[api-minor] Add basic support for PageLayout in the API and the viewer

src/core/obj.js

@@ -376,6 +376,27 @@ class Catalog {
  return pageLabels;
  }
 
+ get pageLayout() {
+ const obj = this.catDict.get('PageLayout');
+ // Purposely use a non-standard default value, rather than 'SinglePage', to
+ // allow differentiating between `undefined` and /SinglePage since that does
+ // affect the Scroll mode (continuous/non-continuous) used in Adobe Reader.
+ let pageLayout = '';
+
+ if (isName(obj)) {
+ switch (obj.name) {
+ case 'SinglePage':
+ case 'OneColumn':
+ case 'TwoColumnLeft':
+ case 'TwoColumnRight':
+ case 'TwoPageLeft':
+ case 'TwoPageRight':
+ pageLayout = obj.name;
+ }
+ }
+ return shadow(this, 'pageLayout', pageLayout);
+ }
+
  get pageMode() {
  const obj = this.catDict.get('PageMode');
  let pageMode = 'UseNone'; // Default value.

src/core/worker.js

@@ -517,6 +517,10 @@ var WorkerMessageHandler = {
  }
  );
 
+ handler.on('GetPageLayout', function wphSetupGetPageLayout(data) {
+ return pdfManager.ensureCatalog('pageLayout');
+ });
+
  handler.on('GetPageMode', function wphSetupGetPageMode(data) {
  return pdfManager.ensureCatalog('pageMode');
  });

src/display/api.js

@@ -657,6 +657,14 @@ class PDFDocumentProxy {
  return this._transport.getPageLabels();
  }
 
+ /**
+ * @return {Promise} A promise that is resolved with a {string} containing
+ * the page layout name.
+ */
+ getPageLayout() {
+ return this._transport.getPageLayout();
+ }
+
  /**
  * @return {Promise} A promise that is resolved with a {string} containing
  * the page mode name.
@@ -2214,6 +2222,10 @@ class WorkerTransport {
  return this.messageHandler.sendWithPromise('GetPageLabels', null);
  }
 
+ getPageLayout() {
+ return this.messageHandler.sendWithPromise('GetPageLayout', null);
+ }
+
  getPageMode() {
  return this.messageHandler.sendWithPromise('GetPageMode', null);
  }

test/unit/api_spec.js

@@ -610,6 +610,24 @@ describe('api', function() {
  }).catch(done.fail);
  });
 
+ it('gets default page layout', function(done) {
+ var loadingTask = getDocument(buildGetDocumentParams('tracemonkey.pdf'));
+
+ loadingTask.promise.then(function(pdfDocument) {
+ return pdfDocument.getPageLayout();
+ }).then(function(mode) {
+ expect(mode).toEqual('');
+
+ loadingTask.destroy().then(done);
+ }).catch(done.fail);
+ });
+ it('gets non-default page layout', function(done) {
+ doc.getPageLayout().then(function(mode) {
+ expect(mode).toEqual('SinglePage');
+ done();
+ }).catch(done.fail);
+ });
+
  it('gets default page mode', function(done) {
  var loadingTask = getDocument(buildGetDocumentParams('tracemonkey.pdf'));
 

web/app.js

@@ -889,6 +889,8 @@ let PDFViewerApplication = {
 
  // Since the `setInitialView` call below depends on this being resolved,
  // fetch it early to avoid delaying initial rendering of the PDF document.
+ const pageLayoutPromise = pdfDocument.getPageLayout().catch(
+ function() { /* Avoid breaking initial rendering; ignoring errors. */ });
  const pageModePromise = pdfDocument.getPageMode().catch(
  function() { /* Avoid breaking initial rendering; ignoring errors. */ });
  const openActionDestPromise = pdfDocument.getOpenActionDestination().catch(
@@ -934,8 +936,8 @@ let PDFViewerApplication = {
  }).catch(() => { /* Unable to read from storage; ignoring errors. */ });
 
  Promise.all([
- storePromise, pageModePromise, openActionDestPromise,
- ]).then(async ([values = {}, pageMode, openActionDest]) => {
+ storePromise, pageLayoutPromise, pageModePromise, openActionDestPromise,
+ ]).then(async ([values = {}, pageLayout, pageMode, openActionDest]) => {
  const viewOnLoad = AppOptions.get('viewOnLoad');
 
  this._initializePdfHistory({
@@ -974,6 +976,9 @@ let PDFViewerApplication = {
  if (pageMode && sidebarView === SidebarView.UNKNOWN) {
  sidebarView = apiPageModeToSidebarView(pageMode);
  }
+ if (pageLayout && spreadMode === SpreadMode.UNKNOWN) {
+ spreadMode = apiPageLayoutToSpreadMode(pageLayout);
+ }
 
  this.setInitialView(hash, {
  rotation, sidebarView, scrollMode, spreadMode,
@@ -2434,6 +2439,29 @@ function webViewerKeyDown(evt) {
  }
 }
 
+/**
+ * Converts API PageLayout values to the format used by `PDFViewer`.
+ * NOTE: This is supported to the extent that the viewer implements the
+ * necessary Scroll/Spread modes (since SinglePage, TwoPageLeft,
+ * and TwoPageRight all suggests using non-continuous scrolling).
+ * @param {string} mode - The API PageLayout value.
+ * @returns {number} A value from {SpreadMode}.
+ */
+function apiPageLayoutToSpreadMode(layout) {
+ switch (layout) {
+ case 'SinglePage':
+ case 'OneColumn':
+ return SpreadMode.NONE;
+ case 'TwoColumnLeft':
+ case 'TwoPageLeft':
+ return SpreadMode.ODD;
+ case 'TwoColumnRight':
+ case 'TwoPageRight':
+ return SpreadMode.EVEN;
+ }
+ return SpreadMode.NONE; // Default value.
+}
+
 /**
  * Converts API PageMode values to the format used by `PDFSidebar`.
  * NOTE: There's also a "FullScreen" parameter which is not possible to support,