Class RadPageViewExplorerBarElement

This class represents the element that implements the ExplorerBar view of the RadPageView control. This view allows for multiple visible pages, whereby items can be expanded/collapsed to show their content in an associated page.

Inheritance
System.Object
DisposableObject
RadObject
RadElement
VisualElement
RadComponentElement
RadItem
UIItemBase
LightVisualElement
RadPageViewElementBase
RadPageViewElement
RadPageViewStackElement
RadPageViewExplorerBarElement
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: Telerik.WinControls.UI
Assembly: Telerik.WinControls.UI.dll

Syntax

public class RadPageViewExplorerBarElement : RadPageViewStackElement, INotifyPropertyChanged, ICustomTypeDescriptor, ISupportSystemSkin, IComponent, IDisposable, IBindableComponent, ISupportDrag, ISupportDrop, IShortcutProvider, IStylableElement, IStylableNode, IPrimitiveElement, IShapedElement, IFillElement, IBorderElement, IBoxStyle, IBoxElement, IDrawFillElement, IImageElement, ITextPrimitive, ITextProvider

Constructors

RadPageViewExplorerBarElement()

Declaration
public RadPageViewExplorerBarElement()

Fields

ContentSizeModeProperty

Declaration
public static readonly RadProperty ContentSizeModeProperty
Field Value
RadProperty

Properties

ContentSizeMode

Gets or sets a value from the ExplorerBarContentSizeMode enum that defines how the content areas for each item are sized.

Declaration
public ExplorerBarContentSizeMode ContentSizeMode { get; set; }
Property Value
ExplorerBarContentSizeMode

EnableNCModification

Gets a value indicating whether non-client area modification is enabled for the explorer bar view.

Declaration
protected override bool EnableNCModification { get; }
Property Value
System.Boolean

Overrides

EnableNCPainting

Gets a value indicating whether non-client area painting is enabled for the explorer bar view.

Declaration
protected override bool EnableNCPainting { get; }
Property Value
System.Boolean

Overrides

Scrollbar

Gets an instance of the RadScrollBarElement that represents the scrollbar of the RadPageViewExplorerBarElement.

Declaration
public RadScrollBarElement Scrollbar { get; }
Property Value
RadScrollBarElement

Methods

ArrangeContent(RectangleF)

Arranges the content areas for all explorer bar items by calculating layout information and positioning each item's associated content area element within the available space.

Declaration
protected override RectangleF ArrangeContent(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for content arrangement.
Returns
System.Drawing.RectangleF

The client rectangle after content arrangement.
Overrides

ArrangeOverride(SizeF)

Arranges the explorer bar element by resetting the layout offset based on scrollbar visibility and delegating to the base arrangement implementation.

Declaration
protected override SizeF ArrangeOverride(SizeF finalSize)
Parameters
System.Drawing.SizeF finalSize

The final size for element arrangement.
Returns
System.Drawing.SizeF

The actual size used for the arrangement.
Overrides

ArrangeScrollbar(RectangleF)

Arranges the scrollbar within the specified client rectangle, positioning it based on the current stack position and RTL settings, then updates the scrollbar metrics.

Declaration
protected virtual RectangleF ArrangeScrollbar(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for scrollbar positioning.
Returns
System.Drawing.RectangleF

The client rectangle after scrollbar arrangement.

CheckShowScrollbar(RectangleF)

Checks whether the scrollbar should be shown by comparing the client rectangle dimensions with the full layout length to determine if content overflow exists.

Declaration
protected virtual bool CheckShowScrollbar(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle to check against.
Returns
System.Boolean

True if the scrollbar should be displayed due to content overflow; otherwise, false.

CreateChildElements()

Creates and initializes the child elements including the scrollbar for the explorer bar view, setting up event handlers and default properties for proper scrolling functionality.

Declaration
protected override void CreateChildElements()
Overrides

CreateItem()

Creates a new explorer bar item instance for use in the explorer bar view.

Declaration
protected override RadPageViewItem CreateItem()
Returns
RadPageViewItem

A new RadPageViewExplorerBarItem instance.
Overrides

DisposeManagedResources()

Disposes of managed resources by unsubscribing from event handlers to prevent memory leaks and ensure proper cleanup of the explorer bar element.

Declaration
protected override void DisposeManagedResources()
Overrides

EnsureItemVisibleCore(RadPageViewItem)

Ensures the specified item is visible by scrolling to it within the explorer bar view.

