A scroll bar (English scroll bar, and scroll bars, scroll bars, scroll bars ) is a control a GUI (Graphical User Interface, GUI) for the implementation and illustration of scrolling ( scrolling). Scroll bars are used to shift the visible section of content shown, for example, a text or a graphic. There are horizontal scroll bars to move the cut from left or right and vertical scroll bars to move upward or downward shift. The operation of both versions is similar. As needed either or both types are simultaneously displayed.
Representation and components
When the scroll bar is located in a rectangular area that is shown in the case of the horizontal scroll bar below the content. A vertical scroll bar is placed as a rule, the right of the content. The following explanations refer to a horizontal scroll bar, they apply analogously under permutation of the dimensions for vertical.
Normally extends a horizontal scroll bar over the entire width of the cutout. In some cases, other control elements are placed next to the scroll bar at the bottom, such as tabs. The height of the scroll bar is considerably smaller than its width and regardless of the size of the cutout. The height is only chosen so large that an acceptable operation of the control element is possible to lose as little display space for the actual content. If the width of the entire content does not exceed the current width of the cut, the scroll bar is disabled or alternatively removed entirely.
A scroll bar consists of various elements, the names for the - vary greatly - both in German and in English. In the following, the appearance of these elements is explained and listed the most common German and English names.
- Scroll arrow (scroll arrow ): As a rule, located on the left and on the right end of the scroll bar, an arrow symbol with the function of a button.
- Scroll box, slider (scroll box, Thumb, You ), often similarly shown a slider from the remaining part mostly by darker presentation remote area of the scroll bar.
- Shaft of the scroll bar ( scroll shaft ): area to the left and right of the scroll box.
The current position of the section is represented by the position of the scroll box, so the slider within the scroll bar. That is, the width of the shaft left and right of the scroll box indicates how much non-visible content in this direction is still present. The width of the scroll box in turn indicates how much total currently to see the content.
In addition to displaying the current position of the scroll bar control of the scroll serves. This is possible in various ways by using the mouse, a touchpad or touch screen:
- By clicking on one of the scroll arrows to the neck moves in small steps to the left or right or up or down. The scroll continuously - When the mouse button is pressed while the mouse pointer rests on one of the scroll arrows will - after a short delay.
- By clicking on the shaft of the scroll bar left or right, or above or below the scroll box of the visible image is shifted in the appropriate direction by page - ie so that the neckline is filled completely or almost completely with new content without content was skipped.
- Drag the scroll box to the desired new position.
The scroll can alternatively be performed using the keyboard or the mouse wheel often.