Properties for controlling the transition origin

Author: mgnslndh

MainDemo.Wpf/TransitionsDemo/TransitionsDemoHome.xaml

@@ -11,6 +11,7 @@
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
+            <RowDefinition Height="256" />
         </Grid.RowDefinitions>
         <TextBlock>Transitions Demo</TextBlock>
 
@@ -47,13 +48,31 @@
             <local:Slide5_TransitioningContent />
 
             <local:Slide6_MVVM />
-            
+
             <local:Slide7_Master />
 
             <local:Slide8_Details />
 
         </materialDesign:Transitioner>
 
+        <Grid Grid.Row="2">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto"/>
+                <ColumnDefinition/>
+            </Grid.ColumnDefinitions>
+            <materialDesign:Transitioner Name="BackgroundTransitioner" Grid.Column="1" Margin="6" SelectedIndex="1" DefaultTransitionOrigin="{x:Static materialDesign:TransitionOrigins.TopLeft}">
+                <Border Background="#009688"/>
+                <materialDesign:TransitionerSlide TransitionOrigin="{x:Static materialDesign:TransitionOrigins.BottomRight}">
+                    <materialDesign:TransitionerSlide.BackwardWipe>
+                        <materialDesign:CircleWipe/>
+                    </materialDesign:TransitionerSlide.BackwardWipe>
+                    <Border Background="#E64A19"/>
+                </materialDesign:TransitionerSlide>
+            </materialDesign:Transitioner>
+            <ToggleButton Name="BackgroundToggleButton" Grid.Column="0" Margin="6" Click="BackgroundToggleButton_Checked"/>
+            <TextBlock Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" Style="{StaticResource MaterialDesignDisplay3TextBlock}" Foreground="{StaticResource PrimaryHueDarkForegroundBrush}" Opacity="0.86">Material Design In XAML Toolkit</TextBlock>
+        </Grid>
+
     </Grid>
 
 </UserControl>

MainDemo.Wpf/TransitionsDemo/TransitionsDemoHome.xaml.cs

@@ -24,5 +24,17 @@ public TransitionsDemoHome()
         {
             InitializeComponent();
         }
+
+        private void BackgroundToggleButton_Checked(object sender, RoutedEventArgs e)
+        {
+            if((bool)BackgroundToggleButton.IsChecked)
+            {
+                BackgroundTransitioner.SelectedIndex = 0;
+            }
+            else
+            {
+                BackgroundTransitioner.SelectedIndex = 1;
+            }
+        }
     }
 }

MaterialDesignThemes.Wpf/MaterialDesignThemes.Wpf.csproj

@@ -356,6 +356,7 @@
     <Compile Include="Transitions\TransitionerSlideState.cs" />
     <Compile Include="Transitions\TransitioningContent.cs" />
     <Compile Include="Transitions\TransitioningContentBase.cs" />
+    <Compile Include="Transitions\TransitionOrigins.cs" />
     <Compile Include="TreeHelper.cs" />
     <Compile Include="Underline.cs" />
     <Compile Include="ValidationAssist.cs" />

MaterialDesignThemes.Wpf/Transitions/TransitionOrigins.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace MaterialDesignThemes.Wpf.Transitions
+{
+    public static class TransitionOrigins
+    {
+        public static readonly Point TopLeft = new Point(0, 0);
+        public static readonly Point TopRight = new Point(1, 0);
+
+        public static readonly Point BottomLeft = new Point(0, 1);
+        public static readonly Point BottomRight = new Point(1, 1);
+
+        public static readonly Point Center = new Point(0.5, 0.5);
+
+        public static readonly Point MiddleLeft = new Point(0, 0.5);
+        public static readonly Point MiddleRight = new Point(1, 0.5);
+
+        public static readonly Point TopMiddle = new Point(0.5, 0);
+        public static readonly Point BottomMiddle = new Point(0.5, 1);
+    }
+}

MaterialDesignThemes.Wpf/Transitions/Transitioner.cs

@@ -42,13 +42,22 @@ static Transitioner()
 
         public static readonly DependencyProperty AutoApplyTransitionOriginsProperty = DependencyProperty.Register(
             "AutoApplyTransitionOrigins", typeof (bool), typeof (Transitioner), new PropertyMetadata(default(bool)));
-
+        
         public bool AutoApplyTransitionOrigins
         {
             get { return (bool) GetValue(AutoApplyTransitionOriginsProperty); }
             set { SetValue(AutoApplyTransitionOriginsProperty, value); }
         }
 
+        public static readonly DependencyProperty DefaultTransitionOriginProperty = DependencyProperty.Register(
+            "DefaultTransitionOrigin", typeof(Point), typeof(Transitioner), new PropertyMetadata(new Point(0.5, 0.5)));
+
+        public Point DefaultTransitionOrigin
+        {
+            get { return (Point)GetValue(DefaultTransitionOriginProperty); }
+            set { SetValue(DefaultTransitionOriginProperty, value); }
+        }
+
         public Transitioner()
         {
             CommandBindings.Add(new CommandBinding(MoveNextCommand, MoveNextHandler));
@@ -189,12 +198,12 @@ private void ActivateFrame(int selectedIndex, int unselectedIndex)
             if (oldSlide != null && newSlide != null)
             {
                 var wipe = selectedIndex > unselectedIndex ? oldSlide.ForwardWipe : oldSlide.BackwardWipe;
-                if (wipe != null)
-                    wipe.Wipe(oldSlide, newSlide, _nextTransitionOrigin ?? new Point(.5, .5), this);
+                if (wipe != null)                
+                    wipe.Wipe(oldSlide, newSlide, GetTransitionOrigin(newSlide), this);                
                 else
                 {
-                    DoStack(newSlide, oldSlide);                    
-                    oldSlide.Opacity = 0;                    
+                    DoStack(newSlide, oldSlide);
+                    oldSlide.Opacity = 0;
                 }
             }
             else if (oldSlide != null || newSlide != null)
@@ -209,6 +218,21 @@ private void ActivateFrame(int selectedIndex, int unselectedIndex)
             _nextTransitionOrigin = null;
         }
 
+        private Point GetTransitionOrigin(TransitionerSlide slide)
+        {
+            if(_nextTransitionOrigin != null)
+            {
+                return _nextTransitionOrigin.Value;
+            }
+
+            if(slide.ReadLocalValue(TransitionerSlide.TransitionOriginProperty) != DependencyProperty.UnsetValue)
+            {
+                return slide.TransitionOrigin;             
+            }
+
+            return DefaultTransitionOrigin;
+        }
+
         void IZIndexController.Stack(params TransitionerSlide[] highestToLowest)
         {
             DoStack(highestToLowest);

MaterialDesignThemes.Wpf/Transitions/TransitionerSlide.cs

@@ -18,6 +18,15 @@ static TransitionerSlide()
             DefaultStyleKeyProperty.OverrideMetadata(typeof(TransitionerSlide), new FrameworkPropertyMetadata(typeof(TransitionerSlide)));
         }
 
+        public static readonly DependencyProperty TransitionOriginProperty = DependencyProperty.Register(
+            "TransitionOrigin", typeof(Point), typeof(Transitioner), new PropertyMetadata(new Point(0.5,0.5)));
+
+        public Point TransitionOrigin
+        {
+            get { return (Point)GetValue(TransitionOriginProperty); }
+            set { SetValue(TransitionOriginProperty, value); }
+        }
+
         public static RoutedEvent InTransitionFinished =
             EventManager.RegisterRoutedEvent("InTransitionFinished", RoutingStrategy.Bubble, typeof (RoutedEventHandler),
                 typeof (TransitionerSlide));