&item.base().metadata.node).or_insert(Vec::new());
+            entries.push(&text_content.text_run.text);
+        }
+    }
+
+    let mut items = Vec::new();
+    for child in node.traverse_preorder() {
+        let node = match child.type_id() {
+            LayoutNodeType::Text => {
+                child.parent_node().unwrap()
+            },
+            _ => child,
+        };
+
+        let element_data = unsafe {
+            node.get_style_and_layout_data().map(|d| {
+                &(*(d.ptr.as_ptr() as *mut StyleData)).element_data
+            })
+        };
+
+        if element_data.is_none() {
+            continue;
+        }
+
+        let style = match element_data.unwrap().borrow().styles.get_primary() {
+            None => continue,
+            Some(style) => style.clone(),
+        };
+
+        // Step 2.
+        if style.get_inheritedbox().visibility != Visibility::Visible {
+            continue;
+        }
+
+        // Step 3.
+        let display = style.get_box().display;
+        if !child.is_in_document() || display == Display::None {
+            continue;
+        }
+
+        match child.type_id() {
+            LayoutNodeType::Text => {
+                // Step 4.
+                if let Some(text_content) = text.get(&child.opaque()) {
+                    for content in text_content {
+                        items.push(InnerTextItem::Text(content.to_string()));
+                    }
+                }
+            },
+            LayoutNodeType::Element(LayoutElementType::HTMLBRElement) => {
+                // Step 5.
+                items.push(InnerTextItem::Text(String::from("\u{000A}" /* line feed */)));
+            },
+            LayoutNodeType::Element(LayoutElementType::HTMLParagraphElement) => {
+                // Step 8.
+                items.insert(0, InnerTextItem::RequiredLineBreakCount(2));
+                items.push(InnerTextItem::RequiredLineBreakCount(2));
+            }
+            _ => {},
+
+        }
+
+        match display {
+            Display::TableCell if !is_last_table_cell() => {
+                // Step 6.
+                items.push(InnerTextItem::Text(String::from("\u{0009}" /* tab */)));
+            },
+            Display::TableRow if !is_last_table_row() => {
+                // Step 7.
+                items.push(InnerTextItem::Text(String::from("\u{000A}" /* line feed */)));
+            },
+            _ => (),
+        }
+
+        // Step 9.
+        if is_block_level_or_table_caption(&display) {
+            items.insert(0, InnerTextItem::RequiredLineBreakCount(1));
+            items.push(InnerTextItem::RequiredLineBreakCount(1));
+        }
+    }
+
+    results.append(&mut items);
+}
+
+fn is_last_table_cell() -> bool {
+    // FIXME(ferjm) Implement this.
+    false
+}
+
+fn is_last_table_row() -> bool {
+    // FIXME(ferjm) Implement this.
+    false
+}
+
+fn is_block_level_or_table_caption(display: &Display) -> bool {
+    match *display {
+        Display::Block | Display::Flex |
+        Display::TableCaption | Display::Table => true,
+        _ => false,
+    }
+}