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ThinkGeoVectorTileOverlay

Namespace: ThinkGeo.UI.Maui

ThinkGeo's vector basemap as an overlay: the newer ThinkGeo vector tiles, drawn from a MapLibre style document. The successor to ThinkGeoVectorOverlay.

public class ThinkGeoVectorTileOverlay : TileOverlay, System.ComponentModel.INotifyPropertyChanged, Microsoft.Maui.Controls.Internals.IDynamicResourceHandler, Microsoft.Maui.Controls.IElementDefinition, Microsoft.Maui.Controls.Internals.INameScope, Microsoft.Maui.Controls.IElementController, Microsoft.Maui.IVisualTreeElement, Microsoft.Maui.IElement, Microsoft.Maui.Controls.IEffectControlProvider, Microsoft.Maui.IToolTipElement, Microsoft.Maui.IContextFlyoutElement, Microsoft.Maui.Controls.IControlsElement, Microsoft.Maui.IHandlerDisconnectPolicies, Microsoft.Maui.Controls.StyleSheets.IStyleSelectable, Microsoft.Maui.Controls.Internals.INavigationProxy, Microsoft.Maui.Controls.IAnimatable, Microsoft.Maui.Controls.IVisualElementController, Microsoft.Maui.Controls.IResourcesProvider, Microsoft.Maui.Controls.IStyleElement, Microsoft.Maui.Controls.IFlowDirectionController, Microsoft.Maui.Controls.IPropertyPropagationController, Microsoft.Maui.Controls.IVisualController, Microsoft.Maui.Controls.IWindowController, Microsoft.Maui.IView, Microsoft.Maui.ITransform, Microsoft.Maui.Controls.IControlsVisualElement, Microsoft.Maui.IConstrainedView, Microsoft.Maui.Controls.StyleSheets.IStylable, Microsoft.Maui.Controls.IViewController, Microsoft.Maui.Controls.Internals.IGestureController, Microsoft.Maui.Controls.IGestureRecognizers, Microsoft.Maui.IPropertyMapperView, Microsoft.Maui.HotReload.IHotReloadableView, Microsoft.Maui.IReplaceableView, Microsoft.Maui.Controls.IControlsView, Microsoft.Maui.ILayout, Microsoft.Maui.IContainer, System.Collections.Generic.IList`1[[Microsoft.Maui.IView, Microsoft.Maui, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]], System.Collections.Generic.ICollection`1[[Microsoft.Maui.IView, Microsoft.Maui, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]], System.Collections.Generic.IEnumerable`1[[Microsoft.Maui.IView, Microsoft.Maui, Version=10.0.0.0, Culture=neutral, PublicKeyToken=null]], System.Collections.IEnumerable, Microsoft.Maui.ISafeAreaView, Microsoft.Maui.IPadding, Microsoft.Maui.ICrossPlatformLayout, Microsoft.Maui.Controls.IBindableLayout, Microsoft.Maui.Controls.IPaddingElement, Microsoft.Maui.Controls.IInputTransparentContainerElement, Microsoft.Maui.ISafeAreaView2, Microsoft.Maui.ISafeAreaElement, Microsoft.Maui.IAbsoluteLayout, System.IDisposable

Inheritance object → BindableObject → Element → StyleableElement → NavigableElement → VisualElement → View → Layout → AbsoluteLayout → Overlay → TileOverlay → ThinkGeoVectorTileOverlay
Implements INotifyPropertyChanged, IDynamicResourceHandler, IElementDefinition, INameScope, IElementController, IVisualTreeElement, IElement, IEffectControlProvider, IToolTipElement, IContextFlyoutElement, IControlsElement, IHandlerDisconnectPolicies, IStyleSelectable, INavigationProxy, IAnimatable, IVisualElementController, IResourcesProvider, IStyleElement, IFlowDirectionController, IPropertyPropagationController, IVisualController, IWindowController, IView, ITransform, IControlsVisualElement, IConstrainedView, IStylable, IViewController, IGestureController, IGestureRecognizers, IPropertyMapperView, IHotReloadableView, IReplaceableView, IControlsView, ILayout, IContainer, IList<IView>, ICollection<IView>, IEnumerable<IView>, IEnumerable, ISafeAreaView, IPadding, ICrossPlatformLayout, IBindableLayout, IPaddingElement, IInputTransparentContainerElement, ISafeAreaView2, ISafeAreaElement, IAbsoluteLayout, IDisposable

Remarks:

The overlay is a ThinkGeoVectorTileAsyncLayer and the tiling around it: what is drawn is the layer's business, and when, in how many pieces and out of which cache is the overlay's. Changing the style or the background redraws the tiles on screen. A TileOverlay.TileCache is left alone: it holds pictures of the map as one style drew it, so give each style a cache of its own rather than one cache to share.

