Modify a number of the viewer preferences, whose current default value is 0, such that they behave as expected with the view history

extensions/chromium/options/options.html

@@ -43,6 +43,19 @@
 </div>
 </template>
 
+<template id="viewOnLoad-template">
+<div class="settings-row">
+  <label>
+    <span></span>
+    <select>
+      <option value="-1">Default</option>
+      <option value="0">Show previous position</option>
+      <option value="1">Show initial position</option>
+    </select>
+  </label>
+</div>
+</template>
+
 <template id="defaultZoomValue-template">
 <div class="settings-row">
   <label>
@@ -71,6 +84,7 @@
   <label>
     <span></span>
     <select>
+      <option value="-1">Default</option>
       <option value="0">Do not show sidebar</option>
       <option value="1">Show thumbnails in sidebar</option>
       <option value="2">Show document outline in sidebar</option>
@@ -125,6 +139,7 @@
   <label>
     <span></span>
     <select>
+      <option value="-1">Default</option>
       <option value="0">Vertical scrolling</option>
       <option value="1">Horizontal scrolling</option>
       <option value="2">Wrapped scrolling</option>
@@ -138,6 +153,7 @@
   <label>
     <span></span>
     <select>
+      <option value="-1">Default</option>
       <option value="0">No spreads</option>
       <option value="1">Odd spreads</option>
       <option value="2">Even spreads</option>

extensions/chromium/preferences_schema.json

@@ -2,11 +2,20 @@
   "type": "object",
   "properties": {
     "showPreviousViewOnLoad": {
-      "title": "Show previous position of PDF upon load",
-      "description": "Whether to view PDF documents in the last page and position upon opening the viewer.",
+      "description": "DEPRECATED. Set viewOnLoad to 1 to disable showing the last page/position on load.",
       "type": "boolean",
       "default": true
     },
+    "viewOnLoad": {
+      "title": "View position on load",
+      "description": "The position in the document upon load.\n -1 = Default (uses OpenAction if available, otherwise equal to `viewOnLoad = 0`).\n 0 = The last viewed page/position.\n 1 = The initial page/position.",
+      "enum": [
+        -1,
+        0,
+        1
+      ],
+      "default": 0
+    },
     "defaultZoomValue": {
       "title": "Default zoom level",
       "description": "Default zoom level of the viewer. Accepted values: 'auto', 'page-actual', 'page-width', 'page-height', 'page-fit', or a zoom level in percents.",
@@ -16,15 +25,16 @@
     },
     "sidebarViewOnLoad": {
       "title": "Sidebar state on load",
-      "description": "Controls the state of the sidebar upon load.\n 0 = do not show sidebar.\n 1 = show thumbnails in sidebar.\n 2 = show document outline in sidebar.\n 3 = Show attachments in sidebar.",
+      "description": "Controls the state of the sidebar upon load.\n -1 = Default (uses PageMode if available, otherwise the last position if available/enabled).\n 0 = Do not show sidebar.\n 1 = Show thumbnails in sidebar.\n 2 = Show document outline in sidebar.\n 3 = Show attachments in sidebar.",
       "type": "integer",
       "enum": [
+        -1,
         0,
         1,
         2,
         3
       ],
-      "default": 0
+      "default": -1
     },
     "enableHandToolOnLoad": {
       "description": "DEPRECATED. Set cursorToolOnLoad to 1 to enable the hand tool by default.",
@@ -117,15 +127,12 @@
       ],
       "default": 0
     },
-    "disableOpenActionDestination": {
-      "type": "boolean",
-      "default": true
-    },
     "disablePageLabels": {
       "type": "boolean",
       "default": false
     },
     "disablePageMode": {
+      "description": "DEPRECATED.",
       "type": "boolean",
       "default": false
     },
@@ -159,25 +166,27 @@
     },
     "scrollModeOnLoad": {
       "title": "Scroll mode on load",
-      "description": "Controls how the viewer scrolls upon load.\n 0 = Vertical scrolling.\n 1 = Horizontal scrolling.\n 2 = Wrapped scrolling.",
+      "description": "Controls how the viewer scrolls upon load.\n -1 = Default (uses the last position if available/enabled).\n 0 = Vertical scrolling.\n 1 = Horizontal scrolling.\n 2 = Wrapped scrolling.",
       "type": "integer",
       "enum": [
+        -1,
         0,
         1,
         2
       ],
-      "default": 0
+      "default": -1
     },
     "spreadModeOnLoad": {
       "title": "Spread mode on load",
-      "description": "Whether the viewer should join pages into spreads upon load.\n 0 = No spreads.\n 1 = Odd spreads.\n 2 = Even spreads.",
+      "description": "Whether the viewer should join pages into spreads upon load.\n -1 = Default (uses the last position if available/enabled).\n 0 = No spreads.\n 1 = Odd spreads.\n 2 = Even spreads.",
       "type": "integer",
       "enum": [
+        -1,
         0,
         1,
         2
       ],
-      "default": 0
+      "default": -1
     }
   }
 }

