Scroll Bar (Control)

Provide a scroll bar if nonnumeric information cannot be fully shown within one window.

Do not use a scroll bar to represent numeric values. Use a slider instead.

Adjust the size of a scroll box so that it is proportional to the amount of information that can be visible in the area that can be scrolled in relation to the total amount of information.

Adjust the position of a scroll box so that it indicates the position of the information visible in the area that can be scrolled in relation to the total amount of information.

Change the size of a scroll box only when one of the following is true:

Provide a scroll bar along each dimension in which more information is available in a scrolling area. For example, if the area can be scrolled vertically to display additional information, provide a vertical scroll bar.

When using an explicit focus policy, do not place the active cursor on or within the scroll bar.

If the information in a scrolled area is completely visible, the scroll bar can be removed.

When the user presses the SELECT button on the scroll bar's arrow button, scroll the associated scrolling area one unit in the direction of the arrow and repeat until the button is released.

When the user presses the SELECT button in the scroll bar's scroll track, scroll the associated scrolling area one page in the direction of the mouse position relative to the scroll box and autorepeat (in the same direction) until the button is released.

When the user presses the SELECT button in the scroll box, track the appropriate mouse coordinate with the scroll box, correspondingly scrolling the associated scrolling area, until the button is released. If the user moves the mouse perpendicularly away from the scroll bar (beyond a range specified by the operating environment), snap the scroll box back to its initial position at the time the user presses SELECT. When the user moves the mouse back into the scrolling range, begin tracking the mouse again.

When the user presses the TRANSFER button in the scroll box or track, move the scroll box to the pointer position and scroll the corresponding area. While TRANSFER remains pressed, track the mouse with the scroll box in the exact same manner as when the user presses SELECT in the scroll box.

When the user clicks Ctrl SELECT on one of the scroll bar's arrow buttons, scroll the scrolling area to the far end of the underlying information in the direction indicated by the arrow.

When the user clicks Ctrl SELECT in the scroll bar's track, scroll the scrolling area to the far end of the underlying data in the direction of the mouse relative to the scroll box.

When the user presses Shift SELECT in the scroll bar, scroll the associated scrolling area so that the scroll box is aligned with the position of the mouse. The alignment may be adjusted as the mouse is moved until the user releases the button.

When the user presses a directional key while focus is in the scroll bar, scroll the associated scrolling area one unit in the indicated direction.

When the user presses Ctrl plus a directional key while focus is in the scroll bar, scroll the associated scrolling area one large scrolling increment in the indicated direction.

When the user presses Begin (or Home) or End in a horizontally aligned scroll bar, scroll the associated scrolling area to the leftmost or rightmost end, respectively.

When the user presses Ctrl Begin (or Ctrl Home) or Ctrl End in a vertically aligned scroll bar, scroll the associated scrolling area to the topmost or bottommost end, respectively.

When the user presses PageUp or PageDown in a horizontally aligned scroll bar, scroll the associated scrolling area by one page in the indicated direction.

When the user presses PageLeft (or Ctrl PageUp) or PageDown (or Ctrl PageRight) in a vertically aligned scroll bar, scroll the associated scrolling area by one page in the indicated direction.