use textbutton

packages/stream_chat_flutter/lib/src/attachment/giphy_attachment.dart

@@ -202,8 +202,9 @@ class GiphyAttachment extends AttachmentWidget {
                 crossAxisAlignment: CrossAxisAlignment.center,
                 children: [
                   Expanded(
-                    child: FlatButton(
+                    child: Container(
                       height: 50,
+                      child: TextButton(
                         onPressed: () {
                           streamChannel.channel.sendAction(message, {
                             'image_action': 'cancel',
@@ -223,6 +224,7 @@ class GiphyAttachment extends AttachmentWidget {
                         ),
                       ),
                     ),
+                  ),
                   Container(
                     width: 0.5,
                     color: StreamChatTheme.of(context)
@@ -232,8 +234,9 @@ class GiphyAttachment extends AttachmentWidget {
                     height: 50.0,
                   ),
                   Expanded(
-                    child: FlatButton(
+                    child: Container(
                       height: 50,
+                      child: TextButton(
                         onPressed: () {
                           streamChannel.channel.sendAction(message, {
                             'image_action': 'send',
@@ -249,6 +252,7 @@ class GiphyAttachment extends AttachmentWidget {
                         ),
                       ),
                     ),
+                  ),
                 ],
               ),
             ],

packages/stream_chat_flutter/lib/src/channel_list_view.dart

@@ -284,7 +284,7 @@ class _ChannelListViewState extends State<ChannelListView> {
                   left: 0,
                   bottom: 32,
                   child: Center(
-                    child: FlatButton(
+                    child: TextButton(
                       onPressed: widget.onStartChatPressed,
                       child: Text(
                         'Start a chat',
@@ -445,7 +445,7 @@ class _ChannelListViewState extends State<ChannelListView> {
             ),
             style: Theme.of(context).textTheme.headline6,
           ),
-          FlatButton(
+          TextButton(
             onPressed: () => _channelListController.loadData(),
             child: Text('Retry'),
           ),

packages/stream_chat_flutter/lib/src/message_actions_modal.dart

@@ -348,7 +348,7 @@ class _MessageActionsModalState extends State<MessageActionsModal> {
             Row(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                FlatButton(
+                TextButton(
                   child: Text(
                     'OK',
                     style: StreamChatTheme.of(context)
@@ -413,7 +413,7 @@ class _MessageActionsModalState extends State<MessageActionsModal> {
             Row(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                FlatButton(
+                TextButton(
                   child: Text(
                     'OK',
                     style: StreamChatTheme.of(context)

packages/stream_chat_flutter/lib/src/message_input.dart

@@ -2139,7 +2139,7 @@ class MessageInputState extends State<MessageInput> {
             Row(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                FlatButton(
+                TextButton(
                   child: Text(
                     'OK',
                     style: StreamChatTheme.of(context)

packages/stream_chat_flutter/lib/src/user_list_view.dart

@@ -242,7 +242,7 @@ class _UserListViewState extends State<UserListView>
             ),
             child: Text(message),
           ),
-          FlatButton(
+          TextButton(
             onPressed: () {
               _userListController.loadData();
             },

packages/stream_chat_flutter/lib/src/utils.dart

@@ -59,7 +59,7 @@ Future<bool> showConfirmationDialog(
             Row(
               mainAxisAlignment: MainAxisAlignment.spaceBetween,
               children: [
-                FlatButton(
+                TextButton(
                   child: Text(
                     cancelText,
                     style: StreamChatTheme.of(context)
@@ -75,7 +75,7 @@ Future<bool> showConfirmationDialog(
                     Navigator.of(context).pop(false);
                   },
                 ),
-                FlatButton(
+                TextButton(
                   child: Text(
                     okText,
                     style: StreamChatTheme.of(context)
@@ -145,7 +145,7 @@ Future<bool> showInfoDialog(
           Row(
             mainAxisAlignment: MainAxisAlignment.spaceBetween,
             children: [
-              FlatButton(
+              TextButton(
                 child: Text(
                   okText,
                   style: TextStyle(