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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.
// Description: Class to provide scroll bars for listview
//
using System;
using System.Runtime.InteropServices;
using System.Windows.Automation;
using System.Windows.Automation.Provider;
using MS.Win32;
namespace MS.Internal.AutomationProxies
{
// The default implementation for scroll bars uses SB_THUMBTRACK and SB_THUMBPOSITION for SetValue
// This does not work with listview so the Scrollbar is overloaded with a derived version that
// uses LVM_SCROLL messages instead
class WindowsListViewScrollBar: WindowsScrollBar, IRangeValueProvider
{
// ------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
internal WindowsListViewScrollBar(IntPtr hwnd, ProxyFragment parent, int item, int sbFlag)
: base( hwnd, parent, item, sbFlag){}
#endregion Constructors
//------------------------------------------------------
//
// Patterns Implementation
//
//------------------------------------------------------
#region RangeValue Pattern
void IRangeValueProvider.SetValue(double val)
{
// Check if the window is disabled
if (!SafeNativeMethods.IsWindowEnabled (_hwnd))
{
throw new ElementNotEnabledException();
}
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.fMask = NativeMethods.SIF_ALL;
si.cbSize = Marshal.SizeOf (si.GetType ());
if (!Misc.GetScrollInfo(_hwnd, _sbFlag, ref si))
{
return;
}
int pos = (int)val;
// Throw if val is greater than the maximum or less than the minimum.
// See remarks for WindowsScrollBar.GetScrollValue(ScrollBarInfo.MaximumPosition)
// regarding this calculation of the allowed maximum.
if (pos > si.nMax - si.nPage + (si.nPage > 0 ? 1 : 0))
{
throw new ArgumentOutOfRangeException("value", val, SR.RangeValueMax);
}
else if (pos < si.nMin)
{
throw new ArgumentOutOfRangeException("value", val, SR.RangeValueMin);
}
// LVM_SCROLL does not work in mode Report, use SetScrollPos instead
bool isVerticalScroll = IsScrollBarVertical(_hwnd, _sbFlag);
if (isVerticalScroll && WindowsListView.InReportView (_hwnd))
{
Misc.SetScrollPos(_hwnd, _sbFlag, pos, true);
return;
}
// get the "full size" of the list-view
int size = WindowsListView.ApproximateViewRect (_hwnd);
// delta between current and user-requested position in pixels
// since the cPelsAll contains the dimension in pels for all items + the 2 pels of the border
// the operation below does a trunc on purpose
int dx = 0, dy = 0;
if (!isVerticalScroll)
{
int cPelsAll = NativeMethods.Util.LOWORD (size);
dx = (int)((pos - si.nPos) * ((double)cPelsAll / (si.nMax + 1 - si.nMin)));
}
else
{
int cPelsAll = NativeMethods.Util.HIWORD (size);
dy = (int)((pos - si.nPos) * ((double)cPelsAll / (si.nMax + 1 - si.nMin)));
}
if (WindowsListView.Scroll (_hwnd, (IntPtr) dx, (IntPtr) dy))
{
// Check the result again, on occasion the result will be different than the value
// we previously got. It's unsure why this is, but for now we'll just reissue the
// scroll command with the new delta.
if (!Misc.GetScrollInfo(_hwnd, _sbFlag, ref si))
{
return;
}
if (si.nPos != pos)
{
if (!isVerticalScroll)
{
int cPelsAll = NativeMethods.Util.LOWORD (size);
dx = (pos - si.nPos) * (cPelsAll / (si.nMax + 1 - si.nMin));
}
else
{
int cPelsAll = NativeMethods.Util.HIWORD (size);
dy = (pos - si.nPos) * (cPelsAll / (si.nMax + 1 - si.nMin));
}
WindowsListView.Scroll (_hwnd, (IntPtr) dx, (IntPtr) dy);
}
}
}
#endregion Value Pattern
}
}
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