diff --git a/io/router/pointer.go b/io/router/pointer.go index 78f04c03..19a8155b 100644 --- a/io/router/pointer.go +++ b/io/router/pointer.go @@ -131,7 +131,6 @@ func (q *pointerQueue) opHit(handlers *[]event.Key, pos f32.Point) { if _, exists := q.handlers[n.key]; exists { *handlers = append(*handlers, n.key) } - } } } @@ -236,6 +235,11 @@ func (q *pointerQueue) Push(e pointer.Event, events *handlerEvents) { if e.Type == pointer.Release { q.pointers = append(q.pointers[:pidx], q.pointers[pidx+1:]...) } + + // Deliver enter and leave events for pointers that entered or left a hit area. + q.deliverEventsToMissingHandlers(q.scratch, p.handlers, pointer.Enter, e, events) + q.deliverEventsToMissingHandlers(p.handlers, q.scratch, pointer.Leave, e, events) + for _, k := range p.handlers { h := q.handlers[k] e := e @@ -260,6 +264,30 @@ func (q *pointerQueue) Push(e pointer.Event, events *handlerEvents) { } } +// deliverEventsToMissingHandlers compares the a and b handler lists to find all +// handlers in b that are missing from a. It then sends an event templated off of +// evTemplate but with the type specified by evType. +// +// This is useful for delivering pointer.Enter and pointer.Leave events. +func (q *pointerQueue) deliverEventsToMissingHandlers(a, b []event.Key, evType pointer.Type, evTemplate pointer.Event, events *handlerEvents) { + for _, newH := range b { + found := false + for _, oldH := range a { + if newH == oldH { + found = true + } + } + if !found { + h := q.handlers[newH] + ev := evTemplate + ev.Hit = q.hit(h.area, evTemplate.Position) + ev.Position = h.transform.Invert().Transform(evTemplate.Position) + ev.Type = evType + events.Add(newH, ev) + } + } +} + func (op *areaOp) Decode(d []byte) { if opconst.OpType(d[0]) != opconst.TypeArea { panic("invalid op")