TiltEffect.cs | searchcode

/TiltEffect.cs

https://bitbucket.org/jeremejevs/milk-manager
C# | 634 lines | 312 code | 104 blank | 218 comment | 46 complexity | 14a6723eeac915d9649e4e182cf41197 MD5 | raw file

using System;

using System.Collections.Generic;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Controls.Primitives;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using Microsoft.Phone.Controls;



namespace NotEdible

{

    /// <summary>

    /// This code provides attached properties for adding a 'tilt' effect to all controls within a container.

    /// </summary>

    public class TiltEffect : DependencyObject

    {



        #region Constructor and Static Constructor

        /// <summary>

        /// This is not a constructable class, but it cannot be static because it derives from DependencyObject.

        /// </summary>

        private TiltEffect()

        {

        }



        /// <summary>

        /// Initialize the static properties

        /// </summary>

        static TiltEffect()

        {

            // The tiltable items list.

            TiltableItems = new List<Type>() { typeof(ButtonBase), typeof(ListBoxItem), };

            UseLogarithmicEase = false;

        }



        #endregion





        #region Fields and simple properties



        // These constants are the same as the built-in effects

        /// <summary>

        /// Maximum amount of tilt, in radians

        /// </summary>

        const double MaxAngle = 0.3;



        /// <summary>

        /// Maximum amount of depression, in pixels

        /// </summary>

        const double MaxDepression = 25;



        /// <summary>

        /// Delay between releasing an element and the tilt release animation playing

        /// </summary>

        static readonly TimeSpan TiltReturnAnimationDelay = TimeSpan.FromMilliseconds(200);



        /// <summary>

        /// Duration of tilt release animation

        /// </summary>

        static readonly TimeSpan TiltReturnAnimationDuration = TimeSpan.FromMilliseconds(100);



        /// <summary>

        /// The control that is currently being tilted

        /// </summary>

        static FrameworkElement currentTiltElement;



        /// <summary>

        /// The single instance of a storyboard used for all tilts

        /// </summary>

        static Storyboard tiltReturnStoryboard;



        /// <summary>

        /// The single instance of an X rotation used for all tilts

        /// </summary>

        static DoubleAnimation tiltReturnXAnimation;



        /// <summary>

        /// The single instance of a Y rotation used for all tilts

        /// </summary>

        static DoubleAnimation tiltReturnYAnimation;



        /// <summary>

        /// The single instance of a Z depression used for all tilts

        /// </summary>

        static DoubleAnimation tiltReturnZAnimation;



        /// <summary>

        /// The center of the tilt element

        /// </summary>

        static Point currentTiltElementCenter;



        /// <summary>

        /// Whether the animation just completed was for a 'pause' or not

        /// </summary>

        static bool wasPauseAnimation = false;



        /// <summary>

        /// Whether to use a slightly more accurate (but slightly slower) tilt animation easing function

        /// </summary>

        public static bool UseLogarithmicEase { get; set; }



        /// <summary>

        /// Default list of items that are tiltable

        /// </summary>

        public static List<Type> TiltableItems { get; private set; }



        #endregion





        #region Dependency properties



        /// <summary>

        /// Whether the tilt effect is enabled on a container (and all its children)

        /// </summary>

        public static readonly DependencyProperty IsTiltEnabledProperty = DependencyProperty.RegisterAttached(

          "IsTiltEnabled",

          typeof(bool),

          typeof(TiltEffect),

          new PropertyMetadata(OnIsTiltEnabledChanged)

          );



        /// <summary>

        /// Gets the IsTiltEnabled dependency property from an object

        /// </summary>

        /// <param name="source">The object to get the property from</param>

        /// <returns>The property's value</returns>

        public static bool GetIsTiltEnabled(DependencyObject source) { return (bool)source.GetValue(IsTiltEnabledProperty); }



        /// <summary>

        /// Sets the IsTiltEnabled dependency property on an object

        /// </summary>

        /// <param name="source">The object to set the property on</param>

        /// <param name="value">The value to set</param>

        public static void SetIsTiltEnabled(DependencyObject source, bool value) { source.SetValue(IsTiltEnabledProperty, value); }



        /// <summary>

        /// Suppresses the tilt effect on a single control that would otherwise be tilted

        /// </summary>

        public static readonly DependencyProperty SuppressTiltProperty = DependencyProperty.RegisterAttached(

          "SuppressTilt",

          typeof(bool),

          typeof(TiltEffect),

          null

          );



