KryptonTrackBar

The KryptonTrackBar is a scrollable control similar to the scroll bar. You can configure ranges through which the value of the Value property of a track bar scrolls by setting the Minimum property to specify the lower end and the Maximum property to specify the upper end of the range. The LargeChange property defines the increment to add or subtract from the Value property when clicks occur either side of the track position indicator. The SmallChange property defines the increment to add or subtract from the Value property when using the keyboard. You can use the Orientation property to change the default horizontal appearance to become vertical.

Appearance

The Orientation property is used to change the direction of the track bar control. Figure 1 shows the vertical and horizontal values. You will see also in Figure 1 that ticks marks are displayed on both sides of the track. You can use the TickStyle to modify this and present tick marks on only one of the sides or not at all. Use the TickFrequency property to define how often a tick mark is drawn. By default the tick marks are drawn for each value between the Minimum and Maximum property values but you can alter the TickFrequency to show them less often. Finally the TrackBarSize is an enumeration property with possible values of Small, Medium and Large and specifies how large the track and track indicator are drawn. Figure 1 shows instances with the default value of Medium.

Figure 1 - Orientation settings.

Four States

The track bar can be in one of four possible states, Disabled, Normal, Tracking and Pressed. If the control has been disabled because the Enabled property is defined as False then the track bar will be in the Disabled state. When enabled the track bar will be in the Normal state until the user moves the mouse over the track bar position indicator at which point it enters the Tracking state. If the user presses the left mouse button whilst over the position indicator then it enters the Pressed state.

In order to customize the appearance of the control in each of the four states you can use the properties StateDisabled, StateNormal, StateTracking and StatePressed.

Common State

To speed up the customization process an extra StateCommon property has been provided. The settings from this are used if no override has been defined for the state specific entry. Note that the specific state values always take precedence and so if you define the border width in StateNormal and StateCommon then the StateNormal value will be used whenever the control is in the Normal state. Only if the StateNormal value is not overridden will it look in StateCommon.

Focus Override

If the control currently has the focus then the OverrideFocus settings are applied. This can occur when the control is in Normal, Tracking or Pressed states. By default the override only alters the appearance so that the track bar position indicator shows that the control has the focus.

Examples of Appearance

Figure 2 shows the appearance when a track bar is using the Office 2010 Blue palette and for each of the different possible states.

Figure 2 - TrackBar states.