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   if (clientRects.length == 0) {
  15     var box = element.getBoundingClientRect();
  16     if (element.tagName.toLowerCase() == 'area') {
  17       var coords = element.coords.split(',');
  18       if (element.shape.toLowerCase() == 'rect') {
  19         if (coords.length != 4)
  20           throw new Error('failed to detect the region of the area');
  21         var leftX = Number(coords[0]);
  22         var topY = Number(coords[1]);
  23         var rightX = Number(coords[2]);
  24         var bottomY = Number(coords[3]);
  25         return {
  26             'left': leftX,
  27             'top': topY,
  28             'width': rightX - leftX,
  29             'height': bottomY - topY
  30         };
  31       } else if (element.shape.toLowerCase() == 'circle') {
  32         if (coords.length != 3)
  33           throw new Error('failed to detect the region of the area');
  34         var centerX = Number(coords[0]);
  35         var centerY = Number(coords[1]);
  36         var radius = Number(coords[2]);
  37         return {
  38             'left': Math.max(0, centerX - radius),
  39             'top': Math.max(0, centerY - radius),
  40             'width': radius * 2,
  41             'height': radius * 2
  42         };
  43       } else if (element.shape.toLowerCase() == 'poly') {
  44         if (coords.length < 2)
  45           throw new Error('failed to detect the region of the area');
  46         var minX = Number(coords[0]);
  47         var minY = Number(coords[1]);
  48         var maxX = minX;
  49         var maxY = minY;
  50         for (i = 2; i < coords.length; i += 2) {
  51           var x = Number(coords[i]);
  52           var y = Number(coords[i + 1]);
  53           minX = Math.min(minX, x);
  54           minY = Math.min(minY, y);
  55           maxX = Math.max(maxX, x);
  56           maxY = Math.max(maxY, y);
  57         }
  58         return {
  59             'left': minX,
  60             'top': minY,
  61             'width': maxX - minX,
  62             'height': maxY - minY
  63         };
  64       } else {
  65         throw new Error('shape=' + element.shape + ' is not supported');
  66       }
  67     }
  68     return {
  69         'left': 0,
  70         'top': 0,
  71         'width': box.width,
  72         'height': box.height
  73     };
  74   } else {
  75     var clientRect = clientRects[0];
  76     var box = element.getBoundingClientRect();
  77     return {
  78         'left': clientRect.left - box.left,
  79         'top': clientRect.top - box.top,
  80         'width': clientRect.right - clientRect.left,
  81         'height': clientRect.bottom - clientRect.top
  82     };
  83   }
  84 }