Bug 1259517 - Make dropping images in editors work in e10s. r=baku

dom/locales/en-US/chrome/dom/dom.properties

@@ -22,6 +22,8 @@ LowMemoryTitle=Warning: Low memory
 LowMemoryMessage=A script on this page has been stopped due to a low memory condition.
 SpeculationFailed=An unbalanced tree was written using document.write() causing data from the network to be reparsed. For more information https://developer.mozilla.org/en/Optimizing_Your_Pages_for_Speculative_Parsing
 DocumentWriteIgnored=A call to document.write() from an asynchronously-loaded external script was ignored.
+# LOCALIZATION NOTE (EditorFileDropFailed): Do not translate contenteditable, %S is the error message explaining why the drop failed.
+EditorFileDropFailed=Dropping a file into a contenteditable element failed: %S.
 FormValidationTextTooLong=Please shorten this text to %S characters or less (you are currently using %S characters).
 FormValidationValueMissing=Please fill out this field.
 FormValidationCheckboxMissing=Please check this box if you want to proceed.

editor/libeditor/EditorUtils.js

@@ -0,0 +1,34 @@
+/* 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/. */
+
+var { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+
+"use strict";
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+
+const EDITORUTILS_CID = Components.ID('{12e63991-86ac-4dff-bb1a-703495d67d17}');
+
+function EditorUtils() {
+}
+
+EditorUtils.prototype = {
+  classID: EDITORUTILS_CID,
+  QueryInterface: XPCOMUtils.generateQI([ Ci.nsIEditorUtils ]),
+
+  slurpBlob(aBlob, aScope, aListener) {
+    let reader = new aScope.FileReader();
+    reader.addEventListener("load", (event) => {
+      aListener.onResult(event.target.result);
+    });
+    reader.addEventListener("error", (event) => {
+      aListener.onError(event.target.error.message);
+    });
+
+    reader.readAsBinaryString(aBlob);
+  },
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([EditorUtils]);

editor/libeditor/EditorUtils.manifest

@@ -0,0 +1,2 @@
+component {12e63991-86ac-4dff-bb1a-703495d67d17} EditorUtils.js
+contract @mozilla.org/editor-utils;1 {12e63991-86ac-4dff-bb1a-703495d67d17}

editor/libeditor/moz.build

@@ -70,6 +70,11 @@ LOCAL_INCLUDES += [
     '/layout/xul',
 ]
 
+EXTRA_COMPONENTS += [
+    'EditorUtils.js',
+    'EditorUtils.manifest',
+]
+
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

editor/libeditor/nsHTMLDataTransfer.cpp

@@ -18,6 +18,7 @@
 #include "nsCRT.h"
 #include "nsCRTGlue.h"
 #include "nsComponentManagerUtils.h"
+#include "nsIScriptError.h"
 #include "nsContentUtils.h"
 #include "nsDebug.h"
 #include "nsDependentSubstring.h"
@@ -1009,6 +1010,77 @@ nsHTMLEditor::ParseCFHTML(nsCString & aCfhtml, char16_t **aStuffToPaste, char16_
   return NS_OK;
 }
 
+static nsresult
+ImgFromData(const nsACString& aType, const nsACString& aData, nsString& aOutput)
+{
+  nsAutoCString data64;
+  nsresult rv = Base64Encode(aData, data64);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aOutput.AssignLiteral("<IMG src=\"data:");
+  AppendUTF8toUTF16(aType, aOutput);
+  aOutput.AppendLiteral(";base64,");
+  AppendUTF8toUTF16(data64, aOutput);
+  aOutput.AppendLiteral("\" alt=\"\" >");
+  return NS_OK;
+}
+
+NS_IMPL_ISUPPORTS(nsHTMLEditor::BlobReader, nsIEditorBlobListener)
+
+nsHTMLEditor::BlobReader::BlobReader(BlobImpl* aBlob, nsHTMLEditor* aEditor,
+                                     bool aIsSafe, nsIDOMDocument* aSourceDoc,
+                                     nsIDOMNode* aDestinationNode,
+                                     int32_t aDestOffset,
+                                     bool aDoDeleteSelection)
+  : mBlob(aBlob)
+  , mEditor(aEditor)
+  , mIsSafe(aIsSafe)
+  , mSourceDoc(aSourceDoc)
+  , mDestinationNode(aDestinationNode)
+  , mDestOffset(aDestOffset)
+  , mDoDeleteSelection(aDoDeleteSelection)
+{
+  MOZ_ASSERT(mBlob);
+  MOZ_ASSERT(mEditor);
+  MOZ_ASSERT(mDestinationNode);
+}
+
+NS_IMETHODIMP
+nsHTMLEditor::BlobReader::OnResult(const nsACString& aResult)
+{
+  nsString blobType;
+  mBlob->GetType(blobType);
+
+  NS_ConvertUTF16toUTF8 type(blobType);
+  nsAutoString stuffToPaste;
+  nsresult rv = ImgFromData(type, aResult, stuffToPaste);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoEditBatch beginBatching(mEditor);
+  rv = mEditor->DoInsertHTMLWithContext(stuffToPaste, EmptyString(), EmptyString(),
+                                        NS_LITERAL_STRING(kFileMime),
+                                        mSourceDoc,
+                                        mDestinationNode, mDestOffset,
+                                        mDoDeleteSelection,
+                                        mIsSafe, false);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsHTMLEditor::BlobReader::OnError(const nsAString& aError)
+{
+  nsCOMPtr<nsINode> destNode = do_QueryInterface(mDestinationNode);
+  const nsPromiseFlatString& flat = PromiseFlatString(aError);
+  const char16_t* error = flat.get();
+  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
+                                  NS_LITERAL_CSTRING("Editor"),
+                                  destNode->OwnerDoc(),
+                                  nsContentUtils::eDOM_PROPERTIES,
+                                  "EditorFileDropFailed",
+                                  &error, 1);
+  return NS_OK;
+}
+
 nsresult nsHTMLEditor::InsertObject(const char* aType, nsISupports* aObject, bool aIsSafe,
                                     nsIDOMDocument *aSourceDoc,
                                     nsIDOMNode *aDestinationNode,
@@ -1017,6 +1089,23 @@ nsresult nsHTMLEditor::InsertObject(const char* aType, nsISupports* aObject, boo
 {
   nsresult rv;
 
