android/app/src/main/AndroidManifest.xml

@@ -30,6 +30,11 @@
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <data android:scheme="https" />
+                <data android:scheme="http" />
+            </intent-filter>
         </activity>
         <!-- Don't delete the meta-data below.
              This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->

lib/settings.dart

@@ -10,6 +10,7 @@ import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 
 const TapirGroupsExperiment = "tapir-groups-experiment";
 const FileSharingExperiment = "filesharing";
+const ClickableLinksExperiment = "clickable-links";
 
 enum DualpaneMode {
   Single,

lib/views/globalsettingsview.dart

@@ -204,6 +204,22 @@ class _GlobalSettingsViewState extends State<GlobalSettingsView> {
                                 inactiveTrackColor: settings.theme.defaultButtonDisabledColor(),
                                 secondary: Icon(Icons.attach_file, color: settings.current().mainTextColor()),
                               ),
+                              SwitchListTile(
+                                title: Text("Enable Clickable Links", style: TextStyle(color: settings.current().mainTextColor())),
+                                subtitle: Text("The clickable links experiment allows you to click on URLs shared in messages."),
+                                value: settings.isExperimentEnabled(ClickableLinksExperiment),
+                                onChanged: (bool value) {
+                                  if (value) {
+                                    settings.enableExperiment(ClickableLinksExperiment);
+                                  } else {
+                                    settings.disableExperiment(ClickableLinksExperiment);
+                                  }
+                                  saveSettings(context);
+                                },
+                                activeTrackColor: settings.theme.defaultButtonActiveColor(),
+                                inactiveTrackColor: settings.theme.defaultButtonDisabledColor(),
+                                secondary: Icon(Icons.link, color: settings.current().mainTextColor()),
+                              ),
                             ],
                           )),
                       AboutListTile(

lib/widgets/messagebubble.dart

@@ -3,9 +3,13 @@ import 'dart:io';
 import 'package:cwtch/models/message.dart';
 import 'package:cwtch/widgets/malformedbubble.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:provider/provider.dart';
 import '../model.dart';
 import 'package:intl/intl.dart';
+import 'package:flutter_linkify/flutter_linkify.dart';
+import 'package:url_launcher/url_launcher.dart';
 
 import '../settings.dart';
 import 'messagebubbledecorations.dart';
@@ -28,6 +32,7 @@ class MessageBubbleState extends State<MessageBubble> {
     var prettyDate = "";
     var borderRadiousEh = 15.0;
     // var myKey = Provider.of<MessageState>(context).profileOnion + "::" + Provider.of<MessageState>(context).contactHandle + "::" + Provider.of<MessageState>(context).messageIndex.toString();
+    var showClickableLinks = Provider.of<Settings>(context).isExperimentEnabled(ClickableLinksExperiment);
 
     DateTime messageDate = Provider.of<MessageMetadata>(context).timestamp;
     prettyDate = DateFormat.yMd(Platform.localeName).add_jm().format(messageDate.toLocal());
@@ -45,16 +50,37 @@ class MessageBubbleState extends State<MessageBubble> {
     var wdgSender = SelectableText(senderDisplayStr,
         style: TextStyle(fontSize: 9.0, color: fromMe ? Provider.of<Settings>(context).theme.messageFromMeTextColor() : Provider.of<Settings>(context).theme.messageFromOtherTextColor()));
 
