added Flatpak manifest and CMake support for Flatpak

.flatpak/de.syping.gta5view.yml

@@ -0,0 +1,21 @@
+app-id: de.syping.gta5view
+runtime: org.kde.Platform
+runtime-version: '5.14'
+sdk: org.kde.Sdk
+command: gta5view
+finish-args:
+  - "--share=network"
+  - "--share=ipc"
+  - "--socket=x11"
+  - "--socket=wayland"
+  - "--filesystem=host"
+  - "--device=dri"
+modules:
+  - name: gta5view
+    buildsystem: cmake-ninja
+    config-opts:
+      - -DFLATPAK_BUILD=ON
+    sources:
+      - branch: 1.8.x
+        type: git
+        url: https://gitlab.com/Syping/gta5view.git

CMakeLists.txt

@@ -157,7 +157,7 @@ else()
     )
 endif()
 
-option(QCONF_BUILD "System installation intended QCONF build" OFF)
+option(QCONF_BUILD "System installation intended Qconf build" OFF)
 
 if(QCONF_BUILD)
     list(APPEND GTA5VIEW_DEFINES
@@ -170,6 +170,15 @@ else()
     )
 endif()
 
+option(FLATPAK_BUILD "Flatpak modifications and identifications" OFF)
+
+if(FLATPAK_BUILD)
+    list(APPEND GTA5VIEW_DEFINES
+        "-DGTA5SYNC_BUILDTYPE=\"Flatpak\""
+        -DGTA5SYNC_FLATPAK
+    )
+endif()
+
 add_executable(gta5view
     ${GTA5VIEW_HEADERS}
     ${GTA5VIEW_SOURCES}
@@ -190,7 +199,7 @@ target_include_directories(gta5view PRIVATE ${GTA5VIEW_INCLUDEDIR})
 target_link_libraries(gta5view PRIVATE Qt5::Network Qt5::Svg Qt5::Widgets)
 
 install(TARGETS gta5view DESTINATION bin)
-install(FILES res/gta5view.desktop DESTINATION share/applications)
+install(FILES res/de.syping.gta5view.desktop DESTINATION share/applications)
 install(FILES res/gta5view.png DESTINATION share/pixmaps)
 
 if(QCONF_BUILD)