735 lines
28 KiB
C#
735 lines
28 KiB
C#
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using System;
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using System.Collections.Specialized;
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using System.ComponentModel;
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using System.Windows;
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using System.Windows.Controls;
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using System.Windows.Controls.Primitives;
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using System.Windows.Media;
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namespace MediaBrowser.UI.Controls
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{
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/// <summary>
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/// http://www.codeproject.com/Articles/75847/Virtualizing-WrapPanel
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/// Positions child elements in sequential position from left to right, breaking content
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/// to the next line at the edge of the containing box. Subsequent ordering happens
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/// sequentially from top to bottom or from right to left, depending on the value of
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/// the Orientation property.
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/// </summary>
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[DefaultProperty("Orientation")]
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public class VirtualizingWrapPanel : VirtualizingPanel, IScrollInfo
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{
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/// <summary>
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/// Identifies the ItemHeight dependency property.
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/// </summary>
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public static readonly DependencyProperty ItemHeightProperty = DependencyProperty.Register("ItemHeight", typeof(double), typeof(VirtualizingWrapPanel), new PropertyMetadata(100.0, new PropertyChangedCallback(VirtualizingWrapPanel.OnAppearancePropertyChanged)));
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/// <summary>
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/// Identifies the Orientation dependency property.
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/// </summary>
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public static readonly DependencyProperty OrientationProperty = DependencyProperty.Register("Orientation", typeof(Orientation), typeof(VirtualizingWrapPanel), new PropertyMetadata(Orientation.Horizontal, new PropertyChangedCallback(VirtualizingWrapPanel.OnAppearancePropertyChanged)));
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/// <summary>
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/// Identifies the ItemWidth dependency property.
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/// </summary>
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public static readonly DependencyProperty ItemWidthProperty = DependencyProperty.Register("ItemWidth", typeof(double), typeof(VirtualizingWrapPanel), new PropertyMetadata(100.0, new PropertyChangedCallback(VirtualizingWrapPanel.OnAppearancePropertyChanged)));
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/// <summary>
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/// Identifies the ScrollStep dependency property.
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/// </summary>
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public static readonly DependencyProperty ScrollStepProperty = DependencyProperty.Register("ScrollStep", typeof(double), typeof(VirtualizingWrapPanel), new PropertyMetadata(10.0, new PropertyChangedCallback(VirtualizingWrapPanel.OnAppearancePropertyChanged)));
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private bool canHorizontallyScroll;
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private bool canVerticallyScroll;
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private Size contentExtent = new Size(0.0, 0.0);
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private Point contentOffset = default(Point);
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private ScrollViewer scrollOwner;
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private Size viewport = new Size(0.0, 0.0);
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private int previousItemCount;
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/// <summary>
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/// Gets or sets a value that specifies the height of all items that are
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/// contained within a VirtualizingWrapPanel. This is a dependency property.
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/// </summary>
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public double ItemHeight
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{
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get
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{
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return (double)base.GetValue(VirtualizingWrapPanel.ItemHeightProperty);
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}
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set
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{
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base.SetValue(VirtualizingWrapPanel.ItemHeightProperty, value);
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}
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}
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/// <summary>
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/// Gets or sets a value that specifies the width of all items that are
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/// contained within a VirtualizingWrapPanel. This is a dependency property.
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/// </summary>
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public double ItemWidth
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{
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get
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{
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return (double)base.GetValue(VirtualizingWrapPanel.ItemWidthProperty);
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}
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set
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{
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base.SetValue(VirtualizingWrapPanel.ItemWidthProperty, value);
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}
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}
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/// <summary>
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/// Gets or sets a value that specifies the dimension in which child
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/// content is arranged. This is a dependency property.
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/// </summary>
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public Orientation Orientation
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{
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get
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{
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return (Orientation)base.GetValue(VirtualizingWrapPanel.OrientationProperty);
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}
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set
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{
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base.SetValue(VirtualizingWrapPanel.OrientationProperty, value);
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}
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}
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/// <summary>
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/// Gets or sets a value that indicates whether scrolling on the horizontal axis is possible.
