element_query

A polyfill for Element Query.

Usage

• Use existing CSS syntax
• Elements/selectors must be registered through code
• Supported query types: min-width, max-width, min-height, max-height
• Supported units: px, em
• Queries are updated automatically when the window is resized. For other cases, a call to update is required.

CSS

header[min-width~="500px"] {
    color: red;
}
header[max-width~="500px"] nav {
    clear: both;
}
header[min-width~="500px"] nav[min-height~="3em"] {
    color: white;
}

Dart

import 'package:element_query/element_query.dart' as eq;

main() {
  // Initialize Element Query.
  // This method is safe to be called multiple times.
  eq.init();

  // Register a selector with two checkpoints for min-width.
  eq.register('.main-pane', minWidths: ['600px', '1000px']);
  
  // Register an element with one checkpoint for max-height.
  eq.register(element, maxHeights: ['3em']);


  document.querySelector('.left-pane')
    ..onClick.listen((e) {
      e.target.classes.toggle('expanded');
    })
    ..onTransitionEnd.listen((_) {
      // Call `update` to trigger a refresh.
      eq.update();
    });
}

Features and bugs

Please file feature requests and bugs at the issue tracker.