Fields

transientNamescope

public INameScope transientNamescope;

Properties

ApiKey

The apiKey every tile request carries. Required before the first draw; given to the constructor, or set here by XAML.

public string ApiKey { get; set; }

Property Value

string

StyleUri

The style document the map is drawn from - its address or its text. ThinkGeoVectorStyles names the published ones, so light and dark are ThinkGeoVectorStyles.Light and ThinkGeoVectorStyles.Dark; any other MapLibre document is given the same way. Light by default. Setting it redraws from the new document without the vector tiles being fetched again.

public string StyleUri { get; set; }

Property Value

string

TransparentBackground

Draws the ink and nothing else: every area fill left out and the background left clear, so whatever is underneath shows through. What to put a street map on top of aerial imagery with. False by default.

public bool TransparentBackground { get; set; }

Property Value

bool

LabelDisplayMode

What the overlay draws: the shapes and the labels (the default), the shapes alone, or the labels alone. With both, the shapes go into the tiles and the labels are drawn once over the whole view on top of them, so no tile edge runs through a label; a single-tile overlay draws both into its one tile. The halves are for two overlays over one map, the shapes in tiles under something of the application's own and the labels above it.

public LabelDisplayMode LabelDisplayMode { get; set; }

Property Value

LabelDisplayMode

VectorTileCache

Where the vector tiles are kept on disk once they have been downloaded, so that a tile is asked of the server once. Null, the default, keeps nothing. These are the tiles themselves and serve every style; TileOverlay.TileCache holds the pictures drawn from them, which are of one style.

public FileTileCache VectorTileCache { get; set; }

Property Value

FileTileCache

WebProxy

The proxy the tile requests go through, or null for none.

public IWebProxy WebProxy { get; set; }

Property Value

IWebProxy

TimeoutInSeconds

How long a tile request may take, in seconds; 15 by default.

public int TimeoutInSeconds { get; set; }

Property Value

int

ShowDebugInfo

Outlines every vector tile a view was drawn from and writes its zoom, column and row over it. For finding out which tiles a view asks for; false by default.

public bool ShowDebugInfo { get; set; }

Property Value

bool

TileWidth

Gets or sets the width of the tile.

public int TileWidth { get; set; }

Property Value

int
The width of the tile.

TileHeight

Gets or sets the height of the tile.

public int TileHeight { get; set; }

Property Value

int
The height of the tile.

IsCacheOnly

Gets or sets a value indicating whether this instance is cache only.

public bool IsCacheOnly { get; set; }

Property Value

bool
true if this instance is cache only; otherwise, false.

TileBuffer

Gets or sets the number of extra tile rows and columns drawn around the minimum grid needed to cover the map.

public int TileBuffer { get; set; }

Property Value

int

Remarks:

Increasing this value can reduce blank areas during pan gestures because tiles just outside the viewport are already drawn. The default value is 0.

CurrentZoomTileCacheCapacity

Gets or sets the maximum number of current zoom tile views retained in memory.

public int CurrentZoomTileCacheCapacity { get; set; }

Property Value

int

Remarks:

Retained tile views can be reused during pan gestures to reduce blank areas while newly requested tiles are still drawing. The default value is 8.

ZoomOutTileCacheCapacity

Gets or sets the maximum number of zoom-out tile views retained in memory.

public int ZoomOutTileCacheCapacity { get; set; }

Property Value

int

Remarks:

Retained zoom-out tile views can be stretched temporarily during zoom or fast pan gestures until current zoom tiles are available. The default value is 16.

MaxConcurrentTileDraws

Maximum number of tiles drawn concurrently per refresh in MultiTile mode. Defaults to int.MaxValue (unbounded) to match historical behavior. Lower it (for example to 4 or 8) to cap memory and threadpool pressure on slow networks or low-memory devices. Mirrors ThinkGeo.UI.Desktop.TileOverlay.MaxConcurrentTileDraws.

public int MaxConcurrentTileDraws { get; set; }

Property Value

int

Remarks:

The cap covers both the per-tile draw stage and the subsequent post-to-UI stage of a single refresh. Has no effect on SingleTile rendering.