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/// </summary>
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public bool CanHorizontallyScroll
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{
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get
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{
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return this.canHorizontallyScroll;
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}
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set
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{
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if (this.canHorizontallyScroll != value)
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{
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this.canHorizontallyScroll = value;
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base.InvalidateMeasure();
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}
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}
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}
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/// <summary>
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/// Gets or sets a value that indicates whether scrolling on the vertical axis is possible.
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/// </summary>
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public bool CanVerticallyScroll
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{
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get
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{
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return this.canVerticallyScroll;
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}
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set
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{
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if (this.canVerticallyScroll != value)
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{
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this.canVerticallyScroll = value;
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base.InvalidateMeasure();
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}
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}
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}
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/// <summary>
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/// Gets or sets a ScrollViewer element that controls scrolling behavior.
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/// </summary>
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public ScrollViewer ScrollOwner
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{
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get
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{
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return this.scrollOwner;
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}
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set
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{
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this.scrollOwner = value;
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}
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}
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/// <summary>
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/// Gets the vertical offset of the scrolled content.
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/// </summary>
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public double VerticalOffset
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{
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get
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{
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return this.contentOffset.Y;
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}
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}
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/// <summary>
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/// Gets the vertical size of the viewport for this content.
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/// </summary>
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public double ViewportHeight
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{
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get
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{
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return this.viewport.Height;
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}
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}
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/// <summary>
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/// Gets the horizontal size of the viewport for this content.
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/// </summary>
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public double ViewportWidth
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{
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get
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{
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return this.viewport.Width;
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}
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}
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/// <summary>
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/// Gets or sets a value for mouse wheel scroll step.
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/// </summary>
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public double ScrollStep
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{
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get
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{
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return (double)base.GetValue(VirtualizingWrapPanel.ScrollStepProperty);
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}
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set
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{
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base.SetValue(VirtualizingWrapPanel.ScrollStepProperty, value);
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}
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}
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/// <summary>
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/// Gets the vertical size of the extent.
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/// </summary>
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public double ExtentHeight
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{
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get
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{
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return this.contentExtent.Height;
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}
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}
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/// <summary>
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/// Gets the horizontal size of the extent.
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/// </summary>
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public double ExtentWidth
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{
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get
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{
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return this.contentExtent.Width;
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}
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}
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/// <summary>
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/// Gets the horizontal offset of the scrolled content.
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/// </summary>
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public double HorizontalOffset
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{
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get
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{
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return this.contentOffset.X;
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}
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}
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/// <summary>
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/// Scrolls down within content by one logical unit.
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/// </summary>
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public void LineDown()
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{
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this.SetVerticalOffset(this.VerticalOffset + this.ScrollStep);
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}
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/// <summary>
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/// Scrolls left within content by one logical unit.
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/// </summary>
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public void LineLeft()
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{
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this.SetHorizontalOffset(this.HorizontalOffset - this.ScrollStep);
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}
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/// <summary>
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/// Scrolls right within content by one logical unit.
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/// </summary>
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public void LineRight()
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{
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this.SetHorizontalOffset(this.HorizontalOffset + this.ScrollStep);
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}
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/// <summary>
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/// Scrolls up within content by one logical unit.
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/// </summary>
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public void LineUp()
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{
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this.SetVerticalOffset(this.VerticalOffset - this.ScrollStep);
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}
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/// <summary>
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/// Forces content to scroll until the coordinate space of a Visual object is visible.
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/// </summary>
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public Rect MakeVisible(Visual visual, Rect rectangle)
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{
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this.MakeVisible(visual as UIElement);
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return rectangle;
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}
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/// <summary>
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/// Scrolls down within content after a user clicks the wheel button on a mouse.
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/// </summary>
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public void MouseWheelDown()
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{
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this.SetVerticalOffset(this.VerticalOffset + this.ScrollStep);
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}
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/// <summary>
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/// Scrolls left within content after a user clicks the wheel button on a mouse.
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/// </summary>
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public void MouseWheelLeft()
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{
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this.SetHorizontalOffset(this.HorizontalOffset - this.ScrollStep);
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}
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/// <summary>
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/// Scrolls right within content after a user clicks the wheel button on a mouse.
