Bug 1312422 - Web Share Base/DOM implementation r=farre

Web Share base implementation just of DOM stuff - working together with @saschanaz.

@Baku, we would greatly appreciate your review.

-Nika, as she is traveling.

Differential Revision: https://phabricator.services.mozilla.com/D44598

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

browser/components/moz.build

@@ -55,6 +55,7 @@ DIRS += [
     'uitour',
     'urlbar',
     'translation',
+    'webshare',
 ]
 
 DIRS += ['build']

browser/components/webshare/SharePicker.js

@@ -0,0 +1,55 @@
+/* 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 { XPCOMUtils } = ChromeUtils.import(
+  "resource://gre/modules/XPCOMUtils.jsm"
+);
+
+class SharePicker {
+  constructor() {}
+
+  get classDescription() {
+    return "Web Share Picker";
+  }
+
+  get classID() {
+    return Components.ID("{1201d357-8417-4926-a694-e6408fbedcf8}");
+  }
+
+  get contractID() {
+    return "@mozilla.org/sharepicker;1";
+  }
+
+  get QueryInterface() {
+    return ChromeUtils.generateQI([Ci.nsISharePicker]);
+  }
+
+  /**
+   * The data being shared by the Document.
+   *
+   * @param {String?} title - title of the share
+   * @param {String?} text - text shared
+   * @param {nsIURI?} url - a URI shared
+   */
+  async share(title, text, url) {
+    // If anything goes wrong, always throw a real DOMException.
+    // e.g., throw new DOMException(someL10nMsg, "AbortError");
+    //
+    // The possible conditions are:
+    //   - User cancels or timeout: "AbortError"
+    //   - Data error:  "DataError"
+    //   - Anything else, please file a bug on the spec:
+    //     https://github.com/w3c/web-share/issues/
+    //
+    // Returning without throwing is success.
+    //
+    // This mock implementation just rejects - it's just here
+    // as a guide to do actual platform integration.
+    throw new DOMException("Not supported.", "AbortError");
+  }
+
+  __init() {}
+}
+
+const NSGetFactory = XPCOMUtils.generateNSGetFactory([SharePicker]);

browser/components/webshare/SharePicker.manifest

@@ -0,0 +1,2 @@
+component {1201d357-8417-4926-a694-e6408fbedcf8} SharePicker.js
+contract @mozilla.org/sharepicker;1 {1201d357-8417-4926-a694-e6408fbedcf8}

browser/components/webshare/moz.build

@@ -0,0 +1,4 @@
+EXTRA_COMPONENTS += [
+    'SharePicker.js',
+    'SharePicker.manifest',
+]

dom/base/Navigator.cpp

@@ -106,6 +106,7 @@
 #include "mozilla/Unused.h"
 
 #include "mozilla/webgpu/Instance.h"
+#include "mozilla/dom/WindowGlobalChild.h"
 
 namespace mozilla {
 namespace dom {
@@ -142,6 +143,7 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(Navigator)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Navigator)
   tmp->Invalidate();
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mWindow)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSharePromise)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
@@ -167,6 +169,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Navigator)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGamepadServiceTest)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mVRGetDisplaysPromises)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mVRServiceTest)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSharePromise)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(Navigator)
@@ -234,6 +237,8 @@ void Navigator::Invalidate() {
   mAddonManager = nullptr;
 
   mWebGpu = nullptr;
+
+  mSharePromise = nullptr;
 }
 
 void Navigator::GetUserAgent(nsAString& aUserAgent, CallerType aCallerType,
@@ -1331,6 +1336,110 @@ Promise* Navigator::GetBattery(ErrorResult& aRv) {
   return mBatteryPromise;
 }
 