Tile drawing (Skia bitmap allocation and path rendering) is CPU-bound work, so strictly speaking this knob caps the degree of parallelism, not just concurrency. The "Concurrent" name is kept to align with the related throttles elsewhere in the SDK (MaxConcurrentTileLoads, MaxConcurrentRequests) so a single autocomplete prefix surfaces them together.

TileCache

Gets or sets the tile cache.

public RasterTileCache TileCache { get; set; }

Property Value

RasterTileCache
The tile cache.

TileType

Gets and sets the overlay is formed by multiple tiles or single tile.

public TileType TileType { get; set; }

Property Value

TileType
The type of the tile.

TransitionEffect

Gets or sets the tile transition effect.

public TransitionEffect TransitionEffect { get; set; }

Property Value

TransitionEffect
The tile snapping mode.

RenderingOptions

Gets or sets all Skia rendering options applied when tiles are drawn.

public RenderingOptions RenderingOptions { get; set; }

Property Value

RenderingOptions

ZoomLevelSet

Gets or sets the ZoomLevelSet for the TileOverlay. By default, this will snap to the scales defined in the ZoomLevelSet to fetch the internal data.

public ZoomLevelSet ZoomLevelSet { get; set; }

Property Value

ZoomLevelSet

Remarks:

Ensure that the ZoomLevelSet scales align with those of the tile provider, especially when using third-party data.

Name

Gets or sets the name of this overlay.

public string Name { get; set; }

Property Value

string

Attribution

Gets the attribution text displayed for this overlay.

public string Attribution { get; protected set; }

Property Value

string

Remarks:

Set by derived overlays to describe the data source rendered on the map.

DrawingExceptionMode

This property gets and sets the DrawingExceptionMode used when an exception occurs during drawing.

public DrawingExceptionMode DrawingExceptionMode { get; set; }

Property Value

DrawingExceptionMode
The drawing exception mode.

IsEmpty

This property gets if this overlay is empty or not.

public bool IsEmpty { get; }

Property Value

bool

Remarks:

This property enhances the performance of the overlay while drawing. If is true, we will skip drawing this overlay and continue drawing the next overlay.