web/app.js

@@ -16,9 +16,10 @@
 
 import {
   animationStarted, DEFAULT_SCALE_VALUE, getGlobalEventBus,
-  getPDFFileNameFromURL, isValidRotation, MAX_SCALE, MIN_SCALE,
-  noContextMenuHandler, normalizeWheelEventDelta, parseQueryString,
-  PresentationModeState, ProgressBar, RendererType, TextLayerMode
+  getPDFFileNameFromURL, isValidRotation, isValidScrollMode, isValidSpreadMode,
+  MAX_SCALE, MIN_SCALE, noContextMenuHandler, normalizeWheelEventDelta,
+  parseQueryString, PresentationModeState, ProgressBar, RendererType,
+  ScrollMode, SpreadMode, TextLayerMode
 } from './ui_utils';
 import {
   build, createObjectURL, getDocument, getFilenameFromUrl, GlobalWorkerOptions,
@@ -52,6 +53,12 @@ const DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT = 5000; // ms
 const FORCE_PAGES_LOADED_TIMEOUT = 10000; // ms
 const WHEEL_ZOOM_DISABLED_TIMEOUT = 1000; // ms
 
+const ViewOnLoad = {
+  UNKNOWN: -1,
+  PREVIOUS: 0, // Default value.
+  INITIAL: 1,
+};
+
 const DefaultExternalServices = {
   updateFindControlState(data) {},
   updateFindMatchesCount(data) {},
@@ -905,7 +912,7 @@ let PDFViewerApplication = {
         // i.e. not when it is embedded in a web page.
         this.pdfHistory.initialize({
           fingerprint: pdfDocument.fingerprint,
-          resetHistory: !AppOptions.get('showPreviousViewOnLoad'),
+          resetHistory: AppOptions.get('viewOnLoad') === ViewOnLoad.INITIAL,
           updateUrl: AppOptions.get('historyUpdateUrl'),
         });
 
@@ -916,30 +923,33 @@ let PDFViewerApplication = {
         }
       }
 
-      let storePromise = store.getMultiple({
+      const storePromise = store.getMultiple({
         page: null,
         zoom: DEFAULT_SCALE_VALUE,
         scrollLeft: '0',
         scrollTop: '0',
         rotation: null,
-        sidebarView: SidebarView.NONE,
-        scrollMode: null,
-        spreadMode: null,
+        sidebarView: SidebarView.UNKNOWN,
+        scrollMode: ScrollMode.UNKNOWN,
+        spreadMode: SpreadMode.UNKNOWN,
       }).catch(() => { /* Unable to read from storage; ignoring errors. */ });
 
       Promise.all([
         storePromise, pageModePromise, openActionDestPromise,
       ]).then(async ([values = {}, pageMode, openActionDest]) => {
+        const viewOnLoad = AppOptions.get('viewOnLoad');
+
+        // Always let the browser history/document hash take precedence.
         if (openActionDest && !this.initialBookmark &&
-            !AppOptions.get('disableOpenActionDestination')) {
-          // Always let the browser history/document hash take precedence.
+            viewOnLoad === ViewOnLoad.UNKNOWN) {
           this.initialBookmark = JSON.stringify(openActionDest);
           // TODO: Re-factor the `PDFHistory` initialization to remove this hack
           // that's currently necessary to prevent weird initial history state.
           this.pdfHistory.push({ explicitDest: openActionDest,
                                  pageNumber: null, });
         }
         const initialBookmark = this.initialBookmark;
+
         // Initialize the default values, from user preferences.
         const zoom = AppOptions.get('defaultZoomValue');
         let hash = zoom ? `zoom=${zoom}` : null;
@@ -949,18 +959,25 @@ let PDFViewerApplication = {
         let scrollMode = AppOptions.get('scrollModeOnLoad');
         let spreadMode = AppOptions.get('spreadModeOnLoad');
 
