protect frame-picker destroy if frame picker init() was not called

src/js/controller/dialogs/importwizard/steps/AbstractImportStep.js

@@ -23,6 +23,10 @@
   };
 
   ns.AbstractImportStep.prototype.destroy = function () {
+    if (this.framePickerWidget) {
+      this.framePickerWidget.destroy();
+    }
+
     pskl.utils.Event.removeAllEventListeners(this);
   };
 

src/js/controller/dialogs/importwizard/steps/InsertLocation.js

@@ -35,7 +35,10 @@
   };
 
   ns.InsertLocation.prototype.onShow = function () {
+    // Initialize the frame picker on show, to be able to calculate correctly the
+    // container's offsetWidth and offsetHeight.
     this.currentPiskelFramePickerWidget.init();
+
     var currentFrameIndex = this.piskelController.getCurrentFrameIndex();
     this.currentPiskelFramePickerWidget.setFrameIndex(currentFrameIndex + 1);
     this.currentPiskelFramePickerWidget.setFirstFrameIndex(0);

src/js/controller/dialogs/importwizard/steps/SelectMode.js

@@ -28,9 +28,6 @@
   };
 
   ns.SelectMode.prototype.destroy = function () {
-    if (this.framePickerWidget) {
-      this.framePickerWidget.destroy();
-    }
     this.superclass.destroy.call(this);
   };
 

src/js/widgets/FramePicker.js

@@ -59,7 +59,10 @@
   };
 
   ns.FramePicker.prototype.destroy = function () {
-    this.container.removeChild(this.wrapper);
+    if (this.wrapper.parentNode) {
+      this.wrapper.parentNode.removeChild(this.wrapper);
+    }
+
     pskl.utils.Event.removeAllEventListeners(this);
   };