Declaration
protected override bool EnsureItemVisibleCore(RadPageViewItem item)
Parameters
RadPageViewItem item

The page view item to make visible.
Returns
System.Boolean

True if the item was successfully made visible through scrolling; otherwise, false.
Overrides

EnsureVisible(RadPageViewExplorerBarItem)

Ensures the specified explorer bar item is visible by calculating the required scroll offset and adjusting the scrollbar value to position the item within the visible area.

Declaration
protected virtual void EnsureVisible(RadPageViewExplorerBarItem item)
Parameters
RadPageViewExplorerBarItem item

The explorer bar item to make visible.

FindParentControl(Control)

Finds the parent control of the specified control by traversing up the hierarchy, excluding RadPageViewPage instances to find the actual parent control.

Declaration
protected virtual Control FindParentControl(Control activeControl)
Parameters
System.Windows.Forms.Control activeControl

The control to find the parent for.
Returns
System.Windows.Forms.Control

The parent control, or the original control if no suitable parent is found.

FindParentItem(Control)

Finds the parent RadPageViewItem associated with the specified control by traversing up the control hierarchy to locate the containing RadPageViewPage.

Declaration
protected virtual RadPageViewItem FindParentItem(Control activeControl)
Parameters
System.Windows.Forms.Control activeControl

The control to find the parent item for.
Returns
RadPageViewItem

The parent page view item, or null if not found.

FindParentOffset(Control)

Finds the vertical offset of the specified control by traversing up the parent hierarchy and accumulating Y coordinates until reaching the element tree control.

Declaration
protected virtual int FindParentOffset(Control activeControl)
Parameters
System.Windows.Forms.Control activeControl

The control to find the offset for.
Returns
System.Int32

The calculated vertical offset of the control.

GetBorderThickness(Boolean)

Gets the border thickness for the explorer bar element, returning empty padding when checking draw border to disable default border drawing in favor of non-client area painting.

Declaration
protected override Padding GetBorderThickness(bool checkDrawBorder)
Parameters
System.Boolean checkDrawBorder

Whether to check if borders should be drawn.
Returns
System.Windows.Forms.Padding

The border thickness, or empty padding if draw border checking is enabled.
Overrides

GetClientRectangle(SizeF)

Gets the client rectangle by adjusting the base client rectangle with non-client area metrics, accounting for header, footer, and border dimensions when an owner is present.

Declaration
protected override RectangleF GetClientRectangle(SizeF finalSize)
Parameters
System.Drawing.SizeF finalSize

The final size to calculate the client rectangle from.
Returns
System.Drawing.RectangleF

The adjusted client rectangle excluding non-client areas.
Overrides

GetContentAreaForItem(RadPageViewItem)

Gets the content area element associated with the specified item. In explorer bar view, each item has its own dedicated content area element for displaying expanded content.

Declaration
public override RadPageViewContentAreaElement GetContentAreaForItem(RadPageViewItem item)
Parameters
RadPageViewItem item

The page view item to get the content area for.
Returns
RadPageViewContentAreaElement

The content area element associated with the item, or the default content area if item is null.
Overrides

GetContentAreaLayoutInfos(RectangleF)

Gets the layout information for all content areas by calculating the content rectangle for each explorer bar item and creating layout info objects for arrangement.

Declaration
protected List<ContentAreaLayoutInfo> GetContentAreaLayoutInfos(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for layout calculations.
Returns
System.Collections.Generic.List<ContentAreaLayoutInfo>

A list of content area layout information for all items in the explorer bar.

GetFocusedControl(Control.ControlCollection)

Gets the focused control from the specified control collection by recursively searching through the hierarchy for a control that contains focus.

Declaration
protected virtual Control GetFocusedControl(Control.ControlCollection controls)
Parameters
System.Windows.Forms.Control.ControlCollection controls

The control collection to search for focused controls.
Returns
System.Windows.Forms.Control

The focused control, or null if no focused control is found.

GetInitialItemsOffset(RectangleF)

Gets the initial offset for positioning items within the client rectangle, based on the current scrolling position and layout requirements.

Declaration
protected override float GetInitialItemsOffset(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for item positioning.
Returns
System.Single

The initial offset value for item layout.
Overrides

GetItemsRect()

Gets the rectangle area available for items layout by adjusting the client rectangle to account for header and footer elements with their margins and desired sizes.

