Syncfusion Flutter Slider Controls

This skill groups three related Syncfusion Flutter components for value selection and range interaction: SfSlider (single value), SfRangeSlider (two-thumb range), and SfRangeSelector (range selector with child content such as charts). They share many visual and configuration features but have distinct responsibilities and integration patterns.

When to Use This Skill

Use this skill when you need to:

• Select a single numeric or date value in a compact UI (use SfSlider).
• Select a start/end range with two thumbs (use SfRangeSlider).
• Select a range that drives another widget (chart zoom/selection) or shows child content (use SfRangeSelector).
• Customize visual track, ticks, labels, thumbs, or tooltips across slider controls.
• Integrate slider range with charts for selection or zooming.
• Support RTL, accessibility, and keyboard navigation for slider controls.

Choosing the Right Component

Use SfSlider when:

• You need a single value picker (volume, progress percentage, timeline scrubber).
• Simplicity and small surface area are required.

Use SfRangeSlider when:

• You need the user to pick a numeric/date interval with two thumbs.
• You need drag modes that control thumb behavior (onThumb, betweenThumbs, both).

Use SfRangeSelector when:

• You need a range control that contains or controls a child widget (commonly charts).
• You require a RangeController for programmatic updates and chart integrations.

Key Differences Summary:

Feature	SfSlider	SfRangeSlider	SfRangeSelector
Primary purpose	Single value	Two-thumb range	Range with child (chart)
Value type	value	values (SfRangeValues)	initialValues / controller
Child content	❌	❌	✅ (any widget, often charts)
Controller support	❌	❌	✅ (RangeController)
Drag modes	—	✅ (dragMode)	✅ (dragMode)
Deferred updates	❌	❌	✅ (enableDeferredUpdate)

Documentation and Navigation Guide

Getting Started

📄 Read: references/getting-started.md

• Installation and package setup for all three slider controls
• Basic SfSlider implementation (horizontal and vertical)
• Basic SfRangeSlider implementation
• Basic SfRangeSelector implementation with chart integration
• Package dependencies and imports
• Quick comparison and first examples
• Numeric and date-based slider examples

Component Overview

📄 For Slider: references/slider-overview.md

• SfSlider widget overview and features
• When to use single-value slider vs range controls
• Numeric and date value support
• Horizontal and vertical orientations
• Slider-specific capabilities
• Basic slider configuration

📄 For Range Slider: references/range-slider-overview.md

• SfRangeSlider widget overview and features
• When to use Range Slider vs Range Selector
• SfRangeValues class for start/end values
• Introduction to drag modes
• Active and inactive track regions
• Range slider-specific examples

📄 For Range Selector: references/range-selector-overview.md

• SfRangeSelector widget overview and features
• When to use Range Selector for chart integration
• Child widget support (charts, graphs, custom content)
• RangeController introduction
• Difference between initialValues and controller
• Deferred updates pattern
• Chart integration patterns

Value Configuration

📄 Read: references/values-and-intervals.md

• Minimum and maximum value configuration
• Value types (double, DateTime) for each widget
• Interval configuration and step values
• Numeric ranges with custom formatting
• Date and DateTime ranges
• DateIntervalType configuration
• NumberFormat and DateFormat usage
• Value constraints and validation

Visual Customization

📄 Read: references/track-and-shapes.md

• Active and inactive track colors
• Track height and thickness customization
• Track corners and shapes
• Custom track styling patterns
• Region colors for RangeSelector
• Track appearance across all three widgets

📄 Read: references/ticks-and-dividers.md

• Enabling and configuring tick marks
• Major ticks configuration
• Minor ticks and intervals
• Divider configuration
• Tick and divider styling
• Complete examples for all three widgets

📄 Read: references/labels-and-formatting.md

• Showing and positioning labels
• NumberFormat for numeric values (currency, percentage, compact)
• DateFormat for date values (various patterns)
• Custom label formatting with labelFormatterCallback
• Label text styling
• Label offset and positioning
• Edge label visibility

📄 Read: references/thumbs-tooltips-overlay.md

• Thumb size, color, and customization
• Thumb icons and custom widgets
• Thumb stroke (border) configuration
• Overlay (ripple) configuration
• Enabling and configuring tooltips
• Tooltip shapes (rectangular, paddle)
• Tooltip text formatting
• Always-visible tooltip option

Advanced Features

📄 Read: references/drag-modes.md

• Drag mode functionality (RangeSlider and RangeSelector only)
• SliderDragMode.onThumb explanation
• SliderDragMode.betweenThumbs explanation
• SliderDragMode.both explanation
• Choosing the right drag mode
• Use cases and examples for each mode

📄 Read: references/range-controller.md

• RangeController overview (RangeSelector only)
• When to use RangeController
• Creating and disposing controllers
• Deferred updates for performance
• Programmatic range updates
• Listening to range changes
• Chart integration with controller
• Controller vs initialValues comparison
• Advanced patterns (apply button, synchronized selectors)

Event Handling

📄 Read: references/callbacks-and-events.md

• onChanged callback (continuous updates)
• onChangeStart callback (interaction start)
• onChangeEnd callback (interaction complete)
• Complete lifecycle examples
• Validation and constraints in callbacks
• Async operations and debouncing
• Event handling patterns
• Best practices for callback usage

