Issue 5932: FBTrace scoped logging

extension/content/firebug/lib/trace.js

@@ -10,6 +10,8 @@ const Cu = Components.utils;
 // ********************************************************************************************* //
 // Firebug Trace - FBTrace
 
+var TraceAPI = ["dump", "sysout", "setScope", "matchesNode", "time", "timeEnd"];
+
 var scope = {};
 
 try
@@ -22,7 +24,6 @@ catch (err)
     {
         getTracer: function(prefDomain)
         {
-            var TraceAPI = ["dump", "sysout", "setScope", "matchesNode", "time", "timeEnd"];
             var TraceObj = {};
             for (var i=0; i<TraceAPI.length; i++)
                 TraceObj[TraceAPI[i]] = function() {};
@@ -32,8 +33,52 @@ catch (err)
 }
 
 // ********************************************************************************************* //
+// Wrapper
+
+/**
+ * Wraps tracer for given option. Logs made throug the wrapper will automatially
+ * be checked against the option and only displayed if the option is true.
+ * If FBTrace console isn't installed all options are false and there is no
+ * additional performance penalty.
+ */
+function TraceWrapper(tracer, option)
+{
+    function createMethodWrapper(method)
+    {
+        return function()
+        {
+            // Check the option before the log is passed to the tracing console.
+            if (tracer[option])
+                tracer[method].apply(tracer, arguments);
+        }
+    }
+
+    for (var i=0; i<TraceAPI.length; i++)
+    {
+        var method = TraceAPI[i];
+        this[method] = createMethodWrapper(method);
+    }
+}
+
+// ********************************************************************************************* //
+
+var tracer = scope.traceConsoleService.getTracer("extensions.firebug");
+
+/**
+ * Support for scoped logging.
+ * 
+ * Example:
+ * FBTrace = FBTrace.to("DBG_NET");
+ * 
+ * // This log will be displayed only if DBG_NET option is on
+ * FBTrace.sysout("net.initialiaze");
+ */
+tracer.to = function(option)
+{
+    return new TraceWrapper(this, option);
+}
 
-return scope.traceConsoleService.getTracer("extensions.firebug");
+return tracer;
 
 // ********************************************************************************************* //
 });