ActivityIndicator

An activity indicator (spinner) for showing indeterminate progress/loading states. Displays an animated spinning arc.

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Basic Usage

// Default spinner
new ActivityIndicator()

// Styled spinner
new ActivityIndicator()
    .SetColor(Colors.Green)
    .SetSpeed(1.5f)
    .SetStrokeThickness(4)

// Controlled spinner (start/stop)
new ActivityIndicator()
    .BindIsRunning(nameof(vm.IsLoading), () => vm.IsLoading)

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ActivityIndicator-Specific Methods

Method	Description
SetIsRunning(bool)	Starts or stops the animation (default: true)
BindIsRunning(name, getter)	Binds running state
SetColor(Color)	Sets spinner color (default: iOS blue)
BindColor(name, getter)	Binds spinner color
SetSpeed(float)	Sets rotation speed multiplier (default: 1.0, minimum: 0.1)
BindSpeed(name, getter)	Binds speed
SetStrokeThickness(float)	Sets line thickness (default: 3.0)
BindStrokeThickness(name, getter)	Binds stroke thickness

ActivityIndicator has a default size of 40x40 pixels. The spinner only animates when IsRunning is true. It automatically adds the Busy accessibility trait when running.

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Layout Methods

Methods inherited from UiElement:

Method	Description
SetMargin(Margin)	Sets outer margin
BindMargin(name, getter)	Binds margin
SetHorizontalAlignment(HorizontalAlignment)	Sets horizontal alignment
BindHorizontalAlignment(name, getter)	Binds horizontal alignment
SetVerticalAlignment(VerticalAlignment)	Sets vertical alignment
BindVerticalAlignment(name, getter)	Binds vertical alignment
SetDesiredSize(Size)	Sets explicit size
BindDesiredSize(name, getter)	Binds size
SetDesiredWidth(float)	Sets explicit width
BindDesiredWidth(name, getter)	Binds width
SetDesiredHeight(float)	Sets explicit height
BindDesiredHeight(name, getter)	Binds height

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Appearance Methods

Methods inherited from UiElement:

Method	Description
SetIsVisible(bool)	Shows/hides element
BindIsVisible(name, getter)	Binds visibility
SetOpacity(float)	Sets opacity 0.0-1.0 (default: 1.0)
BindOpacity(name, getter)	Binds opacity
SetBackground(IBackground)	Sets background (gradient, solid, etc.)
SetBackground(Color)	Sets solid color background
BindBackground(name, getter)	Binds background
SetCornerRadius(float)	Sets corner radius
BindCornerRadius(name, getter)	Binds corner radius
SetVisualOffset(Point)	Offsets visual position
BindVisualOffset(name, getter)	Binds visual offset

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Shadow Methods

Methods inherited from UiElement:

Method	Description
SetShadowColor(Color)	Sets shadow color
BindShadowColor(name, getter)	Binds shadow color
SetShadowOffset(Point)	Sets shadow offset
BindShadowOffset(name, getter)	Binds shadow offset
SetShadowBlur(float)	Sets shadow blur radius
BindShadowBlur(name, getter)	Binds shadow blur
SetShadowSpread(float)	Sets shadow spread
BindShadowSpread(name, getter)	Binds shadow spread

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Accessibility Methods

Methods inherited from UiElement:

Method	Description
SetAccessibilityLabel(string?)	Sets screen reader label (default: “Loading”)
BindAccessibilityLabel(name, getter)	Binds accessibility label
SetAccessibilityHint(string?)	Sets additional context hint
BindAccessibilityHint(name, getter)	Binds accessibility hint
SetAccessibilityValue(string?)	Sets current value description
BindAccessibilityValue(name, getter)	Binds accessibility value
SetAccessibilityTraits(AccessibilityTrait)	Sets accessibility traits
BindAccessibilityTraits(name, getter)	Binds accessibility traits
SetIsAccessibilityElement(bool)	Include in accessibility tree

ActivityIndicator has AccessibilityRole.Spinner by default and automatically adds the Busy trait when running.

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Tooltip Methods

Extension methods available on all UiElement:

Method	Description
SetTooltip(string)	Sets tooltip text
SetTooltip(UiElement)	Sets tooltip with custom content
SetTooltipPlacement(TooltipPlacement)	Sets tooltip position

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Context Menu Methods

Extension methods available on all UiElement:

Method	Description
SetContextMenu(ContextMenu)	Sets context menu
SetContextMenu(Action<ContextMenu>)	Configures context menu via builder

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Other Methods

Method	Description
IgnoreStyling()	Prevents global styles from being applied
SetDebug(bool)	Shows debug bounds (red border)

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Examples

Loading Overlay

new Border()
    .SetBackground(new Color(0, 0, 0, 128))
    .AddChild(
        new VStack()
            .SetHorizontalAlignment(HorizontalAlignment.Center)
            .SetVerticalAlignment(VerticalAlignment.Center)
            .AddChildren(
                new ActivityIndicator()
                    .SetColor(Colors.White)
                    .SetDesiredSize(new Size(60, 60)),
                new Label()
                    .SetText("Loading...")
                    .SetTextColor(Colors.White)
                    .SetMargin(new Margin(0, 16, 0, 0))
            )
    )
    .BindIsVisible(nameof(vm.IsLoading), () => vm.IsLoading)

Button with Loading State

new HStack()
    .SetVerticalAlignment(VerticalAlignment.Center)
    .AddChildren(
        new ActivityIndicator()
            .SetDesiredSize(new Size(20, 20))
            .SetColor(Colors.White)
            .BindIsRunning(nameof(vm.IsSaving), () => vm.IsSaving)
            .BindIsVisible(nameof(vm.IsSaving), () => vm.IsSaving),
        new Label()
            .BindText(nameof(vm.IsSaving), () => vm.IsSaving ? "Saving..." : "Save")
            .SetTextColor(Colors.White)
    )

Custom Styled Spinner

new ActivityIndicator()
    .SetColor(new Color(255, 87, 51))  // Orange
    .SetSpeed(2.0f)                     // Faster rotation
    .SetStrokeThickness(5)              // Thicker line
    .SetDesiredSize(new Size(80, 80))   // Larger size

Inline Loading Indicator

new HStack()
    .AddChildren(
        new Label().SetText("Checking availability"),
        new ActivityIndicator()
            .SetDesiredSize(new Size(16, 16))
            .SetMargin(new Margin(8, 0, 0, 0))
            .BindIsRunning(nameof(vm.IsChecking), () => vm.IsChecking)
    )

Conditional Spinner

new ActivityIndicator()
    .SetIsRunning(false)  // Initially stopped
    .SetColor(Colors.Blue)
// Later programmatically:
// spinner.SetIsRunning(true);