LayoutProvider and item

[sm2017]

I have an use case that LayoutProvider must pass me item to calculate dim.width and dim.height

like the following code

 this._layoutProvider = new LayoutProvider(
            index => {
                if (index % 3 === 0) {
                    return ViewTypes.FULL;
                } else if (index % 3 === 1) {
                    return ViewTypes.HALF_LEFT;
                } else {
                    return ViewTypes.HALF_RIGHT;
                }
            },
            (type, dim , item) => {
                  dim.width = item.width();
                  dim.height = item.height();
            }
        );

(type, dim , item) => {} OR (type, dim , index) => {} is good

[naqvitalha]

Layout provider is anyway a class. It would be very simple to grab reference to the data provider here. You already have the index. To get data use item = dataProvider.getDataForIndex(i) leaving out data here was a conscious design decision.