add image on tap to channel preview

lib/src/channel_list_view.dart

@@ -56,6 +56,7 @@ class ChannelListView extends StatefulWidget {
     this.channelWidget,
     this.channelPreviewBuilder,
     this.errorBuilder,
+    this.onImageTap,
   }) : super(key: key);
 
   final Widget Function(Error error) errorBuilder;
@@ -94,6 +95,9 @@ class ChannelListView extends StatefulWidget {
   /// Builder used to create a custom channel preview
   final ChannelPreviewBuilder channelPreviewBuilder;
 
+  /// The function called when the image is tapped
+  final Function(Channel) onImageTap;
+
   @override
   _ChannelListViewState createState() => _ChannelListViewState();
 }
@@ -215,8 +219,6 @@ class _ChannelListViewState extends State<ChannelListView> {
     if (i < channels.length) {
       final channel = channels[i];
 
-      final channelClient = streamChat.client.channels[channel.cid];
-
       ChannelTapCallback onTap;
       if (widget.onChannelTap != null) {
         onTap = widget.onChannelTap;
@@ -237,11 +239,11 @@ class _ChannelListViewState extends State<ChannelListView> {
       }
 
       return StreamChannel(
-        key: ValueKey<String>('CHANNEL-${channelClient.id}'),
+        key: ValueKey<String>('CHANNEL-${channel.id}'),
-        channel: channelClient,
+        channel: channel,
         child: StreamBuilder<DateTime>(
-          initialData: channelClient.updatedAt,
+          initialData: channel.updatedAt,
-          stream: channelClient.updatedAtStream,
+          stream: channel.updatedAtStream,
           builder: (context, snapshot) {
             Widget child;
             if (widget.channelPreviewBuilder != null) {
@@ -249,14 +251,14 @@ class _ChannelListViewState extends State<ChannelListView> {
                 children: [
                   widget.channelPreviewBuilder(
                     context,
-                    channelClient,
+                    channel,
                   ),
                   Positioned.fill(
                     child: Material(
                       color: Colors.transparent,
                       child: InkWell(
                         onTap: () {
-                          onTap(channelClient, widget.channelWidget);
+                          onTap(channel, widget.channelWidget);
                         },
                       ),
                     ),
@@ -265,9 +267,14 @@ class _ChannelListViewState extends State<ChannelListView> {
               );
             } else {
               child = ChannelPreview(
-                channel: channelClient,
+                channel: channel,
-                onTap: (channelClient) {
+                onImageTap: widget.onImageTap != null
-                  onTap(channelClient, widget.channelWidget);
+                    ? () {
+                        widget.onImageTap(channel);
+                      }
+                    : null,
+                onTap: (channel) {
+                  onTap(channel, widget.channelWidget);
                 },
               );
             }

lib/src/channel_preview.dart

@@ -25,10 +25,14 @@ class ChannelPreview extends StatelessWidget {
   /// Channel displayed
   final Channel channel;
 
+  /// The function called when the image is tapped
+  final VoidCallback onImageTap;
+
   ChannelPreview({
     @required this.channel,
     Key key,
     this.onTap,
+    this.onImageTap,
   }) : super(key: key);
 
   @override
@@ -37,7 +41,9 @@ class ChannelPreview extends StatelessWidget {
       onTap: () {
         onTap(channel);
       },
-      leading: ChannelImage(),
+      leading: ChannelImage(
+        onTap: onImageTap,
+      ),
       title: ChannelName(
         textStyle: StreamChatTheme.of(context).channelPreviewTheme.title,
       ),