        /// <summary>

        /// Gets the SuppressTilt dependency property from an object

        /// </summary>

        /// <param name="source">The object to get the property from</param>

        /// <returns>The property's value</returns>

        public static bool GetSuppressTilt(DependencyObject source) { return (bool)source.GetValue(SuppressTiltProperty); }



        /// <summary>

        /// Sets the SuppressTilt dependency property from an object

        /// </summary>

        /// <param name="source">The object to get the property from</param>

        /// <returns>The property's value</returns>

        public static void SetSuppressTilt(DependencyObject source, bool value) { source.SetValue(SuppressTiltProperty, value); }





        /// <summary>

        /// Property change handler for the IsTiltEnabled dependency property

        /// </summary>

        /// <param name="target">The element that the property is atteched to</param>

        /// <param name="args">Event args</param>

        /// <remarks>

        /// Adds or removes event handlers from the element that has been (un)registered for tilting

        /// </remarks>

        static void OnIsTiltEnabledChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)

        {

            if (target is FrameworkElement)

            {

                // Add / remove the event handler if necessary

                if ((bool)args.NewValue == true)

                {

                    (target as FrameworkElement).ManipulationStarted += TiltEffect_ManipulationStarted;

                }

                else

                {

                    (target as FrameworkElement).ManipulationStarted -= TiltEffect_ManipulationStarted;

                }

            }

        }



        #endregion





        #region Top-level manipulation event handlers



        /// <summary>

        /// Event handler for ManipulationStarted

        /// </summary>

        /// <param name="sender">sender of the event - this will be the tilt container (eg, entire page)</param>

        /// <param name="e">event args</param>

        static void TiltEffect_ManipulationStarted(object sender, ManipulationStartedEventArgs e)

        {

           

            TryStartTiltEffect(sender as FrameworkElement, e);

        }



        /// <summary>

        /// Event handler for ManipulationDelta

        /// </summary>

        /// <param name="sender">sender of the event - this will be the tilting object (eg a button)</param>

        /// <param name="e">event args</param>

        static void TiltEffect_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)

        {

            

            ContinueTiltEffect(sender as FrameworkElement, e);

        }



        /// <summary>

        /// Event handler for ManipulationCompleted

        /// </summary>

        /// <param name="sender">sender of the event - this will be the tilting object (eg a button)</param>

        /// <param name="e">event args</param>

        static void TiltEffect_ManipulationCompleted(object sender, ManipulationCompletedEventArgs e)

        {

            

            EndTiltEffect(currentTiltElement);

        }



        #endregion





        #region Core tilt logic



        /// <summary>

        /// Checks if the manipulation should cause a tilt, and if so starts the tilt effect

        /// </summary>

        /// <param name="source">The source of the manipulation (the tilt container, eg entire page)</param>

        /// <param name="e">The args from the ManipulationStarted event</param>

        static void TryStartTiltEffect(FrameworkElement source, ManipulationStartedEventArgs e)

        {

            foreach (FrameworkElement ancestor in (e.OriginalSource as FrameworkElement).GetVisualAncestors())

            {

                foreach (Type t in TiltableItems)

                {

                    if (t.IsAssignableFrom(ancestor.GetType()))

                    {

                        if ((bool)ancestor.GetValue(SuppressTiltProperty) != true)

                        {

                            // Use first child of the control, so that you can add transforms and not

                            // impact any transforms on the control itself

                            FrameworkElement element = VisualTreeHelper.GetChild(ancestor, 0) as FrameworkElement;

                            FrameworkElement container = e.ManipulationContainer as FrameworkElement;



                            if (element == null || container == null)

                                return;



                            // Touch point relative to the element being tilted

                            Point tiltTouchPoint = container.TransformToVisual(element).Transform(e.ManipulationOrigin);



                            // Center of the element being tilted

                            Point elementCenter = new Point(element.ActualWidth / 2, element.ActualHeight / 2);



                            // Camera adjustment

                            Point centerToCenterDelta = GetCenterToCenterDelta(element, source);



                            BeginTiltEffect(element, tiltTouchPoint, elementCenter, centerToCenterDelta);

                            return;

                        }

                    }

                }

            }

        }



        /// <summary>

        /// Computes the delta between the centre of an element and its container

        /// </summary>

        /// <param name="element">The element to compare</param>

        /// <param name="container">The element to compare against</param>

        /// <returns>A point that represents the delta between the two centers</returns>

        static Point GetCenterToCenterDelta(FrameworkElement element, FrameworkElement container)

        {

            Point elementCenter = new Point(element.ActualWidth / 2, element.ActualHeight / 2);

