Repair room filter, performance improvements

Chnaging delegate heights is a terrible idea that leads to graphic bugs.
Handle filtering (both room and accounts) and collapsing from a function
that sets the JsonListModel source.

src/qml/SidePane/AccountRoomList.qml

@@ -1,16 +1,54 @@
 import QtQuick 2.12
 import QtQuick.Layouts 1.12
 import "../Base"
+import "../utils.js" as Utils
 
 HListView {
     id: accountRoomList
 
-    // property bool forceExpand: paneToolBar.roomFilter && roomList.model.count
-    property bool forceExpand: false
+
+    readonly property var originSource: window.sidePaneModelSource
+    readonly property var collapseAccounts: window.uiState.collapseAccounts
+    readonly property string filter: paneToolBar.roomFilter
+
+    onOriginSourceChanged: Qt.callLater(filterSource)
+    onFilterChanged: Qt.callLater(filterSource)
+    onCollapseAccountsChanged: Qt.callLater(filterSource)
+
+
+    function filterSource() {
+        let show = []
+
+        for (let i = 0;  i < window.sidePaneModelSource.length; i++) {
+            let item = window.sidePaneModelSource[i]
+
+            if (item.type == "Account" ||
+                (filter ?
+                 Utils.filterMatches(filter, item.data.filter_string) :
+                 ! window.uiState.collapseAccounts[item.user_id]))
+            {
+                if (filter && show.length && item.type == "Account" &&
+                    show[show.length - 1].type == "Account" &&
+                    ! Utils.filterMatches(filter, item.data.filter_string)) {
+                    // If current and previous items are both accounts,
+                    // that means the previous account had no matching rooms.
+                    show.pop()
+                }
+
+                show.push(item)
+            }
+        }
+
+        // If last item is an account, that account had no matching rooms.
+        if (show.length && show[show.length - 1].type == "Account") show.pop()
+
+        model.source = show
+    }
+
 
     model: HListModel {
         keyField: "id"
-        source: window.sidePaneModelSource
+        source: originSource
     }
 
     delegate: Loader {

src/qml/SidePane/DelegateAccount.qml

@@ -4,17 +4,22 @@ import "../Base"
 
 HInteractiveRectangle {
     id: accountDelegate
-    height: row.height
     color: theme.sidePane.account.background
+    checked: isCurrent
+    height: row.height
+
 
-    checked: accountDelegate.isCurrent
     readonly property bool isCurrent:
         window.uiState.page == "Pages/EditAccount/EditAccount.qml" &&
         window.uiState.pageProperties.userId == model.data.user_id
 
+    readonly property bool forceExpand:
+        Boolean(accountRoomList.filter)
+
     readonly property bool collapsed:
-        ! accountRoomList.forceExpand &&
-        window.uiState.collapseAccounts[model.data.user_id] || false
+        ! forceExpand &&
+        accountRoomList.collapseAccounts[model.data.user_id] || false
+
 
     function toggleCollapse() {
         window.uiState.collapseAccounts[model.data.user_id] = ! collapsed
@@ -27,6 +32,7 @@ HInteractiveRectangle {
         )
     }
 
+
     TapHandler { onTapped: accountDelegate.activate() }
 
     HRowLayout {
@@ -74,7 +80,7 @@ HInteractiveRectangle {
 
             visible: opacity > 0
             opacity:
-                accountRoomList.forceExpand ? 0 :
+                accountDelegate.forceExpand ? 0 :
                 collapsed ? theme.sidePane.account.collapsedOpacity + 0.2 :
                 1
             Behavior on opacity { HNumberAnimation {} }

src/qml/SidePane/DelegateRoom.qml

@@ -6,29 +6,30 @@ import "../utils.js" as Utils
 HInteractiveRectangle {
     id: roomDelegate
     color: theme.sidePane.room.background
-
-    readonly property bool collapsed:
-        ! accountRoomList.forceExpand &&
-        window.uiState.collapseAccounts[model.user_id] || false
-
     visible: height > 0
-    height: collapsed ? 0 : rowLayout.height
-    Behavior on height { HNumberAnimation {} }
-
+    height: rowLayout.height
     opacity: model.data.left ? theme.sidePane.room.leftRoomOpacity : 1
+    checked: isCurrent
+
+
     Behavior on opacity { HNumberAnimation {} }
 
-    checked: isCurrent
+
+    readonly property bool forceExpand:
+        Boolean(accountRoomList.filter)
+
     readonly property bool isCurrent:
         window.uiState.page == "Chat/Chat.qml" &&
         window.uiState.pageProperties.userId == model.user_id &&
         window.uiState.pageProperties.roomId == model.data.room_id
 
+
     function activate() {
         pageStack.showRoom(model.user_id, model.data.room_id)
         print(model.user_id, model.data.room_id)
     }
 
+
     TapHandler { onTapped: activate() }
 
     HRowLayout {

src/qml/utils.js

@@ -89,11 +89,13 @@ function filterMatches(filter, text) {
 
 
 function filterModelSource(source, filter_text, property="filter_string") {
-    if (! filter_text) { return source }
-
+    if (! filter_text) return source
     let results = []
-    for (let item of source) {
-        if (filterMatches(filter_text, item[property])) { results.push(item) }
+
+    for (let i = 0;  i < source.length; i++) {
+        if (filterMatches(filter_text, source[i][property])) {
+            results.push(item)
+        }
     }
     return results
 }