Factor out a new function to check display property is changed from '…

…none' to other
servo · Feb 21, 2018 · 5ba2e87 · 5ba2e87
1 parent f90e98d
commit 5ba2e87
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Showing 2 changed files with 17 additions and 8 deletions.
diff --git a/components/style/matching.rs b/components/style/matching.rs
@@ -176,14 +176,7 @@ trait PrivateMatchMethods: TElement {
             return;
         }
 
-        let display_changed_from_none = old_values.map_or(false, |old| {
-            let old_display_style = old.get_box().clone_display();
-            let new_display_style = new_values.get_box().clone_display();
-            old_display_style == Display::None &&
-            new_display_style != Display::None
-        });
-
-        if display_changed_from_none {
+        if new_values.is_display_property_changed_from_none(old_values) {
             // When display value is changed from none to other, we need to
             // traverse descendant elements in a subsequent normal
             // traversal (we can't traverse them in this animation-only restyle

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
@@ -144,6 +144,22 @@ impl ComputedValues {
         return our_type == CSSPseudoElementType_InheritingAnonBox ||
                our_type == CSSPseudoElementType::NonInheritingAnonBox;
     }
+
+    /// Returns true if the display property is changed from 'none' to others.
+    pub fn is_display_property_changed_from_none(
+        &self,
+        old_values: Option<<&ComputedValues>
+    ) -> bool {
+        use properties::longhands::display::computed_value::T as Display;
+
+        old_values.map_or(false, |old| {
+            let old_display_style = old.get_box().clone_display();
+            let new_display_style = self.get_box().clone_display();
+            old_display_style == Display::None &&
+            new_display_style != Display::None
+        })
+    }
+
 }
 
 impl Drop for ComputedValues {