Button (computing)

A button or key, also (English) button refers to a commonly used item of graphical user interfaces in an application program. The button allows the user to trigger an associated with the control function.

Designations

The term button is mainly used in Windows terminology, while on Linux and Mac OS X instead the term key is common. The term button is misleading because a switch usually something on and off ( switching between two stable states ), while a button (or buttons) only one gate pulse passes ( the button has been pressed and released ). The very most controls work like a key, so start a process to "Pressure" (ie after the mouse click or through a hotkey ); real " switch " elements are the flip -flop buttons "pressed" the lock - and then are usually represented accordingly or change the label - and disengage again when the second click, or controls more toggle through multiple switching states, eg for text Awards in the word processor ( bold, italic, etc. ), or editing modes in image processing. In the art switching device is the generic term for buttons and switches.

In the relevant literature, the English name button " (print) button" spread. The Amiga Workbench include the buttons to the "gadgets", the collective term for all controls (next example pictograms / icons).

Visual representation

The appearance of buttons is usually dictated by the operating system used. With a sufficiently large programming effort, the appearance can modify them to suit any size.

Because of a perceptual effect of the human visual system, a " prominent ( three-dimensional) " button will appear when its upper boundary line of light and its lower boundary line is dark. In the reverse case, the button appears " pressed ". This effect is due to the fact that the human eye is accustomed to it that items " lit from above " are. In addition, buttons can be be highlighted in the depressed state to simulate a glow, or undergo some other color changes. Often, the 3D effect will appear only when you mouse over the button moves ( hovering ), or it is activated via the keyboard.

In addition to writings are for buttons and icons customary to represent the function of the button.

For flip-flops even simple check mark or set points are common ( radio buttons ).

Buttons in HTML

In HTML, elements are input and button used. These elements, as well as simple text links (a element that contains plain text ) can be graphically designed using CSS, for example, by assigning different frame colors to simulate a 3D effect. The new standard CSS3 also more elaborate designs can be implemented without the use of images using color gradients etc..

On the World Wide Web buttons for example be used to submit form data or to make references graphically attractive.

Application programs

In application programs buttons are designed to address the individual control commands of a program. You are in the menu bar ( safety edges ) around - or free through - arranged the work surface of a window.