I want to move a node and call a block after move done. But sometimes I need to move the node to another position while that node is moving (change destination).
I can't simply stop the previous action and start new one because than the callback will not be called and lead to inconsistent state.
id move = [CCMoveTo actionWithDuration:time position:pos];
id call = [CCCallBlock actionWithBlock:^{
// do something like clean up
}];
CCSequence *action = [CCSequence actions:move, call, nil];
action.tag = kMovingActionTag;
[node runAction:action];
I can get the action by CCSequence *action = (id)[node getActionByTag:kMovingActionTag];
but than the only thing I can do is stop it and lost the CCCallBlock action.
This is improved solution:
@interface CCMoveTo (SetEndPosition)
- (void)setEndPosition:(CGPoint)position;
@end
@implementation CCMoveTo (SetEndPosition)
- (void)setEndPosition:(CGPoint)position {
CGPoint pos = [target_ position];
CGFloat dis = ccpLength(delta_);
CGFloat move = ccpDistance(endPosition_, pos);
CGFloat percent = move / dis;
endPosition_ = position;
delta_ = ccpSub( endPosition_, pos);
delta_.x /= percent;
delta_.y /= percent;
startPosition_ = ccpSub(endPosition_, delta_);
}
@end
You can add a
setEndPosition
method using category (warning: untested, let me know in comments if this doesn't work):Then, modify the destination by calling
[move setEndPosition:newPosition]
(meaning you have to make themove
variable accessible to the code portion which will modify the destination).