Implement event model in C++

Filtering events in JS is too slow with >20,000 events. This moves the
event data model into C++.

Events.qml

@@ -3,139 +3,35 @@
 import QtQuick 2.12
 import QtQuick.Controls 2.13
 import QtQuick.Layouts 1.6
-import QtQml.Models 2.1
-
-import 'util.js' as Util
 
 ListView {
     id: control
 
+    required property var tags // tag definitions
     property bool editing: false
-    property var tags: []
-
-    signal changed
 
     clip: true
     focus: true
     keyNavigationEnabled: true
     highlightMoveDuration: 0
     highlightResizeDuration: 0
-    ScrollBar.vertical: ScrollBar { anchors.right: parent.right }
-
-    // Create a new blank event, insert it and start editing.
-    function create(time, tag, fields) {
-        const index = Util.find(list, 'time', time)
-        list.insert(index, {
-            'time': time,
-            'tag': tag,
-            'fields': fields,
-        })
-        currentIndex = index
-        if (fields.length > 0)
-            editing = true
-        changed()
-    }
-
-    function clear() {
-        list.clear()
-    }
-
-    function load(json) {
-        // Return list of fields for the given tag.
-        function getFields(name) {
-            for (var i = 0; i < tags.length; i++)
-                if (tags[i].tag === name)
-                    return tags[i].fields
-            return []
-        }
-
-        for (var i = 0; i < json.length; i++) {
-            const event = json[i]
-            var fields = getFields(event.tag)
-            for (var j = 0; j < fields.length; j++)
-                fields[j].value = event.fields[fields[j].name]
-            list.append({ 'time': event.time, 'tag': event.tag, 'fields': fields })
-        }
-        forceActiveFocus()
-    }
-
-    function save() {
-        var data = []
-        for (var i = 0; i < list.count; i++) {
-            const event = list.get(i)
-            var fields = {}
-            for (var j = 0; j < event.fields.count; j++) {
-                const field = event.fields.get(j)
-                fields[field.name] = field.value
-            }
-            data.push({ 'time': event.time, 'tag': event.tag, 'fields': fields })
-        }
-        return data
-    }
 
     onCurrentIndexChanged: editing = false
 
-    Keys.onPressed: {
-        switch (event.key) {
-        case Qt.Key_Enter:
-        case Qt.Key_Return:
-            if (editing) {
-                currentItem.store()
-                changed()
-                editing = false
-            } else {
-                if (currentItem.fields.count > 0)
-                    editing = true
-            }
-            break
-        case Qt.Key_Escape:
-            if (editing) {
-                currentItem.reset()
-                editing = false
-            }
-            break
-        case Qt.Key_Delete:
-            editing = false
-            if (currentIndex >= 0 && currentIndex < list.count) {
-                list.remove(currentIndex)
-                changed()
-            }
-            break
-        case Qt.Key_Tab:
-        case Qt.Key_Backtab:
-            // swallow tabs so we don’t lose focus when editing
-            break
-        default:
-            return
-        }
-        event.accepted = true
-    }
-
-    model: ListModel {
-        id: list
-        dynamicRoles: true
-    }
+    ScrollBar.vertical: ScrollBar { anchors.right: parent.right }
 
     delegate: Event {
-        id: item
-
-        time: model.time
-        tag: model.tag
-        fields: model.fields
+        // If field definitions are missing for this event’s tag, use
+        // Text for all field types unless where the value is bool.
+        fields: tags[model.tag] ? tags[model.tag].fields :
+            Object.entries(model.values).map(value => ({
+                'name': value[0],
+                'type': typeof(value[1]) === 'boolean' ? 'Bool' : 'Text',
+            }))
 
         width: control.width
         editing: control.editing && ListView.isCurrentItem
-
-        background: Rectangle {
-            anchors.fill: parent
-            color: border.width > 0 ? Util.alphize(border.color, 0.1) :
-                (index % 2 === 0 ? palette.base : palette.alternateBase)
-            border {
-                color: editing ? palette.highlight : palette.dark
-                width: item.ListView.isCurrentItem ? 1 : 0
-            }
-            radius: border.width
-        }
+        highlighted: ListView.isCurrentItem
 
         Connections {
             enabled: ListView.currentIndex === index
@@ -143,13 +39,10 @@ ListView {
                 control.positionViewAtIndex(index, ListView.Contain)
             }
         }
-        onEditingChanged: {
-            reset()
-            if (editing)
-                forceActiveFocus()
-        }
-        onRemove: {
-            list.remove(ObjectModel.index)
+
+        onClicked: {
+                control.currentIndex = index
+                control.forceActiveFocus()
         }
     }
 }