The following discussion applies to both horizontal and vertical scroll bars. There are five areas of a scroll bar that can be used with a mouse: the Up (or Left) arrow, the Down (or Right) arrow, the page region before the thumb, the page region after the thumb, and the thumb itself.
Figure 43.1: Parts of a Scroll Bar
| Arrows | Clicking on the arrows performs an incremental scroll. The information in the window scrolls in the direction of the arrow, one line at a time. If you press and hold down the left mouse button, Vermont Views performs a "repeat" operation. After the scrolling is done, Vermont Views determines if the mouse is still down. If it is, it performs another incremental scroll. |
| Page Region | Clicking in the page region above or below the thumb scrolls the information one page at a time rather than one row at a time. On a vertical scroll bar, if the mouse is above the thumb the information scrolls up; if below the thumb, the information scrolls down. On a horizontal bar, if the mouse is to the left of the thumb, the information is scrolled to the right; otherwise, it is scrolled to the left. |
| Thumb | To scroll with the thumb, the user must perform a drag operation by pressing the left mouse button and holding it down, then moving the mouse up or down in the page region. The information displayed in the window is scrolled by an amount relative to the thumb position. For example, if the thumb is in the middle of the page region, the middle of the information is displayed; if at the top of the page region, the top portion of the data is displayed. |
