Improve wallpaper handling in initial start

- Use wallpaper directly from breeze instead of having our own copy
- Support dark theme wallpaper (if available)

initialstart/CMakeLists.txt

@@ -41,12 +41,5 @@ qt_target_qml_sources(plasma-mobile-initial-start
         qml/LandingComponent.qml
 )
 
-qt_add_resources(plasma-mobile-initial-start
-    PREFIX
-        "/"
-    FILES
-        assets/background.png
-)
-
 target_include_directories(plasma-mobile-initial-start PRIVATE ${CMAKE_BINARY_DIR})
 install(TARGETS plasma-mobile-initial-start ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})

initialstart/qml/LandingComponent.qml

@@ -1,6 +1,7 @@
 // SPDX-FileCopyrightText: 2023 Devin Lin <devin@kde.org>
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+import QtCore
 import QtQuick 2.15
 import QtQuick.Controls 2.15
 import QtQuick.Layouts 1.15
@@ -8,6 +9,7 @@ import QtQuick.Layouts 1.15
 import org.kde.kirigami 2.20 as Kirigami
 
 import org.kde.plasma.mobileinitialstart.initialstart
+import org.kde.plasma.mobileinitialstart.prepare 1.0 as Prepare
 
 Item {
     id: root
@@ -38,7 +40,17 @@ Item {
     Image {
         id: backgroundImage
         anchors.fill: parent
-        source: "qrc:/assets/background.png"
+        source: {
+            if (Prepare.PrepareUtil.usingDarkTheme) {
+                const wallpaperUrl = StandardPaths.locate(StandardPaths.GenericDataLocation, 'wallpapers/Next/contents/images_dark/720x1440.png');
+                if (!wallpaperUrl) {
+                    return StandardPaths.locate(StandardPaths.GenericDataLocation, 'wallpapers/Next/contents/images/720x1440.png');
+                }
+                return wallpaperUrl;
+            } else {
+                return StandardPaths.locate(StandardPaths.GenericDataLocation, 'wallpapers/Next/contents/images/720x1440.png');
+            }
+        }
         fillMode: Image.PreserveAspectCrop
 
         opacity: 0