Children

public IList<IView> Children { get; }

Property Value

IList<IView>

Count

public int Count { get; }

Property Value

int

IsReadOnly

public bool IsReadOnly { get; }

Property Value

bool

Item

public IView Item { get; set; }

Property Value

IView

IsClippedToBounds

public bool IsClippedToBounds { get; set; }

Property Value

bool

Padding

public Thickness Padding { get; set; }

Property Value

Thickness

SafeAreaEdges

public SafeAreaEdges SafeAreaEdges { get; set; }

Property Value

SafeAreaEdges

IgnoreSafeArea

public bool IgnoreSafeArea { get; set; }

Property Value

bool

CascadeInputTransparent

public bool CascadeInputTransparent { get; set; }

Property Value

bool

GestureRecognizers

public IList<IGestureRecognizer> GestureRecognizers { get; }

Property Value

IList<IGestureRecognizer>

HorizontalOptions

public LayoutOptions HorizontalOptions { get; set; }

Property Value

LayoutOptions

Margin

public Thickness Margin { get; set; }

Property Value

Thickness

VerticalOptions

public LayoutOptions VerticalOptions { get; set; }

Property Value

LayoutOptions

Visual

public IVisual Visual { get; set; }

Property Value

IVisual

FlowDirection

public FlowDirection FlowDirection { get; set; }

Property Value

FlowDirection

Window

public Window Window { get; }

Property Value

Window

AnchorX

public double AnchorX { get; set; }

Property Value

double

AnchorY

public double AnchorY { get; set; }

Property Value

double

BackgroundColor

public Color BackgroundColor { get; set; }

Property Value

Color

Background

public Brush Background { get; set; }

Property Value

Brush

Behaviors

public IList<Behavior> Behaviors { get; }

Property Value

IList<Behavior>

Bounds

public Rect Bounds { get; }

Property Value

Rect

Height

public double Height { get; }

Property Value

double

HeightRequest

public double HeightRequest { get; set; }

Property Value

double

InputTransparent

public bool InputTransparent { get; set; }

Property Value

bool

IsEnabled

public bool IsEnabled { get; set; }

Property Value

bool

IsFocused

public bool IsFocused { get; }

Property Value

bool

IsVisible

public bool IsVisible { get; set; }

Property Value

bool

MinimumHeightRequest

public double MinimumHeightRequest { get; set; }

Property Value

double

MinimumWidthRequest

public double MinimumWidthRequest { get; set; }

Property Value

double

MaximumHeightRequest

public double MaximumHeightRequest { get; set; }

Property Value

double

MaximumWidthRequest

public double MaximumWidthRequest { get; set; }

Property Value

double

Opacity

public double Opacity { get; set; }

Property Value

double

Rotation

public double Rotation { get; set; }

Property Value

double

RotationX

public double RotationX { get; set; }

Property Value

double

RotationY

public double RotationY { get; set; }

Property Value

double

Scale

public double Scale { get; set; }

Property Value

double

ScaleX

public double ScaleX { get; set; }

Property Value

double

ScaleY

public double ScaleY { get; set; }

Property Value

double

TranslationX

public double TranslationX { get; set; }

Property Value

double

TranslationY

public double TranslationY { get; set; }

Property Value

double

Triggers

public IList<TriggerBase> Triggers { get; }

Property Value

IList<TriggerBase>

Width

public double Width { get; }

Property Value

double

WidthRequest

public double WidthRequest { get; set; }

Property Value

double

X

public double X { get; }

Property Value

double

Y

public double Y { get; }

Property Value

double

Clip

public Geometry Clip { get; set; }

Property Value

Geometry

Batched

public bool Batched { get; }

Property Value

bool

DisableLayout

public bool DisableLayout { get; set; }

Property Value

bool

IsInPlatformLayout

public bool IsInPlatformLayout { get; set; }

Property Value

bool

IsPlatformStateConsistent

public bool IsPlatformStateConsistent { get; set; }

Property Value

bool

IsPlatformEnabled

public bool IsPlatformEnabled { get; set; }

Property Value

bool

Resources

public ResourceDictionary Resources { get; set; }

Property Value

ResourceDictionary

Frame

public Rect Frame { get; set; }

Property Value

Rect

Handler

public IViewHandler Handler { get; set; }

Property Value

IViewHandler

Shadow

public Shadow Shadow { get; set; }

Property Value

Shadow

ZIndex

public int ZIndex { get; set; }

Property Value

int

DesiredSize

public Size DesiredSize { get; protected set; }

Property Value

Size

IsLoaded

public bool IsLoaded { get; }

Property Value

bool

public INavigation Navigation { get; internal set; }

Property Value

INavigation

public NavigationProxy NavigationProxy { get; }

Property Value

NavigationProxy

Style

public Style Style { get; set; }

Property Value

Style

StyleClass

public IList<string> StyleClass { get; set; }

Property Value

IList<string>

class

public IList<string> class { get; set; }

Property Value

IList<string>

AutomationId

public string AutomationId { get; set; }

Property Value

string

ClassId

public string ClassId { get; set; }

Property Value

string

Effects

public IList<Effect> Effects { get; }

Property Value

IList<Effect>

Id

public Guid Id { get; }

Property Value

Guid

StyleId

public string StyleId { get; set; }

Property Value

string

LogicalChildren

public ReadOnlyCollection<Element> LogicalChildren { get; }

Property Value

ReadOnlyCollection<Element>

RealParent

public Element RealParent { get; }

Property Value

Element

Parent

public Element Parent { get; set; }

Property Value

Element

EffectControlProvider

public IEffectControlProvider EffectControlProvider { get; set; }

Property Value

IEffectControlProvider

Handler

public IElementHandler Handler { get; set; }

Property Value

IElementHandler

Dispatcher

public IDispatcher Dispatcher { get; }

Property Value

IDispatcher

BindingContext

public object BindingContext { get; set; }

Property Value

object

Constructors

ThinkGeoVectorTileOverlay()

Initializes a new instance with no apiKey yet - for XAML, which constructs first and sets properties after. ThinkGeoVectorTileOverlay.ApiKey must be set before the first draw.

public ThinkGeoVectorTileOverlay()

ThinkGeoVectorTileOverlay(string)

Initializes a new instance over the published WorldStreets tiles, drawn in the light style.

public ThinkGeoVectorTileOverlay(string apiKey)

Parameters

apiKey string
Your ThinkGeo apiKey; every tile request carries it.

