reasonable behavior for title
[dygraphs.git] / dygraph.js
index abd2973..38c1d05 100644 (file)
@@ -2102,7 +2102,10 @@ Dygraph.prototype.predraw_ = function() {
   this.computeYAxes_();
 
   // Create a new plotter.
-  if (this.plotter_) this.plotter_.clear();
+  if (this.plotter_) {
+    this.cascadeEvents_('clearChart');
+    this.plotter_.clear();
+  }
   this.plotter_ = new DygraphCanvasRenderer(this,
                                             this.hidden_,
                                             this.hidden_ctx_,
@@ -2330,8 +2333,13 @@ Dygraph.prototype.drawGraph_ = function() {
  * @private
  */
 Dygraph.prototype.renderGraph_ = function(is_initial_draw) {
+  this.cascadeEvents_('clearChart');
   this.plotter_.clear();
+
   this.plotter_.render();
+
+  // TODO(danvk): is this a performance bottleneck when panning?
+  // The interaction canvas should already be empty in that situation.
   this.canvas_.getContext('2d').clearRect(0, 0, this.canvas_.width,
                                           this.canvas_.height);