Mouse Down / Mouse Up Every time you press a button on the mouse, it first goes down when pressed and then comes up when released. These two states are corresponding to the Mouse Down and Mouse Up ...

Step #1 - Is the mouse pressed? Try moving your mouse over the canvas. Do you see the circles follow your mouse? Do you notice how it's hard to draw a picture because the computer never stops drawing ...

Step #1 - Is the mouse pressed? Try moving your mouse over the canvas. Do you see the circles follow your mouse? Do you notice how it's hard to draw a picture because the computer never stops drawing ...