Music-Library/main_window.py

from PyQt6.QtWidgets import (
    QApplication, QMainWindow, QLabel, QVBoxLayout, 
    QWidget, QFrame, QSplitter, QStackedWidget, QTabWidget
)

from tab_musiclibrary import MusicLibraryTab
from tab_settings import SettingsTab

class MusicLibrary(QFrame):
    def __init__(self):
        super().__init__()

        library = QTabWidget()
        library.addTab(MusicLibraryTab(), "Songs")
        library.addTab(SettingsTab(), "Settings")

        layout = QVBoxLayout()
        layout.addWidget(library)
        self.setLayout(layout)


class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("Music Library")
        self.setFixedSize(800, 600)
        layout = QVBoxLayout()
        layout.addWidget( MusicLibrary() )
        container = QWidget()
        container.setLayout(layout)
        container.layout().setContentsMargins(0, 0, 0, 0)
        self.setCentralWidget(container)