+//*****************************************************************************
+//    Navigator::Share() - Web Share API
+//*****************************************************************************
+
+Promise* Navigator::Share(const ShareData& aData, ErrorResult& aRv) {
+  if (NS_WARN_IF(!mWindow || !mWindow->GetDocShell() ||
+                 !mWindow->GetExtantDoc())) {
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return nullptr;
+  }
+
+  if (mSharePromise) {
+    NS_WARNING("Only one share picker at a time per navigator instance");
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return nullptr;
+  }
+
+  // If none of data's members title, text, or url are present, reject p with
+  // TypeError, and abort these steps.
+  bool someMemberPassed = aData.mTitle.WasPassed() || aData.mText.WasPassed() ||
+                          aData.mUrl.WasPassed();
+  if (!someMemberPassed) {
+    nsAutoString message;
+    nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
+                                       "WebShareAPI_NeedOneMember", message);
+    aRv.ThrowTypeError<MSG_MISSING_REQUIRED_DICTIONARY_MEMBER>(message);
+    return nullptr;
+  }
+
+  // null checked above
+  auto doc = mWindow->GetExtantDoc();
+
+  // If data's url member is present, try to resolve it...
+  nsCOMPtr<nsIURI> url;
+  if (aData.mUrl.WasPassed()) {
+    auto result = doc->ResolveWithBaseURI(aData.mUrl.Value());
+    if (NS_WARN_IF(result.isErr())) {
+      aRv.ThrowTypeError<MSG_INVALID_URL>(aData.mUrl.Value());
+      return nullptr;
+    }
+    url = result.unwrap();
+  }
+
+  // Process the title member...
+  nsCString title;
+  if (aData.mTitle.WasPassed()) {
+    title.Assign(NS_ConvertUTF16toUTF8(aData.mTitle.Value()));
+  } else {
+    title.SetIsVoid(true);
+  }
+
+  // Process the text member...
+  nsCString text;
+  if (aData.mText.WasPassed()) {
+    text.Assign(NS_ConvertUTF16toUTF8(aData.mText.Value()));
+  } else {
+    text.SetIsVoid(true);
+  }
+
+  // The spec does the "triggered by user activation" after the data checks.
+  // Unfortunately, both Chrome and Safari behave this way, so interop wins.
+  // https://github.com/w3c/web-share/pull/118
+  if (!UserActivation::IsHandlingUserInput()) {
+    NS_WARNING("Attempt to share not triggered by user activation");
+    aRv.Throw(NS_ERROR_DOM_NOT_ALLOWED_ERR);
+    return nullptr;
+  }
+
+  // Let mSharePromise be a new promise.
+  mSharePromise = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  IPCWebShareData data(title, text, url);
+  auto wgc = mWindow->GetWindowGlobalChild();
+  if (!wgc) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  auto shareResolver = [self = RefPtr<Navigator>(this)](nsresult aResult) {
+    MOZ_ASSERT(self->mSharePromise);
+    if (NS_SUCCEEDED(aResult)) {
+      self->mSharePromise->MaybeResolveWithUndefined();
+    } else {
+      self->mSharePromise->MaybeReject(aResult);
+    }
+    self->mSharePromise = nullptr;
+  };
+
+  auto shareRejector = [self = RefPtr<Navigator>(this)](
+                           mozilla::ipc::ResponseRejectReason&& aReason) {
+    // IPC died or maybe page navigated...
+    if (self->mSharePromise) {
+      self->mSharePromise = nullptr;
+    }
+  };
+
+  // Do the share
+  wgc->SendShare(data, shareResolver, shareRejector);
+  return mSharePromise;
+}
+
 already_AddRefed<LegacyMozTCPSocket> Navigator::MozTCPSocket() {
   RefPtr<LegacyMozTCPSocket> socket = new LegacyMozTCPSocket(GetWindow());
   return socket.forget();

dom/base/Navigator.h

@@ -80,6 +80,8 @@ class VRDisplay;
 class VRServiceTest;
 class StorageManager;
 class MediaCapabilities;
+struct ShareData;
+class WindowGlobalChild;
 
 class Navigator final : public nsISupports, public nsWrapperCache {
  public:
@@ -131,6 +133,8 @@ class Navigator final : public nsISupports, public nsWrapperCache {
   Geolocation* GetGeolocation(ErrorResult& aRv);
   Promise* GetBattery(ErrorResult& aRv);
 
+  Promise* Share(const ShareData& aData, ErrorResult& aRv);
+
   static void AppName(nsAString& aAppName, nsIPrincipal* aCallerPrincipal,
                       bool aUsePrefOverriddenValue);
 