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/// </summary>
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public void MouseWheelRight()
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{
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this.SetHorizontalOffset(this.HorizontalOffset + this.ScrollStep);
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}
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/// <summary>
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/// Scrolls up within content after a user clicks the wheel button on a mouse.
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/// </summary>
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public void MouseWheelUp()
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{
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this.SetVerticalOffset(this.VerticalOffset - this.ScrollStep);
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}
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/// <summary>
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/// Scrolls down within content by one page.
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/// </summary>
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public void PageDown()
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{
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this.SetVerticalOffset(this.VerticalOffset + this.ViewportHeight);
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}
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/// <summary>
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/// Scrolls left within content by one page.
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/// </summary>
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public void PageLeft()
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{
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this.SetHorizontalOffset(this.HorizontalOffset - this.ViewportHeight);
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}
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/// <summary>
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/// Scrolls right within content by one page.
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/// </summary>
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public void PageRight()
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{
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this.SetHorizontalOffset(this.HorizontalOffset + this.ViewportHeight);
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}
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/// <summary>
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/// Scrolls up within content by one page.
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/// </summary>
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public void PageUp()
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{
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this.SetVerticalOffset(this.VerticalOffset - this.viewport.Height);
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}
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/// <summary>
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/// Sets the amount of vertical offset.
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/// </summary>
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public void SetVerticalOffset(double offset)
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{
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if (offset < 0.0 || this.ViewportHeight >= this.ExtentHeight)
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{
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offset = 0.0;
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}
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else
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{
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if (offset + this.ViewportHeight >= this.ExtentHeight)
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{
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offset = this.ExtentHeight - this.ViewportHeight;
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}
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}
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this.contentOffset.Y = offset;
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if (this.ScrollOwner != null)
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{
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this.ScrollOwner.InvalidateScrollInfo();
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}
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base.InvalidateMeasure();
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}
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/// <summary>
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/// Sets the amount of horizontal offset.
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/// </summary>
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public void SetHorizontalOffset(double offset)
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{
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if (offset < 0.0 || this.ViewportWidth >= this.ExtentWidth)
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{
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offset = 0.0;
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}
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else
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{
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if (offset + this.ViewportWidth >= this.ExtentWidth)
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{
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offset = this.ExtentWidth - this.ViewportWidth;
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}
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}
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this.contentOffset.X = offset;
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if (this.ScrollOwner != null)
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{
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this.ScrollOwner.InvalidateScrollInfo();
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}
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base.InvalidateMeasure();
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}
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/// <summary>
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/// Note: Works only for vertical.
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/// </summary>
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internal void PageLast()
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{
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this.contentOffset.Y = this.ExtentHeight;
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if (this.ScrollOwner != null)
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{
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this.ScrollOwner.InvalidateScrollInfo();
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}
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base.InvalidateMeasure();
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}
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/// <summary>
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/// Note: Works only for vertical.
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/// </summary>
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internal void PageFirst()
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{
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this.contentOffset.Y = 0.0;
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if (this.ScrollOwner != null)
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{
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this.ScrollOwner.InvalidateScrollInfo();
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}
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base.InvalidateMeasure();
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}
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/// <summary>
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/// When items are removed, remove the corresponding UI if necessary.
