func (t *TapRecognizer) OnChange(e *InputEvent) RecognizerState {
if p, ok := (interface{})(e).(PointerEvent); ok {
switch p.Type {
case InputTypeUp:
result := TapEvent{InputEvent{e.Target, InputTypeDown, e.modifier}, t.e.Position}
Tap.Fire(result)
t.down = false
return RecognizerStateEnd
case InputTypeMove:
if math.Distance(p.Position, t.e.Position) > tapTolerance {
t.down = false
return RecognizerStateFail
}
}
}
return RecognizerStateFail
}
func (r *PanRecognizer) OnPossible(e *InputEvent) RecognizerState {
if p, ok := (interface{})(e).(PointerEvent); ok {
if !r.down && p.Type == InputTypeDown {
r.start = p
r.last = p.Position
r.down = true
return RecognizerStatePossible
} else if r.down && p.Type == InputTypeMove {
if math.Distance(p.Position, r.start.Position) > startThreshold {
r.last = p.Position
result := PanEvent{InputEvent{e.Target, InputTypeDown, e.modifier},
p.Position, p.Position.Subtract(r.start.Position)}
Pan.Fire(result)
return RecognizerStateActive
} else {
return RecognizerStatePossible
}
} else {
r.down = false
return RecognizerStateFail
}
}
return RecognizerStateFail
}