@@ -276,6 +280,7 @@ class Navigator final : public nsISupports, public nsWrapperCache {
   RefPtr<dom::MediaCapabilities> mMediaCapabilities;
   RefPtr<AddonManager> mAddonManager;
   RefPtr<webgpu::Instance> mWebGpu;
+  RefPtr<Promise> mSharePromise;  // Web Share API related
 };
 
 }  // namespace dom

dom/ipc/PWindowGlobal.ipdl

@@ -28,6 +28,13 @@ struct JSWindowActorMessageMeta {
   JSWindowActorMessageKind kind;
 };
 
+struct IPCWebShareData
+{
+  nsCString title;
+  nsCString text;
+  nsIURI url;
+};
+
 /**
  * A PWindowGlobal actor has a lifetime matching that of a single Window Global,
  * specifically a |nsGlobalWindowInner|. These actors will form a parent/child
@@ -77,6 +84,9 @@ parent:
   /// Notify the parent that this PWindowGlobal is now the current global.
   async BecomeCurrentWindowGlobal();
 
+  // Attempts to perform a "Web Share".
+  async Share(IPCWebShareData aData) returns (nsresult rv);
+
   async Destroy();
 };
 

dom/ipc/WindowGlobalParent.cpp

@@ -31,6 +31,10 @@
 #include "nsFrameLoaderOwner.h"
 #include "nsSerializationHelper.h"
 #include "nsITransportSecurityInfo.h"
+#include "nsISharePicker.h"
+
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/DOMExceptionBinding.h"
 
 #include "mozilla/dom/JSWindowActorBinding.h"
 #include "mozilla/dom/JSWindowActorParent.h"
@@ -302,6 +306,78 @@ bool WindowGlobalParent::IsCurrentGlobal() {
   return CanSend() && mBrowsingContext->GetCurrentWindowGlobal() == this;
 }
 
+namespace {
+
+class ShareHandler final : public PromiseNativeHandler {
+ public:
+  explicit ShareHandler(
+      mozilla::dom::WindowGlobalParent::ShareResolver&& aResolver)
+      : mResolver(std::move(aResolver)) {}
+
+  NS_DECL_ISUPPORTS
+
+ public:
+  virtual void ResolvedCallback(JSContext* aCx,
+                                JS::Handle<JS::Value> aValue) override {
+    mResolver(NS_OK);
+  }
+
+  virtual void RejectedCallback(JSContext* aCx,
+                                JS::Handle<JS::Value> aValue) override {
+    if (NS_WARN_IF(!aValue.isObject())) {
+      mResolver(NS_ERROR_FAILURE);
+      return;
+    }
+
+    // nsresult is stored as Exception internally in Promise
+    JS::Rooted<JSObject*> obj(aCx, &aValue.toObject());
+    RefPtr<DOMException> unwrapped;
+    nsresult rv = UNWRAP_OBJECT(DOMException, &obj, unwrapped);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      mResolver(NS_ERROR_FAILURE);
+      return;
+    }
+
+    mResolver(unwrapped->GetResult());
+  }
+
+ private:
+  ~ShareHandler() = default;
+
+  mozilla::dom::WindowGlobalParent::ShareResolver mResolver;
+};
+
+NS_IMPL_ISUPPORTS0(ShareHandler)
+
+}  // namespace
+
+mozilla::ipc::IPCResult WindowGlobalParent::RecvShare(
+    IPCWebShareData&& aData, WindowGlobalParent::ShareResolver&& aResolver) {
+  // Widget Layer handoff...
+  nsCOMPtr<nsISharePicker> sharePicker =
+      do_GetService("@mozilla.org/sharepicker;1");
+
+  if (!sharePicker) {
+    aResolver(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
+    return IPC_OK();
+  }
+
+  // And finally share the data...
+  RefPtr<Promise> promise;
+  nsresult rv = sharePicker->Share(aData.title(), aData.text(), aData.url(),
+                                   getter_AddRefs(promise));
+  if (NS_FAILED(rv)) {
+    aResolver(rv);
+    return IPC_OK();
+  }
+
+  // Handler finally awaits response...
+  RefPtr<ShareHandler> handler = new ShareHandler(std::move(aResolver));
+  promise->AppendNativeHandler(handler);
+
+  return IPC_OK();
+}
+
 already_AddRefed<Promise> WindowGlobalParent::ChangeFrameRemoteness(
     dom::BrowsingContext* aBc, const nsAString& aRemoteType,
     uint64_t aPendingSwitchId, ErrorResult& aRv) {

dom/ipc/WindowGlobalParent.h

@@ -158,6 +158,10 @@ class WindowGlobalParent final : public WindowGlobalActor,
                             const Maybe<IntRect>& aRect, float aScale,
                             nscolor aBackgroundColor, uint32_t aFlags);
 