-        if (values.page && AppOptions.get('showPreviousViewOnLoad')) {
-          hash = 'page=' + values.page + '&zoom=' + (zoom || values.zoom) +
-            ',' + values.scrollLeft + ',' + values.scrollTop;
+        if (values.page && viewOnLoad !== ViewOnLoad.INITIAL) {
+          hash = `page=${values.page}&zoom=${zoom || values.zoom},` +
+                 `${values.scrollLeft},${values.scrollTop}`;
 
           rotation = parseInt(values.rotation, 10);
-          sidebarView = sidebarView || (values.sidebarView | 0);
-          scrollMode = scrollMode || (values.scrollMode | 0);
-          spreadMode = spreadMode || (values.spreadMode | 0);
+          // Always let user preferences take precedence over the view history.
+          if (sidebarView === SidebarView.UNKNOWN) {
+            sidebarView = (values.sidebarView | 0);
+          }
+          if (scrollMode === ScrollMode.UNKNOWN) {
+            scrollMode = (values.scrollMode | 0);
+          }
+          if (spreadMode === SpreadMode.UNKNOWN) {
+            spreadMode = (values.spreadMode | 0);
+          }
         }
-        if (pageMode && !AppOptions.get('disablePageMode')) {
-          // Always let the user preference/history take precedence.
-          sidebarView = sidebarView || apiPageModeToSidebarView(pageMode);
+        // Always let the user preference/view history take precedence.
+        if (pageMode && sidebarView === SidebarView.UNKNOWN) {
+          sidebarView = apiPageModeToSidebarView(pageMode);
         }
 
         this.setInitialView(hash, {
@@ -1149,28 +1166,24 @@ let PDFViewerApplication = {
 
   setInitialView(storedHash, { rotation, sidebarView,
                                scrollMode, spreadMode, } = {}) {
-    let setRotation = (angle) => {
+    const setRotation = (angle) => {
       if (isValidRotation(angle)) {
         this.pdfViewer.pagesRotation = angle;
       }
     };
-    let setViewerModes = (scroll, spread) => {
-      if (Number.isInteger(scroll)) {
+    const setViewerModes = (scroll, spread) => {
+      if (isValidScrollMode(scroll)) {
         this.pdfViewer.scrollMode = scroll;
       }
-      if (Number.isInteger(spread)) {
+      if (isValidSpreadMode(spread)) {
         this.pdfViewer.spreadMode = spread;
       }
     };
-
-    // Putting these before isInitialViewSet = true prevents these values from
-    // being stored in the document history (and overriding any future changes
-    // made to the corresponding global preferences), just this once.
-    setViewerModes(scrollMode, spreadMode);
-
     this.isInitialViewSet = true;
     this.pdfSidebar.setInitialView(sidebarView);
 
+    setViewerModes(scrollMode, spreadMode);
+
     if (this.initialBookmark) {
       setRotation(this.initialRotation);
       delete this.initialRotation;

web/app_options.js

@@ -48,21 +48,11 @@ const defaultOptions = {
     value: false,
     kind: OptionKind.VIEWER,
   },
-  disableOpenActionDestination: {
-    /** @type {boolean} */
-    value: true,
-    kind: OptionKind.VIEWER,
-  },
   disablePageLabels: {
     /** @type {boolean} */
     value: false,
     kind: OptionKind.VIEWER,
   },
-  disablePageMode: {
-    /** @type {boolean} */
-    value: false,
-    kind: OptionKind.VIEWER,
-  },
   /**
    * The `disablePreferences` is, conditionally, defined below.
    */
@@ -124,24 +114,19 @@ const defaultOptions = {
     value: false,
     kind: OptionKind.VIEWER,
   },
-  showPreviousViewOnLoad: {
-    /** @type {boolean} */
-    value: true,
-    kind: OptionKind.VIEWER,
-  },
   sidebarViewOnLoad: {
     /** @type {number} */
-    value: 0,
+    value: -1,
     kind: OptionKind.VIEWER,
   },
   scrollModeOnLoad: {
     /** @type {number} */
-    value: 0,
+    value: -1,
     kind: OptionKind.VIEWER,
   },
   spreadModeOnLoad: {
     /** @type {number} */
-    value: 0,
+    value: -1,
     kind: OptionKind.VIEWER,
   },
   textLayerMode: {
@@ -154,6 +139,11 @@ const defaultOptions = {
     value: false,
     kind: OptionKind.VIEWER,
   },
+  viewOnLoad: {
+    /** @type {boolean} */
+    value: 0,
+    kind: OptionKind.VIEWER,
+  },
 
   cMapPacked: {
     /** @type {boolean} */