The circular slider, although different in appearance from the linear slider, provides much the same function. The circular slider control provides an analog user interface and emulates the controls of stereo and video equipment. Because the circular slider takes up less space on the screen, it may be more practical to use in cases where you might want to have several controls in the same window. You may want to use both types of sliders in a window to create a user interface that makes good use of available space and provides a familiar appearance to the user.
The slider arm shows the value currently set by its position on the slider dial. The slider arm can also be represented as a small circular thumb on the dial rather than a line. The user selects slider values by changing the location of the slider arm on the dial. Outside the perimeter of the dial is a circular scale with tick marks representing incremental values the slider arm can point to. Its values can be tracked by pointing to any area on the dial and pressing the select button while moving the mouse on the desktop.
The circular slider can have a set of buttons, one to the left and the other to the right of the scroll range, similar to the buttons found on the linear slider, that can be used to modify the value shown on the slider.
The minus sign on the left button and plus sign on the right button can be replaced with other symbols. For example, you might want to use a left arrow and a right arrow instead of the minus and plus signs.
Another option of the circular slider is to have a window, in the center of the dial, that displays the value of the dial in scrollable numeric text.
The appearance and functionality of the circular slider are controlled by the circular slider control styles specified. These style bits are summarized in the section that follows.