Ever notice how sometimes you touch a link or control on a touch screen and the item registers your touch by, say, blinking or changing color, but the link or control is not activated? WTF’s up with that? If your touch is sufficient to be registered, why (and how) can it be insufficient to initiate activation?
The same thing can happen with a mouse. If you mouse over a button, it may respond with a changed UI, but not yet be activated. If you perform the click when the cursor is no longer over the button it won’t trigger the action. Registering being on top of a UI element and actually activating the element are often two different actions that take place at separate times.
The same can happen with a touch screen, especially since you don’t really have an indicator of where the screen is registering your finger. You may think you’re still over the button when your point of control has slipped to the side. By the time you “click” the button you are no longer over it.
One thing that may be happening is that you’re inadvertently touching the screen in such a way as to highlight the link rather than to click on it.
Again like a mouse, if you don’t lift your finger away ‘cleanly’ but instead move it the tiniest bit a touch screen will interpret it as a ‘click-and-drag’ rather than a ‘click-to-open’ (and the item will remain highlighted). Touch screens do this even more so than a mouse because you don’t ever ‘double-click’ anything.
Different pieces of code handle different parts of an event. That code that detected the touch was waiting to see what you did with it before it sent it to the event handler.
One thing a lot of code about such situations has to do is rule out false touches/clicks/keypresses, etc. A lot of things could look like the thing was pressed- at first- but it turns out later was just some random noise.
If you know about “key debounce” circuits in hardware, it’s the same thing, only with software thrown in for extra fun.
Sometimes the code guesses right, sometimes not.
My DVR drives me nuts in this regard. It flash-highlights a selection sometimes when I click, but doesn’t carry out the action.
This can lead to interesting effects. Once in a great while, in MS-Windows Minesweeper, I see a click get only partially registered. For a brief semi-second I see the hidden squares contents before they go gray again.
OK yes I can recreate this by intentionally sliding my finger a smidge. It’s still annoying but no longer mysterious. Thanks for the info.