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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.
using Windows.Win32.System.Variant;
using Windows.Win32.UI.Accessibility;
using IScrollProvider = Windows.Win32.UI.Accessibility.IScrollProvider;
using ScrollAmount = Windows.Win32.UI.Accessibility.ScrollAmount;
namespace System.Windows.Forms;
public partial class PrintPreviewControl
{
internal sealed class PrintPreviewControlAccessibleObject : ControlAccessibleObject, IScrollProvider.Interface
{
public PrintPreviewControlAccessibleObject(PrintPreviewControl owner) : base(owner)
{
}
internal override VARIANT GetPropertyValue(UIA_PROPERTY_ID propertyID)
=> !this.TryGetOwnerAs(out PrintPreviewControl? owner) ? default : propertyID switch
{
UIA_PROPERTY_ID.UIA_AutomationIdPropertyId => (VARIANT)owner.Name,
UIA_PROPERTY_ID.UIA_HasKeyboardFocusPropertyId => (VARIANT)owner.Focused,
UIA_PROPERTY_ID.UIA_IsKeyboardFocusablePropertyId => (VARIANT)State.HasFlag(AccessibleStates.Focusable),
_ => base.GetPropertyValue(propertyID)
};
public override int GetChildCount()
{
if (!this.TryGetOwnerAs(out PrintPreviewControl? owner))
{
return 0;
}
return owner._vScrollBar.Visible
? owner._hScrollBar.Visible ? 2 : 1
: owner._hScrollBar.Visible ? 1 : 0;
}
public override AccessibleObject? GetChild(int index)
{
if (!this.TryGetOwnerAs(out PrintPreviewControl? owner))
{
return null;
}
return index switch
{
0 => owner._vScrollBar.Visible ? owner._vScrollBar.AccessibilityObject
: owner._hScrollBar.Visible ? owner._hScrollBar.AccessibilityObject : null,
1 => owner._vScrollBar.Visible && owner._hScrollBar.Visible ? owner._hScrollBar.AccessibilityObject : null,
_ => null
};
}
private protected override bool IsInternal => true;
internal override bool IsPatternSupported(UIA_PATTERN_ID patternId)
=> patternId switch
{
UIA_PATTERN_ID.UIA_ScrollPatternId => this.TryGetOwnerAs(out PrintPreviewControl? owner)
&& (owner._vScrollBar.Visible || owner._hScrollBar.Visible),
_ => base.IsPatternSupported(patternId)
};
internal override IRawElementProviderFragmentRoot.Interface FragmentRoot => this;
internal override IRawElementProviderFragment.Interface? FragmentNavigate(NavigateDirection direction)
{
if (!this.TryGetOwnerAs(out PrintPreviewControl? owner))
{
return base.FragmentNavigate(direction);
}
return direction switch
{
NavigateDirection.NavigateDirection_FirstChild
=> owner._vScrollBar.Visible
? owner._vScrollBar.AccessibilityObject
: owner._hScrollBar.Visible
? owner._hScrollBar.AccessibilityObject
: null,
NavigateDirection.NavigateDirection_LastChild
=> owner._hScrollBar.Visible
? owner._hScrollBar.AccessibilityObject
: owner._vScrollBar.Visible
? owner._vScrollBar.AccessibilityObject
: null,
_ => base.FragmentNavigate(direction),
};
}
HRESULT IScrollProvider.Interface.Scroll(ScrollAmount horizontalAmount, ScrollAmount verticalAmount)
{
if (!this.TryGetOwnerAs(out PrintPreviewControl? owner))
{
return HRESULT.E_FAIL;
}
int scrollValue = 0;
if (owner._hScrollBar.Visible && horizontalAmount != ScrollAmount.ScrollAmount_NoAmount)
{
switch (horizontalAmount)
{
case ScrollAmount.ScrollAmount_LargeIncrement:
scrollValue = owner._hScrollBar.Value + owner._hScrollBar.LargeChange;
owner._hScrollBar.Value = (scrollValue > owner._hScrollBar.Maximum ? owner._hScrollBar.Maximum : scrollValue);
break;
case ScrollAmount.ScrollAmount_SmallIncrement:
scrollValue = owner._hScrollBar.Value + owner._hScrollBar.SmallChange;
owner._hScrollBar.Value = (scrollValue > owner._hScrollBar.Maximum ? owner._hScrollBar.Maximum : scrollValue);
