Class Scroller

Definition

Namespace:: ElmSharp

Assembly:: ElmSharp.dll

API Level:: preview

The Scroller is a container that holds and clips a single object and allows you to scroll across it.


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public class Scroller : Layout, IAccessibleObject

Inheritance: System.Object

EvasObject

AccessibleObject

Widget

Container

Layout

Scroller

Derived: CircleScroller

CircleScroller

CircleScroller

Implements: IAccessibleObject

Constructors

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Scroller()

Creates and initializes a new instance of the Scroller class.

Declaration


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public Scroller()

API Level: preview

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Scroller(EvasObject)

Creates and initializes a new instance of the Scroller class.

Declaration


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public Scroller(EvasObject parent)

Parameters

Type	Name	Description
EvasObject	parent	The EvasObject to which the new Scroller will be attached as a child.

API Level: preview

Properties

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ChildHeight

Gets the height of the content object of the scroller.

Declaration


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public int ChildHeight { get; }

Property Value

Type	Description
System.Int32

API Level: preview

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ChildWidth

Gets the width of the content object of the scroller.

Declaration


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public int ChildWidth { get; }

Property Value

Type	Description
System.Int32

API Level: preview

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ContentPropagateEvents

Gets or sets the event propagation for a scroller. This enables or disables event propagation from the scroller content to the scroller and its parent. By default, event propagation is enabled.

Declaration


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public bool ContentPropagateEvents { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

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CurrentRegion

Gets the current region in the content object that is visible through the scroller.

Declaration


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public Rect CurrentRegion { get; }

Property Value

Type	Description
Rect

API Level: preview

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HorizontalBounce

Sets or gets the horizontal bounce behaviour. When scrolling, the scroller may "bounce" when reaching an edge of the content object. This is a visual way to indicate the end has been reached. This is enabled by default for both axis. This API will set if it is enabled for the given axis with the boolean parameters for each axis.

Declaration


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public bool HorizontalBounce { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

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HorizontalGravity

Sets the scrolling gravity values for a scroller. The gravity defines how the scroller will adjust its view when the size of the scroller contents increase. The scroller will adjust the view to glue itself as follows: x=0.0, for staying where it is relative to the left edge of the content, x=1.0, for staying where it is relative to the rigth edge of the content, y=0.0, for staying where it is relative to the top edge of the content, y=1.0, for staying where it is relative to the bottom edge of the content. Default values for x and y are 0.0.

Declaration


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public double HorizontalGravity { get; set; }

Property Value

Type	Description
System.Double

API Level: preview

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HorizontalLoop

Sets an infinite loop_ for a scroller. This function sets the infinite loop horizontally. If the content is set, it will be shown repeatedly.

Declaration


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public bool HorizontalLoop { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

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HorizontalPageIndex

Sets or gets the scroll current page number.

Declaration


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public int HorizontalPageIndex { get; }

Property Value

Type	Description
System.Int32

Remarks

Current page means the page which meets the left of the viewport. If there are two or more pages in the viewport, it returns the number of the page which meets the left of the viewport. The page number starts from 0. 0 is the first page.

API Level: preview

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HorizontalPageScrollLimit

Sets or gets the maximum limit of the movable page at horizontal direction.

Declaration


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public int HorizontalPageScrollLimit { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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HorizontalRelativePageSize

Gets or sets a given scroller widget's scrolling page size, relative to its viewport size.

Declaration


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public double HorizontalRelativePageSize { get; set; }

Property Value

Type	Description
System.Double

API Level: preview

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HorizontalScrollBarVisiblePolicy

Sets or gets the value of HorizontalScrollBarVisiblePolicy.

Declaration


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public virtual ScrollBarVisiblePolicy HorizontalScrollBarVisiblePolicy { get; set; }

Property Value

Type	Description
ScrollBarVisiblePolicy

Remarks

ScrollBarVisiblePolicy.Auto means the horizontal scrollbar is made visible if it is needed, and otherwise kept hidden. ScrollBarVisiblePolicy.Visible turns it on all the time, and ScrollBarVisiblePolicy.Invisible always keeps it off.

API Level: preview

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HorizontalSnap

Gets or sets the page snapping behavior of a scroller.

Declaration


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public bool HorizontalSnap { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

When scrolling, if a scroller is paged (see HorizontalRelativePageSize), the scroller may snap to pages when being scrolled, i.e., even if it had momentum to scroll further, it will stop at the next page boundaries. This is disabled, by default, for both axis. This function will set if it that is enabled or not, for each axis.

API Level: preview

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HorizontalStepSize

Gets or sets the step size to move scroller by key event.

