Added Relative view support

Author: Sathish-087

maui/src/Calendar/Model/SfCalendar.cs

@@ -605,6 +605,20 @@ public partial class SfCalendar
                 CalendarRelativePosition.AlignTop,
                 propertyChanged: OnRelativePositionChanged);
 
+        /// <summary>
+        /// Identifies the <see cref="RelativeView"/> dependency property.
+        /// </summary>
+        /// <value>
+        /// The identifier for <see cref="RelativeView"/> dependency property.
+        /// </value>
+        public static readonly BindableProperty RelativeViewProperty =
+            BindableProperty.Create(
+                nameof(RelativeView),
+                typeof(View),
+                typeof(SfCalendar),
+                null,
+                propertyChanged: OnRelativeViewChanged);
+
 #if WINDOWS
         /// <summary>
         /// Identifies the <see cref="FlowDirectionProperty"/> dependency property.
@@ -2265,6 +2279,47 @@ public CalendarRelativePosition RelativePosition
             set { SetValue(RelativePositionProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the view relative to which the calendar dialog should be displayed based on the RelativePosition.
+        /// <seealso cref="SfCalendar.RelativePosition"/>
+        /// </summary>
+        /// <remarks>
+        /// It is only applicable for RelativeDialog mode. If no relative view is given, the calendar will be set as the relative view.
+        /// </remarks>
+        /// <example>
+        /// The following code demonstrates, how to use the RelativeView property in the calendar
+        /// #[XAML](#tab/tabid-1)
+        /// <code Lang="XAML"><![CDATA[
+        /// <Grid WidthRequest="500">
+        ///     <calendar:SfCalendar x:Name="calendar"
+        ///                         Mode="RelativeDialog"
+        ///                         RelativePosition="AlignToRightOf"
+        ///                         RelativeView="{x:Reference calendarButton}">
+        ///     </calendar:SfCalendar>
+        ///     <Button Text="Open calendar"
+        ///             x:Name="calendarButton"
+        ///             Clicked="Button_Clicked"
+        ///             HorizontalOptions="Center"
+        ///             VerticalOptions="Center"
+        ///             HeightRequest="50"
+        ///             WidthRequest="150">
+        ///     </Button>
+        /// </Grid>
+        /// ]]></code>
+        /// # [C#](#tab/tabid-2)
+        /// <code Lang="C#"><![CDATA[
+        /// private void Button_Clicked(object sender, System.EventArgs e)
+        /// {
+        ///     this.calendar.IsOpen = true;
+        /// }
+        /// ]]></code>
+        /// </example>
+        public View RelativeView
+        {
+            get { return (View)GetValue(RelativeViewProperty); }
+            set { SetValue(RelativeViewProperty, value); }
+        }
+
         //// TODO: Workaround for RTL (Right-to-Left) layout issue - The coordinate points are not calculated correctly in RTL layouts,
         //// causing incorrect positioning. This flag helps to apply RTL-specific adjustments.
 #if WINDOWS
@@ -2497,7 +2552,7 @@ protected override void OnPropertyChanged(string? propertyName = null)
                     CloseCalendarPopup();
                 }
             }
-            else if(propertyName == "FlowDirection")
+            else if (propertyName == "FlowDirection")
             {
                 if (FlowDirection == FlowDirection.RightToLeft)
                 {
@@ -3519,6 +3574,26 @@ static void OnRelativePositionChanged(BindableObject bindable, object oldValue,
             }
         }
 
+        /// <summary>
+        /// Called when <see cref="RelativeView"/> property changed.
+        /// </summary>
+        /// <param name="bindable">The bindable.</param>
+        /// <param name="oldValue">The old value.</param>
+        /// <param name="newValue">The new value.</param>
+        static void OnRelativeViewChanged(BindableObject bindable, object oldValue, object newValue)
+        {
+            SfCalendar? calendar = bindable as SfCalendar;
+            if (calendar == null)
+            {
+                return;
+            }
+
+            if (calendar.IsOpen && calendar.Mode == CalendarMode.RelativeDialog && calendar.RelativeView != null)
+            {
+                calendar.ShowPopup();
+            }
+        }
+
 #if WINDOWS
         /// <summary>
         /// Method invoke when flow direction property changed.

maui/src/Calendar/SfCalendar.cs

@@ -1973,7 +1973,14 @@ void ShowPopup()
 
             if (Mode == CalendarMode.RelativeDialog)
             {
-                ShowRelativeToView(this, RelativePosition);
+                if (RelativeView != null)
+                {
+                    ShowRelativeToView(RelativeView, RelativePosition);
+                }
+                else
+                {
+                    ShowRelativeToView(this, RelativePosition);
+                }
             }
             else
             {
@@ -2203,7 +2210,7 @@ protected override Size MeasureContent(double widthConstraint, double heightCons
             {
                 return _availableSize;
             }
-    #endif
+#endif
 
             if (_layout.Children.Count == 0)
             {
@@ -2250,7 +2257,7 @@ protected override void OnDraw(ICanvas canvas, RectF dirtyRect)
             {
                 currentClip = new RoundRectangleGeometry(CornerRadius, rectangle);
             }
-    #endif
+#endif
             RoundRectangleGeometry? previousClip = null;
             if (Clip != null && Clip is RoundRectangleGeometry)
             {