+  if (nsCOMPtr<BlobImpl> blob = do_QueryInterface(aObject)) {
+    RefPtr<BlobReader> br = new BlobReader(blob, this, aIsSafe, aSourceDoc,
+                                           aDestinationNode, aDestOffset,
+                                           aDoDeleteSelection);
+    nsCOMPtr<nsIEditorUtils> utils =
+      do_GetService("@mozilla.org/editor-utils;1");
+    NS_ENSURE_TRUE(utils, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsINode> node = do_QueryInterface(aDestinationNode);
+    MOZ_ASSERT(node);
+
+    nsCOMPtr<nsIDOMBlob> domBlob = Blob::Create(node->GetOwnerGlobal(), blob);
+    NS_ENSURE_TRUE(domBlob, NS_ERROR_FAILURE);
+
+    return utils->SlurpBlob(domBlob, node->OwnerDoc()->GetWindow(), br);
+  }
+
   nsAutoCString type(aType);
 
   // Check to see if we can insert an image file
@@ -1064,16 +1153,10 @@ nsresult nsHTMLEditor::InsertObject(const char* aType, nsISupports* aObject, boo
       NS_ENSURE_SUCCESS(rv, rv);
     }
 
-    nsAutoCString data64;
-    rv = Base64Encode(imageData, data64);
+    nsAutoString stuffToPaste;
+    rv = ImgFromData(type, imageData, stuffToPaste);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    nsAutoString stuffToPaste;
-    stuffToPaste.AssignLiteral("<IMG src=\"data:");
-    AppendUTF8toUTF16(type, stuffToPaste);
-    stuffToPaste.AppendLiteral(";base64,");
-    AppendUTF8toUTF16(data64, stuffToPaste);
-    stuffToPaste.AppendLiteral("\" alt=\"\" >");
     nsAutoEditBatch beginBatching(this);
     rv = DoInsertHTMLWithContext(stuffToPaste, EmptyString(), EmptyString(),
                                  NS_LITERAL_STRING(kFileMime),

editor/libeditor/nsHTMLEditor.h

@@ -13,6 +13,7 @@
 #include "nsITableEditor.h"
 #include "nsIEditorMailSupport.h"
 #include "nsIEditorStyleSheets.h"
+#include "nsIEditorUtils.h"
 
 #include "nsEditor.h"
 #include "nsIDOMElement.h"
@@ -56,6 +57,7 @@ struct PropItem;
 namespace mozilla {
 template<class T> class OwningNonNull;
 namespace dom {
+class BlobImpl;
 class DocumentFragment;
 } // namespace dom
 namespace widget {
@@ -405,6 +407,30 @@ public:
   }
 
 protected:
+  class BlobReader final : public nsIEditorBlobListener
+  {
+  public:
+    BlobReader(mozilla::dom::BlobImpl* aBlob, nsHTMLEditor* aEditor,
+               bool aIsSafe, nsIDOMDocument* aSourceDoc,
+               nsIDOMNode* aDestinationNode, int32_t aDestOffset,
+               bool aDoDeleteSelection);
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIEDITORBLOBLISTENER
+
+  private:
+    ~BlobReader()
+    {
+    }
+
+    RefPtr<mozilla::dom::BlobImpl> mBlob;
+    RefPtr<nsHTMLEditor> mEditor;
+    bool mIsSafe;
+    nsCOMPtr<nsIDOMDocument> mSourceDoc;
+    nsCOMPtr<nsIDOMNode> mDestinationNode;
+    int32_t mDestOffset;
+    bool mDoDeleteSelection;
+  };
 
   NS_IMETHOD  InitRules() override;
 

editor/moz.build

@@ -21,6 +21,7 @@ XPIDL_SOURCES += [
     'nsIEditorObserver.idl',
     'nsIEditorSpellCheck.idl',
     'nsIEditorStyleSheets.idl',
+    'nsIEditorUtils.idl',
     'nsIHTMLAbsPosEditor.idl',
     'nsIHTMLEditor.idl',
     'nsIHTMLInlineTableEditor.idl',

editor/nsIEditorUtils.idl

@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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/. */
+
+#include "nsISupports.idl"
+#include "domstubs.idl"
+
+interface nsIDOMBlob;
+interface mozIDOMWindowProxy;
+
+[scriptable, uuid(eb8b8ad9-5d8f-43bd-8ce5-5b943c180d56)]
+interface nsIEditorBlobListener : nsISupports
+{
+  void onResult(in ACString aResult);
+  void onError(in AString aErrorName);
+};
+
+/**
+ * A collection of utility functions that editors can use that are more easily
+ * done in JavaScript.
+ */
+[scriptable, uuid(4bf94928-575e-4bd1-8321-a2c4b3d0119e)]
+interface nsIEditorUtils : nsISupports
+{
+  /**
+   * Given a blob, returns the data from that blob, asynchronously.
+   */
+  void slurpBlob(in nsIDOMBlob aBlob, in mozIDOMWindowProxy aScope,
+                 in nsIEditorBlobListener aListener);
+};