GroupStatePrimitive
Represents a primitive element that renders visual indicators for expandable/collapsible group states, commonly used in panel bars, tree views, and other hierarchical controls within the Telerik WinControls framework.
Definition
Namespace:Telerik.WinControls.Primitives
Assembly:Telerik.WinControls.dll
Syntax:
public class GroupStatePrimitive : BasePrimitive, IDisposable, INotifyPropertyChanged, ICustomTypeDescriptor, ISupportSystemSkin, IStylableNode, IPrimitiveInheritance: objectDisposableObjectRadObjectRadElementVisualElementBasePrimitiveGroupStatePrimitive...
Implements:
Inherited Members
Constructors
public GroupStatePrimitive()Fields
Identifies the State dependency property.
public static readonly RadProperty GroupStatePropertyThis property controls whether the group is currently expanded or collapsed, which directly affects the visual representation of the state indicator.
Identifies the PanelBarStyle dependency property.
public static readonly RadProperty GroupStylePropertyThis property determines the visual style used for rendering the group state indicator, affecting how the expand/collapse visual cues are displayed to the user.
Properties
Gets or sets the visual style for the panel bar group state indicator.
public PanelBarStyles PanelBarStyle { get; set; }A PanelBarStyles enumeration value that determines the visual appearance of the group state indicator. The default value is ExplorerBarStyle.
This property controls how the expand/collapse indicator is visually represented:
- VisualStudio2005ToolBox: Renders simple line-based indicators similar to Visual Studio's toolbox
- ExplorerBarStyle: Renders filled arrow-shaped indicators with double arrows for enhanced visibility
Changing this property triggers a repaint of the primitive to reflect the new visual style. The style affects both the expanded and collapsed state representations.
Gets or sets the current state of the group (expanded or collapsed).
public GroupStatePrimitive.GroupState State { get; set; }A GroupStatePrimitive.GroupState enumeration value indicating whether the group is expanded or collapsed. The default value is Expanded.
This property determines the visual representation of the group state indicator:
- Expanded: Shows collapse indicators (minus signs, down arrows, etc.)
- Collapsed: Shows expand indicators (plus signs, right arrows, etc.)
The exact visual representation depends on the current PanelBarStyle setting. Changing this property triggers an immediate repaint to show the updated state.
Gets or sets a value indicating whether the primitive should stretch horizontally to fill available space.
public override bool StretchHorizontally { get; set; }false by default. Group state indicators typically maintain fixed width for consistent appearance.
Overrides:
Group state primitives are generally designed to have a fixed size to ensure consistent visual appearance
across different container sizes. Setting this to true may cause the indicator to appear distorted.
Gets or sets a value indicating whether the primitive should stretch vertically to fill available space.
public override bool StretchVertically { get; set; }false by default. Group state indicators typically maintain fixed height for consistent appearance.
Overrides:
Group state primitives are generally designed to have a fixed size to ensure consistent visual appearance
across different container sizes. Setting this to true may cause the indicator to appear distorted.
Methods
Initializes the default field values for the group state primitive.
protected override void InitializeFields()Overrides:
This method sets up the primitive to have fixed sizing by default, as group state indicators typically have a predetermined size and should not stretch to fill available space. The primitive is configured to maintain its intrinsic dimensions for consistent appearance.
Measures the desired size of the group state primitive within the specified available size.
protected override SizeF MeasureOverride(SizeF availableSize)The available size that this primitive can be given.
Returns:The SizeF representing the desired size of the primitive. Returns a minimum size of 10x10 pixels to ensure the indicator remains visible and interactive.
Overrides:
This method ensures that all child elements have their Measure method called during the layout process, then returns a consistent minimum size for the group state indicator. The fixed minimum size ensures that the indicator remains visible and clickable regardless of the available space.
The 10x10 pixel minimum size provides sufficient area for rendering both simple line-based indicators (Visual Studio ToolBox style) and more complex polygon-based indicators (Explorer Bar style) while maintaining good usability for mouse and touch interactions.
Renders the group state indicator using the specified graphics context, applying rotation and scaling transformations.
public override void PaintPrimitive(IGraphics graphics, float angle, SizeF scale)The IGraphics interface used for drawing the state indicator.
anglefloatThe rotation angle in degrees to apply to the rendered content.
scaleSizeFThe scaling factor to apply to the rendered content.
Overrides:
This method renders different visual indicators based on the current PanelBarStyle and State values:
Visual Studio 2005 ToolBox Style:
- Expanded: Renders a horizontal line across the center
- Collapsed: Renders both horizontal and vertical lines forming a plus sign
Explorer Bar Style:
- Expanded: Renders double up-pointing arrow polygons with shadow effect
- Collapsed: Renders double down-pointing arrow polygons with shadow effect
The method uses anti-aliased rendering for smooth visual appearance and applies the primitive's ForeColor for the main indicator elements.