            Point containerCenter;



#if WINDOWS_PHONE



            // Need to special-case the frame to handle different orientations

            if (container is PhoneApplicationFrame)

            {

                PhoneApplicationFrame frame = container as PhoneApplicationFrame;



                // Switch width and height in landscape mode

                if ((frame.Orientation & PageOrientation.Landscape) == PageOrientation.Landscape)

                {

                   

                    containerCenter = new Point(container.ActualHeight / 2, container.ActualWidth / 2);

                }

                else

                    containerCenter = new Point(container.ActualWidth / 2, container.ActualHeight / 2);

            }

            else

                containerCenter = new Point(container.ActualWidth / 2, container.ActualHeight / 2);

#else



            containerCenter = new Point(container.ActualWidth / 2, container.ActualHeight / 2);



#endif



            Point transformedElementCenter = element.TransformToVisual(container).Transform(elementCenter);

            Point result = new Point(containerCenter.X - transformedElementCenter.X, containerCenter.Y - transformedElementCenter.Y);

           

            return result;

        }



        /// <summary>

        /// Begins the tilt effect by preparing the control and doing the initial animation

        /// </summary>

        /// <param name="element">The element to tilt </param>

        /// <param name="touchPoint">The touch point, in element coordinates</param>

        /// <param name="centerPoint">The center point of the element in element coordinates</param>

        /// <param name="centerDelta">The delta between the <paramref name="element"/>'s center and 

        /// the container's center</param>

        static void BeginTiltEffect(FrameworkElement element, Point touchPoint, Point centerPoint, Point centerDelta)

        {

           



            if (tiltReturnStoryboard != null)

                StopTiltReturnStoryboardAndCleanup();



            if (PrepareControlForTilt(element, centerDelta) == false)

                return;



            currentTiltElement = element;

            currentTiltElementCenter = centerPoint;

            PrepareTiltReturnStoryboard(element);



            ApplyTiltEffect(currentTiltElement, touchPoint, currentTiltElementCenter);

        }



        /// <summary>

        /// Prepares a control to be tilted by setting up a plane projection and some event handlers

        /// </summary>

        /// <param name="element">The control that is to be tilted</param>

        /// <param name="centerDelta">Delta between the element's center and the tilt container's</param>

        /// <returns>true if successful; false otherwise</returns>

        /// <remarks>

        /// This method is conservative; it will fail any attempt to tilt a control that already

        /// has a projection on it

        /// </remarks>

        static bool PrepareControlForTilt(FrameworkElement element, Point centerDelta)

        {

            // Prevents interference with any existing transforms

            if (element.Projection != null || (element.RenderTransform != null && element.RenderTransform.GetType() != typeof(MatrixTransform)))

                return false;



            TranslateTransform transform = new TranslateTransform();

            transform.X = centerDelta.X;

            transform.Y = centerDelta.Y;

            element.RenderTransform = transform;



            PlaneProjection projection = new PlaneProjection();

            projection.GlobalOffsetX = -1 * centerDelta.X;

            projection.GlobalOffsetY = -1 * centerDelta.Y;

            element.Projection = projection;



            element.ManipulationDelta += TiltEffect_ManipulationDelta;

            element.ManipulationCompleted += TiltEffect_ManipulationCompleted;



            return true;

        }



        /// <summary>

        /// Removes modifications made by PrepareControlForTilt

        /// </summary>

        /// <param name="element">THe control to be un-prepared</param>

        /// <remarks>

        /// This method is basic; it does not do anything to detect if the control being un-prepared

        /// was previously prepared

        /// </remarks>

        static void RevertPrepareControlForTilt(FrameworkElement element)

        {

            element.ManipulationDelta -= TiltEffect_ManipulationDelta;

            element.ManipulationCompleted -= TiltEffect_ManipulationCompleted;

            element.Projection = null;

            element.RenderTransform = null;

        }



        /// <summary>

        /// Creates the tilt return storyboard (if not already created) and targets it to the projection

        /// </summary>

        /// <param name="projection">the projection that should be the target of the animation</param>

        static void PrepareTiltReturnStoryboard(FrameworkElement element)

        {



            if (tiltReturnStoryboard == null)

            {

                tiltReturnStoryboard = new Storyboard();

                tiltReturnStoryboard.Completed += TiltReturnStoryboard_Completed;



                tiltReturnXAnimation = new DoubleAnimation();

