There is something not correct with the mouseUp events for multiple touches on iOS. Rather, some are getting dropped / ignored.
Specifically, I notice that if I put several fingers on the ipad, then lift them (at the same time),I don’t receive all the mouseUp calls. Some of the touches remain down.
I can reproduce this very easily in the JuceDemo code just by painting the mouse positions on the ipad:
.. in paint()
for (short i=0; i < Desktop::getInstance().getNumMouseSources(); i++)
{
Point<int> p = Desktop::getInstance().getMouseSource(i)->getScreenPosition();
g.setColour(Colours::black);
g.drawEllipse(p.x - 10, p.y - 10, 20, 20, 3);
}
It seems fine with just 2 fingers down, but more than that cause issues. I think if there are multiple mouseUps at about the same time, it is only seeing one of them.
Probably related to this:
http://www.rawmaterialsoftware.com/viewtopic.php?f=4&t=7067&hilit=ios+mouse