drag.setData('group', group);
drag.setData('choice', choice);
-
},
draggable_for_form : function (drag) {
var dd = new Y.DD.Drag({
* This is the code for question rendering.
*/
Y.extend(DDIMAGEORTEXT_QUESTION, M.qtype_ddimageortext.dd_base_class, {
+ touchscrolldisable: null,
pendingid: '',
initializer : function() {
this.pendingid = 'qtype_ddimageortext-' + Math.random().toString(36).slice(2); // Random string.
false, 0, this.create_all_drag_and_drops);
Y.later(500, this, this.reposition_drags_for_question, [this.pendingid], true);
},
+
+ /**
+ * prevent_touchmove_from_scrolling allows users of touch screen devices to
+ * use drag and drop and normal scrolling at the same time. I.e. when
+ * touching and dragging a draggable item, the screen does not scroll, but
+ * you can scroll by touching other area of the screen apart from the
+ * draggable items.
+ */
+ prevent_touchmove_from_scrolling : function(drag) {
+ var touchstart = (Y.UA.ie) ? 'MSPointerStart' : 'touchstart';
+ var touchend = (Y.UA.ie) ? 'MSPointerEnd' : 'touchend';
+ var touchmove = (Y.UA.ie) ? 'MSPointerMove' : 'touchmove';
+
+ // Disable scrolling when touching the draggable items.
+ drag.on(touchstart, function() {
+ if (this.touchscrolldisable) {
+ return; // Already disabled.
+ }
+ this.touchscrolldisable = Y.one('body').on(touchmove, function(e) {
+ e = e || window.event;
+ e.preventDefault();
+ });
+ }, this);
+
+ // Allow scrolling after releasing the draggable items.
+ drag.on(touchend, function() {
+ if (this.touchscrolldisable) {
+ this.touchscrolldisable.detach();
+ this.touchscrolldisable = null;
+ }
+ }, this);
+ },
create_all_drag_and_drops : function () {
this.init_drops();
this.update_padding_sizes_all();
i++;
if (!this.get('readonly')) {
this.doc.draggable_for_question(dragnode, group, choice);
+
+ // Prevent scrolling whilst dragging on Adroid devices.
+ this.prevent_touchmove_from_scrolling(dragnode);
}
if (dragnode.hasClass('infinite')) {
var dragstocreate = groupsize - 1;
i++;
if (!this.get('readonly')) {
this.doc.draggable_for_question(dragnode, group, choice);
+
+ // Prevent scrolling whilst dragging on Adroid devices.
+ this.prevent_touchmove_from_scrolling(dragnode);
}
dragstocreate--;
}
