Maybe fix the DelegateModel + ListView.add bug

TODO.md

@@ -4,7 +4,6 @@
 - add account number binds
 - rename goto*account → scrollto*account
 
-- fix interrupted transitions
 - fix back/front buttons in small window
 - fix message delegate too tall
 - fix left rooms opacity

src/gui/Base/HListView.qml

@@ -29,39 +29,34 @@ ListView {
 
     // property bool debug: false
 
-    // Make sure to handle when a previous transition gets interrupted
+    // https://doc.qt.io/qt-5/qml-qtquick-viewtransition.html
+    // #handling-interrupted-animations
+    // XXX: add transitions are buggy when using DelegateModel, `add` should be
+    // set to `null` and delegates should have `ListView.onAdd: ...` instead.
     add: Transition {
-        ParallelAnimation {
-            // ScriptAction { script: if (listView.debug) print("add") }
-            HNumberAnimation { property:   "opacity"; from: 0; to: 1 }
-            HNumberAnimation { property:   "scale";   from: 0; to: 1 }
-        }
+        // ScriptAction { script: if (listView.debug) print("add") }
+        HNumberAnimation { property: "opacity"; from: 0; to: 1 }
+        HNumberAnimation { property: "scale";   from: 0; to: 1 }
     }
 
     move: Transition {
-        ParallelAnimation {
-            // ScriptAction { script: if (listView.debug) print("move") }
-            HNumberAnimation { property:   "opacity"; to: 1 }
-            HNumberAnimation { property:   "scale";   to: 1 }
-            HNumberAnimation { properties: "x,y" }
-        }
+        // ScriptAction { script: if (listView.debug) print("move") }
+        HNumberAnimation { property:   "opacity"; to: 1 }
+        HNumberAnimation { property:   "scale";   to: 1 }
+        HNumberAnimation { properties: "x,y" }
     }
 
     remove: Transition {
-        ParallelAnimation {
-            // ScriptAction { script: if (listView.debug) print("remove") }
-            HNumberAnimation { property:   "opacity"; to: 0 }
-            HNumberAnimation { property:   "scale";   to: 0 }
-        }
+        // ScriptAction { script: if (listView.debug) print("remove") }
+        HNumberAnimation { property: "opacity"; to: 0 }
+        HNumberAnimation { property: "scale";   to: 0 }
     }
 
     displaced: Transition {
-        ParallelAnimation {
-            // ScriptAction { script: if (listView.debug) print("displaced") }
-            HNumberAnimation { property:   "opacity"; to: 1 }
-            HNumberAnimation { property:   "scale";   to: 1 }
-            HNumberAnimation { properties: "x,y" }
-        }
+        // ScriptAction { script: if (listView.debug) print("displaced") }
+        HNumberAnimation { property:   "opacity"; to: 1 }
+        HNumberAnimation { property:   "scale";   to: 1 }
+        HNumberAnimation { properties: "x,y" }
     }
 
     onSelectedCountChanged: if (! selectedCount) lastCheckedDelegateIndex = 0

src/gui/MainPane/RoomList.qml

@@ -7,14 +7,25 @@ import "../Base"
 
 HListView {
     id: roomList
+    add: null  // See the XXX comment in HListView.qml
 
     model: HStringFilterModel {
         id: filterModel
         sourceModel: ModelStore.get("every_room")
         field: "display_name"
+
         delegate: Room {
+            id: room
             width: roomList.width
             onActivated: showRoomAtIndex(model.index)
+            ListView.onAdd: ParallelAnimation {
+                HNumberAnimation {
+                    target: room; property: "opacity"; from: 0; to: 1;
+                }
+                HNumberAnimation {
+                    target: room; property: "scale"; from: 0; to: 1;
+                }
+            }
         }
     }
 

src/gui/Pages/Chat/RoomPane/MemberView.qml

@@ -12,12 +12,25 @@ HColumnLayout {
     HListView {
         id: memberList
         clip: true
+        add: null  // See the XXX comment in HListView.qml
 
         model: HStringFilterModel {
             sourceModel: ModelStore.get(chat.userId, chat.roomId, "members")
             field: "display_name"
             filter: filterField.text
-            delegate: MemberDelegate { width: memberList.width }
+
+            delegate: MemberDelegate {
+                id: member
+                width: memberList.width
+                ListView.onAdd: ParallelAnimation {
+                    HNumberAnimation {
+                        target: member; property: "opacity"; from: 0; to: 1;
+                    }
+                    HNumberAnimation {
+                        target: member; property: "scale"; from: 0; to: 1;
+                    }
+                }
+            }
         }
 
         Layout.fillWidth: true