Declaration


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public int HorizontalStepSize { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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LastHorizontalPageNumber

Gets the scroll last page number. The page number starts from 0. 0 is the first page. This returns the last page number among the pages.

Declaration


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public int LastHorizontalPageNumber { get; }

Property Value

Type	Description
System.Int32

API Level: preview

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LastVerticalPageNumber

Gets the scroll last page number. The page number starts from 0. 0 is the first page. This returns the last page number among the pages.

Declaration


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public int LastVerticalPageNumber { get; }

Property Value

Type	Description
System.Int32

API Level: preview

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PageHeight

Gets or sets the page size to an absolute fixed value, with 0 turning it off for that axis.

Declaration


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public int PageHeight { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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PageWidth

Gets or sets the page size to an absolute fixed value, with 0 turning it off for that axis.

Declaration


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public int PageWidth { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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ScrollBlock

Sets or gets the value of ScrollBlock.

Declaration


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public ScrollBlock ScrollBlock { get; set; }

Property Value

Type	Description
ScrollBlock

Remarks

This function will block scrolling movement in a given direction. One can disable movements in the X-axis, the Y-axis, or both. The default value is ScrollBlock.None, where movements are allowed in both directions.

API Level: preview

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SingleDirection

Gets or sets the type of single direction scroll.

Declaration


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public ScrollSingleDirection SingleDirection { get; set; }

Property Value

Type	Description
ScrollSingleDirection

API Level: preview

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VerticalBounce

Sets or gets the vertical bounce behaviour. When scrolling, the scroller may "bounce" when reaching an edge of the content object. This is a visual way to indicate the end has been reached. This is enabled by default for both axis. This API will set if it is enabled for the given axis with the boolean parameters for each axis.

Declaration


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public bool VerticalBounce { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

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VerticalGravity

Declaration


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public double VerticalGravity { get; set; }

Property Value

Type	Description
System.Double

API Level: preview

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VerticalLoop

Sets an infinite loop_ for a scroller. This function sets the infinite loop vertically. If the content is set, it will be shown repeatedly.

Declaration


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public bool VerticalLoop { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

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VerticalPageIndex

Sets or gets the scroll current page number.

Declaration


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public int VerticalPageIndex { get; }

Property Value

Type	Description
System.Int32

Remarks

Current page means the page which meets the top of the viewport. If there are two or more pages in the viewport, it returns the number of the page which meets the top of the viewport. The page number starts from 0. 0 is the first page.

API Level: preview

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VerticalPageScrollLimit

Sets or gets the maximum limit of the movable page at vertical direction.

Declaration


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public int VerticalPageScrollLimit { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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VerticalRelativePageSize

Gets or sets a given scroller widget's scrolling page size, relative to its viewport size.

Declaration


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public double VerticalRelativePageSize { get; set; }

Property Value

Type	Description
System.Double

API Level: preview

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VerticalScrollBarVisiblePolicy

Sets or gets the value of VerticalScrollBarVisiblePolicy.

Declaration


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public virtual ScrollBarVisiblePolicy VerticalScrollBarVisiblePolicy { get; set; }

Property Value

Type	Description
ScrollBarVisiblePolicy

Remarks

ScrollBarVisiblePolicy.Auto means the vertical scrollbar is made visible if it is needed, and otherwise kept hidden. ScrollBarVisiblePolicy.Visible turns it on all the time, and ScrollBarVisiblePolicy.Invisible always keeps it off.

API Level: preview

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VerticalSnap

Gets or sets the page snapping behavior of a scroller.

Declaration


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public bool VerticalSnap { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

When scrolling, if a scroller is paged (see VerticalRelativePageSize), the scroller may snap to pages when being scrolled, i.e., even if it had momentum to scroll further, it will stop at the next page boundaries. This is disabled, by default, for both axis. This function will set if it that is enabled or not, for each axis.

API Level: preview

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VerticalStepSize

Gets or sets the step size to move scroller by key event.

Declaration


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public int VerticalStepSize { get; set; }

Property Value

Type	Description
System.Int32

API Level: preview

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WheelDisabled

Gets or sets a value whether mouse wheel is enabled or not over the scroller.

Declaration


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public bool WheelDisabled { get; set; }

Property Value

Type	Description
System.Boolean

API Level: preview

Methods

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CreateHandle(EvasObject)

Creates a widget handle.

Declaration


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protected override IntPtr CreateHandle(EvasObject parent)

Parameters

Type	Name	Description
EvasObject	parent	Parent EvasObject.

Returns

Type	Description
System.IntPtr	Handle IntPtr.