                Storyboard.SetTargetProperty(tiltReturnXAnimation, new PropertyPath(PlaneProjection.RotationXProperty));

                tiltReturnXAnimation.BeginTime = TiltReturnAnimationDelay;

                tiltReturnXAnimation.To = 0;

                tiltReturnXAnimation.Duration = TiltReturnAnimationDuration;



                tiltReturnYAnimation = new DoubleAnimation();

                Storyboard.SetTargetProperty(tiltReturnYAnimation, new PropertyPath(PlaneProjection.RotationYProperty));

                tiltReturnYAnimation.BeginTime = TiltReturnAnimationDelay;

                tiltReturnYAnimation.To = 0;

                tiltReturnYAnimation.Duration = TiltReturnAnimationDuration;



                tiltReturnZAnimation = new DoubleAnimation();

                Storyboard.SetTargetProperty(tiltReturnZAnimation, new PropertyPath(PlaneProjection.GlobalOffsetZProperty));

                tiltReturnZAnimation.BeginTime = TiltReturnAnimationDelay;

                tiltReturnZAnimation.To = 0;

                tiltReturnZAnimation.Duration = TiltReturnAnimationDuration;



                if (UseLogarithmicEase)

                {

                    tiltReturnXAnimation.EasingFunction = new LogarithmicEase();

                    tiltReturnYAnimation.EasingFunction = new LogarithmicEase();

                    tiltReturnZAnimation.EasingFunction = new LogarithmicEase();

                }



                tiltReturnStoryboard.Children.Add(tiltReturnXAnimation);

                tiltReturnStoryboard.Children.Add(tiltReturnYAnimation);

                tiltReturnStoryboard.Children.Add(tiltReturnZAnimation);

            }



            Storyboard.SetTarget(tiltReturnXAnimation, element.Projection);

            Storyboard.SetTarget(tiltReturnYAnimation, element.Projection);

            Storyboard.SetTarget(tiltReturnZAnimation, element.Projection);

        }





        /// <summary>

        /// Continues a tilt effect that is currently applied to an element, presumably because

        /// the user moved their finger

        /// </summary>

        /// <param name="element">The element being tilted</param>

        /// <param name="e">The manipulation event args</param>

        static void ContinueTiltEffect(FrameworkElement element, ManipulationDeltaEventArgs e)

        {

            FrameworkElement container = e.ManipulationContainer as FrameworkElement;

            if (container == null || element == null)

                return;



            Point tiltTouchPoint = container.TransformToVisual(element).Transform(e.ManipulationOrigin);



            // If touch moved outside bounds of element, then pause the tilt (but don't cancel it)

            if (new Rect(0, 0, currentTiltElement.ActualWidth, currentTiltElement.ActualHeight).Contains(tiltTouchPoint) != true)

            {

               

                PauseTiltEffect();

                return;

            }



            // Apply the updated tilt effect

            ApplyTiltEffect(currentTiltElement, e.ManipulationOrigin, currentTiltElementCenter);

        }



        /// <summary>

        /// Ends the tilt effect by playing the animation  

        /// </summary>

        /// <param name="element">The element being tilted</param>

        static void EndTiltEffect(FrameworkElement element)

        {

            if (element != null)

            {

                element.ManipulationCompleted -= TiltEffect_ManipulationCompleted;

                element.ManipulationDelta -= TiltEffect_ManipulationDelta;

            }



            if (tiltReturnStoryboard != null)

            {

                wasPauseAnimation = false;

                if (tiltReturnStoryboard.GetCurrentState() != ClockState.Active)

                    tiltReturnStoryboard.Begin();

            }

            else

                StopTiltReturnStoryboardAndCleanup();

        }



        /// <summary>

        /// Handler for the storyboard complete event

        /// </summary>

        /// <param name="sender">sender of the event</param>

        /// <param name="e">event args</param>

        static void TiltReturnStoryboard_Completed(object sender, EventArgs e)

        {

            if (wasPauseAnimation)

                ResetTiltEffect(currentTiltElement);

            else

                StopTiltReturnStoryboardAndCleanup();

        }



        /// <summary>

        /// Resets the tilt effect on the control, making it appear 'normal' again 

        /// </summary>

        /// <param name="element">The element to reset the tilt on</param>

        /// <remarks>

        /// This method doesn't turn off the tilt effect or cancel any current

        /// manipulation; it just temporarily cancels the effect

        /// </remarks>

        static void ResetTiltEffect(FrameworkElement element)

        {

            PlaneProjection projection = element.Projection as PlaneProjection;

            projection.RotationY = 0;

            projection.RotationX = 0;

            projection.GlobalOffsetZ = 0;

        }



        /// <summary>

        /// Stops the tilt effect and release resources applied to the currently-tilted control

        /// </summary>

        static void StopTiltReturnStoryboardAndCleanup()

        {

            if (tiltReturnStoryboard != null)

                tiltReturnStoryboard.Stop();



            RevertPrepareControlForTilt(currentTiltElement);

        }



        /// <summary>

        /// Pauses the tilt effect so that the control returns to the 'at rest' position, but doesn't

        /// stop the tilt effect (handlers are still attached, etc.)