ThinkGeoVectorTileOverlay(string, string)

Initializes a new instance over the published WorldStreets tiles, drawn from the style document given.

public ThinkGeoVectorTileOverlay(string apiKey, string styleUri)

Parameters

apiKey string
Your ThinkGeo apiKey; every tile request carries it.

styleUri string
The style document: see .

Methods

GetBoundingBoxCore()

protected RectangleShape GetBoundingBoxCore()

Returns

RectangleShape

GetTileCore()

protected TileView GetTileCore()

Returns

TileView

OpenAsyncCore(IMapView, CancellationToken)

protected Task OpenAsyncCore(IMapView mapView, CancellationToken cancellationToken)

Parameters

mapView IMapView

cancellationToken CancellationToken

Returns

Task

CloseAsyncCore(CancellationToken)

protected Task CloseAsyncCore(CancellationToken cancellationToken)

Parameters

cancellationToken CancellationToken

Returns

Task

DrawAsyncCore(OverlayRefreshType, CancellationToken)

protected Task DrawAsyncCore(OverlayRefreshType refreshType, CancellationToken cancellationToken)

Parameters

refreshType OverlayRefreshType

cancellationToken CancellationToken

Returns

Task

DrawWithoutPostingAsyncCore(OverlayRefreshType, CancellationToken)

protected Task DrawWithoutPostingAsyncCore(OverlayRefreshType refreshType, CancellationToken cancellationToken)

Parameters

refreshType OverlayRefreshType

cancellationToken CancellationToken

Returns

Task

PostAsyncCore(CancellationToken)

protected Task PostAsyncCore(CancellationToken cancellationToken)

Parameters

cancellationToken CancellationToken

Returns

Task

TransformCore(RectangleShape, IMapView)

protected void TransformCore(RectangleShape extent, IMapView mapView)

Parameters

extent RectangleShape

mapView IMapView

Returns

void

Events

SendingHttpRequest

Raised before each tile request is sent: rewrite the request, or set Cancel to skip it.

public event EventHandler<SendingHttpRequestMessageEventArgs> SendingHttpRequest;

ReceivedHttpResponse

Raised when a tile response has arrived, before its status is read.

public event EventHandler<ReceivedHttpResponseMessageEventArgs> ReceivedHttpResponse;

DrawingTile

The event raised before Drawing a tile

public event EventHandler<DrawingTileTileOverlayEventArgs> DrawingTile;

PostedTile

The event raised after Posted a tile

public event EventHandler<PostedTileTileOverlayEventArgs> PostedTile;

CreatingSKTypefaceForCharacter

Raised when a tile needs to resolve a custom SKTypeface for a character that is missing in the default font set.

public event EventHandler<CreatingSKTypefaceForCharacterEventArgs> CreatingSKTypefaceForCharacter;

Drawing

This event raises before the overlay is drawing.

public event EventHandler<DrawingOverlayEventArgs> Drawing;

Drawn

This event raises after the overlay is drawn.

public event EventHandler<DrawnOverlayEventArgs> Drawn;

ChildrenReordered

public event EventHandler ChildrenReordered;

Focused

public event EventHandler<FocusEventArgs> Focused;

MeasureInvalidated

public event EventHandler MeasureInvalidated;

SizeChanged

public event EventHandler SizeChanged;

Unfocused

public event EventHandler<FocusEventArgs> Unfocused;

BatchCommitted

public event EventHandler<EventArg<VisualElement>> BatchCommitted;

FocusChangeRequested

public event EventHandler<FocusRequestArgs> FocusChangeRequested;

Loaded

public event EventHandler Loaded;

Unloaded

public event EventHandler Unloaded;

ChildAdded

public event EventHandler<ElementEventArgs> ChildAdded;

ChildRemoved

public event EventHandler<ElementEventArgs> ChildRemoved;

DescendantAdded

public event EventHandler<ElementEventArgs> DescendantAdded;

DescendantRemoved

public event EventHandler<ElementEventArgs> DescendantRemoved;

ParentChanging

public event EventHandler<ParentChangingEventArgs> ParentChanging;

ParentChanged

public event EventHandler ParentChanged;

HandlerChanging

public event EventHandler<HandlerChangingEventArgs> HandlerChanging;

HandlerChanged

public event EventHandler HandlerChanged;

PropertyChanged

public event PropertyChangedEventHandler PropertyChanged;

PropertyChanging

public event PropertyChangingEventHandler PropertyChanging;

BindingContextChanged

public event EventHandler BindingContextChanged;