When you press Alt to make the normal computer mouse cursor appear to click on things, if you click somewhere that isn't a button and hold the mouse down, you can see that the cursor becomes invisible whenever you click, and reappears when you release the button. Moving the mouse around while LMB is held down will not result in any cursor movement once the button is released.
When you press Alt to make the normal computer mouse cursor appear to click on things, if you click somewhere that isn't a button and hold the mouse down, you can see that the cursor becomes invisible whenever you click, and reappears when you release the button. Moving the mouse around while LMB is held down will not result in any cursor movement once the button is released.