CustomEmptyWidget class

A highly customizable empty state widget for displaying "no content" scenarios.

This widget provides a flexible solution for showing empty states throughout the CulicidaeLab application. It supports various customization options including custom images, text styling, and complete widget replacement for maximum flexibility.

Design Philosophy

Empty states are crucial for user experience as they:

  • Provide clear feedback when no content is available
  • Guide users on what actions they can take
  • Maintain visual consistency across the application
  • Prevent confusion and improve usability

Usage Scenarios

  • Search Results: When no mosquito species match search criteria
  • Gallery Loading: While species data is being fetched
  • Classification: When no image has been selected yet
  • Disease Information: When no diseases are associated with a species
  • Network Errors: When data cannot be loaded from remote sources

Customization Options

The widget supports multiple levels of customization:

  • Standard: Use predefined image, title, and subtitle
  • Styled: Apply custom text styles and formatting
  • Widget-based: Replace image with custom widget (icons, illustrations)
  • Complete Override: Use entirely custom widget for unique layouts

Example Usage

// Basic usage with text only
CustomEmptyWidget(
  title: 'No mosquito species found',
  subtitle: 'Try adjusting your search criteria',
)

// With custom image and styling
CustomEmptyWidget(
  title: 'No classification results',
  subtitle: 'Please select an image to analyze',
  image: 'assets/images/empty_classification.png',
  titleTextStyle: TextStyle(fontSize: 20, color: Colors.teal),
)

// With custom icon widget
CustomEmptyWidget(
  title: 'No diseases found',
  imageWidget: Icon(Icons.health_and_safety, size: 64, color: Colors.grey),
)

Accessibility

The widget follows accessibility best practices:

  • Proper semantic structure for screen readers
  • Sufficient color contrast for text elements
  • Scalable text that respects user font size preferences
  • Meaningful content descriptions

See also:

Inheritance

Constructors

CustomEmptyWidget({Key? key, String? title, String? subtitle, String? image, String? packageImage, Widget? customWidget, Widget? imageWidget, bool hideTitle = false, bool hideSubTitle = false, TextStyle? titleTextStyle, TextStyle? subtitleTextStyle})
A highly customizable empty state widget for displaying "no content" scenarios.
const

Properties

customWidget → Widget?
A custom widget to display instead of the default content.
final
hashCode → int
The hash code for this object.
no setterinherited
hideSubTitle → bool
Whether to hide the subtitle text.
final
hideTitle → bool
Whether to hide the title text.
final
image → String?
The path to the image asset to display in the empty state.
final
imageWidget → Widget?
A custom widget to display in place of the default image.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
packageImage → String?
The package name if the image is from a package.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
subtitle → String?
The subtitle text to display in the empty state.
final
subtitleTextStyle → TextStyle?
The text style to apply to the subtitle text.
final
title → String?
The title text to display in the empty state.
final
titleTextStyle → TextStyle?
The text style to apply to the title text.
final

Methods

build(BuildContext context) → Widget
Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited