The following patch fixes this behavior. (This has already been fixed in the 8.0 release).
Code:
//---------------------------------------------------------------------------- // Isomorphic SmartClient 7.0rc2 patch // Purpose: Avoid doubled mouse events on items embedded in DynamicForm // written into a CanvasItem, displayed in an outer DynamicForm. // // Applies to SmartClient 7.0RC2 builds only //---------------------------------------------------------------------------- if (window.isc) { if (isc.version.startsWith("7.0rc2/")) { if (isc.DynamicForm != null) { isc.DynamicForm.addProperties({ _origHMSD:isc.DynamicForm.getPrototype().handleMouseStillDown, handleMouseStillDown : function (event, eventInfo) { var targetInfo = this.$ne(event), item = ((targetInfo.overTitle || targetInfo.inactiveContext) ? null : targetInfo.item); // avoid double delivery of events if there are nested DynamicForm elements all receiving // this event via bubbling - only deliver to item if it's one of ours if (item && item.containerWidget != this) return; return this._origHMSD(event,eventInfo); } }); } } else { isc.logWarn("Patch code for SmartClient version 7.0rc2 included in this application. You are running SmartClient version " + isc.version + ". The patch code will have no effect in this application and should be removed."); } }