Declaration
public override RectangleF GetItemsRect()
Returns
System.Drawing.RectangleF

The rectangle area available for positioning explorer bar items.
Overrides

GetNCMetrics()

Gets the non-client area metrics including border thickness and header/footer dimensions, with processing controlled by the allowNCCALCSIZEProcessing flag.

Declaration
protected override Padding GetNCMetrics()
Returns
System.Windows.Forms.Padding

The padding representing the non-client area metrics.
Overrides

GetNextFocusedControl(Control.ControlCollection, Int32, Int32)

Gets the next focused control from the control collection based on tab index navigation, supporting both forward and backward navigation through controls.

Declaration
protected virtual Control GetNextFocusedControl(Control.ControlCollection controls, int currentTabIndex, int step)
Parameters
System.Windows.Forms.Control.ControlCollection controls

The control collection to search for the next focusable control.
System.Int32 currentTabIndex

The current tab index as reference point.
System.Int32 step

The step direction for navigation (positive for forward, negative for backward).
Returns
System.Windows.Forms.Control

The next control to focus based on tab order, or null if none found.

GetPeekPopupArrowDirection()

Gets the arrow direction for peek popup displays in the explorer bar view, returning up direction to align with the vertical layout of the explorer bar items.

Declaration
protected override ArrowDirection GetPeekPopupArrowDirection()
Returns
ArrowDirection

The ArrowDirection for peek popup positioning.
Overrides

InitializeFields()

Initializes default field values for the explorer bar element, setting the item selection mode to content after selected and stack position to top for proper explorer bar behavior.

Declaration
protected override void InitializeFields()
Overrides

IsChildElementExternal(RadElement)

Determines whether the specified element is considered external to the normal child element hierarchy, excluding the scrollbar from external element checks.

Declaration
protected override bool IsChildElementExternal(RadElement element)
Parameters
RadElement element

The element to check for external status.
Returns
System.Boolean

True if the element is external (excluding the scrollbar); otherwise, false.
Overrides

IsNextKey(Keys)

Determines whether the specified key represents a "next" navigation key based on the current stack position, with Up key for top position and Left key for left position.

Declaration
protected override bool IsNextKey(Keys key)
Parameters
System.Windows.Forms.Keys key

The key to check for next navigation.
Returns
System.Boolean

True if the key represents next navigation for the current orientation; otherwise, false.
Overrides

IsPreviousKey(Keys)

Determines whether the specified key represents a "previous" navigation key based on the current stack position, with Down key for top position and Right key for left position.

Declaration
protected override bool IsPreviousKey(Keys key)
Parameters
System.Windows.Forms.Keys key

The key to check for previous navigation.
Returns
System.Boolean

True if the key represents previous navigation for the current orientation; otherwise, false.
Overrides

MeasureContentArea(ref SizeF)

Measures the content area by measuring the scrollbar and returns empty size since content areas are handled individually for each explorer bar item.

Declaration
protected override SizeF MeasureContentArea(ref SizeF availableSize)
Parameters
System.Drawing.SizeF availableSize

The available size for content area measurement.
Returns
System.Drawing.SizeF

Empty size as content areas are managed per item in explorer bar view.
Overrides

MeasureItems(SizeF)

Measures all items in the explorer bar, accounting for scrollbar space and calculating content sizes for each expanded item based on their associated content area requirements.

Declaration
protected override SizeF MeasureItems(SizeF availableSize)
Parameters
System.Drawing.SizeF availableSize

The available size for measuring items.
Returns
System.Drawing.SizeF

The desired size for all measured items combined.
Overrides

OnBoundsChanged(RadPropertyChangedEventArgs)

Handles bounds changes by checking if non-client area metrics have changed and refreshing the non-client area accordingly to maintain proper visual layout.

Declaration
protected override void OnBoundsChanged(RadPropertyChangedEventArgs e)
Parameters
RadPropertyChangedEventArgs e

The event arguments containing information about the bounds change.
Overrides

OnContentBoundsChanged()

Handles content bounds changes by updating the bounds of all visible pages to match their associated content area elements, ensuring proper page layout synchronization.

Declaration
protected override void OnContentBoundsChanged()
Overrides

OnExpandedChanged(RadPageViewExpandedChangedEventArgs)

Raises the ExpandedChanged event when an explorer bar item's expanded state changes, allowing subscribers to respond to expansion and collapse operations.

