Implement event model in C++

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

Event.qml

@@ -7,61 +7,77 @@ import QtQuick.Layouts 1.6
 import 'util.js' as Util
 
 // This is the delegate for event list items.
-Pane {
-    id: control
+ItemDelegate {
+    required property var model
+    required property int index
+    required property int time
 
-    property int time
-    property alias tag: tag.text
-    property alias fields: inputs.model
+    property alias fields: inputs.model // field definitions
     property bool editing: false
 
-    signal remove
-
     clip: true
-    height: visible ? stuff.height + 2*padding : 0 // TODO fix filtering and remove this
     padding: 2
 
-    // set to current value or default
+    background: Rectangle {
+        anchors.fill: parent
+        color: highlighted ? Util.alphize(border.color, 0.1) :
+            (index % 2 === 0 ? palette.base : palette.alternateBase)
+        border {
+            color: editing ? palette.highlight : palette.dark
+            width: highlighted ? 1 : 0
+        }
+        radius: border.width
+    }
+
+    // Set inputs to current model values.
     function reset() {
-        for (var i = 0; i < fields.count; i++) {
+        for (var i = 0; i < fields.length; i++) {
             const child = inputs.itemAt(i)
             if (child && child.item)
-                child.item.set(fields.get(i).value)
+                child.item.set(model.values[fields[i].name])
         }
     }
 
+    // Store current inputs in model.
     function store() {
-        for (var i = 0; i < fields.count; i++)
-            fields.setProperty(i, 'value', inputs.itemAt(i).item.value)
+        var values = {}
+        for (var i = 0; i < fields.length; i++)
+            values[fields[i].name] = inputs.itemAt(i).item.value
+        model.values = values
     }
 
-    // Pass keys to each field input in order.
+    Component.onCompleted: reset()
+    onEditingChanged: {
+        if (editing)
+            forceActiveFocus()
+    }
+
+    // Try passing key to each field input in order.
     Keys.forwardTo: Array.from({ length: inputs.count }, (_, i) => inputs.itemAt(i).item)
 
-    Behavior on height { NumberAnimation { duration: 50 } }
-
-    ColumnLayout {
-        id: stuff
+    contentItem: ColumnLayout {
         anchors { left: parent.left; right: parent.right; margins: 5 }
 
+        // Event time, tag and summary.
         RowLayout {
             Label {
-                text: new Date(time).toISOString().substr(12, 9)
+                text: new Date(model.time).toISOString().substr(12, 9)
                 font.pixelSize: 10
                 Layout.alignment: Qt.AlignBaseline
             }
             Label {
-                id: tag
+                text: model.tag
                 font.weight: Font.DemiBold
                 Layout.alignment: Qt.AlignBaseline
             }
             Label {
                 text: {
                     var str = ''
-                    for (var i = 0; i < fields.count; i++) {
-                        const field = fields.get(i)
-                        if (field.value && field.type !== 'TextArea')
-                            str += (field.type === 'Bool' ? field.name : field.value) + ' '
+                    for (var i = 0; i < inputs.count; i++) {
+                        const field = inputs.model[i]
+                        const value = inputs.itemAt(i).item.value
+                        if (value && field.type !== 'TextArea')
+                            str += (field.type === 'Bool' ? field.name : value) + ' '
                     }
                     return str
                 }
@@ -72,10 +88,8 @@ Pane {
             }
         }
 
-        // Event‐specific inputs.
+        // Event‐specific input fields.
         GridLayout {
-            id: fieldset
-
             flow: GridLayout.TopToBottom
             rows: inputs.count
 
@@ -86,7 +100,7 @@ Pane {
             Repeater {
                 model: inputs.model
                 delegate: Label {
-                    text: Util.addShortcut(model.name, model.key)
+                    text: Util.addShortcut(modelData.name, modelData.key)
                     Layout.alignment: Qt.AlignRight
                 }
             }
@@ -95,12 +109,12 @@ Pane {
             Repeater {
                 id: inputs
                 delegate: Loader {
-                    source: 'qrc:/Fields/' + model.type + '.qml'
+                    source: 'qrc:/Fields/' + modelData.type + '.qml'
                     Layout.fillHeight: true
                     Layout.fillWidth: true
                     Binding {
-                        target: item; property: 'definition'
-                        value: model
+                        target: item; property: 'model'
+                        value: modelData
                     }
                 }
             }