OOP PDF: Do not call setZoom in response to an onZoomChange event.

chrome/test/data/pdf/zoom_manager_test.js

+// Copyright 2015 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.
+
+chrome.test.runTests(function() {
+  'use strict';
+
+  class MockViewport {
+    constructor() {
+      this.zooms = [];
+      this.zoom = 1;
+    }
+
+    setZoom(zoom) {
+      this.zooms.push(zoom);
+      this.zoom = zoom;
+    }
+  }
+
+  /**
+   * A mock implementation of the function used by ZoomManager to set the
+   * browser zoom level.
+   */
+  class MockBrowserZoomSetter {
+    constructor() {
+      this.zoom = 1;
+      this.started = false;
+    }
+
+    /**
+     * The function implementing setBrowserZoomFunction.
+     */
+    setBrowserZoom(zoom) {
+      chrome.test.assertFalse(this.started);
+
+      this.zoom = zoom;
+      this.started = true;
+      return new Promise(function(resolve, reject) {
+        this.resolve_ = resolve;
+      }.bind(this));
+    }
+
+    /**
+     * Resolves the promise returned by a call to setBrowserZoom.
+     */
+    complete() {
+      this.resolve_();
+      this.started = false;
+    }
+  };
+
+  return [
+    function testZoomChange() {
+      let viewport = new MockViewport();
+      let browserZoomSetter = new MockBrowserZoomSetter();
+      let zoomManager = new ZoomManager(
+          viewport, browserZoomSetter.setBrowserZoom.bind(browserZoomSetter));
+      viewport.zoom = 2;
+      zoomManager.onPdfZoomChange();
+      chrome.test.assertEq(2, browserZoomSetter.zoom);
+      chrome.test.assertTrue(browserZoomSetter.started);
+      chrome.test.succeed();
+    },
+
+    function testZoomChangedBeforeConstruction() {
+      let viewport = new MockViewport();
+      viewport.zoom = 2;
+      let browserZoomSetter = new MockBrowserZoomSetter();
+      let zoomManager = new ZoomManager(
+          viewport, browserZoomSetter.setBrowserZoom.bind(browserZoomSetter));
+      chrome.test.assertEq(2, browserZoomSetter.zoom);
+      chrome.test.assertTrue(browserZoomSetter.started);
+      chrome.test.succeed();
+    },
+
+    function testBrowserZoomChange() {
+      let viewport = new MockViewport();
+      let zoomManager = new ZoomManager(viewport, Promise.resolve.bind(Promise),
+                                        chrome.test.fail);
+      zoomManager.onBrowserZoomChange(3);
+      chrome.test.assertEq(1, viewport.zooms.length);
+      chrome.test.assertEq(3, viewport.zooms[0]);
+      chrome.test.assertEq(3, viewport.zoom);
+      chrome.test.succeed();
+    },
+
+    function testSmallZoomChange() {
+      let viewport = new MockViewport();
+      let browserZoomSetter = new MockBrowserZoomSetter();
+      let zoomManager = new ZoomManager(
+          viewport, browserZoomSetter.setBrowserZoom.bind(browserZoomSetter));
+      viewport.zoom = 1.0001;
+      zoomManager.onPdfZoomChange();
+      chrome.test.assertEq(1, browserZoomSetter.zoom);
+      chrome.test.assertFalse(browserZoomSetter.started);
+      chrome.test.succeed();
+    },
+
+    function testSmallBrowserZoomChange() {
+      let viewport = new MockViewport();
+      let zoomManager = new ZoomManager(viewport, Promise.resolve.bind(Promise),
+                                        chrome.test.fail);
+      zoomManager.onBrowserZoomChange(0.999);
+      chrome.test.assertEq(0, viewport.zooms.length);
+      chrome.test.assertEq(1, viewport.zoom);
+      chrome.test.succeed();
+    },
+
+    function testMultiplePdfZoomChanges() {
+      let viewport = new MockViewport();
+      let browserZoomSetter = new MockBrowserZoomSetter();
+      let zoomManager = new ZoomManager(
+          viewport, browserZoomSetter.setBrowserZoom.bind(browserZoomSetter));
+      viewport.zoom = 2;
+      zoomManager.onPdfZoomChange();
+      viewport.zoom = 3;
+      zoomManager.onPdfZoomChange();
+      chrome.test.assertTrue(browserZoomSetter.started);
+      chrome.test.assertEq(2, browserZoomSetter.zoom);
+      browserZoomSetter.complete();
+      Promise.resolve().then(function() {
+        chrome.test.assertTrue(browserZoomSetter.started);
+        chrome.test.assertEq(3, browserZoomSetter.zoom);
+        chrome.test.succeed();
+      });
+    },
+
+    function testMultipleBrowserZoomChanges() {
+      let viewport = new MockViewport();
+      let zoomManager = new ZoomManager(viewport, Promise.resolve.bind(Promise),
+                                        chrome.test.fail);
+      zoomManager.onBrowserZoomChange(2);
+      zoomManager.onBrowserZoomChange(3);
+      chrome.test.assertEq(2, viewport.zooms.length);
+      chrome.test.assertEq(2, viewport.zooms[0]);
+      chrome.test.assertEq(3, viewport.zooms[1]);
+      chrome.test.assertEq(3, viewport.zoom);
+      chrome.test.succeed();
+    },
+  ];
+}());