Declaration
protected virtual void OnExpandedChanged(RadPageViewExpandedChangedEventArgs e)
Parameters
RadPageViewExpandedChangedEventArgs e

The event arguments containing information about the expanded state change.

OnItemCollapsing(RadPageViewExplorerBarItem)

Handles the collapsing event for an explorer bar item by raising the appropriate events and allowing cancellation of the collapse operation.

Declaration
protected virtual bool OnItemCollapsing(RadPageViewExplorerBarItem item)
Parameters
RadPageViewExplorerBarItem item

The explorer bar item that is about to collapse.
Returns
System.Boolean

True if the collapse should be cancelled; otherwise, false.

OnItemExpanding(RadPageViewExplorerBarItem)

Handles the expanding event for an explorer bar item by raising the appropriate events and allowing cancellation of the expansion operation.

Declaration
protected virtual bool OnItemExpanding(RadPageViewExplorerBarItem item)
Parameters
RadPageViewExplorerBarItem item

The explorer bar item that is about to expand.
Returns
System.Boolean

True if the expansion should be cancelled; otherwise, false.

OnItemMouseUp(RadPageViewItem, MouseEventArgs)

Handles mouse up events on explorer bar items by toggling their expanded state when left-clicked, providing the primary interaction mechanism for expand/collapse operations.

Declaration
protected override void OnItemMouseUp(RadPageViewItem sender, MouseEventArgs e)
Parameters
RadPageViewItem sender

The explorer bar item that received the mouse up event.
System.Windows.Forms.MouseEventArgs e

The mouse event arguments containing button and position information.
Overrides

OnLoaded()

Handles the loaded event by setting the page visibility for all explorer bar items based on their expanded state, ensuring proper initial display of content areas.

Declaration
protected override void OnLoaded()
Overrides

OnMouseWheel(MouseEventArgs)

Handles mouse wheel events by translating wheel movements into scrollbar value changes, enabling smooth scrolling through the explorer bar items.

Declaration
protected override void OnMouseWheel(MouseEventArgs e)
Parameters
System.Windows.Forms.MouseEventArgs e

The mouse event arguments containing wheel delta information.
Overrides

OnNCPaint(Graphics)

Handles non-client area painting by rendering header, footer, and border elements in separate bitmaps for each area (top, left, right, bottom) and compositing them onto the graphics context.

Declaration
protected override void OnNCPaint(Graphics g)
Parameters
System.Drawing.Graphics g

The graphics context for non-client area painting.
Overrides

OnPageAdded(RadPageViewEventArgs)

Handles page addition by creating an explorer bar item and associating it with a content area element, setting up the proper item-to-content relationship for the explorer bar view.

Declaration
protected override void OnPageAdded(RadPageViewEventArgs e)
Parameters
RadPageViewEventArgs e

The event arguments containing information about the added page.
Overrides

OnPageRemoved(RadPageViewEventArgs)

Handles page removal by disposing of the associated content area element and cleaning up the item-to-content relationship for the explorer bar view.

Declaration
protected override void OnPageRemoved(RadPageViewEventArgs e)
Parameters
RadPageViewEventArgs e

The event arguments containing information about the removed page.
Overrides

OnPropertyChanged(RadPropertyChangedEventArgs)

Handles property change events, with special handling for stack position changes to update scrollbar parameters and ensure proper layout orientation.

Declaration
protected override void OnPropertyChanged(RadPropertyChangedEventArgs e)
Parameters
RadPropertyChangedEventArgs e

The event arguments containing information about the changed property.
Overrides

OnSelectedPageChanged(RadPageViewEventArgs)

Handles selected page changes by refreshing the non-client area to ensure proper visual updates when the selected explorer bar item changes.

Declaration
protected override void OnSelectedPageChanged(RadPageViewEventArgs e)
Parameters
RadPageViewEventArgs e

The event arguments containing information about the page change.
Overrides

PageWithFocusedControl()

Finds the explorer bar item that contains a control with focus by checking all items for focused controls within their page control collections.

Declaration
protected virtual RadPageViewStackItem PageWithFocusedControl()
Returns
RadPageViewStackItem

The stack item containing a focused control, or null if none found.

PaintBorder(IGraphics, Single, SizeF)

Overrides border painting to disable default border rendering for the explorer bar view, as borders are handled through the non-client area painting mechanism.

