Add preferences for default scroll/spread modes

This commit adds `scrollModeOnLoad` and `spreadModeOnLoad` preferences
that control the default viewer state when opening a new document for
the first time.

This commit also contains a minor refactoring of some of the option UI
rendering code in extensions/chromium/options/options.js, as I couldn't
bear creating two more functions nearly identical to the four that
already existed.

extensions/chromium/options/options.html

@@ -120,6 +120,32 @@ body {
 </div>
 </template>
 
+<template id="scrollModeOnLoad-template">
+<div class="settings-row">
+  <label>
+    <span></span>
+    <select>
+      <option value="0">Vertical scrolling</option>
+      <option value="1">Horizontal scrolling</option>
+      <option value="2">Wrapped scrolling</option>
+    </select>
+  </label>
+</div>
+</template>
+
+<template id="spreadModeOnLoad-template">
+<div class="settings-row">
+  <label>
+    <span></span>
+    <select>
+      <option value="0">No spreads</option>
+      <option value="1">Odd spreads</option>
+      <option value="2">Even spreads</option>
+    </select>
+  </label>
+</div>
+</template>
+
 <script src="options.js"></script>
 </body>
 </html>

extensions/chromium/options/options.js

@@ -75,16 +75,15 @@ Promise.all([
       renderPreference = renderBooleanPref(prefSchema.title,
                                            prefSchema.description,
                                            prefName);
+    } else if (prefSchema.type === 'integer' && prefSchema.enum) {
+      // Most other prefs are integer-valued enumerations, render them in a
+      // generic way too.
+      // Unlike the renderBooleanPref branch, each preference handled by this
+      // branch still needs its own template in options.html with
+      // id="$prefName-template".
+      renderPreference = renderEnumPref(prefSchema.title, prefName);
     } else if (prefName === 'defaultZoomValue') {
       renderPreference = renderDefaultZoomValue(prefSchema.title);
-    } else if (prefName === 'sidebarViewOnLoad') {
-      renderPreference = renderSidebarViewOnLoad(prefSchema.title);
-    } else if (prefName === 'cursorToolOnLoad') {
-      renderPreference = renderCursorToolOnLoad(prefSchema.title);
-    } else if (prefName === 'textLayerMode') {
-      renderPreference = renderTextLayerMode(prefSchema.title);
-    } else if (prefName === 'externalLinkTarget') {
-      renderPreference = renderExternalLinkTarget(prefSchema.title);
     } else {
       // Should NEVER be reached. Only happens if a new type of preference is
       // added to the storage manifest.
@@ -156,6 +155,23 @@ function renderBooleanPref(shortDescription, description, prefName) {
   return renderPreference;
 }
 
