Add StayOnCenter property

Add StayOnCenter which means that bubble effect raising up from center
of control instead of cursor. Also apply StayOnCenter property to
toolbar buttons

Author: l1pton17

MaterialDesignThemes.Wpf/Ripple.cs

@@ -37,14 +37,35 @@ public Ripple()
 
         private void OnSizeChanged(object sender, SizeChangedEventArgs sizeChangedEventArgs)
         {
-            double width = sizeChangedEventArgs.NewSize.Width;
-            double height = sizeChangedEventArgs.NewSize.Height;
-            double radius = Math.Sqrt(Math.Pow(width, 2) + Math.Pow(height, 2));
+            var innerContent = (Content as FrameworkElement);
+
+            double width, height;
 
-            Debug.WriteLine("Width: {0} Height: {1} Radius: {2}", width, height, radius);
+            if (innerContent != null)
+            {
+                width = innerContent.ActualWidth;
+                height = innerContent.ActualHeight;
+            }
+            else
+            {
+                width = sizeChangedEventArgs.NewSize.Width;
+                height = sizeChangedEventArgs.NewSize.Height;
+            }
+
+            double radius = Math.Sqrt(Math.Pow(width, 2) + Math.Pow(height, 2));
+            
             RippleSize = 2 * radius * RippleSizeMultiplier;
         }
 
+        public static readonly DependencyProperty StayOnCenterProperty = DependencyProperty.Register(
+            "StayOnCenter", typeof(bool), typeof(Ripple), new PropertyMetadata(false));
+
+        public bool StayOnCenter
+        {
+            get { return (bool)GetValue(StayOnCenterProperty); }
+            set { SetValue(StayOnCenterProperty, value); }
+        }
+
         public static readonly DependencyProperty FeedbackProperty = DependencyProperty.Register(
             "Feedback", typeof(Brush), typeof(Ripple), new PropertyMetadata(default(Brush)));
 
@@ -58,8 +79,16 @@ protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
         {
             var point = e.GetPosition(this);
 
-            RippleX = point.X - RippleSize / 2;
-            RippleY = point.Y - RippleSize / 2;
+            if (StayOnCenter)
+            {
+                RippleX = this.ActualWidth / 2 - RippleSize / 2;
+                RippleY = this.ActualHeight / 2 - RippleSize / 2;
+            }
+            else
+            {
+                RippleX = point.X - RippleSize / 2;
+                RippleY = point.Y - RippleSize / 2;
+            }
 
             base.OnPreviewMouseLeftButtonDown(e);
         }

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.RatingBar.xaml

@@ -35,6 +35,7 @@
                                                 VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                                                 Padding="{TemplateBinding Padding}" 
                                                 SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
+                                                StayOnCenter="True"
                                                 RenderTransformOrigin=".5, .5">
                                         <wpf:Ripple.RenderTransform>
                                             <RotateTransform x:Name="RotateTransform"></RotateTransform>

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ToolBar.xaml

@@ -227,6 +227,7 @@
             <Setter.Value>
                 <ControlTemplate TargetType="{x:Type Button}">
                     <wpf:Ripple Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}" Focusable="False"
+                                StayOnCenter="True"
                                 x:Name="RippleWrapper"
                                 Feedback="{TemplateBinding Foreground}"
                                 ClipToBounds="False"