add user custom playlist support

CMakeLists.txt

@@ -4,7 +4,7 @@ project(SubWave LANGUAGES CXX)
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-find_package(Qt6 REQUIRED COMPONENTS Widgets Multimedia OpenGL OpenGLWidgets)
+find_package(Qt6 REQUIRED COMPONENTS Widgets Multimedia OpenGL OpenGLWidgets Core)
 
 # require ffmpeg
 find_package(PkgConfig REQUIRED)
@@ -35,7 +35,10 @@ set(SOURCES
     src/GradientDialog.cpp
     src/EqualizerWidget.cpp
     src/TrackDelegate.cpp
-    src/PlaylistModel.cpp
+    src/playlists/PlaylistModel.cpp
+    src/playlists/PlaylistManager.cpp
+    src/playlists/PlaylistCreatorDialog.cpp
+    src/playlists/PlaylistBrowserDialog.cpp
     src/MainWindow.cpp
 )
 
@@ -50,7 +53,10 @@ set(HEADERS
     src/GradientDialog.h
     src/EqualizerWidget.h
     src/TrackDelegate.h
-    src/PlaylistModel.h
+    src/playlists/PlaylistModel.h
+    src/playlists/PlaylistManager.h
+    src/playlists/PlaylistCreatorDialog.h
+    src/playlists/PlaylistBrowserDialog.h
     src/MainWindow.h
 )
 
@@ -66,7 +72,11 @@ if(WIN32)
     set_target_properties(SubWave PROPERTIES WIN32_EXECUTABLE TRUE)
 endif()
 
-target_include_directories(SubWave PRIVATE src src/engine)
+target_include_directories(SubWave PRIVATE
+    src
+    src/engine
+    src/playlists
+)
 
 target_link_libraries(SubWave PRIVATE
     Qt6::Widgets