1 files changed, 260 insertions, 0 deletions
diff --git a/toolkit/actors/PrintingChild.sys.mjs b/toolkit/actors/PrintingChild.sys.mjs
new file mode 100644
index 0000000000..4fca3ab403
--- /dev/null
+++ b/toolkit/actors/PrintingChild.sys.mjs
@@ -0,0 +1,260 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  DeferredTask: "resource://gre/modules/DeferredTask.sys.mjs",
+  ReaderMode: "resource://gre/modules/ReaderMode.sys.mjs",
+  setTimeout: "resource://gre/modules/Timer.sys.mjs",
+});
+
+let gPendingPreviewsMap = new Map();
+
+export class PrintingChild extends JSWindowActorChild {
+  actorCreated() {
+    // When the print preview page is loaded, the actor will change, so update
+    // the state/progress listener to the new actor.
+    let listener = gPendingPreviewsMap.get(this.browsingContext.id);
+    if (listener) {
+      listener.actor = this;
+    }
+    this.contentWindow.addEventListener("scroll", this);
+  }
+
+  didDestroy() {
+    this._scrollTask?.disarm();
+    this.contentWindow?.removeEventListener("scroll", this);
+  }
+
+  handleEvent(event) {
+    switch (event.type) {
+      case "PrintingError": {
+        let win = event.target.defaultView;
+        let wbp = win.getInterface(Ci.nsIWebBrowserPrint);
+        let nsresult = event.detail;
+        this.sendAsyncMessage("Printing:Error", {
+          isPrinting: wbp.doingPrint,
+          nsresult,
+        });
+        break;
+      }
+
+      case "scroll":
+        if (!this._scrollTask) {
+          this._scrollTask = new lazy.DeferredTask(
+            () => this.updateCurrentPage(),
+            16,
+            16
+          );
+        }
+        this._scrollTask.arm();
+        break;
+    }
+  }
+
+  receiveMessage(message) {
+    let data = message.data;
+    switch (message.name) {
+      case "Printing:Preview:Navigate": {
+        this.navigate(data.navType, data.pageNum);
+        break;
+      }
+
+      case "Printing:Preview:ParseDocument": {
+        return this.parseDocument(
+          data.URL,
+          Services.wm.getOuterWindowWithId(data.windowID)
+        );
+      }
+    }
+
+    return undefined;
+  }
+
+  async parseDocument(URL, contentWindow) {
+    // The document in 'contentWindow' will be simplified and the resulting nodes
+    // will be inserted into this.contentWindow.
+    let thisWindow = this.contentWindow;
+
+    // By using ReaderMode primitives, we parse given document and place the
+    // resulting JS object into the DOM of current browser.
+    let article;
+    try {
+      article = await lazy.ReaderMode.parseDocument(contentWindow.document);
+    } catch (ex) {
+      console.error(ex);
+    }
+
+    await new Promise(resolve => {
+      // We make use of a web progress listener in order to know when the content we inject
+      // into the DOM has finished rendering. If our layout engine is still painting, we
+      // will wait for MozAfterPaint event to be fired.
+      let actor = thisWindow.windowGlobalChild.getActor("Printing");
+      let webProgressListener = {
+        onStateChange(webProgress, req, flags, status) {
+          if (flags & Ci.nsIWebProgressListener.STATE_STOP) {
+            webProgress.removeProgressListener(webProgressListener);
+            let domUtils = contentWindow.windowUtils;
+            // Here we tell the parent that we have parsed the document successfully
+            // using ReaderMode primitives and we are able to enter on preview mode.
+            if (domUtils.isMozAfterPaintPending) {
+              let onPaint = function () {
+                contentWindow.removeEventListener("MozAfterPaint", onPaint);
+                actor.sendAsyncMessage("Printing:Preview:ReaderModeReady");
+                resolve();
+              };
+              contentWindow.addEventListener("MozAfterPaint", onPaint);
+              // This timer is needed for when display list invalidation doesn't invalidate.
+              lazy.setTimeout(() => {
+                contentWindow.removeEventListener("MozAfterPaint", onPaint);
+                actor.sendAsyncMessage("Printing:Preview:ReaderModeReady");
+                resolve();
+              }, 100);
+            } else {
+              actor.sendAsyncMessage("Printing:Preview:ReaderModeReady");
+              resolve();
+            }
+          }
+        },
+
+        QueryInterface: ChromeUtils.generateQI([
+          "nsIWebProgressListener",
+          "nsISupportsWeakReference",
+          "nsIObserver",
+        ]),
+      };
+
+      // Here we QI the docShell into a nsIWebProgress passing our web progress listener in.
