Adding initial playback bar logic.

Harmonia.UI/Views/PlaybackBar.axaml.cs

@@ -1,11 +1,73 @@
 using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Harmonia.UI.ViewModels;
 
 namespace Harmonia.UI.Views;
 
 public partial class PlaybackBar : UserControl
 {
+    private readonly PlaybackBarViewModel _viewModel;
+
     public PlaybackBar()
     {
         InitializeComponent();
+        _viewModel = (PlaybackBarViewModel)DataContext!;
+    }
+
+    private void Slider_Loaded(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        if (sender is not Slider slider)
+            return;
+
+        slider.AddHandler(PointerPressedEvent, OnSliderPointerPressed, RoutingStrategies.Tunnel);
+        slider.AddHandler(PointerReleasedEvent, OnSliderPointerReleased, RoutingStrategies.Tunnel);
+    }
+
+    private void OnSliderPointerPressed(object? sender, PointerPressedEventArgs e)
+    {
+        if (sender is not Slider slider)
+            return;
+
+        PointerPoint currentPoint = e.GetCurrentPoint(slider);
+
+        if (currentPoint.Properties.IsLeftButtonPressed == false)
+            return;
+
+        _viewModel.IsPositionChangeInProgress = true;
+    }
+
+    private void OnSliderPointerReleased(object? sender, PointerReleasedEventArgs e)
+    {
+        if (sender is not Slider slider)
+            return;
+
+        _viewModel.CurrentPosition = slider.Value;
+        _viewModel.IsPositionChangeInProgress = false;
+    }
+
+    private void PlayButton_Click(object? sender, RoutedEventArgs e)
+    {
+        _viewModel.Play();
+    }
+
+    private void StopButton_Click(object? sender, RoutedEventArgs e)
+    {
+        _viewModel.Stop();
+    }
+
+    private void PauseButton_Click(object? sender, RoutedEventArgs e)
+    {
+        _viewModel.Pause();
+    }
+
+    private void PreviousSongButton_Click(object? sender, RoutedEventArgs e)
+    {
+        _viewModel.Previous();
+    }
+
+    private void NextSongButton_Click(object sender, RoutedEventArgs e)
+    {
+        _viewModel.Next();
     }
 }