+  // WebShare API - try to share
+  mozilla::ipc::IPCResult RecvShare(IPCWebShareData&& aData,
+                                    ShareResolver&& aResolver);
+
  private:
   ~WindowGlobalParent();
 

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

@@ -384,3 +384,5 @@ MathML_DeprecatedMencloseNotationRadical=The “radical” value is deprecated f
 MathML_DeprecatedStyleAttributeWarning=MathML attributes “background”, “color”, “fontfamily”, “fontsize”, “fontstyle” and “fontweight” are deprecated and will be removed at a future date.
 # LOCALIZATION NOTE: Do not translate MathML and XLink.
 MathML_DeprecatedXLinkAttributeWarning=XLink attributes “href”, “type”, “show” and “actuate” are deprecated on MathML elements and will be removed at a future date.
+# LOCALIZATION NOTE: Do not translate title, text, url as they are the names of JS properties.
+WebShareAPI_NeedOneMember=title or text or url member of the ShareData dictionary. At least one of the members is required.

dom/webidl/Navigator.webidl

@@ -322,3 +322,15 @@ partial interface Navigator {
   [Pref="dom.events.asyncClipboard", SecureContext, SameObject]
   readonly attribute Clipboard clipboard;
 };
+
+// https://wicg.github.io/web-share/#navigator-interface
+partial interface Navigator {
+  [SecureContext, Throws, Pref="dom.webshare.enabled"]
+  Promise<void> share(optional ShareData data = {});
+};
+// https://wicg.github.io/web-share/#sharedata-dictionary
+dictionary ShareData {
+  USVString title;
+  USVString text;
+  USVString url;
+};

modules/libpref/init/StaticPrefList.yaml

@@ -2693,6 +2693,12 @@
   value: true
   mirror: always
 
+# WebShare API - exposes navigator.share()
+- name: dom.webshare.enabled
+  type: bool
+  value: false
+  mirror: always
+
 #---------------------------------------------------------------------------
 # Prefs starting with "editor"
 #---------------------------------------------------------------------------

testing/web-platform/meta/web-share/__dir__.ini

@@ -0,0 +1 @@
+prefs: [dom.webshare.enabled:true]

testing/web-platform/meta/web-share/idlharness.https.window.js.ini

@@ -1,10 +0,0 @@
-[idlharness.https.window.html]
-  [Navigator interface: operation share(ShareData)]
-    expected: FAIL
-
-  [Navigator interface: calling share(ShareData) on navigator with too few arguments must throw TypeError]
-    expected: FAIL
-
-  [Navigator interface: navigator must inherit property "share(ShareData)" with the proper type]
-    expected: FAIL
-

testing/web-platform/meta/web-share/share-empty.https.html.ini

@@ -1,16 +0,0 @@
-[share-empty.https.html]
-  [share with no arguments (same as empty dictionary)]
-    expected: FAIL
-
-  [share with an empty dictionary]
-    expected: FAIL
-
-  [share with a undefined argument (same as empty dictionary)]
-    expected: FAIL
-
-  [share with a null argument (same as empty dictionary)]
-    expected: FAIL
-
-  [share with a dictionary containing only surplus fields]
-    expected: FAIL
-

testing/web-platform/meta/web-share/share-sharePromise-internal-slot.https.html.ini