Declaration
protected override void PaintBorder(IGraphics graphics, float angle, SizeF scale)
Parameters
IGraphics graphics

The graphics context for painting operations.
System.Single angle

The rotation angle for painting transformations.
System.Drawing.SizeF scale

The scale factor for painting operations.
Overrides

PerformArrange(RectangleF)

Performs the arrangement of elements by correcting the client rectangle for scrollbar space, arranging content and items, and updating scrollbar positioning.

Declaration
protected override RectangleF PerformArrange(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for element arrangement.
Returns
System.Drawing.RectangleF

The corrected client rectangle after scrollbar adjustments.
Overrides

ProcessAutoScroll(Control, Boolean)

Processes auto-scroll functionality for the specified control by calculating the required scroll offset and updating the scrollbar value to ensure the control becomes visible.

Declaration
protected virtual void ProcessAutoScroll(Control activeControl, bool ensureVisibility)
Parameters
System.Windows.Forms.Control activeControl

The control to make visible through scrolling.
System.Boolean ensureVisibility

Whether to force scrolling even if the control appears to be visible.

ProcessKeyDown(KeyEventArgs)

Processes key down events to handle expansion and collapse of explorer bar items using arrow keys, with key mappings that depend on the current stack position orientation.

Declaration
protected override void ProcessKeyDown(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

The key event arguments containing information about the pressed key.
Overrides

ScrollToControl(Control)

Scrolls to make the specified control visible in the explorer bar view by expanding its parent item if needed, processing auto-scroll, and focusing the control.

Declaration
public virtual void ScrollToControl(Control control)
Parameters
System.Windows.Forms.Control control

The control to scroll to and focus.

ScrollToItem(RadPageViewExplorerBarItem)

Scrolls the view to make the specified explorer bar item visible within the client area, adjusting the scrollbar value and layout offset as needed.

Declaration
public virtual bool ScrollToItem(RadPageViewExplorerBarItem item)
Parameters
RadPageViewExplorerBarItem item

The explorer bar item to scroll to.
Returns
System.Boolean

True if scrolling was performed; false if the item is already fully visible or layout info is unavailable.

SetItemIndex(Int32, Int32)

Sets the index of an explorer bar item by moving it within both the items collection and the children collection, ensuring proper synchronization between logical and visual ordering.

Declaration
protected override void SetItemIndex(int currentIndex, int newIndex)
Parameters
System.Int32 currentIndex

The current index of the item to move.
System.Int32 newIndex

The new index where the item should be positioned.
Overrides

SetSelectedContent(RadPageViewItem)

Sets the selected content for the specified item. In explorer bar view, content selection is handled differently as each item has its own associated content area.

Declaration
protected override void SetSelectedContent(RadPageViewItem item)
Parameters
RadPageViewItem item

The item to set as selected content.
Overrides

SetValueCore(RadPropertyValue, Object, Object, ValueSource)

Sets the value of a property with validation for explorer bar specific constraints, preventing invalid item selection modes and stack positions that are not supported by the explorer bar view.

Declaration
protected override ValueUpdateResult SetValueCore(RadPropertyValue propVal, object propModifier, object newValue, ValueSource source)
Parameters
RadPropertyValue propVal

The property value container.
System.Object propModifier

The property modifier object.
System.Object newValue

The new value to set.
ValueSource source

The source of the value change.
Returns
ValueUpdateResult

The result of the value update operation.
Overrides

UpdateAndArrangeScrollbar(RectangleF)

Updates scrollbar metrics and arranges the scrollbar within the client rectangle, managing scrollbar visibility based on content overflow and correcting layout offsets as needed.

Declaration
protected virtual void UpdateAndArrangeScrollbar(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle for scrollbar arrangement.

UpdateScrollbarMetrics(RectangleF)

Updates the scrollbar metrics including large change, minimum, and maximum values based on the client rectangle dimensions and full layout length calculations.

Declaration
protected virtual void UpdateScrollbarMetrics(RectangleF clientRect)
Parameters
System.Drawing.RectangleF clientRect

The client rectangle used for scrollbar metric calculations.

Events

ExpandedChanged

Occurs when an explorer bar item's expanded state changes, allowing subscribers to respond to expansion and collapse operations.

Declaration
public event EventHandler<RadPageViewExpandedChangedEventArgs> ExpandedChanged
Event Type
System.EventHandler<RadPageViewExpandedChangedEventArgs>

Extension Methods