TcxDBTrackBar Class

A data-aware track bar editor.

Declaration

TcxDBTrackBar = class(
    TcxCustomTrackBar
)

Remarks

A simple track bar editor (TcxTrackBar/TcxDBTrackBar) uses a thumb to specify a numeric value.

VCL Editors: A Track Bar Editor Example

You can arrange a track bar editor horizontally or vertically, flip the scale direction, and customize the appearance of scale, thumb, tick marks, and other track bar elements.

In this topic…

How to Use TcxDBTrackBar
End-User Options
Main API Members
Repository Item Class
Related Compiled Demo
Other Track Bar Editor Types
- Unbound Editors
- Data-Aware Editors

How to Use TcxDBTrackBar

At design time, you can add a TcxDBTrackBar using the Component Palette in your RAD Studio IDE. To create and use TcxDBTrackBar components in code, add the cxDBTrackBar unit to the uses clause of your project (in Delphi) or include the cxDBTrackBar header in the source code file (in C++Builder).

End-User Options

Track bar editors (TcxCustomTrackBar descendants) support multiple mouse/touch and keyboard-based user interaction options.

Track Click & Thumb Drag Operations

Users can drag the thumb to modify the edit value.

VCL Editors: A Thumb Dragging Process Example

In addition, a click on the track bar before or after the thumb changes its position in increments specified by the Properties.PageSize property value. If the Properties.ThumbStep property is set to cxtsJump, a click on the track bar moves the thumb directly to the target position.

Supported Keystrokes

If the track bar editor has focus, the following keys increment or decrement the edit value (depending on the Properties.ReverseDirection property value):

Page Up | Page Down: Increment/decrement the edit value by Properties.PageSize.
→ | ↑ | ↓ | ← | + | -: Increment/decrement the edit value by Properties.LineSize. These keys correspond to change buttons.

Mouse Wheel Support

Users can rotate the mouse wheel to increment/decrement^[1] the editor value when the following conditions are met:

The track bar editor has focus
The mouse pointer is within the editor client area
The Properties.UseMouseWheel property is set to True (default)

Main API Members

The list below outlines key members of the TcxDBTrackBar class. These members allow you to configure data-aware track bar editors.

Appearance Settings

Style | StyleDisabled | StyleFocused | StyleHot | StyleReadOnly: Allow you to define individual appearance settings for different track bar editor states.

Tip
To apply the same style settings to multiple editors, use a TcxEditStyleController component. If you need to apply the same style settings to all editors in your application, you can use a TcxDefaultEditStyleController component.
Styles: Provides access to individual styles applied to the track bar editor in different states.
Transparent: Specifies if the track bar editor is transparent in GDI render mode.

EditValue: Specifies the edit value.
Position: Specifies the track thumb position.

CanPostEditValue: Identifies if the track bar can post its edit value to the bound data storage.
DataBinding: Allows you to bind the track bar editor to data.
OnPostEditValue: Allows you to execute custom code when the track bar editor posts a value to the bound data storage.
PostEditValue: Posts the edit value to the bound data storage.

Editor Settings and Repository Items

ActiveProperties: Provides access to the current track bar editor settings regardless of their source. This property set does not allow you to customize editor settings.
Properties: Allows you to customize track bar editor settings directly if the editor does not have an assigned repository item.
RepositoryItem: Specifies a repository item as an external source of track bar editor settings. A repository item has priority over other editor settings.

General-Purpose API Members

AutoSize: Specifies if the track bar editor automatically adjusts its size to fit all visible UI elements in full.
Enabled: Specifies if the editor is enabled.
CanModify: Identifies if the editor is in read-only mode.
ShowHint: Specifies if the track bar editor can display hints.
Width | Height: Allow you to explicitly define editor dimensions.

Repository Item Class

You can create a TcxEditRepositoryTrackBar component in an edit repository to store track bar settings and share them across multiple editors.

To see the TcxTrackBar editor in action (the TcxDBTrackBar editor has the same user experience), run the Data Editors and Controls demo in the VCL Demo Center installed with compiled VCL DevExpress demos. Click Track Bar in the sidebar on the left to activate the corresponding demo.

Download: Compiled VCL Demos

Tip

You can find full source code for the installed compiled editor demo in the following folder:

%PUBLIC%\Documents\DevExpress VCL Demos\MegaDemos\Product Demos\ExpressEditors\