polish autodetection

2026-04-22 12:26:30 +00:00 · 2024-11-02 20:59:51 +02:00
parent 418a2116b7
commit addf7ccc11
6 changed files with 90 additions and 27 deletions
@@ -0,0 +1,54 @@
+using System.Windows;
+using System.Windows.Controls;
+
+namespace Azaion.Annotator.Extensions;
+
+public class ScrollViewerExtensions
+{
+    public static readonly DependencyProperty AlwaysScrollToEndProperty =
+        DependencyProperty.RegisterAttached("AlwaysScrollToEnd", typeof(bool), typeof(ScrollViewerExtensions), new PropertyMetadata(false, AlwaysScrollToEndChanged));
+
+    private static bool _autoScroll;
+
+    private static void AlwaysScrollToEndChanged(object sender, DependencyPropertyChangedEventArgs e)
+    {
+        if (sender is not ScrollViewer scroll)
+            throw new InvalidOperationException("The attached AlwaysScrollToEnd property can only be applied to ScrollViewer instances.");
+
+        var alwaysScrollToEnd = e.NewValue != null && (bool)e.NewValue;
+        if (alwaysScrollToEnd)
+        {
+            scroll.ScrollToEnd();
+            scroll.ScrollChanged += ScrollChanged;
+        }
+        else
+            scroll.ScrollChanged -= ScrollChanged;
+    }
+
+    public static bool GetAlwaysScrollToEnd(ScrollViewer scroll)
+    {
+        if (scroll == null)
+            throw new ArgumentNullException("scroll");
+        return (bool)scroll.GetValue(AlwaysScrollToEndProperty);
+    }
+
+    public static void SetAlwaysScrollToEnd(ScrollViewer scroll, bool alwaysScrollToEnd)
+    {
+        if (scroll == null)
+            throw new ArgumentNullException("scroll");
+        scroll.SetValue(AlwaysScrollToEndProperty, alwaysScrollToEnd);
+    }
+
+    private static void ScrollChanged(object sender, ScrollChangedEventArgs e)
+    {
+        var scroll = sender as ScrollViewer;
+        if (scroll == null)
+            throw new InvalidOperationException("The attached AlwaysScrollToEnd property can only be applied to ScrollViewer instances.");
+
+        if (e.ExtentHeightChange == 0)
+            _autoScroll = scroll.VerticalOffset == scroll.ScrollableHeight;
+
+        if (_autoScroll && e.ExtentHeightChange != 0)
+            scroll.ScrollToVerticalOffset(scroll.ExtentHeight);
+    }
+}