private void DismissComposerView()
        {
            composer.Projection = new PlaneProjection { CenterOfRotationX = 0, RotationX = 0 };

            Storyboard animation = new Storyboard();
            Duration duration = new Duration(TimeSpan.FromSeconds(0.3));
            animation.Duration = duration;

            var alphaAnimation = new DoubleAnimation();
            alphaAnimation.Duration = duration;
            animation.Children.Add(alphaAnimation);
            alphaAnimation.To = 0;
            Storyboard.SetTarget(alphaAnimation, composer);
            Storyboard.SetTargetProperty(alphaAnimation, new PropertyPath("Opacity"));

            var yAnimation = new DoubleAnimation();
            yAnimation.Duration = duration;
            yAnimation.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseOut };
            animation.Children.Add(yAnimation);
            yAnimation.To = -composer.Height;
            Storyboard.SetTarget(yAnimation, composer);
            Storyboard.SetTargetProperty(yAnimation, new PropertyPath("(UIElement.RenderTransform).(CompositeTransform.TranslateY)"));

            var planeAnimation = new DoubleAnimation();
            planeAnimation.Duration = duration;
            planeAnimation.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseOut };
            animation.Children.Add(planeAnimation);
            planeAnimation.To = -90;
            Storyboard.SetTarget(planeAnimation, composer.Projection);
            Storyboard.SetTargetProperty(planeAnimation, new PropertyPath("RotationX"));

            animation.Completed += (sender, e) =>
            {
                composerPopup.IsOpen = false;
                composerPopup = null;
                composer = null;

                LayoutRoot.Opacity = 1;
                LayoutRoot.IsHitTestVisible = true;

                ApplicationBar = AppBarBeforeComposerPopup;
                ApplicationBar.IsVisible = true;
            };

            animation.Begin();
        }
        private void ShowComposerView()
        {
            LayoutRoot.IsHitTestVisible = false;

            AppBarBeforeComposerPopup = (ApplicationBar)this.ApplicationBar;

            composer = new TopicReplyComposerView();
            composer.Width = LayoutRoot.ActualWidth;

            var ct = (CompositeTransform)composer.RenderTransform;
            ct.TranslateY = -composer.Height;

            composerPopup = new Popup();
            composerPopup.Child = composer;
            composerPopup.IsOpen = true;

            composer.Projection = new PlaneProjection { CenterOfRotationX = 0, RotationX = -90 };

            Storyboard animation = new Storyboard();
            Duration duration = new Duration(TimeSpan.FromSeconds(0.3));
            animation.Duration = duration;

            // Content view
            DoubleAnimation contentAnimation = new DoubleAnimation();
            animation.Children.Add(contentAnimation);
            contentAnimation.Duration = new Duration(TimeSpan.FromSeconds(0.2));
            contentAnimation.To = 0.2;
            contentAnimation.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseIn };
            Storyboard.SetTarget(contentAnimation, LayoutRoot);
            Storyboard.SetTargetProperty(contentAnimation, new PropertyPath("Opacity"));

            DoubleAnimation yAnimation = new DoubleAnimation();
            animation.Children.Add(yAnimation);
            yAnimation.Duration = new Duration(TimeSpan.FromSeconds(0.2));
            yAnimation.To = 0;
            yAnimation.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseOut };
            Storyboard.SetTarget(yAnimation, composer);
            Storyboard.SetTargetProperty(yAnimation, new PropertyPath("(UIElement.RenderTransform).(CompositeTransform.TranslateY)"));

            var planeAnimation = new DoubleAnimation();
            planeAnimation.Duration = duration;
            planeAnimation.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseOut };
            animation.Children.Add(planeAnimation);
            planeAnimation.To = 0;
            Storyboard.SetTarget(planeAnimation, composer.Projection);
            Storyboard.SetTargetProperty(planeAnimation, new PropertyPath("RotationX"));

            animation.Completed += (sender, e) =>
            {
                Dispatcher.BeginInvoke(() =>
                {
                    ApplicationBar = Resources["ComposerAppBar"] as ApplicationBar;

                    // Auto focus on subject field
                    composer.MessageTextBox.Focus();
                });
            };
            animation.Begin();
        }