Hello Sencha Team,

Just wanted to draw your attention to the thing I discovered today.


It appears that whenever you make your component draggable and try to add a constraint to the drag at runtime, ExtJS will throw an error while invoking calculateConstrainRegion method on drag start:



Code:



calculateConstrainRegion: function() {
        var me = this,
            comp = me.comp,
            constrainTo = me.initialConstrainTo, //here is why the error is thrown 
            constraintInsets = comp.constraintInsets,
            constrainEl,
            delegateRegion,
            elRegion,
            dragEl = me.proxy ? me.proxy.el : comp.el,
            shadowSize = (!me.constrainDelegate && dragEl.shadow && comp.constrainShadow && !dragEl.shadowDisabled) ? dragEl.shadow.getShadowSize() : 0;


        
        if (!(constrainTo instanceof Ext.util.Region)) {
            constrainEl = Ext.fly(constrainTo);
            constrainTo =  constrainEl.getViewRegion();  //here is where the error is thrown 


            
            constrainTo.right = constrainTo.left + constrainEl.dom.clientWidth;
        } else {
            
            constrainTo = constrainTo.copy();
        }


        
        if (constraintInsets) {
            constraintInsets = Ext.isObject(constraintInsets) ? constraintInsets : Ext.Element.parseBox(constraintInsets);
            constrainTo.adjust(constraintInsets.top, constraintInsets.right, constraintInsets.bottom, constraintInsets.length);
        }


        
        if (shadowSize) {
            constrainTo.adjust(shadowSize[0], -shadowSize[1], -shadowSize[2], shadowSize[3]);
        }


        
        
        
        if (!me.constrainDelegate) {
            delegateRegion = Ext.fly(me.dragTarget).getRegion();
            elRegion = dragEl.getRegion();


            constrainTo.adjust(
                delegateRegion.top - elRegion.top,
                delegateRegion.right - elRegion.right,
                delegateRegion.bottom - elRegion.bottom,
                delegateRegion.left - elRegion.left
            );
        }
        return constrainTo;
    }

(not)Working example: