only activate background highlighter when needed (#1643)

rstudio · Dec 6, 2017 · 30fd018 · 30fd018
1 parent 119d868
commit 30fd018
Showing 1 changed file with 22 additions and 4 deletions.
diff --git a/...tudio/studio/client/workbench/views/source/editors/text/ace/AceBackgroundHighlighter.java b/...tudio/studio/client/workbench/views/source/editors/text/ace/AceBackgroundHighlighter.java
@@ -35,6 +35,7 @@
 import com.google.gwt.event.logical.shared.AttachEvent;
 import com.google.gwt.event.logical.shared.ValueChangeEvent;
 import com.google.gwt.event.logical.shared.ValueChangeHandler;
+import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Timer;
 import com.google.inject.Inject;
 
@@ -173,7 +174,6 @@ public AceBackgroundHighlighter(AceEditor editor)
       highlightPatterns_ = new ArrayList<HighlightPattern>();
       handlers_ = new HandlerRegistrations(
             editor.addEditorModeChangedHandler(this),
-            editor.addDocumentChangedHandler(this),
             editor.addAttachHandler(this));
 
       int n = editor.getRowCount();
@@ -224,7 +224,18 @@ public void onEditorModeChanged(EditorModeChangedEvent event)
       clearMarkers();
       clearRowState();
       refreshHighlighters();
-      synchronizeFrom(0);
+
+      if (documentChangedHandler_ != null)
+      {
+         documentChangedHandler_.removeHandler();
+         documentChangedHandler_ = null;
+      }
+
+      if (!highlightPatterns_.isEmpty())
+      {
+         documentChangedHandler_ = editor_.addDocumentChangedHandler(this);
+         synchronizeFrom(0);
+      }
    }
 
    @Override
@@ -267,6 +278,11 @@ public void onAttachOrDetach(AttachEvent event)
       if (!event.isAttached())
       {
          handlers_.removeHandler();
+         if (documentChangedHandler_ != null)
+         {
+            documentChangedHandler_.removeHandler();
+            documentChangedHandler_ = null;
+         }
       }
    }
 
@@ -442,11 +458,13 @@ private static final List<HighlightPattern> rMarkdownHighlightPatterns()
 
    private final AceEditor editor_;
    private final EditSession session_;
+   private final List<HighlightPattern> highlightPatterns_;
+   private final HandlerRegistrations handlers_;
+
    private HighlightPattern activeHighlightPattern_;
    private String activeModeId_;
+   private HandlerRegistration documentChangedHandler_;
    private boolean enabled_;
-   private final List<HighlightPattern> highlightPatterns_;
-   private final HandlerRegistrations handlers_;
 
    private final JsVectorInteger rowStates_;
    private final JsVectorInteger markerIds_;