Simplify timeline item creation

include/TimelineView.h

@@ -90,16 +90,14 @@ public:
                      const QString &room_id,
                      QWidget *parent = 0);
 
-        TimelineItem *createTimelineItem(const events::MessageEvent<msgs::Image> &e,
-                                         bool with_sender);
-        TimelineItem *createTimelineItem(const events::MessageEvent<msgs::Notice> &e,
-                                         bool with_sender);
-        TimelineItem *createTimelineItem(const events::MessageEvent<msgs::Text> &e,
-                                         bool with_sender);
-        TimelineItem *createTimelineItem(const events::MessageEvent<msgs::Emote> &e,
-                                         bool with_sender);
-        TimelineItem *createTimelineItem(const events::MessageEvent<msgs::File> &e,
-                                         bool with_sender);
+        // For events with custom display widgets.
+        template<class Event, class Widget>
+        TimelineItem *createTimelineItem(const Event &event, bool withSender);
+
+        // For events without custom display widgets.
+        // TODO: All events should have custom widgets.
+        template<class Event>
+        TimelineItem *createTimelineItem(const Event &event, bool withSender);
 
         // Add new events at the end of the timeline.
         int addEvents(const Timeline &timeline);
@@ -222,3 +220,21 @@ TimelineView::addUserMessage(const QString &url, const QString &filename)
         PendingMessage message(MsgType, txn_id, url, filename, "", view_item);
         handleNewUserMessage(message);
 }
+
+template<class Event>
+TimelineItem *
+TimelineView::createTimelineItem(const Event &event, bool withSender)
+{
+        TimelineItem *item = new TimelineItem(event, withSender, scroll_widget_);
+        return item;
+}
+
+template<class Event, class Widget>
+TimelineItem *
+TimelineView::createTimelineItem(const Event &event, bool withSender)
+{
+        auto eventWidget = new Widget(client_, event);
+        auto item        = new TimelineItem(eventWidget, event, withSender, scroll_widget_);
+
+        return item;
+}

src/TimelineView.cc

@@ -255,7 +255,8 @@ TimelineView::parseMessageEvent(const QJsonObject &event, TimelineDirection dire
 
                         updateLastSender(text.sender(), direction);
 
-                        return createTimelineItem(text, with_sender);
+                        using Text = events::MessageEvent<msgs::Text>;
+                        return createTimelineItem<Text>(text, with_sender);
                 } else if (msg_type == events::MessageEventType::Notice) {
                         events::MessageEvent<msgs::Notice> notice;
 
@@ -275,7 +276,8 @@ TimelineView::parseMessageEvent(const QJsonObject &event, TimelineDirection dire
 
                         updateLastSender(notice.sender(), direction);
 
-                        return createTimelineItem(notice, with_sender);
+                        using Notice = events::MessageEvent<msgs::Notice>;
+                        return createTimelineItem<Notice>(notice, with_sender);
                 } else if (msg_type == events::MessageEventType::Image) {
                         events::MessageEvent<msgs::Image> img;
 
@@ -302,7 +304,8 @@ TimelineView::parseMessageEvent(const QJsonObject &event, TimelineDirection dire
 
                         updateLastSender(img.sender(), direction);
 
-                        return createTimelineItem(img, with_sender);
+                        using Image = events::MessageEvent<msgs::Image>;
+                        return createTimelineItem<Image, ImageItem>(img, with_sender);
                 } else if (msg_type == events::MessageEventType::Emote) {
                         events::MessageEvent<msgs::Emote> emote;
 
@@ -329,7 +332,8 @@ TimelineView::parseMessageEvent(const QJsonObject &event, TimelineDirection dire
 
                         updateLastSender(emote.sender(), direction);
 
-                        return createTimelineItem(emote, with_sender);
+                        using Emote = events::MessageEvent<msgs::Emote>;
+                        return createTimelineItem<Emote>(emote, with_sender);
                 } else if (msg_type == events::MessageEventType::File) {
                         events::MessageEvent<msgs::File> file;
 
@@ -357,7 +361,8 @@ TimelineView::parseMessageEvent(const QJsonObject &event, TimelineDirection dire
 
                         updateLastSender(file.sender(), direction);
 
-                        return createTimelineItem(file, withSender);
+                        using File = events::MessageEvent<msgs::File>;
+                        return createTimelineItem<File, FileItem>(file, withSender);
                 } else if (msg_type == events::MessageEventType::Unknown) {
                         // TODO Handle redacted messages.
                         // Silenced for now.
@@ -487,45 +492,6 @@ TimelineView::isSenderRendered(const QString &user_id, TimelineDirection directi
                 return firstSender_ != user_id;
 }
 
-TimelineItem *
-TimelineView::createTimelineItem(const events::MessageEvent<msgs::Image> &event, bool with_sender)
-{
-        auto image = new ImageItem(client_, event);
-        auto item  = new TimelineItem(image, event, with_sender, scroll_widget_);
-
-        return item;
-}
-
-TimelineItem *
-TimelineView::createTimelineItem(const events::MessageEvent<msgs::File> &event, bool withSender)
-{
-        auto file = new FileItem(client_, event);
-        auto item = new TimelineItem(file, event, withSender, scroll_widget_);
-
-        return item;
-}
-
-TimelineItem *
-TimelineView::createTimelineItem(const events::MessageEvent<msgs::Notice> &event, bool with_sender)
-{
-        TimelineItem *item = new TimelineItem(event, with_sender, scroll_widget_);
-        return item;
-}
-
-TimelineItem *
-TimelineView::createTimelineItem(const events::MessageEvent<msgs::Text> &event, bool with_sender)
-{
-        TimelineItem *item = new TimelineItem(event, with_sender, scroll_widget_);
-        return item;
-}
-
-TimelineItem *
-TimelineView::createTimelineItem(const events::MessageEvent<msgs::Emote> &event, bool with_sender)
-{
-        TimelineItem *item = new TimelineItem(event, with_sender, scroll_widget_);
-        return item;
-}
-
 void
 TimelineView::addTimelineItem(TimelineItem *item, TimelineDirection direction)
 {