Remove recursiveness from directionality search

servo · Feb 24, 2020 · edb940e · edb940e
1 parent 7e2107b
commit edb940e
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Showing 4 changed files with 35 additions and 26 deletions.
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
@@ -543,8 +543,11 @@ impl Element {
 
     // https://html.spec.whatwg.org/multipage/#the-directionality
     pub fn directionality(&self) -> String {
-        if let Some(html_element) = self.downcast::<HTMLElement>() {
-            html_element.directionality()
+        if let Some(directionality) = self
+            .downcast::<HTMLElement>()
+            .and_then(|html_element| html_element.directionality())
+        {
+            directionality
         } else {
             let node = self.upcast::<Node>();
             node.parent_directionality()

diff --git a/components/script/dom/htmlelement.rs b/components/script/dom/htmlelement.rs
@@ -774,29 +774,29 @@ impl HTMLElement {
             .count() as u32
     }
 
-    pub fn directionality(&self) -> String {
-        println!("HTMLElement#directionality");
+    // returns Some if can infer direction by itself or from child nodes
+    // returns None if requires to go up to parent
+    pub fn directionality(&self) -> Option<String> {
         let element_direction: &str = &self.Dir();
-        println!("HTMLElement#element_direction={}", element_direction);
 
         if element_direction == "ltr" {
-            return "ltr".to_owned();
+            return Some("ltr".to_owned());
         }
 
         if element_direction == "rtl" {
-            return "rtl".to_owned();
+            return Some("rtl".to_owned());
         }
 
         if element_direction == "auto" {
             if let Some(directionality) = self
                 .downcast::<HTMLInputElement>()
                 .and_then(|input| input.auto_directionality())
             {
-                return directionality;
+                return Some(directionality);
             }
 
             if let Some(area) = self.downcast::<HTMLTextAreaElement>() {
-                return area.auto_directionality();
+                return Some(area.auto_directionality());
             }
         }
 
@@ -806,8 +806,7 @@ impl HTMLElement {
         // (i.e. it is not present or has an invalid value)
         // Requires bdi element implementation (https://html.spec.whatwg.org/multipage/#the-bdi-element)
 
-        let node = self.upcast::<Node>();
-        node.parent_directionality()
+        None
     }
 }
 

diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
@@ -952,11 +952,10 @@ impl HTMLFormElement {
                         let input = child.downcast::<HTMLInputElement>().unwrap();
                         data_set.append(&mut input.form_datums(submitter, encoding));
 
-                        let input_html_element = child.downcast::<HTMLElement>().unwrap();
+                        let input_element = child.downcast::<Element>().unwrap();
                         let dirname: DOMString = input.DirName();
                         if !dirname.is_empty() {
-                            let directionality =
-                                DOMString::from(input_html_element.directionality());
+                            let directionality = DOMString::from(input_element.directionality());
                             data_set.push(FormDatum {
                                 ty: input.Type().clone(),
                                 name: dirname.clone(),
@@ -989,11 +988,10 @@ impl HTMLFormElement {
                             });
                         }
 
-                        let area_html_element = child.downcast::<HTMLElement>().unwrap();
+                        let area_element = child.downcast::<Element>().unwrap();
                         let dirname: DOMString = textarea.DirName();
                         if !dirname.is_empty() {
-                            let directionality =
-                                DOMString::from(area_html_element.directionality());
+                            let directionality = DOMString::from(area_element.directionality());
                             data_set.push(FormDatum {
                                 ty: textarea.Type().clone(),
                                 name: dirname.clone(),

diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
@@ -434,16 +434,25 @@ impl Node {
     }
 
     pub fn parent_directionality(&self) -> String {
-        match self.GetParentNode() {
-            Some(parent) => {
-                if let Some(parent_html) = parent.downcast::<Element>() {
-                    parent_html.directionality()
-                } else {
-                    parent.parent_directionality()
-                }
-            },
-            None => "ltr".to_owned(),
+        let mut current = self.GetParentNode();
+
+        loop {
+            match current {
+                Some(parent) => {
+                    if let Some(directionality) = parent
+                        .downcast::<HTMLElement>()
+                        .and_then(|html_element| html_element.directionality())
+                    {
+                        return directionality;
+                    } else {
+                        current = parent.GetParentNode();
+                    }
+                },
+                None => break,
+            }
         }
+
+        "ltr".to_owned()
     }
 }