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/// </summary>
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/// <param name="sender"></param>
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/// <param name="args"></param>
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protected override void OnItemsChanged(object sender, ItemsChangedEventArgs args)
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{
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switch (args.Action)
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{
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case NotifyCollectionChangedAction.Remove:
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case NotifyCollectionChangedAction.Replace:
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case NotifyCollectionChangedAction.Move:
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base.RemoveInternalChildRange(args.Position.Index, args.ItemUICount);
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return;
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case NotifyCollectionChangedAction.Reset:
|
|||
|
|
{
|
|||
|
|
ItemsControl itemsControl = ItemsControl.GetItemsOwner(this);
|
|||
|
|
if (itemsControl != null)
|
|||
|
|
{
|
|||
|
|
if (this.previousItemCount != itemsControl.Items.Count)
|
|||
|
|
{
|
|||
|
|
if (this.Orientation == Orientation.Horizontal)
|
|||
|
|
{
|
|||
|
|
this.SetVerticalOffset(0.0);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
this.SetHorizontalOffset(0.0);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
this.previousItemCount = itemsControl.Items.Count;
|
|||
|
|
}
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
default:
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
/// <summary>
|
|||
|
|
/// Measure the children.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="availableSize">The available size.</param>
|
|||
|
|
/// <returns>The desired size.</returns>
|
|||
|
|
protected override Size MeasureOverride(Size availableSize)
|
|||
|
|
{
|
|||
|
|
this.InvalidateScrollInfo(availableSize);
|
|||
|
|
int firstVisibleIndex;
|
|||
|
|
int lastVisibleIndex;
|
|||
|
|
if (this.Orientation == Orientation.Horizontal)
|
|||
|
|
{
|
|||
|
|
this.GetVerticalVisibleRange(out firstVisibleIndex, out lastVisibleIndex);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
this.GetHorizontalVisibleRange(out firstVisibleIndex, out lastVisibleIndex);
|
|||
|
|
}
|
|||
|
|
UIElementCollection children = base.Children;
|
|||
|
|
IItemContainerGenerator generator = base.ItemContainerGenerator;
|
|||
|
|
if (generator != null)
|
|||
|
|
{
|
|||
|
|
GeneratorPosition startPos = generator.GeneratorPositionFromIndex(firstVisibleIndex);
|
|||
|
|
int childIndex = (startPos.Offset == 0) ? startPos.Index : (startPos.Index + 1);
|
|||
|
|
if (childIndex == -1)
|
|||
|
|
{
|
|||
|
|
this.RefreshOffset();
|
|||
|
|
}
|
|||
|
|
using (generator.StartAt(startPos, GeneratorDirection.Forward, true))
|
|||
|
|
{
|
|||
|
|
int itemIndex = firstVisibleIndex;
|
|||
|
|
while (itemIndex <= lastVisibleIndex)
|
|||
|
|
{
|
|||
|
|
bool newlyRealized;
|
|||
|
|
UIElement child = generator.GenerateNext(out newlyRealized) as UIElement;
|
|||
|
|
if (newlyRealized)
|
|||
|
|
{
|
|||
|
|
if (childIndex >= children.Count)
|
|||
|
|
{
|
|||
|
|
base.AddInternalChild(child);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
base.InsertInternalChild(childIndex, child);
|
|||
|
|
}
|
|||
|
|
generator.PrepareItemContainer(child);
|
|||
|
|
}
|
|||
|
|
if (child != null)
|
|||
|
|
{
|
|||
|
|
child.Measure(new Size(this.ItemWidth, this.ItemHeight));
|
|||
|
|
}
|
|||
|
|
itemIndex++;
|
|||
|
|
childIndex++;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
this.CleanUpChildren(firstVisibleIndex, lastVisibleIndex);
|
|||
|
|
}
|
|||
|
|
if (IsCloseTo(availableSize.Height, double.PositiveInfinity) || IsCloseTo(availableSize.Width, double.PositiveInfinity))
|
|||
|
|
{
|
|||
|
|
return base.MeasureOverride(availableSize);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
var itemsControl = ItemsControl.GetItemsOwner(this);
|
|||
|
|
var numItems = itemsControl.Items.Count;
|
|||
|
|
|
|||
|
|
var width = availableSize.Width;
|
|||
|
|
var height = availableSize.Height;
|
|||
|
|
|
|||
|
|
if (Orientation == Orientation.Vertical)
|
|||
|
|
{
|
|||
|
|
var numRows = Math.Floor(availableSize.Height / ItemHeight);
|
|||
|
|
|
|||
|
|
height = numRows * ItemHeight;
|
|||
|
|
|
|||
|
|
var requiredColumns = Math.Ceiling(numItems / numRows);
|
|||
|
|
|
|||
|
|
width = Math.Min(requiredColumns * ItemWidth, width);
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
var numColumns = Math.Floor(availableSize.Width / ItemWidth);
|
|||
|
|
|
|||
|
|
width = numColumns * ItemWidth;
|
|||
|
|
|
|||
|
|
//if (numItems > 0 && numItems < numColumns)
|
|||
|
|
//{
|
|||
|
|
// width = Math.Min(numColumns, numItems) * ItemWidth;
|
|||
|
|
//}
|
|||
|
|
|
|||
|
|
var requiredRows = Math.Ceiling(numItems / numColumns);
|
|||
|
|
|
|||
|
|
height = Math.Min(requiredRows * ItemHeight, height);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return new Size(width, height);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// <summary>
|
|||
|
|
/// Arranges the children.