+function renderEnumPref(shortDescription, prefName) {
+  var wrapper = importTemplate(prefName + '-template');
+  var select = wrapper.querySelector('select');
+  select.onchange = function() {
+    var pref = {};
+    pref[prefName] = parseInt(this.value);
+    storageArea.set(pref);
+  };
+  wrapper.querySelector('span').textContent = shortDescription;
+  document.getElementById('settings-boxes').appendChild(wrapper);
+
+  function renderPreference(value) {
+    select.value = value;
+  }
+  return renderPreference;
+}
+
 function renderDefaultZoomValue(shortDescription) {
   var wrapper = importTemplate('defaultZoomValue-template');
   var select = wrapper.querySelector('select');
@@ -184,71 +200,3 @@ function renderDefaultZoomValue(shortDescription) {
   }
   return renderPreference;
 }
-
-function renderSidebarViewOnLoad(shortDescription) {
-  var wrapper = importTemplate('sidebarViewOnLoad-template');
-  var select = wrapper.querySelector('select');
-  select.onchange = function() {
-    storageArea.set({
-      sidebarViewOnLoad: parseInt(this.value),
-    });
-  };
-  wrapper.querySelector('span').textContent = shortDescription;
-  document.getElementById('settings-boxes').appendChild(wrapper);
-
-  function renderPreference(value) {
-    select.value = value;
-  }
-  return renderPreference;
-}
-
-function renderCursorToolOnLoad(shortDescription) {
-  var wrapper = importTemplate('cursorToolOnLoad-template');
-  var select = wrapper.querySelector('select');
-  select.onchange = function() {
-    storageArea.set({
-      cursorToolOnLoad: parseInt(this.value),
-    });
-  };
-  wrapper.querySelector('span').textContent = shortDescription;
-  document.getElementById('settings-boxes').appendChild(wrapper);
-
-  function renderPreference(value) {
-    select.value = value;
-  }
-  return renderPreference;
-}
-
-function renderTextLayerMode(shortDescription) {
-  var wrapper = importTemplate('textLayerMode-template');
-  var select = wrapper.querySelector('select');
-  select.onchange = function() {
-    storageArea.set({
-      textLayerMode: parseInt(this.value),
-    });
-  };
-  wrapper.querySelector('span').textContent = shortDescription;
-  document.getElementById('settings-boxes').appendChild(wrapper);
-
-  function renderPreference(value) {
-    select.value = value;
-  }
-  return renderPreference;
-}
-
-function renderExternalLinkTarget(shortDescription) {
-  var wrapper = importTemplate('externalLinkTarget-template');
-  var select = wrapper.querySelector('select');
-  select.onchange = function() {
-    storageArea.set({
-      externalLinkTarget: parseInt(this.value),
-    });
-  };
-  wrapper.querySelector('span').textContent = shortDescription;
-  document.getElementById('settings-boxes').appendChild(wrapper);
-
-  function renderPreference(value) {
-    select.value = value;
-  }
-  return renderPreference;
-}

extensions/chromium/preferences_schema.json

@@ -144,6 +144,28 @@
       "description": "When enabled, pages whose orientation differ from the first page are rotated when printed.",
       "type": "boolean",
       "default": false
+    },
+    "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.",
+      "type": "integer",
+      "enum": [
+        0,
+        1,
+        2
+      ],
+      "default": 0
+    },
+    "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.",
+      "type": "integer",
+      "enum": [
+        0,
+        1,
+        2
+      ],
+      "default": 0
     }
   }
 }

web/app.js

@@ -242,6 +242,12 @@ let PDFViewerApplication = {
       preferences.get('enablePrintAutoRotate').then(function resolved(value) {
         AppOptions.set('enablePrintAutoRotate', value);
       }),
+      preferences.get('scrollModeOnLoad').then(function resolved(value) {
+        AppOptions.set('scrollModeOnLoad', value);
+      }),
+      preferences.get('spreadModeOnLoad').then(function resolved(value) {
+        AppOptions.set('spreadModeOnLoad', value);
+      }),
     ]).catch(function(reason) { });
   },
 
@@ -1040,8 +1046,8 @@ let PDFViewerApplication = {
           ('zoom=' + AppOptions.get('defaultZoomValue')) : null;
         let rotation = null;
         let sidebarView = AppOptions.get('sidebarViewOnLoad');
-        let scrollMode = null;
+        let scrollMode = AppOptions.get('scrollModeOnLoad');
-        let spreadMode = null;
+        let spreadMode = AppOptions.get('spreadModeOnLoad');
 
         if (values.exists && AppOptions.get('showPreviousViewOnLoad')) {
           hash = 'page=' + values.page +
@@ -1248,6 +1254,10 @@ let PDFViewerApplication = {
         this.pdfViewer.pagesRotation = angle;
       }
     };
+
+    // 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.
     if (Number.isInteger(scrollMode)) {
       this.pdfViewer.setScrollMode(scrollMode);
     }

web/default_preferences.json

@@ -16,5 +16,7 @@
   "renderInteractiveForms": false,
   "enablePrintAutoRotate": false,
   "disablePageMode": false,
-  "disablePageLabels": false
+  "disablePageLabels": false,
+  "scrollModeOnLoad": 0,
+  "spreadModeOnLoad": 0
 }