Fix the one-line events combining

When there's a one line (emote or non-message) event with its avatar
shown and combinable events follow it, that first event delegate's height
is supposed to be one line with the avatar overflowing into
the following event's blank space.

This behavior hasn't been working for a long time. This commit restores
it, along with improving the related code's quality.

src/gui/Pages/Chat/Timeline/EventContent.qml

@@ -26,7 +26,7 @@ HRowLayout {
     }
 
     readonly property string senderText:
-        hideNameLine ? "" : (
+        asOneLine || onRight || combine ? "" : (
             `<${compact ? "span" : "div"} class='sender'>` +
             utils.coloredNameHtml(model.sender_name, model.sender_id) +
             (compact ? ": " : "") +
@@ -82,12 +82,25 @@ HRowLayout {
         opacity: combine ? 0 : 1
 
         Layout.alignment: Qt.AlignTop
-        Layout.preferredHeight: combine ? 1 : Layout.preferredWidth
+
         Layout.preferredWidth:
             compact ?
             theme.chat.message.collapsedAvatarSize :
             theme.chat.message.avatarSize
 
+        Layout.preferredHeight:
+            combine ?
+            1 :
+
+            compact || (
+                asOneLine &&
+                nextModel &&
+                eventList.canCombine(model, nextModel)
+            ) ?
+            theme.chat.message.collapsedAvatarSize :
+
+            theme.chat.message.avatarSize
+
         HUserAvatar {
             id: avatar
             clientUserId: chat.userId
@@ -97,7 +110,6 @@ HRowLayout {
             width: parent.width
             height: combine ? 1 : parent.Layout.preferredWidth
             radius: theme.chat.message.avatarRadius
-
         }
     }
 

src/gui/Pages/Chat/Timeline/EventDelegate.qml

@@ -25,20 +25,12 @@ HColumnLayout {
     readonly property bool isRedacted: model.event_type === "RedactedEvent"
     readonly property bool onRight: ! eventList.ownEventsOnLeft && isOwn
     readonly property bool combine: eventList.canCombine(previousModel, model)
+    readonly property bool asOneLine: eventList.renderEventAsOneLine(model)
     readonly property bool talkBreak:
         eventList.canTalkBreak(previousModel, model)
     readonly property bool dayBreak:
         eventList.canDayBreak(previousModel, model)
 
-    readonly property bool hideNameLine:
-        model.event_type === "RoomMessageEmote" ||
-        ! (
-            model.event_type.startsWith("RoomMessage") ||
-            model.event_type.startsWith("RoomEncrypted")
-        ) ||
-        onRight ||
-        combine
-
     readonly property int cursorShape:
         eventContent.hoveredLink || hoveredMediaTypeUrl.length === 3 ?
         Qt.PointingHandCursor :

src/gui/Pages/Chat/Timeline/EventList.qml

@@ -323,6 +323,14 @@ Rectangle {
             return item.date.getDate() !== itemAfter.date.getDate()
         }
 
+        function renderEventAsOneLine(event) {
+            return (
+                event.event_type !== "RoomMessageEmote" &&
+                ! event.event_type.startsWith("RoomMessage") &&
+                ! event.event_type.startsWith("RoomEncrypted")
+            )
+        }
+
         function loadPastEvents() {
             loadPastEventsFuture = py.callClientCoro(
                 chat.userId,