|
|||
|
|
/// </summary>
|
|||
|
|
/// <param name="finalSize">The available size.</param>
|
|||
|
|
/// <returns>The used size.</returns>
|
|||
|
|
protected override Size ArrangeOverride(Size finalSize)
|
|||
|
|
{
|
|||
|
|
bool isHorizontal = this.Orientation == Orientation.Horizontal;
|
|||
|
|
this.InvalidateScrollInfo(finalSize);
|
|||
|
|
int i = 0;
|
|||
|
|
foreach (object item in base.Children)
|
|||
|
|
{
|
|||
|
|
this.ArrangeChild(isHorizontal, finalSize, i++, item as UIElement);
|
|||
|
|
}
|
|||
|
|
return finalSize;
|
|||
|
|
}
|
|||
|
|
private static void OnAppearancePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
|
|||
|
|
{
|
|||
|
|
UIElement panel = d as UIElement;
|
|||
|
|
if (panel != null)
|
|||
|
|
{
|
|||
|
|
panel.InvalidateMeasure();
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private void MakeVisible(UIElement element)
|
|||
|
|
{
|
|||
|
|
ItemContainerGenerator generator = base.ItemContainerGenerator.GetItemContainerGeneratorForPanel(this);
|
|||
|
|
if (element != null && generator != null)
|
|||
|
|
{
|
|||
|
|
for (int itemIndex = generator.IndexFromContainer(element); itemIndex == -1; itemIndex = generator.IndexFromContainer(element))
|
|||
|
|
{
|
|||
|
|
element = element.ParentOfType<UIElement>();
|
|||
|
|
}
|
|||
|
|
ScrollViewer scrollViewer = element.ParentOfType<ScrollViewer>();
|
|||
|
|
if (scrollViewer != null)
|
|||
|
|
{
|
|||
|
|
GeneralTransform elementTransform = element.TransformToVisual(scrollViewer);
|
|||
|
|
Rect elementRectangle = elementTransform.TransformBounds(new Rect(new Point(0.0, 0.0), element.RenderSize));
|
|||
|
|
|
|||
|
|
if (this.Orientation == Orientation.Horizontal)
|
|||
|
|
{
|
|||
|
|
var padding = ItemHeight / 3;
|
|||
|
|
|
|||
|
|
if (elementRectangle.Bottom > this.ViewportHeight)
|
|||
|
|
{
|
|||
|
|
this.SetVerticalOffset(this.contentOffset.Y + elementRectangle.Bottom - this.ViewportHeight + padding);
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
if (elementRectangle.Top < 0.0)
|
|||
|
|
{
|
|||
|
|
this.SetVerticalOffset(this.contentOffset.Y + elementRectangle.Top - padding);
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
var padding = ItemWidth / 3;
|
|||
|
|
|
|||
|
|
if (elementRectangle.Right > this.ViewportWidth)
|
|||
|
|
{
|
|||
|
|
this.SetHorizontalOffset(this.contentOffset.X + elementRectangle.Right - this.ViewportWidth + padding);
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
if (elementRectangle.Left < 0.0)
|
|||
|
|
{
|
|||
|
|
this.SetHorizontalOffset(this.contentOffset.X + elementRectangle.Left - padding);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private void GetVerticalVisibleRange(out int firstVisibleItemIndex, out int lastVisibleItemIndex)
|
|||
|
|
{
|
|||
|
|
int childrenPerRow = this.GetVerticalChildrenCountPerRow(this.contentExtent);
|
|||
|
|
firstVisibleItemIndex = (int)Math.Floor(this.VerticalOffset / this.ItemHeight) * childrenPerRow;
|
|||
|
|
lastVisibleItemIndex = (int)Math.Ceiling((this.VerticalOffset + this.ViewportHeight) / this.ItemHeight) * childrenPerRow - 1;