Accessibility and States

📄 Read: references/accessibility-and-states.md

• Accessibility overview and importance
• Semantic labels for screen readers
• Enabled and disabled states
• Keyboard navigation support
• Screen reader support (VoiceOver, TalkBack)
• Right-to-Left (RTL) language support
• WCAG compliance guidelines
• Color contrast considerations
• Touch target sizing
• Testing accessibility features

Quick Start Examples

SfSlider — Basic single-value slider

double _value = 40.0;

SfSlider(
  min: 0.0,
  max: 100.0,
  value: _value,
  interval: 20,
  showLabels: true,
  onChanged: (dynamic newValue) {
    setState(() { _value = newValue; });
  },
)

SfRangeSlider — Basic range

SfRangeValues _values = const SfRangeValues(40.0, 60.0);

SfRangeSlider(
  min: 0.0,
  max: 100.0,
  values: _values,
  interval: 20,
  showLabels: true,
  onChanged: (SfRangeValues newValues) {
    setState(() { _values = newValues; });
  },
)

SfRangeSelector — Range with chart child and controller

final SfRangeValues _initial = SfRangeValues(0.3, 0.7);
RangeController _controller = RangeController(start: 0.3, end: 0.7);

SfRangeSelector(
  min: 0,
  max: 1,
  initialValues: _initial,
  controller: _controller,
  child: SizedBox(height: 130, child: SfCartesianChart(...)),
)

Common Patterns

Pattern 1: Choose widget by need

• Single value → SfSlider
• Range selection → SfRangeSlider
• Range controlling chart/child → SfRangeSelector

Pattern 2: Controlled vs Uncontrolled

• SfSlider and SfRangeSlider are typically controlled by parent state via value/values and onChanged.
• SfRangeSelector can be driven via RangeController for programmatic updates and chart integrations.

Key Properties

SfSlider Essential Properties

• min - Minimum value (double or DateTime)
• max - Maximum value (double or DateTime)
• value - Current slider value
• interval - Interval between divisions
• stepSize - Step interval for discrete values
• onChanged - Callback when value changes
• onChangeStart - Callback when drag starts
• onChangeEnd - Callback when drag ends
• showLabels - Display labels at intervals
• showTicks - Display tick marks
• showDividers - Display dividers
• enableTooltip - Enable tooltip on interaction
• activeColor - Active track color
• inactiveColor - Inactive track color
• numberFormat - NumberFormat for numeric values
• dateFormat - DateFormat for DateTime values
• dateIntervalType - Interval type for dates (years, months, days, etc.)
• labelFormatterCallback - Custom label formatting
• tooltipTextFormatterCallback - Custom tooltip formatting
• semanticFormatterCallback - Accessibility label formatting

SfRangeSlider Essential Properties

• min - Minimum value (double or DateTime)
• max - Maximum value (double or DateTime)
• values - Current range values (SfRangeValues with start and end)
• interval - Interval between divisions
• stepSize - Step interval for discrete values
• onChanged - Callback when values change
• onChangeStart - Callback when drag starts
• onChangeEnd - Callback when drag ends
• dragMode - Drag interaction mode (onDragStart, onThumb, betweenThumbs, both)
• showLabels - Display labels at intervals
• showTicks - Display tick marks
• showDividers - Display dividers
• enableTooltip - Enable tooltips on interaction
• activeColor - Active track color (between thumbs)
• inactiveColor - Inactive track color
• numberFormat - NumberFormat for numeric values
• dateFormat - DateFormat for DateTime values
• dateIntervalType - Interval type for dates
• labelFormatterCallback - Custom label formatting
• tooltipTextFormatterCallback - Custom tooltip formatting
• semanticFormatterCallback - Accessibility label formatting

SfRangeSelector Essential Properties

• min - Minimum value (double or DateTime)
• max - Maximum value (double or DateTime)
• initialValues - Initial range values (SfRangeValues)
• controller - RangeController for programmatic control
• interval - Interval between divisions
• stepSize - Step interval for discrete values
• onChanged - Callback when values change (optional with controller)
• onChangeStart - Callback when drag starts
• onChangeEnd - Callback when drag ends
• dragMode - Drag interaction mode (onDragStart, onThumb, betweenThumbs, both)
• enableDeferredUpdate - Enable deferred updates for performance
• deferredUpdateDelay - Delay for deferred updates
• showLabels - Display labels at intervals
• showTicks - Display tick marks
• showDividers - Display dividers
• enableTooltip - Enable tooltips on interaction
• activeColor - Active track color (between thumbs)
• inactiveColor - Inactive track color
• child - Child widget (typically charts)
• numberFormat - NumberFormat for numeric values
• dateFormat - DateFormat for DateTime values
• dateIntervalType - Interval type for dates
• labelFormatterCallback - Custom label formatting
• tooltipTextFormatterCallback - Custom tooltip formatting
• semanticFormatterCallback - Accessibility label formatting
• enableIntervalSelection - Enable selection by interval
• showDivisors - Show region dividers

Common Use Cases

1. Volume or brightness controls — SfSlider
2. Date range filters — SfRangeSlider
3. Chart zoom/segment selection — SfRangeSelector + chart integration
4. Time-range pickers for analytics dashboards — SfRangeSelector
5. Two-ended price range filter in product lists — SfRangeSlider