//******************************************************************************************************//  PanAndZoomViewer.cs - Gbtc////  Copyright © 2012, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may//  not use this file except in compliance with the License. You may obtain a copy of the License at:////      http://www.opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  09/13/2011 - Mehulbhai P Thakkar//       Generated original version of source code.//  12/20/2012 - Starlynn Danyelle Gilliam//       Modified Header.////****************************************************************************************************** using System;using System.Windows;using System.Windows.Controls;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation; namespace GSF.TimeSeries.UI{    /// <summary>    /// <see cref="ContentControl"/> class which allows deep zoom composoer type functionalities in WPF apps.    /// </summary>    public class PanAndZoom : ContentControl    {        #region [ Members ]         // Fields        private readonly double m_defaultZoomFactor;        private FrameworkElement m_source;        private Point m_screenStartPoint;        private TranslateTransform m_translateTransform;        private ScaleTransform m_zoomTransform;        private TransformGroup m_transformGroup;        private Point m_startOffset;         #endregion         #region [ Constructors ]         /// <summary>        /// Creates an instance of <see cref="PanAndZoom"/> class.        /// </summary>        public PanAndZoom()        {            m_screenStartPoint = new Point(0, 0);            m_defaultZoomFactor = 1.4;        }         #endregion         #region [ Methods ]         /// <summary>        /// Overrides OnApplyTemplate method from <see cref="ContentControl"/> class.        /// </summary>        public override void OnApplyTemplate()        {            base.OnApplyTemplate();            Setup(this);        }         private void Setup(FrameworkElement control)        {            m_source = VisualTreeHelper.GetChild(this, 0) as FrameworkElement;            m_translateTransform = new TranslateTransform();            m_zoomTransform = new ScaleTransform();            m_transformGroup = new TransformGroup();            m_transformGroup.Children.Add(m_zoomTransform);            m_transformGroup.Children.Add(m_translateTransform);            m_source.RenderTransform = m_transformGroup;            this.Focusable = true;            this.KeyDown += source_KeyDown;            this.MouseMove += control_MouseMove;            this.MouseDown += source_MouseDown;            this.MouseUp += source_MouseUp;            this.MouseWheel += source_MouseWheel;        }         private void source_KeyDown(object sender, KeyEventArgs e)        {            // hit escape to reset everything            if (e.Key == Key.Escape) Reset();        }         private void source_MouseWheel(object sender, MouseWheelEventArgs e)        {            // Zoom into the content.  Calculate the zoom factor based on the direction of the mouse wheel.            double zoomFactor = m_defaultZoomFactor;            if (e.Delta <= 0) zoomFactor = 1.0 / m_defaultZoomFactor;             // DoZoom requires both the logical and physical location of the mouse pointer            Point physicalPoint = e.GetPosition(this);             DoZoom(zoomFactor, m_transformGroup.Inverse.Transform(physicalPoint), physicalPoint);         }         private void source_MouseUp(object sender, MouseButtonEventArgs e)        {            if (this.IsMouseCaptured)            {                // We're done.  reset the cursor and release the mouse pointer                this.Cursor = Cursors.Arrow;                this.ReleaseMouseCapture();            }        }         private void source_MouseDown(object sender, MouseButtonEventArgs e)        {            // Save starting point, used later when determining how much to scroll.            m_screenStartPoint = e.GetPosition(this);            m_startOffset = new Point(m_translateTransform.X, m_translateTransform.Y);            this.CaptureMouse();            this.Cursor = Cursors.ScrollAll;        }         private void control_MouseMove(object sender, MouseEventArgs e)        {            if (this.IsMouseCaptured)            {                // if the mouse is captured then move the content by changing the translate transform.                  // use the Pan Animation to animate to the new location based on the delta between the                 // starting point of the mouse and the current point.                Point physicalPoint = e.GetPosition(this);                m_translateTransform.BeginAnimation(TranslateTransform.XProperty, CreatePanAnimation(physicalPoint.X - m_screenStartPoint.X + m_startOffset.X), HandoffBehavior.Compose);                m_translateTransform.BeginAnimation(TranslateTransform.YProperty, CreatePanAnimation(physicalPoint.Y - m_screenStartPoint.Y + m_startOffset.Y), HandoffBehavior.Compose);            }        }         /// <summary>Helper to create the panning animation for x,y coordinates.</summary>        /// <param name="toValue">New value of the coordinate.</param>        /// <returns>Double animation</returns>        private DoubleAnimation CreatePanAnimation(double toValue)        {            DoubleAnimation da = new DoubleAnimation(toValue, new Duration(TimeSpan.FromMilliseconds(300)));             da.AccelerationRatio = 0.1;            da.DecelerationRatio = 0.9;            da.FillBehavior = FillBehavior.HoldEnd;            da.Freeze();             return da;        }         /// <summary>Helper to create the zoom double animation for scaling.</summary>        /// <param name="toValue">Value to animate to.</param>        /// <returns>Double animation.</returns>        private DoubleAnimation CreateZoomAnimation(double toValue)        {            DoubleAnimation da = new DoubleAnimation(toValue, new Duration(TimeSpan.FromMilliseconds(500)));             da.AccelerationRatio = 0.1;            da.DecelerationRatio = 0.9;            da.FillBehavior = FillBehavior.HoldEnd;            da.Freeze();             return da;        }         /// <summary>Zoom into or out of the content.</summary>        /// <param name="deltaZoom">Factor to mutliply the zoom level by. </param>        /// <param name="mousePosition">Logical mouse position relative to the original content.</param>        /// <param name="physicalPosition">Actual mouse position on the screen (relative to the parent window)</param>        public void DoZoom(double deltaZoom, Point mousePosition, Point physicalPosition)        {            double currentZoom = m_zoomTransform.ScaleX;            currentZoom *= deltaZoom;            m_translateTransform.BeginAnimation(TranslateTransform.XProperty, CreateZoomAnimation(-1 * (mousePosition.X * currentZoom - physicalPosition.X)));            m_translateTransform.BeginAnimation(TranslateTransform.YProperty, CreateZoomAnimation(-1 * (mousePosition.Y * currentZoom - physicalPosition.Y)));            m_zoomTransform.BeginAnimation(ScaleTransform.ScaleXProperty, CreateZoomAnimation(currentZoom));            m_zoomTransform.BeginAnimation(ScaleTransform.ScaleYProperty, CreateZoomAnimation(currentZoom));        }         /// <summary>Reset to default zoom level and centered content.</summary>        public void Reset()        {            m_translateTransform.BeginAnimation(TranslateTransform.XProperty, CreateZoomAnimation(0));            m_translateTransform.BeginAnimation(TranslateTransform.YProperty, CreateZoomAnimation(0));            m_zoomTransform.BeginAnimation(ScaleTransform.ScaleXProperty, CreateZoomAnimation(1));            m_zoomTransform.BeginAnimation(ScaleTransform.ScaleYProperty, CreateZoomAnimation(1));        }         #endregion    }}