Added structure for default values

lib/graph3d/Graph3d.js

@@ -44,7 +44,74 @@ var OPTIONKEYS = [
 
 
 /**
- * Copy fields from src to dst in a controlled manner.
+ * Default values for certain option fields.
+ *
+ * These are the values used when a Graph3d instance is initialized
+ * without custom settings.
+ *
+ * If a field is not in this list, a default value of 'undefined' can
+ * be assumed. Of course, it does no harm to set a field explicitly to
+ * 'undefined' here.
+ *
+ * A value of 'undefined' here normally means:
+ *
+ *     'derive from current data and graph style'
+ *
+ * In the code, this is indicated by the comment 'auto by default'.
+ */
+var DEFAULTS = {
+  width            : '400px',
+  height           : '400px',
+  filterLabel      : 'time',
+  legendLabel      : 'value',
+  xLabel           : 'poep',
+  yLabel           : 'y',
+  zLabel           : 'z',
+  xValueLabel      : function(v) { return v; },
+  yValueLabel      : function(v) { return v; },
+  zValueLabel      : function(v) { return v; },
+  showGrid         : true,
+  showPerspective  : true,
+  showShadow       : false,
+  keepAspectRatio  : true,
+  verticalRatio    : 0.5,       // 0.1 to 1.0, where 1.0 results in a 'cube'
+  animationInterval: 1000,      // milliseconds
+  animationPreload : false,
+  axisColor        : '#4D4D4D',
+  gridColor        : '#D3D3D3'
+
+
+  // Following not in defaults (yet) but present in user settings
+  // These will be initialized as 'undefined'
+  //'showAnimationControls',
+  //'animationAutoStart'
+};
+
+
+
+/**
+ * forcibly copy fields from src to dst in a controlled manner.
+ *
+ * A given field in dst will always be overwitten. If this field
+ * is undefined or not present in src, the field in dst will 
+ * be explicitly set to undefined.
+ * 
+ * The intention here is to be able to reset all option fields.
+ * 
+ * Only the fields mentioned in array 'fields' will be handled.
+ *
+ * @param fields  array with names of fields to copy
+ */
+function forceCopy(src, dst, fields) {
+  for (var i in fields) {
+    var field = fields[i];
+    dst[field] = src[field];
+  }
+}
+
+
+/**
+ * Copy fields from src to dst in a safe and controlled manner.
  *
  * Only the fields mentioned in array 'fields' will be copied over,
  * and only if these are actually defined.
@@ -85,45 +152,41 @@ function Graph3d(container, data, options) {
 
   // create variables and set default values
   this.containerElement = container;
-  this.width = '400px';
-  this.height = '400px';
+
+  this.dataTable = null;  // The original data table
+  this.dataPoints = null; // The table with point objects
+
+
+  //
+  // Start Settings
+  //
+
+  // Handle the defaults which can be simply copied over
+  forceCopy(DEFAULTS, this, OPTIONKEYS);
+
+  // Following are internal fields, not part of the user settings
   this.margin = 10; // px
+  this.showGrayBottom = false; // TODO: this does not work correctly
+  this.showTooltip = false;
+  this.dotSizeRatio = 0.02; // size of the dots as a fraction of the graph width
+
+  // The rest of the fields.
+  // These require special attention in some way
+  // TODO: handle these
+
   this.defaultXCenter = '55%';
   this.defaultYCenter = '50%';
 
-  this.xLabel = 'x';
-  this.yLabel = 'y';
-  this.zLabel = 'z';
-
-  var passValueFn = function(v) { return v; };
-  this.xValueLabel = passValueFn;
-  this.yValueLabel = passValueFn;
-  this.zValueLabel = passValueFn;
-  
-  this.filterLabel = 'time';
-  this.legendLabel = 'value';
   this.showLegend  = undefined; // auto by default (based on graph style)
 
   this.style = Graph3d.STYLE.DOT;
-  this.showPerspective = true;
-  this.showGrid = true;
-  this.keepAspectRatio = true;
-  this.showShadow = false;
-  this.showGrayBottom = false; // TODO: this does not work correctly
-  this.showTooltip = false;
-  this.verticalRatio = 0.5; // 0.1 to 1.0, where 1.0 results in a 'cube'
 
-  this.animationInterval = 1000; // milliseconds
-  this.animationPreload = false;
 
   this.camera = new Camera();
   this.camera.setArmRotation(1.0, 0.5);
   this.camera.setArmLength(1.7);
   this.eye = new Point3d(0, 0, -1);  // TODO: set eye.z about 3/4 of the width of the window?
 
-  this.dataTable = null;  // The original data table
-  this.dataPoints = null; // The table with point objects
-
   // the column indexes
   this.colX = undefined;
   this.colY = undefined;
@@ -147,15 +210,16 @@ function Graph3d(container, data, options) {
   // TODO: customize axis range
 
   // colors
-  this.axisColor = '#4D4D4D';
-  this.gridColor = '#D3D3D3';
   this.dataColor = {
     fill: '#7DC1FF',
     stroke: '#3267D2',
     strokeWidth: 1  // px
   };
 
-  this.dotSizeRatio = 0.02; // size of the dots as a fraction of the graph width
+
+  //
+  // End Settings
+  //
 
   // create a frame and canvas
   this.create();