style: Improve logging for attribute changes.

And general Element logging. We now print all the attributes for comparison.

If this turns out to be too verbose we can change it to diff them or something.

Differential Revision: https://phabricator.services.mozilla.com/D2471

1 files changed, 26 insertions, 14 deletions

diff --git a/components/style/invalidation/element/state_and_attributes.rs b/components/style/invalidation/element/state_and_attributes.rs
index 73d73282910..a0f85ae30bb 100644
--- a/components/style/invalidation/element/state_and_attributes.rs
+++ b/components/style/invalidation/element/state_and_attributes.rs
@@ -208,20 +208,32 @@ where
             }
         }
 
-        debug!("Collecting changes for: {:?}", element);
-        debug!(" > state: {:?}", state_changes);
-        debug!(
-            " > id changed: {:?} -> +{:?} -{:?}",
-            snapshot.id_changed(),
-            id_added,
-            id_removed
-        );
-        debug!(
-            " > class changed: {:?} -> +{:?} -{:?}",
-            snapshot.class_changed(),
-            classes_added,
-            classes_removed
-        );
+        if log_enabled!(::log::Level::Debug) {
+            debug!("Collecting changes for: {:?}", element);
+            if !state_changes.is_empty() {
+                debug!(" > state: {:?}", state_changes);
+            }
+            if snapshot.id_changed() {
+                debug!(
+                    " > id changed: +{:?} -{:?}",
+                    id_added,
+                    id_removed
+                );
+            }
+            if snapshot.class_changed() {
+                debug!(
+                    " > class changed: +{:?} -{:?}",
+                    classes_added,
+                    classes_removed
+                );
+            }
+            if snapshot.other_attr_changed() {
+                debug!(
+                    " > attributes changed, old: {}",
+                    snapshot.debug_list_attributes()
+                )
+            }
+        }
 
         let lookup_element = if element.implemented_pseudo_element().is_some() {
             element.pseudo_element_originating_element().unwrap()