-    var wdgMessage = SelectableText(
-      widget.content + '\u202F',
-      //key: Key(myKey),
-      focusNode: _focus,
-      style: TextStyle(
-        color: fromMe ? Provider.of<Settings>(context).theme.messageFromMeTextColor() : Provider.of<Settings>(context).theme.messageFromOtherTextColor(),
-      ),
-      textAlign: TextAlign.left,
-      textWidthBasis: TextWidthBasis.longestLine,
-    );
+    var wdgMessage;
+
+    if (!showClickableLinks) {   
+      wdgMessage = SelectableText(
+        widget.content + '\u202F',
+        //key: Key(myKey),
+        focusNode: _focus,
+        style: TextStyle(
+          color: fromMe ? Provider.of<Settings>(context).theme.messageFromMeTextColor() : Provider.of<Settings>(context).theme.messageFromOtherTextColor(),
+        ),
+        textAlign: TextAlign.left,
+        textWidthBasis: TextWidthBasis.longestLine,
+      );
+    } else {
+      wdgMessage = SelectableLinkify(
+        text: widget.content + '\u202F',
+        // TODO: onOpen breaks the "selectable" functionality. Maybe something to do with gesture handler?
+        options: LinkifyOptions(humanize: false),
+        linkifiers: [UrlLinkifier()],  // TODO: double-check on this (only web links to avoid Android messiness)
+        onOpen: (link) {
+          _modalOpenLink(context, link);
+        },
+        //key: Key(myKey),
+        focusNode: _focus,
+        style: TextStyle(
+          color: fromMe ? Provider.of<Settings>(context).theme.messageFromMeTextColor() : Provider.of<Settings>(context).theme.messageFromOtherTextColor(),
+        ),
+        textAlign: TextAlign.left,
+        textWidthBasis: TextWidthBasis.longestLine,
+      );
+    }
 
     var wdgDecorations = MessageBubbleDecoration(ackd: Provider.of<MessageMetadata>(context).ackd, errored: Provider.of<MessageMetadata>(context).error, fromMe: fromMe, prettyDate: prettyDate);
 
@@ -90,4 +116,58 @@ class MessageBubbleState extends State<MessageBubble> {
                           children: fromMe ? [wdgMessage, wdgDecorations] : [wdgSender, wdgMessage, wdgDecorations])))));
     });
   }
+
+  void _modalOpenLink(BuildContext ctx, LinkableElement link) {
+    showModalBottomSheet<void>(
+        context: ctx,
+        builder: (BuildContext bcontext) {
+          return Container(
+              // TODO: Ask re: hard-coded height
+              height: 200, // bespoke value courtesy of the [TextField] docs
+              child: Center(
+                child: Padding(
+                    padding: EdgeInsets.all(30.0),
+                    child: Column(
+                      mainAxisAlignment: MainAxisAlignment.center,
+                      mainAxisSize: MainAxisSize.min,
+                      children: <Widget>[
+                        Text(
+                          "Opening this link will launch an application outside of Cwtch and may reveal metadata or otherwise compromise the security of Cwtch. Only open links from people you trust. Are you sure you want to continue?"
+                        ),
+                        // TODO: Ask about styling preferences (should this be a reusable "inline-button"?)
+                        Flex(direction: Axis.horizontal, mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[
+                          Container(
+                            margin: EdgeInsets.symmetric(vertical: 20, horizontal: 10),
+                            child: ElevatedButton(
+                              child: Text("Copy link", semanticsLabel: "Copy link"),
+                              onPressed: () {
+                                Clipboard.setData(new ClipboardData(text: link.url));
+
+                                // TODO: Ask about desired SnackBar + modal behaviour
+                                final snackBar = SnackBar(
+                                  content: Text(AppLocalizations.of(context)!.copiedClipboardNotification),
+                                );
+                                ScaffoldMessenger.of(context).showSnackBar(snackBar);
+                              },
+                            ),
+                          ),
+                          Container(
+                            margin: EdgeInsets.symmetric(vertical: 20, horizontal: 10),
+                            child: ElevatedButton(
+                              child: Text("Open link", semanticsLabel: "Open link"),
+                              onPressed: () async {
+                                if (await canLaunch(link.url)) {
+                                  await launch(link.url);
+                                } else {
+                                  throw 'Could not launch $link';
+                                }
+                              },
+                            ),
+                          ),
+                        ]),
+                      ],
+                    )),
+              ));
+      });
+  }
 }

