chrome/browser/resources/net_internals/util.js

   1 // Copyright (c) 2012 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 /**
   6  * Sets the width (in pixels) on a DOM node.
   7  * @param {!HtmlNode} node The node whose width is being set.
   8  * @param {number} widthPx The width in pixels.
   9  */
  10 function setNodeWidth(node, widthPx) {
  11   node.style.width = widthPx.toFixed(0) + 'px';
  12 }
  13
  14 /**
  15  * Sets the height (in pixels) on a DOM node.
  16  * @param {!HtmlNode} node The node whose height is being set.
  17  * @param {number} heightPx The height in pixels.
  18  */
  19 function setNodeHeight(node, heightPx) {
  20   node.style.height = heightPx.toFixed(0) + 'px';
  21 }
  22
  23 /**
  24  * Sets the position and size of a DOM node (in pixels).
  25  * @param {!HtmlNode} node The node being positioned.
  26  * @param {number} leftPx The left position in pixels.
  27  * @param {number} topPx The top position in pixels.
  28  * @param {number} widthPx The width in pixels.
  29  * @param {number} heightPx The height in pixels.
  30  */
  31 function setNodePosition(node, leftPx, topPx, widthPx, heightPx) {
  32   node.style.left = leftPx.toFixed(0) + 'px';
  33   node.style.top = topPx.toFixed(0) + 'px';
  34   setNodeWidth(node, widthPx);
  35   setNodeHeight(node, heightPx);
  36 }
  37
  38 /**
  39  * Sets the visibility for a DOM node.
  40  * @param {!HtmlNode} node The node being positioned.
  41  * @param {boolean} isVisible Whether to show the node or not.
  42  */
  43 function setNodeDisplay(node, isVisible) {
  44   node.style.display = isVisible ? '' : 'none';
  45 }
  46
  47 /**
  48  * Adds a node to |parentNode|, of type |tagName|.
  49  * @param {!HtmlNode} parentNode The node that will be the parent of the new
  50  *     element.
  51  * @param {string} tagName the tag name of the new element.
  52  * @return {!HtmlElement} The newly created element.
  53  */
  54 function addNode(parentNode, tagName) {
  55   var elem = parentNode.ownerDocument.createElement(tagName);
  56   parentNode.appendChild(elem);
  57   return elem;
  58 }
  59
  60 /**
  61  * Adds |text| to node |parentNode|.
  62  * @param {!HtmlNode} parentNode The node to add text to.
  63  * @param {string} text The text to be added.
  64  * @return {!Object} The newly created text node.
  65  */
  66 function addTextNode(parentNode, text) {
  67   var textNode = parentNode.ownerDocument.createTextNode(text);
  68   parentNode.appendChild(textNode);
  69   return textNode;
  70 }
  71
  72 /**
  73  * Adds a node to |parentNode|, of type |tagName|.  Then adds
  74  * |text| to the new node.
  75  * @param {!HtmlNode} parentNode The node that will be the parent of the new
  76  *     element.
  77  * @param {string} tagName the tag name of the new element.
  78  * @param {string} text The text to be added.
  79  * @return {!HtmlElement} The newly created element.
  80  */
  81 function addNodeWithText(parentNode, tagName, text) {
  82   var elem = parentNode.ownerDocument.createElement(tagName);
  83   parentNode.appendChild(elem);
  84   addTextNode(elem, text);
  85   return elem;
  86 }
  87
  88 /**
  89  * Returns the key such that map[key] == value, or the string '?' if
  90  * there is no such key.
  91  * @param {!Object} map The object being used as a lookup table.
  92  * @param {Object} value The value to be found in |map|.
  93  * @return {string} The key for |value|, or '?' if there is no such key.
  94  */
  95 function getKeyWithValue(map, value) {
  96   for (var key in map) {
  97     if (map[key] == value)
  98       return key;
  99   }
 100   return '?';
 101 }
 102
 103 /**
 104  * Returns a new map with the keys and values of the input map inverted.
 105  * @param {!Object} map The object to have its keys and values reversed.  Not
 106  *     modified by the function call.
 107  * @return {Object} The new map with the reversed keys and values.
 108  */
 109 function makeInverseMap(map) {
 110   var reversed = {};
 111   for (var key in map)
 112     reversed[map[key]] = key;
 113   return reversed;
 114 }
 115
 116 /**
 117  * Looks up |key| in |map|, and returns the resulting entry, if there is one.
 118  * Otherwise, returns |key|.  Intended primarily for use with incomplete
 119  * tables, and for reasonable behavior with system enumerations that may be
 120  * extended in the future.
 121  * @param {!Object} map The table in which |key| is looked up.
 122  * @param {string} key The key to look up.
 123  * @return {Object|string} map[key], if it exists, or |key| if it doesn't.
 124  */
 125 function tryGetValueWithKey(map, key) {
 126   if (key in map)
 127     return map[key];
 128   return key;
 129 }
 130
 131 /**
 132  * Builds a string by repeating |str| |count| times.
 133  * @param {string} str The string to be repeated.
 134  * @param {number} count The number of times to repeat |str|.
 135  * @return {string} The constructed string
 136  */
 137 function makeRepeatedString(str, count) {
 138   var out = [];
 139   for (var i = 0; i < count; ++i)
 140     out.push(str);
 141   return out.join('');
 142 }
 143
 144 /**
 145  * Clones a basic POD object.  Only a new top level object will be cloned.  It
 146  * will continue to reference the same values as the original object.
 147  * @param {Object} object The object to be cloned.
 148  * @return {Object} A copy of |object|.
 149  */
 150 function shallowCloneObject(object) {
 151   if (!(object instanceof Object))
 152     return object;
 153   var copy = {};
 154   for (var key in object) {
 155     copy[key] = object[key];
 156   }
 157   return copy;
 158 }
 159
 160 /**
 161  * Helper to make sure singleton classes are not instantiated more than once.
 162  * @param {Function} ctor The constructor function being checked.
 163  */
 164 function assertFirstConstructorCall(ctor) {
 165   // This is the variable which is set by cr.addSingletonGetter().
 166   if (ctor.hasCreateFirstInstance_) {
 167     throw Error('The class ' + ctor.name + ' is a singleton, and should ' +
 168                 'only be accessed using ' + ctor.name + '.getInstance().');
 169   }
 170   ctor.hasCreateFirstInstance_ = true;
 171 }
 172
 173 function hasTouchScreen() {
 174   return 'ontouchstart' in window;
 175 }