Fixed annoying bug whre if you dragged any part of the base image or other parts of the Drag and Drop problem, then the browser would start highlighting the elements.

common/static/js/capa/drag_and_drop/base_image.js

@@ -35,6 +35,10 @@ define(['logme'], function (logme) {
             state.baseImageEl.appendTo(baseImageElContainer);
             baseImageElContainer.appendTo(state.containerEl);
 
+            state.baseImageEl.mousedown(function (event) {
+                event.preventDefault();
+            });
+
             state.baseImageLoaded = true;
         });
         state.baseImageEl.error(function () {

common/static/js/capa/drag_and_drop/scroller.js

@@ -113,6 +113,10 @@ define(['logme'], function (logme) {
         );
         state.sliderEl.appendTo(showEl);
 
+        state.sliderEl.mousedown(function (event) {
+            event.preventDefault();
+        });
+
         moveRightEl = $(
             '<div ' +
                 'style=" ' +

common/static/js/capa/drag_and_drop/targets.js

@@ -43,6 +43,10 @@ define(['logme'], function (logme) {
 
             targetEl.appendTo(state.baseImageEl.parent());
 
+            targetEl.mousedown(function (event) {
+                event.preventDefault();
+            });
+
             state.targets.push({
                 'id': obj.id,