+ * Combined animation logic for all zoom functions.
+ * either the x parameters or y parameters may be null.
+ * @private
+ */
+Dygraph.prototype.doAnimatedZoom = function(oldXRange, newXRange, oldYRanges, newYRanges, callback) {
+ var steps = this.attr_("animatedZooms") ? Dygraph.ANIMATION_STEPS : 1;
+
+ var windows = [];
+ var valueRanges = [];
+ var step, frac;
+
+ if (oldXRange !== null && newXRange !== null) {
+ for (step = 1; step <= steps; step++) {
+ frac = Dygraph.zoomAnimationFunction(step, steps);
+ windows[step-1] = [oldXRange[0]*(1-frac) + frac*newXRange[0],
+ oldXRange[1]*(1-frac) + frac*newXRange[1]];
+ }
+ }
+
+ if (oldYRanges !== null && newYRanges !== null) {
+ for (step = 1; step <= steps; step++) {
+ frac = Dygraph.zoomAnimationFunction(step, steps);
+ var thisRange = [];
+ for (var j = 0; j < this.axes_.length; j++) {
+ thisRange.push([oldYRanges[j][0]*(1-frac) + frac*newYRanges[j][0],
+ oldYRanges[j][1]*(1-frac) + frac*newYRanges[j][1]]);
+ }
+ valueRanges[step-1] = thisRange;
+ }
+ }
+
+ var that = this;
+ Dygraph.repeatAndCleanup(function(step) {
+ if (valueRanges.length) {
+ for (var i = 0; i < that.axes_.length; i++) {
+ var w = valueRanges[step][i];
+ that.axes_[i].valueWindow = [w[0], w[1]];
+ }
+ }
+ if (windows.length) {
+ that.dateWindow_ = windows[step];
+ }
+ that.drawGraph_();
+ }, steps, Dygraph.ANIMATION_DURATION / steps, callback);
+};
+
+/**