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// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
using System; using System.Collections.Generic; using System.Diagnostics; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Controls.Primitives; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media;
namespace ICSharpCode.ILSpy.Controls { public class ZoomScrollViewer : ScrollViewer { static ZoomScrollViewer() { DefaultStyleKeyProperty.OverrideMetadata(typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(typeof(ZoomScrollViewer))); }
public static readonly DependencyProperty CurrentZoomProperty = DependencyProperty.Register("CurrentZoom", typeof(double), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(1.0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, CalculateZoomButtonCollapsed, CoerceZoom));
public double CurrentZoom { get { return (double)GetValue(CurrentZoomProperty); } set { SetValue(CurrentZoomProperty, value); } }
static object CoerceZoom(DependencyObject d, object baseValue) { var zoom = (double)baseValue; ZoomScrollViewer sv = (ZoomScrollViewer)d; return Math.Max(sv.MinimumZoom, Math.Min(sv.MaximumZoom, zoom)); }
public static readonly DependencyProperty MinimumZoomProperty = DependencyProperty.Register("MinimumZoom", typeof(double), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(0.2));
public double MinimumZoom { get { return (double)GetValue(MinimumZoomProperty); } set { SetValue(MinimumZoomProperty, value); } }
public static readonly DependencyProperty MaximumZoomProperty = DependencyProperty.Register("MaximumZoom", typeof(double), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(5.0));
public double MaximumZoom { get { return (double)GetValue(MaximumZoomProperty); } set { SetValue(MaximumZoomProperty, value); } }
public static readonly DependencyProperty MouseWheelZoomProperty = DependencyProperty.Register("MouseWheelZoom", typeof(bool), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(true));
public bool MouseWheelZoom { get { return (bool)GetValue(MouseWheelZoomProperty); } set { SetValue(MouseWheelZoomProperty, value); } }
public static readonly DependencyProperty AlwaysShowZoomButtonsProperty = DependencyProperty.Register("AlwaysShowZoomButtons", typeof(bool), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(false, CalculateZoomButtonCollapsed));
public bool AlwaysShowZoomButtons { get { return (bool)GetValue(AlwaysShowZoomButtonsProperty); } set { SetValue(AlwaysShowZoomButtonsProperty, value); } }
static readonly DependencyPropertyKey ComputedZoomButtonCollapsedPropertyKey = DependencyProperty.RegisterReadOnly("ComputedZoomButtonCollapsed", typeof(bool), typeof(ZoomScrollViewer), new FrameworkPropertyMetadata(true));
public static readonly DependencyProperty ComputedZoomButtonCollapsedProperty = ComputedZoomButtonCollapsedPropertyKey.DependencyProperty;
public bool ComputedZoomButtonCollapsed { get { return (bool)GetValue(ComputedZoomButtonCollapsedProperty); } private set { SetValue(ComputedZoomButtonCollapsedPropertyKey, value); } }
static void CalculateZoomButtonCollapsed(DependencyObject d, DependencyPropertyChangedEventArgs e) { ZoomScrollViewer z = d as ZoomScrollViewer; if (z != null) z.ComputedZoomButtonCollapsed = (z.AlwaysShowZoomButtons == false) && (z.CurrentZoom == 1.0); }
protected override void OnPreviewMouseWheel(MouseWheelEventArgs e) { if (!e.Handled && Keyboard.Modifiers == ModifierKeys.Control && MouseWheelZoom) { double oldZoom = CurrentZoom; double newZoom = RoundToOneIfClose(CurrentZoom * Math.Pow(1.001, e.Delta)); newZoom = Math.Max(this.MinimumZoom, Math.Min(this.MaximumZoom, newZoom));
// adjust scroll position so that mouse stays over the same virtual coordinate
ContentPresenter presenter = Template.FindName("PART_Presenter", this) as ContentPresenter; Vector relMousePos; if (presenter != null) { Point mousePos = e.GetPosition(presenter); relMousePos = new Vector(mousePos.X / presenter.ActualWidth, mousePos.Y / presenter.ActualHeight); } else { relMousePos = new Vector(0.5, 0.5); }
Point scrollOffset = new Point(this.HorizontalOffset, this.VerticalOffset); Vector oldHalfViewport = new Vector(this.ViewportWidth / 2, this.ViewportHeight / 2); Vector newHalfViewport = oldHalfViewport / newZoom * oldZoom; Point oldCenter = scrollOffset + oldHalfViewport; Point virtualMousePos = scrollOffset + new Vector(relMousePos.X * this.ViewportWidth, relMousePos.Y * this.ViewportHeight);
// As newCenter, we want to choose a point between oldCenter and virtualMousePos. The more we zoom in, the closer
// to virtualMousePos. We'll create the line x = oldCenter + lambda * (virtualMousePos-oldCenter).
// On this line, we need to choose lambda between -1 and 1:
// -1 = zoomed out completely
// 0 = zoom unchanged
// +1 = zoomed in completely
// But the zoom factor (newZoom/oldZoom) we have is in the range [0,+Infinity].
// Basically, I just played around until I found a function that maps this to [-1,1] and works well.
// "f" is squared because otherwise the mouse simply stays over virtualMousePos, but I wanted virtualMousePos
// to move towards the middle -> squaring f causes lambda to be closer to 1, giving virtualMousePos more weight
// then oldCenter.
double f = Math.Min(newZoom, oldZoom) / Math.Max(newZoom, oldZoom); double lambda = 1 - f * f; if (oldZoom > newZoom) lambda = -lambda;
Debug.Print("old: " + oldZoom + ", new: " + newZoom);
Point newCenter = oldCenter + lambda * (virtualMousePos - oldCenter); scrollOffset = newCenter - newHalfViewport;
SetCurrentValue(CurrentZoomProperty, newZoom);
this.ScrollToHorizontalOffset(scrollOffset.X); this.ScrollToVerticalOffset(scrollOffset.Y);
e.Handled = true; } base.OnPreviewMouseWheel(e); }
internal static double RoundToOneIfClose(double val) { if (Math.Abs(val - 1.0) < 0.001) return 1.0; else return val; } } }
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