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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Security;
using System.Text;
using System.Windows;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Interop;
using System.Windows.Media;
using MS.Internal;
using MS.Win32;
namespace System.Windows.Automation.Peers
{
///
public class ScrollViewerAutomationPeer : FrameworkElementAutomationPeer, IScrollProvider
{
///
public ScrollViewerAutomationPeer(ScrollViewer owner): base(owner)
{}
///
override protected string GetClassNameCore()
{
return "ScrollViewer";
}
///
override protected AutomationControlType GetAutomationControlTypeCore()
{
return AutomationControlType.Pane;
}
///
override protected bool IsControlElementCore()
{
// Return false if ScrollViewer is part of a ControlTemplate, otherwise return the base method
ScrollViewer sv = (ScrollViewer)Owner;
DependencyObject templatedParent = sv.TemplatedParent;
// If the templatedParent is a ContentPresenter, this ScrollViewer is generated from a DataTemplate
if (templatedParent == null || templatedParent is ContentPresenter)
{
return base.IsControlElementCore();
}
return false;
}
///
override public object GetPattern(PatternInterface patternInterface)
{
if (patternInterface == PatternInterface.Scroll)
{
return this;
}
else
{
return base.GetPattern(patternInterface);
}
}
//-------------------------------------------------------------------
//
// IScrollProvider
//
//-------------------------------------------------------------------
/// <summary>
/// Request to scroll horizontally and vertically by the specified amount.
/// The ability to call this method and simultaneously scroll horizontally
/// and vertically provides simple panning support.
/// </summary>
/// <see cref="IScrollProvider.Scroll"/>
void IScrollProvider.Scroll(ScrollAmount horizontalAmount, ScrollAmount verticalAmount)
{
if(!IsEnabled())
throw new ElementNotEnabledException();
bool scrollHorizontally = (horizontalAmount != ScrollAmount.NoAmount);
bool scrollVertically = (verticalAmount != ScrollAmount.NoAmount);
ScrollViewer owner = (ScrollViewer)Owner;
if (scrollHorizontally && !HorizontallyScrollable || scrollVertically && !VerticallyScrollable)
{
throw new InvalidOperationException(SR.UIA_OperationCannotBePerformed);
}
switch (horizontalAmount)
{
case ScrollAmount.LargeDecrement:
owner.PageLeft();
break;
case ScrollAmount.SmallDecrement:
owner.LineLeft();
break;
case ScrollAmount.SmallIncrement:
owner.LineRight();
break;
case ScrollAmount.LargeIncrement:
owner.PageRight();
break;
case ScrollAmount.NoAmount:
break;
default:
throw new InvalidOperationException(SR.UIA_OperationCannotBePerformed);
}
switch (verticalAmount)
{
case ScrollAmount.LargeDecrement:
owner.PageUp();
break;
case ScrollAmount.SmallDecrement:
owner.LineUp();
break;
case ScrollAmount.SmallIncrement:
owner.LineDown();
break;
case ScrollAmount.LargeIncrement:
owner.PageDown();
break;
case ScrollAmount.NoAmount:
break;
default:
throw new InvalidOperationException(SR.UIA_OperationCannotBePerformed);
}
}
/// <summary>
/// Request to set the current horizontal and Vertical scroll position by percent (0-100).
/// Passing in the value of "-1", represented by the constant "NoScroll", will indicate that scrolling
/// in that direction should be ignored.
/// The ability to call this method and simultaneously scroll horizontally and vertically provides simple panning support.
/// </summary>
/// <see cref="IScrollProvider.SetScrollPercent"/>
void IScrollProvider.SetScrollPercent(double horizontalPercent, double verticalPercent)
{
if(!IsEnabled())
throw new ElementNotEnabledException();
bool scrollHorizontally = (horizontalPercent != (double)ScrollPatternIdentifiers.NoScroll);
bool scrollVertically = (verticalPercent != (double)ScrollPatternIdentifiers.NoScroll);
ScrollViewer owner = (ScrollViewer)Owner;
if (scrollHorizontally && !HorizontallyScrollable || scrollVertically && !VerticallyScrollable)
{
throw new InvalidOperationException(SR.UIA_OperationCannotBePerformed);
}
if (scrollHorizontally && (horizontalPercent < 0.0) || (horizontalPercent > 100.0))
{
throw new ArgumentOutOfRangeException("horizontalPercent", SR.Format(SR.ScrollViewer_OutOfRange, "horizontalPercent", horizontalPercent.ToString(CultureInfo.InvariantCulture), "0", "100"));
}
if (scrollVertically && (verticalPercent < 0.0) || (verticalPercent > 100.0))
{
throw new ArgumentOutOfRangeException("verticalPercent", SR.Format(SR.ScrollViewer_OutOfRange, "verticalPercent", verticalPercent.ToString(CultureInfo.InvariantCulture), "0", "100"));
}
if (scrollHorizontally)
{
owner.ScrollToHorizontalOffset((owner.ExtentWidth - owner.ViewportWidth) * (double)horizontalPercent * 0.01);
}
if (scrollVertically)
{
owner.ScrollToVerticalOffset((owner.ExtentHeight - owner.ViewportHeight) * (double)verticalPercent * 0.01);
}
}
/// <summary>
/// Get the current horizontal scroll position
/// </summary>
/// <see cref="IScrollProvider.HorizontalScrollPercent"/>
double IScrollProvider.HorizontalScrollPercent
{
get
{
if (!HorizontallyScrollable) { return ScrollPatternIdentifiers.NoScroll; }
ScrollViewer owner = (ScrollViewer)Owner;
return (double)(owner.HorizontalOffset * 100.0 / (owner.ExtentWidth - owner.ViewportWidth));
}
}
/// <summary>
/// Get the current vertical scroll position
/// </summary>
/// <see cref="IScrollProvider.VerticalScrollPercent"/>
double IScrollProvider.VerticalScrollPercent
{
get
{
if (!VerticallyScrollable) { return ScrollPatternIdentifiers.NoScroll; }
ScrollViewer owner = (ScrollViewer)Owner;
return (double)(owner.VerticalOffset * 100.0 / (owner.ExtentHeight - owner.ViewportHeight));
}
}
/// <summary>
/// Equal to the horizontal percentage of the entire control that is currently viewable.
