When the card is dragging, the previous card should be displayed in place of that card, so I’ll be doing this inside childWhenDragging property.At line 16, I passed the single item of list i.e single CardItem as the data of Draggable.Firstly, this file is only responsible for building the Draggable widget for the particular index of CardItem list that I passed from CardStackWidget, so don’t get confused, I’ll explain the whole code.Let’s move to our demo app which I will be building using these two widgets. I hope your basics of Draggable and DragTarget are clear now. onLeaveĬalled when Draggable leaves the DragTarget and not dropped into DragTarget. Takes a function which provides the data of Draggable which was accepted by DragTarget. Takes a function which provides the data of Draggable to use as a parameter and returns bool based on whether Draggable will be accepted or not, if onWillAccept returns true then onAccept is called. rejectedData: It contains the list of Draggable data which will not be accepted by DragTarget.candidateData: It contains the list of draggable data which will be accepted by DragTarget.Takes a function which is called to build the contents of DragTarget, we can build different widgets based on Draggable. In line 27, inside onAccept I am changing the value of isSuccessful to true, as the Draggable is dropped on DragTarget and data is accepted by DragTarget.ĭragTarget class generally made of four main parameters: Builder.After this control will be transferred to the onAccept property of DragTarget (line 27). In line 24, onWillAccept will contain the data of a Draggable, if you want your DragTarget to accept the data of Draggable then return true like in this case.In line 4, if the value of isSuccessful is true then Container with FlutterLogo child will be returned, else empty Container will be returned.

Flutter ui builder drag and drop