add ToggleButtonFlip Style

src/Shared/HandyControl_Shared/Tools/Extension/FrameworkElementExtension.cs

@@ -0,0 +1,58 @@
+using System.Windows;
+
+namespace HandyControl.Tools.Extension
+{
+    public static class FrameworkElementExtension
+    {
+
+        public static double GetValidWidth(this FrameworkElement element)
+        {
+            if (!double.IsNaN(element.Width))
+            {
+                if (element.Width > 0)
+                {
+                    return element.Width;
+                }
+            }
+            else
+            {
+                if (element.ActualWidth > 0)
+                {
+                    return element.ActualWidth;
+                }
+
+                if (element.DesiredSize.Width > 0)
+                {
+                    return element.DesiredSize.Width;
+                }
+            }
+
+            return 0;
+        }
+
+        public static double GetValidHeight(this FrameworkElement element)
+        {
+            if (!double.IsNaN(element.Height))
+            {
+                if (element.Height > 0)
+                {
+                    return element.Height;
+                }
+            }
+            else
+            {
+                if (element.ActualHeight > 0)
+                {
+                    return element.ActualHeight;
+                }
+
+                if (element.DesiredSize.Height > 0)
+                {
+                    return element.DesiredSize.Height;
+                }
+            }
+
+            return 0;
+        }
+    }
+}