/// </summary>
/// <see cref="IScrollProvider.HorizontalViewSize"/>
double IScrollProvider.HorizontalViewSize
{
get
{
ScrollViewer owner = (ScrollViewer)Owner;
if (owner.ScrollInfo == null || DoubleUtil.IsZero(owner.ExtentWidth)) { return 100.0; }
return Math.Min(100.0, (double)(owner.ViewportWidth * 100.0 / owner.ExtentWidth));
}
}
/// <summary>
/// Equal to the vertical percentage of the entire control that is currently viewable.
/// </summary>
/// <see cref="IScrollProvider.VerticalViewSize"/>
double IScrollProvider.VerticalViewSize
{
get
{
ScrollViewer owner = (ScrollViewer)Owner;
if (owner.ScrollInfo == null || DoubleUtil.IsZero(owner.ExtentHeight)) { return 100f; }
return Math.Min(100.0, (double)(owner.ViewportHeight * 100.0 / owner.ExtentHeight));
}
}
/// <summary>
/// True if control can scroll horizontally
/// </summary>
/// <see cref="IScrollProvider.HorizontallyScrollable"/>
bool IScrollProvider.HorizontallyScrollable
{
get { return HorizontallyScrollable; }
}
/// <summary>
/// True if control can scroll vertically
/// </summary>
/// <see cref="IScrollProvider.VerticallyScrollable"/>
bool IScrollProvider.VerticallyScrollable
{
get { return VerticallyScrollable; }
}
private static bool AutomationIsScrollable(double extent, double viewport)
{
return DoubleUtil.GreaterThan(extent, viewport);
}
private static double AutomationGetScrollPercent(double extent, double viewport, double actualOffset)
{
if (!AutomationIsScrollable(extent, viewport)) { return ScrollPatternIdentifiers.NoScroll; }
return (double)(actualOffset * 100.0 / (extent - viewport));
}
private static double AutomationGetViewSize(double extent, double viewport)
{
if (DoubleUtil.IsZero(extent)) { return 100.0; }
return Math.Min(100.0, (double)(viewport * 100.0 / extent));
}
// Private *Scrollable properties used to determine scrollability for IScrollProvider implemenation.
private bool HorizontallyScrollable
{
get
{
ScrollViewer owner = (ScrollViewer)Owner;
return owner.ScrollInfo != null && DoubleUtil.GreaterThan(owner.ExtentWidth, owner.ViewportWidth);
}
}
private bool VerticallyScrollable
{
get
{
ScrollViewer owner = (ScrollViewer)Owner;
return owner.ScrollInfo != null && DoubleUtil.GreaterThan(owner.ExtentHeight, owner.ViewportHeight);
}
}
// This helper synchronously fires automation PropertyChange events for every IScrollProvider property that has changed.
// BUG 1555137: Never inline, as we don't want to unnecessarily link the automation DLL
[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
internal void RaiseAutomationEvents(double extentX,
double extentY,
double viewportX,
double viewportY,
double offsetX,
double offsetY)
{
IScrollProvider isp = (IScrollProvider)this;
if (AutomationIsScrollable(extentX, viewportX) != isp.HorizontallyScrollable)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.HorizontallyScrollableProperty,
AutomationIsScrollable(extentX, viewportX),
isp.HorizontallyScrollable);
}
if (AutomationIsScrollable(extentY, viewportY) != isp.VerticallyScrollable)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.VerticallyScrollableProperty,
AutomationIsScrollable(extentY, viewportY),
isp.VerticallyScrollable);
}
if (AutomationGetViewSize(extentX, viewportX) != isp.HorizontalViewSize)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.HorizontalViewSizeProperty,
AutomationGetViewSize(extentX, viewportX),
isp.HorizontalViewSize);
}
if (AutomationGetViewSize(extentY, viewportY) != isp.VerticalViewSize)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.VerticalViewSizeProperty,
AutomationGetViewSize(extentY, viewportY),
isp.VerticalViewSize);
}
if (AutomationGetScrollPercent(extentX, viewportX, offsetX) != isp.HorizontalScrollPercent)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.HorizontalScrollPercentProperty,
AutomationGetScrollPercent(extentX, viewportX, offsetX),
isp.HorizontalScrollPercent);
}
if (AutomationGetScrollPercent(extentY, viewportY, offsetY) != isp.VerticalScrollPercent)
{
RaisePropertyChangedEvent(
ScrollPatternIdentifiers.VerticalScrollPercentProperty,
AutomationGetScrollPercent(extentY, viewportY, offsetY),
isp.VerticalScrollPercent);
}
}
}
}
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