        /// </summary>

        static void PauseTiltEffect()

        {

            if ((tiltReturnStoryboard != null) && !wasPauseAnimation)

            {

                tiltReturnStoryboard.Stop();

                wasPauseAnimation = true;

                tiltReturnStoryboard.Begin();

            }

        }



        /// <summary>

        /// Resets the storyboard to not running

        /// </summary>

        private static void ResetTiltReturnStoryboard()

        {

            tiltReturnStoryboard.Stop();

            wasPauseAnimation = false;

        }



        /// <summary>

        /// Applies the tilt effect to the control

        /// </summary>

        /// <param name="element">the control to tilt</param>

        /// <param name="touchPoint">The touch point, in the container's coordinates</param>

        /// <param name="centerPoint">The center point of the container</param>

        static void ApplyTiltEffect(FrameworkElement element, Point touchPoint, Point centerPoint)

        {

            // Stop any active animation

            ResetTiltReturnStoryboard();



            // Get relative point of the touch in percentage of container size

            Point normalizedPoint = new Point(

                Math.Min(Math.Max(touchPoint.X / (centerPoint.X * 2), 0), 1),

                Math.Min(Math.Max(touchPoint.Y / (centerPoint.Y * 2), 0), 1));



            // Shell values

            double xMagnitude = Math.Abs(normalizedPoint.X - 0.5);

            double yMagnitude = Math.Abs(normalizedPoint.Y - 0.5);

            double xDirection = -Math.Sign(normalizedPoint.X - 0.5);

            double yDirection = Math.Sign(normalizedPoint.Y - 0.5);

            double angleMagnitude = xMagnitude + yMagnitude;

            double xAngleContribution = xMagnitude + yMagnitude > 0 ? xMagnitude / (xMagnitude + yMagnitude) : 0;



            double angle = angleMagnitude * MaxAngle * 180 / Math.PI;

            double depression = (1 - angleMagnitude) * MaxDepression;



            // RotationX and RotationY are the angles of rotations about the x- or y-*axis*;

            // to achieve a rotation in the x- or y-*direction*, we need to swap the two.

            // That is, a rotation to the left about the y-axis is a rotation to the left in the x-direction,

            // and a rotation up about the x-axis is a rotation up in the y-direction.

            PlaneProjection projection = element.Projection as PlaneProjection;

            projection.RotationY = angle * xAngleContribution * xDirection;

            projection.RotationX = angle * (1 - xAngleContribution) * yDirection;

            projection.GlobalOffsetZ = -depression;

        }



        #endregion





        #region Custom easing function



        /// <summary>

        /// Provides an easing function for the tilt return

        /// </summary>

        private class LogarithmicEase : EasingFunctionBase

        {

            /// <summary>

            /// Computes the easing function

            /// </summary>

            /// <param name="normalizedTime">The time</param>

            /// <returns>The eased value</returns>

            protected override double EaseInCore(double normalizedTime)

            {

                return Math.Log(normalizedTime + 1) / 0.693147181; // ln(t + 1) / ln(2)

            }

        }



        #endregion

    }



    /// <summary>

    /// Couple of simple helpers for walking the visual tree

    /// </summary>

    static class TreeHelpers

    {

        /// <summary>

        /// Gets the ancestors of the element, up to the root

        /// </summary>

        /// <param name="node">The element to start from</param>

        /// <returns>An enumerator of the ancestors</returns>

        public static IEnumerable<FrameworkElement> GetVisualAncestors(this FrameworkElement node)

        {

            FrameworkElement parent = node.GetVisualParent();

            while (parent != null)

            {

                yield return parent;

                parent = parent.GetVisualParent();

            }

        }



        /// <summary>

        /// Gets the visual parent of the element

        /// </summary>

        /// <param name="node">The element to check</param>

        /// <returns>The visual parent</returns>

        public static FrameworkElement GetVisualParent(this FrameworkElement node)

        {

            return VisualTreeHelper.GetParent(node) as FrameworkElement;

        }

    }

}