chrome/test/chromedriver/js/get_element_region.js

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 function getElementRegion(element) {
   6   // Check that node type is element.
   7   if (element.nodeType != 1)
   8     throw new Error(element + ' is not an element');
   9
  10   // We try 2 methods to determine element region. Try the first client rect,
  11   // and then the bounding client rect.
  12   // SVG is one case that doesn't have a first client rect.
  13   var clientRects = element.getClientRects();
  14
  15   // Element area of a map has same first ClientRect and BoundingClientRect
  16   // after blink roll at chromium commit position 290738 which includes blink
  17   // revision 180610. Thus handle area as a special case.
  18   if (clientRects.length == 0 || element.tagName.toLowerCase() == 'area') {
  19     var box = element.getBoundingClientRect();
  20     if (element.tagName.toLowerCase() == 'area') {
  21       var coords = element.coords.split(',');
  22       if (element.shape.toLowerCase() == 'rect') {
  23         if (coords.length != 4)
  24           throw new Error('failed to detect the region of the area');
  25         var leftX = Number(coords[0]);
  26         var topY = Number(coords[1]);
  27         var rightX = Number(coords[2]);
  28         var bottomY = Number(coords[3]);
  29         return {
  30             'left': leftX,
  31             'top': topY,
  32             'width': rightX - leftX,
  33             'height': bottomY - topY
  34         };
  35       } else if (element.shape.toLowerCase() == 'circle') {
  36         if (coords.length != 3)
  37           throw new Error('failed to detect the region of the area');
  38         var centerX = Number(coords[0]);
  39         var centerY = Number(coords[1]);
  40         var radius = Number(coords[2]);
  41         return {
  42             'left': Math.max(0, centerX - radius),
  43             'top': Math.max(0, centerY - radius),
  44             'width': radius * 2,
  45             'height': radius * 2
  46         };
  47       } else if (element.shape.toLowerCase() == 'poly') {
  48         if (coords.length < 2)
  49           throw new Error('failed to detect the region of the area');
  50         var minX = Number(coords[0]);
  51         var minY = Number(coords[1]);
  52         var maxX = minX;
  53         var maxY = minY;
  54         for (i = 2; i < coords.length; i += 2) {
  55           var x = Number(coords[i]);
  56           var y = Number(coords[i + 1]);
  57           minX = Math.min(minX, x);
  58           minY = Math.min(minY, y);
  59           maxX = Math.max(maxX, x);
  60           maxY = Math.max(maxY, y);
  61         }
  62         return {
  63             'left': minX,
  64             'top': minY,
  65             'width': maxX - minX,
  66             'height': maxY - minY
  67         };
  68       } else {
  69         throw new Error('shape=' + element.shape + ' is not supported');
  70       }
  71     }
  72     return {
  73         'left': 0,
  74         'top': 0,
  75         'width': box.width,
  76         'height': box.height
  77     };
  78   } else {
  79     var clientRect = clientRects[0];
  80     var box = element.getBoundingClientRect();
  81     return {
  82         'left': clientRect.left - box.left,
  83         'top': clientRect.top - box.top,
  84         'width': clientRect.right - clientRect.left,
  85         'height': clientRect.bottom - clientRect.top
  86     };
  87   }
  88 }