chrome/browser/resources/local_ntp/instant_iframe_validation.js

   1 // Copyright 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
   6 /**
   7  * @fileoverview Helpers for validating parameters to chrome-search:// iframes.
   8  */
   9
  10
  11 /**
  12  * Converts an RGB color number to a hex color string if valid.
  13  * @param {number} color A 6-digit hex RGB color code as a number.
  14  * @return {?string} A CSS representation of the color or null if invalid.
  15  */
  16 function convertToHexColor(color) {
  17   // Color must be a number, finite, with no fractional part, in the correct
  18   // range for an RGB hex color.
  19   if (isFinite(color) && Math.floor(color) == color &&
  20       color >= 0 && color <= 0xffffff) {
  21     var hexColor = color.toString(16);
  22     // Pads with initial zeros and # (e.g. for 'ff' yields '#0000ff').
  23     return '#000000'.substr(0, 7 - hexColor.length) + hexColor;
  24   }
  25   return null;
  26 }
  27
  28
  29 /**
  30  * Validates a RGBA color component. It must be a number between 0 and 255.
  31  * @param {number} component An RGBA component.
  32  * @return {boolean} True if the component is valid.
  33  */
  34 function isValidRBGAComponent(component) {
  35   return isFinite(component) && component >= 0 && component <= 255;
  36 }
  37
  38
  39 /**
  40  * Converts an Array of color components into RGBA format "rgba(R,G,B,A)".
  41  * @param {Array<number>} rgbaColor Array of rgba color components.
  42  * @return {?string} CSS color in RGBA format or null if invalid.
  43  */
  44 function convertArrayToRGBAColor(rgbaColor) {
  45   // Array must contain 4 valid components.
  46   if (rgbaColor instanceof Array && rgbaColor.length === 4 &&
  47       isValidRBGAComponent(rgbaColor[0]) &&
  48       isValidRBGAComponent(rgbaColor[1]) &&
  49       isValidRBGAComponent(rgbaColor[2]) &&
  50       isValidRBGAComponent(rgbaColor[3])) {
  51     return 'rgba(' +
  52             rgbaColor[0] + ',' +
  53             rgbaColor[1] + ',' +
  54             rgbaColor[2] + ',' +
  55             rgbaColor[3] / 255 + ')';
  56   }
  57   return null;
  58 }