|
|||
|
|
this.AdjustVisibleRange(ref firstVisibleItemIndex, ref lastVisibleItemIndex);
|
|||
|
|
}
|
|||
|
|
private void GetHorizontalVisibleRange(out int firstVisibleItemIndex, out int lastVisibleItemIndex)
|
|||
|
|
{
|
|||
|
|
int childrenPerRow = this.GetHorizontalChildrenCountPerRow(this.contentExtent);
|
|||
|
|
firstVisibleItemIndex = (int)Math.Floor(this.HorizontalOffset / this.ItemWidth) * childrenPerRow;
|
|||
|
|
lastVisibleItemIndex = (int)Math.Ceiling((this.HorizontalOffset + this.ViewportWidth) / this.ItemWidth) * childrenPerRow - 1;
|
|||
|
|
this.AdjustVisibleRange(ref firstVisibleItemIndex, ref lastVisibleItemIndex);
|
|||
|
|
}
|
|||
|
|
private void AdjustVisibleRange(ref int firstVisibleItemIndex, ref int lastVisibleItemIndex)
|
|||
|
|
{
|
|||
|
|
firstVisibleItemIndex--;
|
|||
|
|
lastVisibleItemIndex++;
|
|||
|
|
ItemsControl itemsControl = ItemsControl.GetItemsOwner(this);
|
|||
|
|
if (itemsControl != null)
|
|||
|
|
{
|
|||
|
|
if (firstVisibleItemIndex < 0)
|
|||
|
|
{
|
|||
|
|
firstVisibleItemIndex = 0;
|
|||
|
|
}
|
|||
|
|
if (lastVisibleItemIndex >= itemsControl.Items.Count)
|
|||
|
|
{
|
|||
|
|
lastVisibleItemIndex = itemsControl.Items.Count - 1;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private void CleanUpChildren(int minIndex, int maxIndex)
|
|||
|
|
{
|
|||
|
|
UIElementCollection children = base.Children;
|
|||
|
|
IItemContainerGenerator generator = base.ItemContainerGenerator;
|
|||
|
|
for (int i = children.Count - 1; i >= 0; i--)
|
|||
|
|
{
|
|||
|
|
GeneratorPosition pos = new GeneratorPosition(i, 0);
|
|||
|
|
int itemIndex = generator.IndexFromGeneratorPosition(pos);
|
|||
|
|
if (itemIndex < minIndex || itemIndex > maxIndex)
|
|||
|
|
{
|
|||
|
|
generator.Remove(pos, 1);
|
|||
|
|
base.RemoveInternalChildRange(i, 1);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private void ArrangeChild(bool isHorizontal, Size finalSize, int index, UIElement child)
|
|||
|
|
{
|
|||
|
|
if (child == null)
|
|||
|
|
{
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
int count = isHorizontal ? this.GetVerticalChildrenCountPerRow(finalSize) : this.GetHorizontalChildrenCountPerRow(finalSize);
|
|||
|
|
int itemIndex = base.ItemContainerGenerator.IndexFromGeneratorPosition(new GeneratorPosition(index, 0));
|
|||
|
|
int row = isHorizontal ? (itemIndex / count) : (itemIndex % count);
|
|||
|
|
int column = isHorizontal ? (itemIndex % count) : (itemIndex / count);
|
|||
|
|
Rect rect = new Rect((double)column * this.ItemWidth, (double)row * this.ItemHeight, this.ItemWidth, this.ItemHeight);
|
|||
|
|
if (isHorizontal)
|
|||
|
|
{
|
|||
|
|
rect.Y -= this.VerticalOffset;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
rect.X -= this.HorizontalOffset;
|
|||
|
|
}
|
|||
|
|
child.Arrange(rect);
|
|||
|
|
}
|
|||
|
|
private void InvalidateScrollInfo(Size availableSize)
|
|||
|
|
{
|
|||
|
|
ItemsControl ownerItemsControl = ItemsControl.GetItemsOwner(this);
|
|||
|
|
if (ownerItemsControl != null)
|
