OOP PDF - Update zoom factor to fall within range

chrome/browser/resources/pdf/viewport.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Returns the area of the intersection of two rectangles.
  * @param {Object} rect1 the first rect
  * @param {Object} rect2 the second rect
  * @return {number} the area of the intersection of the rects
  */
@@ skipping 59 matching lines @@
 
 /**
  * Predefined zoom factors to be used when zooming in/out. These are in
  * ascending order. This should match the list in
  * chrome/browser/chrome_page_zoom_constants.cc.
  */
 Viewport.ZOOM_FACTORS = [0.25, 0.333, 0.5, 0.666, 0.75, 0.9, 1,
                          1.1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 5];
 
 /**
+ * The minimum and maximum range to be used to clip zoom factor.
+ */
+Viewport.ZOOM_FACTOR_RANGE = {
+  min: Viewport.ZOOM_FACTORS[0],
+  max: Viewport.ZOOM_FACTORS[Viewport.ZOOM_FACTORS.length - 1]
+};
+
+/**
  * The width of the page shadow around pages in pixels.
  */
 Viewport.PAGE_SHADOW = {top: 3, bottom: 7, left: 5, right: 5};
 
 Viewport.prototype = {
   /**
    * @private
    * Returns true if the document needs scrollbars at the given zoom level.
    * @param {number} zoom compute whether scrollbars are needed at this zoom
    * @return {Object} with 'horizontal' and 'vertical' keys which map to bool
@@ skipping 134 matching lines @@
     this.window_.scrollTo(
         currentScrollPos[0] * newZoom - this.window_.innerWidth / 2,
         currentScrollPos[1] * newZoom - this.window_.innerHeight / 2);
   },
 
   /**
    * Sets the zoom to the given zoom level.
    * @param {number} newZoom the zoom level to zoom to.
    */
   setZoom: function(newZoom) {
+    newZoom = Math.max(Viewport.ZOOM_FACTOR_RANGE.min,
+                       Math.min(newZoom, Viewport.ZOOM_FACTOR_RANGE.max));
     this.mightZoom_(function() {
       this.setZoomInternal_(newZoom);
       this.updateViewport_();
     }.bind(this));
   },
 
   /**
    * @type {number} the width of scrollbars in the viewport in pixels.
    */
   get scrollbarWidth() {
@@ skipping 286 matching lines @@
     spaceOnLeft = Math.max(spaceOnLeft, 0);
 
     return {
       x: x * this.zoom_ + spaceOnLeft - this.window_.pageXOffset,
       y: insetDimensions.y * this.zoom_ - this.window_.pageYOffset,
       width: insetDimensions.width * this.zoom_,
       height: insetDimensions.height * this.zoom_
     };
   }
 };