break;
case ScrollAmount.ScrollAmount_LargeDecrement:
scrollValue = owner._hScrollBar.Value - owner._hScrollBar.LargeChange;
owner._hScrollBar.Value = (scrollValue < owner._hScrollBar.Minimum ? owner._hScrollBar.Minimum : scrollValue);
break;
case ScrollAmount.ScrollAmount_SmallDecrement:
scrollValue = owner._hScrollBar.Value - owner._hScrollBar.SmallChange;
owner._hScrollBar.Value = (scrollValue < owner._hScrollBar.Minimum ? owner._hScrollBar.Minimum : scrollValue);
break;
}
}
if (owner._vScrollBar.Visible && verticalAmount != ScrollAmount.ScrollAmount_NoAmount)
{
switch (verticalAmount)
{
case ScrollAmount.ScrollAmount_LargeIncrement:
scrollValue = owner._vScrollBar.Value + owner._vScrollBar.LargeChange;
owner._vScrollBar.Value = (scrollValue > owner._vScrollBar.Maximum ? owner._vScrollBar.Maximum : scrollValue);
break;
case ScrollAmount.ScrollAmount_SmallIncrement:
scrollValue = owner._vScrollBar.Value + owner._vScrollBar.SmallChange;
owner._vScrollBar.Value = (scrollValue > owner._vScrollBar.Maximum ? owner._vScrollBar.Maximum : scrollValue);
break;
case ScrollAmount.ScrollAmount_LargeDecrement:
scrollValue = owner._vScrollBar.Value - owner._vScrollBar.LargeChange;
owner._vScrollBar.Value = (scrollValue < owner._vScrollBar.Minimum ? owner._vScrollBar.Minimum : scrollValue);
break;
case ScrollAmount.ScrollAmount_SmallDecrement:
scrollValue = owner._vScrollBar.Value - owner._vScrollBar.SmallChange;
owner._vScrollBar.Value = (scrollValue < owner._vScrollBar.Minimum ? owner._vScrollBar.Minimum : scrollValue);
break;
}
}
return HRESULT.S_OK;
}
HRESULT IScrollProvider.Interface.SetScrollPercent(double horizontalPercent, double verticalPercent)
{
if (!this.TryGetOwnerAs(out PrintPreviewControl? owner))
{
return HRESULT.E_FAIL;
}
int scrollValue = 0;
if (owner._hScrollBar.Visible && horizontalPercent >= 0 && horizontalPercent <= 100)
{
scrollValue = owner._hScrollBar.Minimum + (int)((owner._hScrollBar.Maximum - owner._hScrollBar.Minimum) * horizontalPercent);
owner._hScrollBar.Value = scrollValue;
}
if (owner._vScrollBar.Visible && verticalPercent >= 0 && verticalPercent <= 100)
{
scrollValue = owner._vScrollBar.Minimum + (int)((owner._vScrollBar.Maximum - owner._vScrollBar.Minimum) * verticalPercent);
owner._vScrollBar.Value = scrollValue;
}
return HRESULT.S_OK;
}
public double HorizontalScrollPercent
{
get
{
if (this.TryGetOwnerAs(out PrintPreviewControl? owner) && owner._hScrollBar.Visible)
{
double percent = owner._hScrollBar.Value * 100.0 / (owner._hScrollBar.Maximum - owner._hScrollBar.LargeChange);
return percent > 100 ? 100 : percent;
}
return 0;
}
}
public double VerticalScrollPercent
{
get
{
if (this.TryGetOwnerAs(out PrintPreviewControl? owner) && owner._vScrollBar.Visible)
{
double percent = owner._vScrollBar.Value * 100.0 / (owner._vScrollBar.Maximum - owner._vScrollBar.LargeChange);
return percent > 100 ? 100 : percent;
}
return 0;
}
}
public double HorizontalViewSize => this.TryGetOwnerAs(out PrintPreviewControl? owner)
&& owner._hScrollBar.Visible ? owner.HorizontalViewSize : 100;
public double VerticalViewSize => this.TryGetOwnerAs(out PrintPreviewControl? owner)
&& owner._vScrollBar.Visible ? owner.VerticalViewSize : 100;
BOOL IScrollProvider.Interface.HorizontallyScrollable =>
this.TryGetOwnerAs(out PrintPreviewControl? owner) && owner._hScrollBar.Visible;
BOOL IScrollProvider.Interface.VerticallyScrollable =>
this.TryGetOwnerAs(out PrintPreviewControl? owner) && owner._vScrollBar.Visible;
}
}
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