Bug 786674 - Forward browser chrome zoom events to the PDF.js viewer. r=bdahl,Gijs

Differential Revision: https://phabricator.services.mozilla.com/D26338

--HG--
extra : moz-landing-system : lando

browser/base/content/browser-fullZoom.js

@@ -167,6 +167,10 @@ var FullZoom = {
       return;
     }
 
+    if (this._isPDFViewer(browser)) {
+      return;
+    }
+
     let ctxt = this._loadContextFromBrowser(browser);
     let domain = this._cps2.extractDomain(browser.currentURI.spec);
     if (aGroup) {
@@ -268,6 +272,17 @@ var FullZoom = {
       return;
     }
 
+    // The PDF viewer zooming isn't handled by `ZoomManager`, ensure that the
+    // browser zoom level always gets reset on load.
+    if (this._isPDFViewer(browser)) {
+      this._applyPrefToZoom(
+        undefined,
+        browser,
+        this._notifyOnLocationChange.bind(this, browser)
+      );
+      return;
+    }
+
     // See if the zoom pref is cached.
     let ctxt = this._loadContextFromBrowser(browser);
     let pref = this._cps2.getCachedByDomainAndName(aURI.spec, this.name, ctxt);
@@ -319,6 +334,8 @@ var FullZoom = {
     let browser = gBrowser.selectedBrowser;
     if (browser.currentURI.spec.startsWith("about:reader")) {
       browser.messageManager.sendAsyncMessage("Reader:ZoomOut");
+    } else if (this._isPDFViewer(browser)) {
+      browser.messageManager.sendAsyncMessage("PDFJS:ZoomOut");
     } else {
       ZoomManager.reduce();
       this._ignorePendingZoomAccesses(browser);
@@ -334,6 +351,8 @@ var FullZoom = {
     let browser = gBrowser.selectedBrowser;
     if (browser.currentURI.spec.startsWith("about:reader")) {
       browser.messageManager.sendAsyncMessage("Reader:ZoomIn");
+    } else if (this._isPDFViewer(browser)) {
+      browser.messageManager.sendAsyncMessage("PDFJS:ZoomIn");
     } else {
       ZoomManager.enlarge();
       this._ignorePendingZoomAccesses(browser);
@@ -346,6 +365,9 @@ var FullZoom = {
    * point value, where 1 is the default zoom level.
    */
   setZoom(value, browser = gBrowser.selectedBrowser) {
+    if (this._isPDFViewer(browser)) {
+      return;
+    }
     ZoomManager.setZoomForBrowser(browser, value);
     this._ignorePendingZoomAccesses(browser);
     this._applyZoomToPref(browser);
@@ -360,6 +382,8 @@ var FullZoom = {
   reset: function FullZoom_reset(browser = gBrowser.selectedBrowser) {
     if (browser.currentURI.spec.startsWith("about:reader")) {
       browser.messageManager.sendAsyncMessage("Reader:ResetZoom");
+    } else if (this._isPDFViewer(browser)) {
+      browser.messageManager.sendAsyncMessage("PDFJS:ZoomReset");
     } else {
       let token = this._getBrowserToken(browser);
       let result = this._getGlobalValue(browser).then(value => {
@@ -635,4 +659,12 @@ var FullZoom = {
     }
     Services.tm.dispatchToMainThread(callback);
   },
+
+  _isPDFViewer(browser) {
+    return !!(
+      browser.contentPrincipal &&
+      browser.contentPrincipal.URI &&
+      browser.contentPrincipal.URI.spec == "resource://pdf.js/web/viewer.html"
+    );
+  },
 };

browser/extensions/pdfjs/content/PdfStreamConverter.jsm

@@ -930,6 +930,45 @@ class FindEventManager {
   }
 }
 
+/**
+ * Forwards zoom events from the browser chrome to the currently active viewer.
+ */
+class ZoomEventManager {
+  constructor(contentWindow) {
+    this.contentWindow = contentWindow;
+    this.winmm = contentWindow.docShell.messageManager;
+  }
+
+  bind() {
+    this.contentWindow.addEventListener(
+      "unload",
+      evt => {
+        this.unbind();
+      },
+      { once: true }
+    );
+
+    this.winmm.addMessageListener("PDFJS:ZoomIn", this);
+    this.winmm.addMessageListener("PDFJS:ZoomOut", this);
+    this.winmm.addMessageListener("PDFJS:ZoomReset", this);
+  }
+
+  receiveMessage(msg) {
+    const type = msg.name.split("PDFJS:")[1].toLowerCase();
+    const contentWindow = this.contentWindow;
+
+    const forward = contentWindow.document.createEvent("CustomEvent");
+    forward.initCustomEvent(type, true, true, null);
+    contentWindow.dispatchEvent(forward);
+  }
+
+  unbind() {
+    this.winmm.removeMessageListener("PDFJS:ZoomIn", this);
+    this.winmm.removeMessageListener("PDFJS:ZoomOut", this);
+    this.winmm.removeMessageListener("PDFJS:ZoomReset", this);
+  }
+}
+
 function PdfStreamConverter() {}
 
 PdfStreamConverter.prototype = {
@@ -1109,6 +1148,9 @@ PdfStreamConverter.prototype = {
           var findEventManager = new FindEventManager(domWindow);
           findEventManager.bind();
         }
+        const zoomEventManager = new ZoomEventManager(domWindow);
+        zoomEventManager.bind();
+
         listener.onStopRequest(aRequest, statusCode);
 
         if (domWindow.frameElement) {

browser/extensions/pdfjs/test/browser_pdfjs_zoom.js

@@ -189,3 +189,62 @@ add_task(async function test() {
     }
   );
 });
+
+async function waitForRenderAndGetWidth(newTabBrowser) {
+  return ContentTask.spawn(newTabBrowser, null, async function() {
+    function waitForRender(document) {
+      return new Promise(resolve => {
+        document.addEventListener(
+          "pagerendered",
+          function onPageRendered(e) {
+            if (e.detail.pageNumber !== 1) {
+              return;
+            }
+
+            document.removeEventListener("pagerendered", onPageRendered, true);
+            resolve();
+          },
+          true
+        );
+      });
+    }
+    // check that PDF is opened with internal viewer
+    Assert.ok(
+      content.document.querySelector("div#viewer"),
+      "document content has viewer UI"
+    );
+
+    await waitForRender(content.document);
+
+    return parseInt(
+      content.document.querySelector("div.page[data-page-number='1']").style
+        .width
+    );
+  });
+}
+
+add_task(async function test_browser_zoom() {
+  await BrowserTestUtils.withNewTab(
+    { gBrowser, url: "about:blank" },
+    async function(newTabBrowser) {
+      await waitForPdfJS(newTabBrowser, TESTROOT + "file_pdfjs_test.pdf");
+
+      const initialWidth = await waitForRenderAndGetWidth(newTabBrowser);
+
+      // Zoom in
+      FullZoom.enlarge();
+      let newWidth = await waitForRenderAndGetWidth(newTabBrowser);
+      ok(newWidth > initialWidth, "Zoom in makes the page bigger.");
+
+      // Reset
+      FullZoom.reset();
+      newWidth = await waitForRenderAndGetWidth(newTabBrowser);
+      is(newWidth, initialWidth, "Zoom reset restores page.");
+
+      // Zoom out
+      FullZoom.reduce();
+      newWidth = await waitForRenderAndGetWidth(newTabBrowser);
+      ok(newWidth < initialWidth, "Zoom out makes the page smaller.");
+    }
+  );
+});