Overrides

Layout.CreateHandle(EvasObject)

API Level: preview

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MinimumLimit(Boolean, Boolean)

Sets the scroller minimum size limited to the minimum size of the content. By default, the scroller will be as small as its design allows, irrespective of its content. This will make the scroller minimum size the right size horizontally and/or vertically to perfectly fit its content in that direction.

Declaration


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public void MinimumLimit(bool horizontal, bool vertical)

Parameters

Type	Name	Description
System.Boolean	horizontal	Enable limiting minimum size horizontally.
System.Boolean	vertical	Enable limiting minimum size vertically.

API Level: preview

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OnRealized()

The callback of the Realized event.

Declaration


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protected override void OnRealized()

Overrides

Layout.OnRealized()

API Level: preview

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ScrollTo(Rect, Boolean)

Shows a specific virtual region within the scroller content object.

Declaration


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public void ScrollTo(Rect region, bool animated)

Parameters

Type	Name	Description
Rect	region	Rect struct of region.
System.Boolean	animated	True means allows the scroller to "smoothly slide" to this location.

Remarks

This ensures that all (or part, if it does not fit) of the designated region in the virtual content object ((0, 0) starting at the top-left of the virtual content object) is shown within the scroller. If set "animated" to true, it will allows the scroller to "smoothly slide" to this location (if configuration in general calls for transitions). It may not jump immediately to the new location and may take a while and show other content along the way.

API Level: preview

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ScrollTo(Int32, Int32, Boolean)

Shows a specific virtual region within the scroller content object by the page number. (0, 0) of the indicated page is located at the top-left corner of the viewport.

Declaration


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public void ScrollTo(int horizontalPageIndex, int verticalPageIndex, bool animated)

Parameters

Type	Name	Description
System.Int32	horizontalPageIndex	The horizontal page number.
System.Int32	verticalPageIndex	The vertical page number.
System.Boolean	animated	True means slider with animation.

API Level: preview

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SetPageSize(Double, Double)

Sets the scroll page size relative to the viewport size.

Declaration


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public void SetPageSize(double width, double height)

Parameters

Type	Name	Description
System.Double	width	The horizontal page relative size.
System.Double	height	The vertical page relative size.

Remarks

The scroller is capable of limiting scrolling by the user to "pages". That is to jump by and only show a "whole page" at a time as if the continuous area of the scroller content is split into page sized pieces. This sets the size of a page relative to the viewport of the scroller. 1.0 is "1 viewport" which is the size (horizontally or vertically). 0.0 turns it off in that axis. This is mutually exclusive with the page size (see elm_scroller_page_size_set() for more information). Likewise 0.5 is "half a viewport". Usable values are normally between 0.0 and 1.0 including 1.0. If you only want 1 axis to be page "limited", use 0.0 for the other axis.

API Level: preview

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SetPageSize(Int32, Int32)

Sets the page size to an absolute fixed value, with 0 turning it off for that axis.

Declaration


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public void SetPageSize(int width, int height)

Parameters

Type	Name	Description
System.Int32	width	The horizontal page size.
System.Int32	height	The vertical page size.

API Level: preview

Events

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DragStart

DragStart will be triggered when dragging the contents around has started.

Declaration


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public event EventHandler DragStart

Event Type

Type	Description
System.EventHandler

API Level: preview

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DragStop

DragStop will be triggered when dragging the contents around has stopped.

Declaration


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public event EventHandler DragStop

Event Type

Type	Description
System.EventHandler

API Level: preview

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PageScrolled

PageScrolled will be triggered when the visible page has changed.

Declaration


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public event EventHandler PageScrolled

Event Type

Type	Description
System.EventHandler

API Level: preview

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ScrollAnimationStarted

ScrollAnimationStarted will be triggered when the content animation has been started.

Declaration


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public event EventHandler ScrollAnimationStarted

Event Type

Type	Description
System.EventHandler

API Level: preview

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ScrollAnimationStopped

ScrollAnimationStopped will be triggered when the content animation has been stopped.

Declaration


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public event EventHandler ScrollAnimationStopped

Event Type

Type	Description
System.EventHandler

API Level: preview

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Scrolled

Scrolled will be triggered when the content has been scrolled.

Declaration


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public event EventHandler Scrolled

Event Type

Type	Description
System.EventHandler

API Level: preview

Implements

IAccessibleObject

Extension Methods

RotaryEventExtensions.AddRotaryEventHandler(EvasObject, RotaryEventHandler)

RotaryEventExtensions.RemoveRotaryEventHandler(EvasObject, RotaryEventHandler)

RotaryEventExtensions.Activate(EvasObject)

RotaryEventExtensions.Deactivate(EvasObject)