@@ -1,4 +0,0 @@
-[share-sharePromise-internal-slot.https.html]
-  [Only allow one share call at a time, which is controlled by the [[sharePromise\]\] internal slot.]
-    expected: FAIL
-

testing/web-platform/meta/web-share/share-url-invalid.https.html.ini

@@ -1,4 +0,0 @@
-[share-url-invalid.https.html]
-  [share with an invalid URL]
-    expected: FAIL
-

testing/web-platform/meta/web-share/share-without-user-gesture.https.html.ini

@@ -1,4 +0,0 @@
-[share-without-user-gesture.https.html]
-  [share without a user gesture]
-    expected: FAIL
-

testing/web-platform/tests/web-share/share-sharePromise-internal-slot.https.html

@@ -10,21 +10,27 @@
     <script src="/resources/testdriver-vendor.js"></script>
   </head>
   <body>
+    <button>
     <script>
+      setup({ allow_uncaught_exception:true });
       promise_test(async t => {
-        const [, promise2, promise3] = await test_driver.bless(
-          "share needs user activation",
-          () => {
-            return [
+        const button = document.querySelector("button");
+        const p = new Promise(r => {
+          button.onclick = () => {
+            const promises = [];
+            promises.push(
               navigator.share({ title: "should be pending" }),
               navigator.share({ title: "should reject" }),
-              navigator.share({ title: "should also reject" }),
-            ];
-          }
-        );
+              navigator.share({ title: "should also reject" })
+            );
+            r(promises);
+          };
+        });
+        test_driver.click(button);
+        const [, promise2, promise3] = await p;
         await Promise.all([
           promise_rejects(t, "InvalidStateError", promise2),
-          promise_rejects(t, "InvalidStateError", promise3),
+          promise_rejects(t, "InvalidStateError", promise3)
         ]);
       }, "Only allow one share call at a time, which is controlled by the [[sharePromise]] internal slot.");
     </script>

widget/moz.build

@@ -117,6 +117,7 @@ XPIDL_SOURCES += [
     'nsIPrintSettingsService.idl',
     'nsIScreen.idl',
     'nsIScreenManager.idl',
+    'nsISharePicker.idl',
     'nsISound.idl',
     'nsITransferable.idl',
 ]

widget/nsContentProcessWidgetFactory.cpp

@@ -30,6 +30,7 @@ NS_DEFINE_NAMED_CID(NS_COLORPICKER_CID);
 NS_DEFINE_NAMED_CID(NS_DRAGSERVICE_CID);
 NS_DEFINE_NAMED_CID(NS_FILEPICKER_CID);
 NS_DEFINE_NAMED_CID(NS_SOUND_CID);
+NS_DEFINE_NAMED_CID(NS_SHAREPICKER_CID);
 NS_DEFINE_NAMED_CID(NS_SCREENMANAGER_CID);
 
 static const mozilla::Module::CIDEntry kWidgetCIDs[] = {
@@ -59,6 +60,8 @@ static const mozilla::Module::ContractIDEntry kWidgetContracts[] = {
     {"@mozilla.org/sound;1", &kNS_SOUND_CID, Module::CONTENT_PROCESS_ONLY},
     {"@mozilla.org/widget/dragservice;1", &kNS_DRAGSERVICE_CID,
      Module::CONTENT_PROCESS_ONLY},
+    {"@mozilla.org/sharepicker;1", &kNS_SHAREPICKER_CID,
+     Module::CONTENT_PROCESS_ONLY},
     {nullptr}};
 
 extern const mozilla::Module kContentProcessWidgetModule = {

widget/nsISharePicker.idl

@@ -0,0 +1,19 @@
+/* -*- Mode: C++; tab-width: 2; 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"
+
+interface nsIURI;
+
+[scriptable, uuid(1201d357-8417-4926-a694-e6408fbedcf8)]
+interface nsISharePicker : nsISupports
+{
+  /**
+   * XPCOM Analog of navigator.share() as per:
+   * https://w3c.github.io/web-share/#share-method
+   */
+  Promise share(in AUTF8String title, in AUTF8String text, in nsIURI url);
+};

widget/nsWidgetsCID.h

@@ -51,6 +51,14 @@
     }                                                \
   }
 
+/*1201d357-8417-4926-a694-e6408fbedcf8*/
+#define NS_SHAREPICKER_CID                           \
+  {                                                  \
+    0x1201d357, 0x8417, 0x4926, {                    \
+      0xa6, 0x94, 0xe6, 0x40, 0x8f, 0xbe, 0xdc, 0xf8 \
+    }                                                \
+  }
+
 /* XXX the following CID's are not in order. This needs
    to be fixed. */