feat(ui): add application about dialog

- Add an overflow action for About CodecDeck
- Show the application icon, version, project link, and MIT license
- Keep the displayed version sourced from Qt application metadata

Author: mizuikki

CMakeLists.txt

@@ -39,6 +39,7 @@ qt_add_qml_module(codecdeck
     VERSION 1.0
     NO_IMPORT_SCAN
     QML_FILES
+        qml/AboutDialog.qml
         qml/Main.qml
 )
 

qml/AboutDialog.qml

@@ -0,0 +1,64 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import org.kde.kirigami as Kirigami
+
+Kirigami.Dialog {
+    title: "About CodecDeck"
+    preferredWidth: Kirigami.Units.gridUnit * 24
+    standardButtons: Kirigami.Dialog.Close
+
+    Item {
+        implicitWidth: Kirigami.Units.gridUnit * 22
+        implicitHeight: aboutLayout.implicitHeight + Kirigami.Units.largeSpacing * 2
+
+        ColumnLayout {
+            id: aboutLayout
+            anchors.fill: parent
+            anchors.margins: Kirigami.Units.largeSpacing
+            spacing: Kirigami.Units.smallSpacing
+
+            Kirigami.Icon {
+                source: "qrc:/icons/io.github.mizuikki.CodecDeck.png"
+                Layout.alignment: Qt.AlignHCenter
+                Layout.preferredWidth: Kirigami.Units.iconSizes.huge
+                Layout.preferredHeight: Kirigami.Units.iconSizes.huge
+            }
+
+            Kirigami.Heading {
+                text: "CodecDeck"
+                level: 2
+                Layout.alignment: Qt.AlignHCenter
+            }
+
+            Label {
+                text: "Version " + Qt.application.version
+                color: Kirigami.Theme.disabledTextColor
+                Layout.alignment: Qt.AlignHCenter
+            }
+
+            Label {
+                text: "Control Bluetooth audio codecs on PipeWire and WirePlumber."
+                horizontalAlignment: Text.AlignHCenter
+                wrapMode: Text.WordWrap
+                Layout.fillWidth: true
+                Layout.topMargin: Kirigami.Units.smallSpacing
+            }
+
+            Label {
+                text: '<a href="https://github.com/mizuikki/codecdeck">github.com/mizuikki/codecdeck</a>'
+                textFormat: Text.RichText
+                Layout.alignment: Qt.AlignHCenter
+                Layout.topMargin: Kirigami.Units.smallSpacing
+                onLinkActivated: function(link) { Qt.openUrlExternally(link) }
+            }
+
+            Label {
+                text: '<a href="https://github.com/mizuikki/codecdeck/blob/main/LICENSE">MIT License</a>'
+                textFormat: Text.RichText
+                Layout.alignment: Qt.AlignHCenter
+                onLinkActivated: function(link) { Qt.openUrlExternally(link) }
+            }
+        }
+    }
+}

qml/Main.qml

@@ -47,6 +47,10 @@ Kirigami.ApplicationWindow {
         return profiles.length > 0 ? 0 : -1
     }
 
+    AboutDialog {
+        id: aboutDialog
+    }
+
     pageStack.initialPage: Kirigami.Page {
         title: "CodecDeck"
         padding: 0
@@ -62,6 +66,12 @@ Kirigami.ApplicationWindow {
                 icon.name: "network-bluetooth"
                 enabled: !!root.currentDevice.bluezPath && !Backend.busy
                 onTriggered: Backend.refreshCapabilities()
+            },
+            Kirigami.Action {
+                text: "About CodecDeck"
+                icon.name: "help-about"
+                displayHint: Kirigami.DisplayHint.AlwaysHide
+                onTriggered: aboutDialog.open()
             }
         ]