factor generic configuration stuff out of BlockBased into a new base …

…class JBrowse/Component that will be used by more than just tracks

src/JBrowse/Component.js

@@ -0,0 +1,73 @@
+/**
+ * A JBrowse component keeps a reference to the main browser object, and is configurable.
+ */
+
+define([
+           'dojo/_base/declare'
+       ],
+       function(
+           declare
+       ) {
+
+return declare( null, {
+
+    constructor: function( args ) {
+        args = args || {};
+
+        // merge our config with the config defaults
+        this.config = args.config || {};
+        this.config = this._mergeConfigs( dojo.clone( this._defaultConfig() ), this.config );
+
+        this.browser = args.browser;
+    },
+
+    _defaultConfig: function() {
+        return {};
+    },
+
+    _mergeConfigs: function(a, b) {
+        for (var prop in b) {
+            if ((prop in a)
+                && ("object" == typeof b[prop])
+                && ("object" == typeof a[prop]) ) {
+                this._mergeConfigs( a[prop], b[prop] );
+            } else if( typeof a[prop] == 'undefined' || typeof b[prop] != 'undefined' ){
+                a[prop] = b[prop];
+            }
+        }
+        return a;
+    },
+
+    _compileConfigurationPath: function( path ) {
+        var confVal = this.config;
+
+        if( typeof path == 'string' )
+            path = path.split('.');
+        while( path.length && confVal )
+            confVal = confVal[ path.shift() ];
+
+        if( path.length )
+            return function() { return null; };
+
+        return typeof confVal == 'function'
+            ? confVal
+            : function() { return confVal; };
+    },
+
+    /**
+     * Given a dot-separated string configuration path into the config
+     * (e.g. "style.bg_color"), get the value of the configuration.
+     * If args are given, evaluate the configuration using them.
+     * Otherwise, return a function that returns the value of the
+     * configuration when called.
+     */
+    getConf: function( path, args ) {
+        var func = this.compiledConfig[path];
+        if( ! func ) {
+            func = this.compiledConfig[path] = this._compileConfigurationPath( path );
+        }
+
+        return args ? func.apply( this, args ) : func;
+    }
+});
+});

src/JBrowse/View/Track/BlockBased.js

@@ -12,6 +12,7 @@ define( [
             'dijit/CheckedMenuItem',
             'dijit/MenuSeparator',
             'JBrowse/Util',
+            'JBrowse/Component',
             'JBrowse/Errors',
             'JBrowse/View/TrackConfigEditor',
             'JBrowse/View/ConfirmDialog'
@@ -29,12 +30,13 @@ define( [
                   dijitCheckedMenuItem,
                   dijitMenuSeparator,
                   Util,
+                  Component,
                   Errors,
                   TrackConfigEditor,
                   ConfirmDialog
                 ) {
 
-return declare( null,
+return declare( Component,
 /**
  * @lends JBrowse.View.Track.BlockBased.prototype
  */
@@ -46,10 +48,6 @@ return declare( null,
     constructor: function( args ) {
         args = args || {};
 
-        // merge our config with the config defaults
-        this.config = args.config || {};
-        this.config = Util.deepUpdate( dojo.clone( this._defaultConfig() ), this.config );
-
         this.refSeq = args.refSeq;
         this.name = args.label || this.config.label;
         this.key = args.key || this.config.key || this.name;
@@ -822,38 +820,6 @@ return declare( null,
             : confVal;
     },
 
-    _compileConfigurationPath: function( path ) {
-        var confVal = this.config;
-
-        if( typeof path == 'string' )
-            path = path.split('.');
-        while( path.length && confVal )
-            confVal = confVal[ path.shift() ];
-
-        if( path.length )
-            return function() { return null; };
-
-        return typeof confVal == 'function'
-            ? confVal
-            : function() { return confVal; };
-    },
-
-    /**
-     * Given a dot-separated string configuration path into the config
-     * (e.g. "style.bg_color"), get the value of the configuration.
-     * If args are given, evaluate the configuration using them.
-     * Otherwise, return a function that returns the value of the
-     * configuration when called.
-     */
-    getConf: function( path, args ) {
-        var func = this.compiledConfig[path];
-        if( ! func ) {
-            func = this.compiledConfig[path] = this._compileConfigurationPath( path );
-        }
-
-        return args ? func.apply( this, args ) : func;
-    },
-
     /**
      * Like getConf, but get a conf value that explicitly can vary
      * feature by feature.  Provides a uniform function signature for