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -7,8 +7,10 @@ import Foundation
 
 import package_info_plus_macos
 import path_provider_macos
+import url_launcher_macos
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   FLTPackageInfoPlusPlugin.register(with: registry.registrar(forPlugin: "FLTPackageInfoPlusPlugin"))
   PathProviderPlugin.register(with: registry.registrar(forPlugin: "PathProviderPlugin"))
+  UrlLauncherPlugin.register(with: registry.registrar(forPlugin: "UrlLauncherPlugin"))
 }

macos/Podfile.lock

@@ -4,11 +4,14 @@ PODS:
     - FlutterMacOS
   - path_provider_macos (0.0.1):
     - FlutterMacOS
+  - url_launcher_macos (0.0.1):
+    - FlutterMacOS
 
 DEPENDENCIES:
   - FlutterMacOS (from `Flutter/ephemeral`)
   - package_info_plus_macos (from `Flutter/ephemeral/.symlinks/plugins/package_info_plus_macos/macos`)
   - path_provider_macos (from `Flutter/ephemeral/.symlinks/plugins/path_provider_macos/macos`)
+  - url_launcher_macos (from `Flutter/ephemeral/.symlinks/plugins/url_launcher_macos/macos`)
 
 EXTERNAL SOURCES:
   FlutterMacOS:
@@ -17,12 +20,15 @@ EXTERNAL SOURCES:
     :path: Flutter/ephemeral/.symlinks/plugins/package_info_plus_macos/macos
   path_provider_macos:
     :path: Flutter/ephemeral/.symlinks/plugins/path_provider_macos/macos
+  url_launcher_macos:
+    :path: Flutter/ephemeral/.symlinks/plugins/url_launcher_macos/macos
 
 SPEC CHECKSUMS:
   FlutterMacOS: 57701585bf7de1b3fc2bb61f6378d73bbdea8424
   package_info_plus_macos: f010621b07802a241d96d01876d6705f15e77c1c
   path_provider_macos: a0a3fd666cb7cd0448e936fb4abad4052961002b
+  url_launcher_macos: 45af3d61de06997666568a7149c1be98b41c95d4
 
 PODFILE CHECKSUM: 6eac6b3292e5142cfc23bdeb71848a40ec51c14c
 
-COCOAPODS: 1.9.3
+COCOAPODS: 1.11.2

pubspec.lock

@@ -35,7 +35,7 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   charcode:
     dependency: transitive
     description:
@@ -125,6 +125,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_linkify:
+    dependency: "direct main"
+    description:
+      name: flutter_linkify
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "5.0.2"
   flutter_localizations:
     dependency: "direct main"
     description: flutter
@@ -189,6 +196,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.6.3"
+  linkify:
+    dependency: transitive
+    description:
+      name: linkify
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "4.1.0"
   matcher:
     dependency: transitive
     description:
@@ -411,6 +425,48 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.0"
+  url_launcher:
+    dependency: "direct main"
+    description:
+      name: url_launcher
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.0.12"
+  url_launcher_linux:
+    dependency: transitive
+    description:
+      name: url_launcher_linux
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.2"
+  url_launcher_macos:
+    dependency: transitive
+    description:
+      name: url_launcher_macos
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.2"
+  url_launcher_platform_interface:
+    dependency: transitive
+    description:
+      name: url_launcher_platform_interface
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.4"
+  url_launcher_web:
+    dependency: transitive
+    description:
+      name: url_launcher_web
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.4"
+  url_launcher_windows:
+    dependency: transitive
+    description:
+      name: url_launcher_windows
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.2"
   vector_math:
     dependency: transitive
     description:
@@ -447,5 +503,5 @@ packages:
     source: hosted
     version: "3.1.0"
 sdks:
-  dart: ">=2.13.0 <3.0.0"
-  flutter: ">=2.0.0"
+  dart: ">=2.14.0 <3.0.0"
+  flutter: ">=2.5.0"

pubspec.yaml

@@ -43,6 +43,8 @@ dependencies:
   scrollable_positioned_list: ^0.2.0-nullsafety.0
   file_picker: ^4.0.1
   file_picker_desktop: ^1.1.0
+  flutter_linkify: ^5.0.2
+  url_launcher: ^6.0.12
 
 dev_dependencies:
   msix: ^2.1.3