Bug 1265004 - Try to save in-memory reader view article instead of downloading r=margaret

This should guarantee that any reader view page will also be successfully saved offline.

MozReview-Commit-ID: 4J8cY6hYeyU

--HG--
extra : rebase_source : 689a2db7a7d81dbe89e5e58c170afe473563b2f6

mobile/android/base/java/org/mozilla/gecko/Tab.java

@@ -553,7 +553,7 @@ public class Tab {
         });
 
         if (AboutPages.isAboutReader(url)) {
-            ReadingListHelper.cacheReaderItem(pageUrl, mAppContext);
+            ReadingListHelper.cacheReaderItem(pageUrl, mId, mAppContext);
         }
     }
 

mobile/android/base/java/org/mozilla/gecko/reader/ReadingListHelper.java

@@ -91,7 +91,7 @@ public final class ReadingListHelper implements NativeEventListener {
         rch.put(url, path, size);
     }
 
-    public static void cacheReaderItem(final String url, Context context) {
+    public static void cacheReaderItem(final String url, final int tabID, Context context) {
         if (AboutPages.isAboutReader(url)) {
             throw new IllegalArgumentException("Page url must be original (not about:reader) url");
         }
@@ -99,7 +99,7 @@ public final class ReadingListHelper implements NativeEventListener {
         SavedReaderViewHelper rch = SavedReaderViewHelper.getSavedReaderViewHelper(context);
 
         if (!rch.isURLCached(url)) {
-            GeckoAppShell.notifyObservers("Reader:AddToCache", url);
+            GeckoAppShell.notifyObservers("Reader:AddToCache", Integer.toString(tabID));
         }
     }
 

mobile/android/chrome/content/Reader.js

@@ -82,8 +82,13 @@ var Reader = {
       }
 
       case "Reader:AddToCache": {
+        let tab = BrowserApp.getTabForId(aData);
+        if (!tab) {
+          throw new Error("No tab for tabID = " + aData + " when trying to save reader view article");
+        }
+
         // If the article is coming from reader mode, we must have fetched it already.
-        this._getArticle(aData).then((article) => {
+        this._getArticleData(tab.browser).then((article) => {
           ReaderMode.storeArticleInCache(article);
         }).catch(e => Cu.reportError("Error storing article in cache: " + e));
         break;
@@ -281,6 +286,23 @@ var Reader = {
     });
   }),
 
+  _getArticleData: function(browser) {
+    return new Promise((resolve, reject) => {
+      if (browser == null) {
+        reject("_getArticleData needs valid browser");
+      }
+
+      let mm = browser.messageManager;
+      let listener = (message) => {
+        mm.removeMessageListener("Reader:StoredArticleData", listener);
+        resolve(message.data.article);
+      };
+      mm.addMessageListener("Reader:StoredArticleData", listener);
+      mm.sendAsyncMessage("Reader:GetStoredArticleData");
+    });
+  },
+
+
   /**
    * Migrates old indexedDB reader mode cache to new JSON cache.
    */

toolkit/components/reader/AboutReader.jsm

@@ -37,6 +37,7 @@ var AboutReader = function(mm, win, articlePromise) {
   this._mm.addMessageListener("Reader:CloseDropdown", this);
   this._mm.addMessageListener("Reader:AddButton", this);
   this._mm.addMessageListener("Reader:RemoveButton", this);
+  this._mm.addMessageListener("Reader:GetStoredArticleData", this);
 
   this._docRef = Cu.getWeakReference(doc);
   this._winRef = Cu.getWeakReference(win);
@@ -205,6 +206,9 @@ AboutReader.prototype = {
         }
         break;
       }
+      case "Reader:GetStoredArticleData": {
+        this._mm.sendAsyncMessage("Reader:StoredArticleData", { article: this._article });
+      }
     }
   },
 
@@ -253,6 +257,7 @@ AboutReader.prototype = {
         this._mm.removeMessageListener("Reader:CloseDropdown", this);
         this._mm.removeMessageListener("Reader:AddButton", this);
         this._mm.removeMessageListener("Reader:RemoveButton", this);
+        this._mm.removeMessageListener("Reader:GetStoredArticleData", this);
         this._windowUnloaded = true;
         break;
     }