Gauge Control Components
- 3 minutes to read
The components used to in a particular application determine the Gauge Control‘s appearance and functionality. ExpressGauge control components can be used without the TdxGaugeControl component as a master container for other components:
Scales;
Containers;
Captions;
Range Bars.
Gauge Control
The Gauge Control is the TdxGaugeControl instance, and the master node in the scales hierarchy is designed to host all types of scales and therefore, all optional decoration objects, such as the custom captions and range bars.
Scales
A Scale is a key visual component of the ExpressGauge control that determines both its appearance and functionality. Scales are the major components that can be created within the Gauge Control. Various scale types are designed to imitate both digital and analog display devices and measuring instruments. Scales are used to focus an end-user’s attention to certain important values in your application.
Within the same instance of the Gauge Control, you can customize the scale appearance individually:
Using their StyleName property to assign the general visual style of a scale;
By customizing the assigned style’s appearance using the scale’s OptionsView property.
Note that the Gauge Control‘s LookAndFeel settings do not affect the appearance of scales created within it.
The ExpressGauge control allows you to create both the unbound and data-aware versions of scales:
Containers
Containers are the scales without display settings, designed only to host other scales, including other container scales. A container scale allows you move and resize the group of scales as a single scale.
Container scales are displayed as colored rectangles only at design time:
Captions
Captions are optional custom labels that can be placed anywhere within a scale of any type:
Custom captions are positioned within the scale layout in the same manner as a nested scale. However, unlike scales, these custom labels support only relative positioning. Custom caption’s dimensions depend only on the selected font size. Since the custom captions are a scale’s optional decorative elements, such operations as scale copying or deleting, are applied to these captions as well.
The ExpressGauge control provides two custom caption objects:
TdxGaugeQuantitativeScaleCaption, designed for labeled quantitative scales;
TdxGaugeCustomCaption, used in digital scales whose styles contain no font parameters.
Note that custom captions can be placed only within a visual scale. You cannot create custom labels directly within the Gauge Control or container scales.
Range Bars
The range bars are the optional decorative elements that can be used to mark certain ranges of values within a quantitative scale:
Like custom captions, the range bars created within a scale become its parts. Therefore, the scale copying and deleting operations are applied to range bars as well.
Since either the starting or ending point of a range bar can be bound to the current scale value by using the LinkedWithScaleValue property, you can use range bars instead of value indicators:
For more information on scale range bars, refer to the How to Work with Scale Range Bars topic.