+      let webProgress = thisWindow.docShell
+        .QueryInterface(Ci.nsIInterfaceRequestor)
+        .getInterface(Ci.nsIWebProgress);
+      webProgress.addProgressListener(
+        webProgressListener,
+        Ci.nsIWebProgress.NOTIFY_STATE_REQUEST
+      );
+
+      let document = thisWindow.document;
+      document.head.innerHTML = "";
+
+      // Set base URI of document. Print preview code will read this value to
+      // populate the URL field in print settings so that it doesn't show
+      // "about:blank" as its URI.
+      let headBaseElement = document.createElement("base");
+      headBaseElement.setAttribute("href", URL);
+      document.head.appendChild(headBaseElement);
+
+      // Create link element referencing aboutReader.css and append it to head
+      let headStyleElement = document.createElement("link");
+      headStyleElement.setAttribute("rel", "stylesheet");
+      headStyleElement.setAttribute(
+        "href",
+        "chrome://global/skin/aboutReader.css"
+      );
+      headStyleElement.setAttribute("type", "text/css");
+      document.head.appendChild(headStyleElement);
+
+      // Create link element referencing simplifyMode.css and append it to head
+      headStyleElement = document.createElement("link");
+      headStyleElement.setAttribute("rel", "stylesheet");
+      headStyleElement.setAttribute(
+        "href",
+        "chrome://global/content/simplifyMode.css"
+      );
+      headStyleElement.setAttribute("type", "text/css");
+      document.head.appendChild(headStyleElement);
+
+      document.body.innerHTML = "";
+
+      // Create container div (main element) and append it to body
+      let containerElement = document.createElement("div");
+      containerElement.setAttribute("class", "container");
+      document.body.appendChild(containerElement);
+
+      // Reader Mode might return null if there's a failure when parsing the document.
+      // We'll render the error message for the Simplify Page document when that happens.
+      if (article) {
+        // Set title of document
+        document.title = article.title;
+
+        // Create header div and append it to container
+        let headerElement = document.createElement("div");
+        headerElement.setAttribute("class", "reader-header");
+        headerElement.setAttribute("class", "header");
+        containerElement.appendChild(headerElement);
+
+        // Jam the article's title and byline into header div
+        let titleElement = document.createElement("h1");
+        titleElement.setAttribute("class", "reader-title");
+        titleElement.textContent = article.title;
+        headerElement.appendChild(titleElement);
+
+        let bylineElement = document.createElement("div");
+        bylineElement.setAttribute("class", "reader-credits credits");
+        bylineElement.textContent = article.byline;
+        headerElement.appendChild(bylineElement);
+
+        // Display header element
+        headerElement.style.display = "block";
+
+        // Create content div and append it to container
+        let contentElement = document.createElement("div");
+        contentElement.setAttribute("class", "content");
+        containerElement.appendChild(contentElement);
+
+        // Jam the article's content into content div
+        let readerContent = document.createElement("div");
+        readerContent.setAttribute("class", "moz-reader-content");
+        contentElement.appendChild(readerContent);
+
+        let articleUri = Services.io.newURI(article.url);
+        let parserUtils = Cc["@mozilla.org/parserutils;1"].getService(
+          Ci.nsIParserUtils
+        );
+        let contentFragment = parserUtils.parseFragment(
+          article.content,
+          Ci.nsIParserUtils.SanitizerDropForms |
+            Ci.nsIParserUtils.SanitizerAllowStyle,
+          false,
+          articleUri,
+          readerContent
+        );
+
+        readerContent.appendChild(contentFragment);
+
+        // Display reader content element
+        readerContent.style.display = "block";
+      } else {
+        const l10n = new Localization(["toolkit/about/aboutReader.ftl"], true);
+        const errorMessage = l10n.formatValueSync("about-reader-load-error");
+
+        document.title = errorMessage;
+
+        // Create reader message div and append it to body
+        let readerMessageElement = document.createElement("div");
+        readerMessageElement.setAttribute("class", "reader-message");
+        readerMessageElement.textContent = errorMessage;
+        containerElement.appendChild(readerMessageElement);
+
+        // Display reader message element
+        readerMessageElement.style.display = "block";
+      }
+    });
+  }
+
+  updateCurrentPage() {
+    let cv = this.docShell.docViewer;
+    cv.QueryInterface(Ci.nsIWebBrowserPrint);
+    this.sendAsyncMessage("Printing:Preview:CurrentPage", {
+      currentPage: cv.printPreviewCurrentPageNumber,
+    });
+  }
+
+  navigate(navType, pageNum) {
+    let cv = this.docShell.docViewer;
+    cv.QueryInterface(Ci.nsIWebBrowserPrint);
+    cv.printPreviewScrollToPage(navType, pageNum);
+  }
+}