|||
|
|
{
|
|||
|
|
Size extent = this.GetExtent(availableSize, ownerItemsControl.Items.Count);
|
|||
|
|
if (extent != this.contentExtent)
|
|||
|
|
{
|
|||
|
|
this.contentExtent = extent;
|
|||
|
|
this.RefreshOffset();
|
|||
|
|
}
|
|||
|
|
if (availableSize != this.viewport)
|
|||
|
|
{
|
|||
|
|
this.viewport = availableSize;
|
|||
|
|
this.InvalidateScrollOwner();
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private void RefreshOffset()
|
|||
|
|
{
|
|||
|
|
if (this.Orientation == Orientation.Horizontal)
|
|||
|
|
{
|
|||
|
|
this.SetVerticalOffset(this.VerticalOffset);
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
this.SetHorizontalOffset(this.HorizontalOffset);
|
|||
|
|
}
|
|||
|
|
private void InvalidateScrollOwner()
|
|||
|
|
{
|
|||
|
|
if (this.ScrollOwner != null)
|
|||
|
|
{
|
|||
|
|
this.ScrollOwner.InvalidateScrollInfo();
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
private Size GetExtent(Size availableSize, int itemCount)
|
|||
|
|
{
|
|||
|
|
if (this.Orientation == Orientation.Horizontal)
|
|||
|
|
{
|
|||
|
|
int childrenPerRow = this.GetVerticalChildrenCountPerRow(availableSize);
|
|||
|
|
return new Size((double)childrenPerRow * this.ItemWidth, this.ItemHeight * Math.Ceiling((double)itemCount / (double)childrenPerRow));
|
|||
|
|
}
|
|||
|
|
int childrenPerRow2 = this.GetHorizontalChildrenCountPerRow(availableSize);
|
|||
|
|
return new Size(this.ItemWidth * Math.Ceiling((double)itemCount / (double)childrenPerRow2), (double)childrenPerRow2 * this.ItemHeight);
|
|||
|
|
}
|
|||
|
|
private int GetVerticalChildrenCountPerRow(Size availableSize)
|
|||
|
|
{
|
|||
|
|
int childrenCountPerRow;
|
|||
|
|
if (availableSize.Width == double.PositiveInfinity)
|
|||
|
|
{
|
|||
|
|
childrenCountPerRow = base.Children.Count;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
childrenCountPerRow = Math.Max(1, (int)Math.Floor(availableSize.Width / this.ItemWidth));
|
|||
|
|
}
|
|||
|
|
return childrenCountPerRow;
|
|||
|
|
}
|
|||
|
|
private int GetHorizontalChildrenCountPerRow(Size availableSize)
|
|||
|
|
{
|
|||
|
|
int childrenCountPerRow;
|
|||
|
|
if (availableSize.Height == double.PositiveInfinity)
|
|||
|
|
{
|
|||
|
|
childrenCountPerRow = base.Children.Count;
|
|||
|
|
}
|
|||
|
|
else
|
|||
|
|
{
|
|||
|
|
childrenCountPerRow = Math.Max(1, (int)Math.Floor(availableSize.Height / this.ItemHeight));
|
|||
|
|
}
|
|||
|
|
return childrenCountPerRow;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
private static bool IsCloseTo(double value1, double value2)
|
|||
|
|
{
|
|||
|
|
return AreClose(value1, value2);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
private static bool AreClose(double value1, double value2)
|
|||
|
|
{
|
|||
|
|
if (value1 == value2)
|
|||
|
|
{
|
|||
|
|
return true;
|
|||
|
|
}
|
|||
|
|
double num = (Math.Abs(value1) + Math.Abs(value2) + 10.0) * 2.2204460492503131E-16;
|
|||
|
|
double num2 = value1 - value2;
|
|||
|
|
return -num < num2 && num > num2;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|