Mode (user interface): Difference between revisions

Revision as of 17:21, 13 March 2023

Revision as of 10:19, 8 June 2023

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* The most common source of mode errors may be the [[caps lock|Caps Lock]] key. Other common modes available in [[PC keyboard]]s are the other [[lock key]]s, [[Num lock]] and [[Scroll lock]], and often the [[Insert key]]. [[Dead key]]s for [[diacritics]] also create a short-term mode, at least if they don't provide visual feedback that the next typed character will be modified. While the Lock keys on PC keyboards are designed with the intention that they be used as modal keys, the IBM PC hardware design does not require these nor any other specific keys to be modal but allows software to treat any key as modal. (The PC [[BIOS]] normally implements Caps Lock, Num Lock, and Scroll Lock states, so the modality of these keys may appear intrinsic, but it is neither technically nor practically necessary to use the BIOS for keyboard I/O, and in fact most modern operating systems do not use BIOS keyboard I/O.)

* PC users whose language is not based on the [[Latin alphabet]] commonly have to interact using two different [[keyboard layout]]s: a local one and [[QWERTY]]. This gives rise to mode errors linked to the current keyboard layout: quite often, the synchronization of "current layout" mode between the human and the interface is lost, and text is typed in a layout which is not the intended one, producing meaningless text and confusion. Keyboard keys in user interface elements like "(y/n)" can have opposite effect if a program is translated.

* A frequent example is the sudden appearance of a [[modal window|modal]] [[Alert dialog box|error dialog]] in an application while the user is typing, knownwhich asis a form of [[focus stealing]]; the user expects the typed text to be introduced into a text field, but the unexpected dialog may discard all the input, or may interpret some keystrokes (like "Y" for "yes" and "N" for "no") in a way that the user did not intend, often triggering a destructive action that can notcannot be [[undo|reverted]]. Programmers can mitigate this by implementing a short delay between the modal dialog displaying and it beginning to accept keyboard input.

* The [[Unix]] [[text editor]] [[vi]] can be notoriously difficult for beginners precisely because it uses modes, and because earlier versions configured mode indication to be turned off by default.

* In many computer video games, the keyboard is used both for controlling the game and typing messages. A user may forget they are in "typing mode" as they attempt to react to something sudden in the game and find the controls unresponsive (and instead their text bar full of the command keys pressed).