is invoked when a mouse button is 圧力（をかける）d on a window and then
dragged.
Mouse drag events will continue to be 配達するd to
the window where the first event 起こる／始まるd until the mouse button is
解放（する）d (関わりなく whether the mouse position is within the
bounds of the window).
Returns
When 誤った is returned the other handlers are called and a
に引き続いて 扱うing of the event by the 放送者 takes place.
さもなければ, when true is returned, no other handler will be
called and the 放送者 will take no その上の 活動／戦闘s
regarding the event.
is invoked when the mouse button has been moved on a window
(with no buttons 負かす／撃墜する).
Returns
When 誤った is returned the other handlers are called and a
に引き続いて 扱うing of the event by the 放送者 takes place.
さもなければ, when true is returned, no other handler will be
called and the 放送者 will take no その上の 活動／戦闘s
regarding the event.
