samples-dev/swarm/test/swarm_ui_lib/layout/grid_layout_demo.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

part of layout_tests;

/**
 * An app for testing the grid layout system.
 */

/** Creates a grid view structure given the CSS styles. */
View createGrid(Map<String, Map<String, String>> styles) {
  final gridStyle = styles['#grid'];

  final children = new List<MockView>();
  for (final String id in styles.keys) {
    // All selectors in this test are id selectors string the # prefix.
    assert(id.startsWith('#'));
    String elemId = id.substring(1);
    if (elemId != 'grid') {
      children.add(new MockView(elemId, styles[id]));
    }
  }

  return new MockCompositeView('grid', gridStyle, children);
}

void _onLoad() {
  var query = SwarmUri.parsequerySelector(window.location.search)['q'];
  if (query != null && query.length == 1) {
    query = SwarmUri.decodeComponent(query[0]);
    addGridStyles('100%', '100%', 'margin:0px;');
    final view = createGrid(GridExamples.styles[query]);
    view.addToDocument(document.body);
    _addColorStyles();
    printMetrics(query);
  } else {
    final html = new StringBuffer();
    for (String ex in GridExamples.styles.keys) {
      html.write('<div><a href="?q=$ex">Grid Example $ex</a></div>');
    }
    document.body.innerHtml = html.toString();
  }
}

void addGridStyles(String width, String height, [String margin = '']) {
  // Use monospace font and fixed line-height so the text size is predictable.
  // TODO(jmesserly): only tested on Chromium Mac/Linux
  Dom.addStyle('''
    body { $margin }
    #grid {
      position: absolute;
      width: $width;
      height: $height;
      border-color: black;
    }
    .grid-item {
      border: solid 2px;
      border-radius: 8px;
      font-family:monospace;
      font-size:16px;
      line-height:20px;
    }
    ''');
}

void _addColorStyles() {
  final grid = document.body.querySelector('#grid');
  final colors = const [
    'darkred',
    'darkorange',
    'darkgoldenrod',
    'darkgreen',
    'darkblue',
    'darkviolet'
  ];
  int c = 0;
  var node = grid.children[0];
  while (node != null) {
    if (node.id != '') {
      node.style.cssText += "color:" + colors[c++];
    }
    node = node.nextElementSibling;
  }
}

class MockCompositeView extends CompositeView {
  MockCompositeView(String id, Map styles, List childViews) : super('') {
    node.id = id;
    CollectionUtils.copyMap(customStyle, styles);

    for (final v in childViews) {
      addChild(v);
    }
  }
}

class MockView extends View {
  MockView(String id, Map styles)
      : super.fromNode(
            new Element.html('<div class="grid-item">MockView-$id</div>')) {
    node.id = id;
    CollectionUtils.copyMap(customStyle, styles);
    // TODO(jmesserly): this is needed to get horizontal content-sizing to work
    node.style.display = 'inline-block';
  }
}

void printMetrics(String example) {
  final node = document.body.querySelector('#grid');
  String exampleId = example.split(' ')[0];
  final sb = new StringBuffer();
  sb.write("test('Spec Example $exampleId', () {\n");
  sb.write("  verifyExample('$example', {\n");
  final children = node.children;

  scheduleMicrotask(() {
    for (int i = 0; i < children.length; i++) {
      _appendMetrics(sb, children[i], '    ');
    }
    sb.write('  });\n');
    sb.write('});\n\n');
    window.console.log(sb.toString());
  });
}

void _appendMetrics(StringBuffer sb, Element node, [String indent = '']) {
  String id = node.id;
  num left = node.offsetLeft, top = node.offsetTop;
  num width = node.offsetWidth, height = node.offsetHeight;
  sb.write("${indent}'$id': [$left, $top, $width, $height],\n");
}