private int GetScrollValue (ScrollBarInfo info)
{
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 0;
}
switch (info)
{
case ScrollBarInfo.CurrentPosition:
//
// Builds prior to Vista 5359 failed to correctly account for RTL scrollbar layouts.
//
if ((Environment.OSVersion.Version.Major < 6) && (_sbFlag == NativeMethods.SB_HORZ) && (Misc.IsControlRTL(_parent._hwnd)))
{
return GetScrollMaxValue(si) - si.nPos;
}
return si.nPos;
case ScrollBarInfo.MaximumPosition:
return GetScrollMaxValue(si);
case ScrollBarInfo.MinimumPosition:
return si.nMin;
case ScrollBarInfo.PageSize:
return si.nPage;
case ScrollBarInfo.TrackPosition:
return si.nTrackPos;
case ScrollBarInfo.LargeChange:
return si.nPage;
case ScrollBarInfo.SmallChange:
return 1;
}
return 0;
}
private void SetScrollValue (int 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))
{
throw new InvalidOperationException(SR.Get(SRID.OperationCannotBePerformed));
}
// No move, exit
if (val == si.nPos)
{
return;
}
// NOTE:
// Proportional scrollbars have a few key values: min, max, page, and current.
//
// Min and max represent the endpoints of the scrollbar; page is the side of the thumb,
// and current is the position of the leading edge of the thumb (top for a vert scrollbar).
//
// Because of this arrangment, current can't be any value between min and max, it's actually
// confied to min...(max-page)+1. That +1 is a quirk of the scrollbar's internal logic.
//
// For example, in an edit in notepad, these might be:
// min = 0
// max = 33 (~total lines in file)
// current = { any value from 0 .. 12 inclusive }
// page = 22
//
// Most controls just let the scrollbar do all the proportional logic: they pass the incoming
// values from the scroll messages (eg as a reuslt of dragging with a mouse or from UIA's SetValue)
// straight down to the scrollbar APIs.
//
// RichEdit is different: it does its own extra 'validation', and limits the current value to
// (max-page) - without that +1.
//
// The end result of this is that it's not possible using UIA to scroll a richedit to the max value:
// the richedit is exposing (implicitly through the scrollbar APIs) a max value one higher than the
// max value that it will actually allow.
int max;
string classname = Misc.GetClassName(_hwnd);
if (classname.ToLower(System.Globalization.CultureInfo.InvariantCulture).Contains("richedit"))
{
max = si.nMax - si.nPage;
}
else
{
max = (si.nMax - si.nPage) + (si.nPage > 0 ? 1 : 0);
}
// Explicit comparisions are made to the MaxPercentage and MinPercentage,
// so that we dont miss out the fractions
if (val > max )
{
throw new ArgumentOutOfRangeException("value", val, SR.Get(SRID.RangeValueMax));
}
else if (val < si.nMin)
{
throw new ArgumentOutOfRangeException("value", val, SR.Get(SRID.RangeValueMin));
}
if (_sbFlag == NativeMethods.SB_CTL)
{
Misc.SetScrollPos(_hwnd, _sbFlag, val, true);
}
else
{
// Determine the msg from the style.
int msg =
IsScrollBarVertical(_hwnd, _sbFlag) ? NativeMethods.WM_VSCROLL : NativeMethods.WM_HSCROLL;
// An application is generally programmed to process either the
// SB_THUMBTRACK or SB_THUMBPOSITION request code.
int wParam = NativeMethods.Util.MAKELONG ((short) NativeMethods.SB_THUMBPOSITION, (short) val);
Misc.ProxySendMessage(_hwnd, msg, (IntPtr)wParam, IntPtr.Zero);
wParam = NativeMethods.Util.MAKELONG ((short) NativeMethods.SB_THUMBTRACK, (short) val);
Misc.ProxySendMessage(_hwnd, msg, (IntPtr)wParam, IntPtr.Zero);
}
}
// ------------------------------------------------------
//
// Private Methods
//
// ------------------------------------------------------
#region Private Methods
// Scroll by a given amount
private void Scroll (ScrollAmount amount, int style)
{
IntPtr parentHwnd = _sbFlag == NativeMethods.SB_CTL ? Misc.GetWindowParent(_hwnd) : _hwnd;
int wParam = 0;
switch (amount)
{
case ScrollAmount.LargeDecrement :
wParam = NativeMethods.SB_PAGEUP;
break;
case ScrollAmount.SmallDecrement :
wParam = NativeMethods.SB_LINEUP;
break;
case ScrollAmount.LargeIncrement :
wParam = NativeMethods.SB_PAGEDOWN;
break;
case ScrollAmount.SmallIncrement :
wParam = NativeMethods.SB_LINEDOWN;
break;
}
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;
}
// If the scrollbar is at the maximum position and the user passes
// pagedown or linedown, just return
if ((si.nPos == si.nMax) && (wParam == NativeMethods.SB_PAGEDOWN || wParam == NativeMethods.SB_LINEDOWN))
{
return;
}
// If the scrollbar is at the minimum position and the user passes
// pageup or lineup, just return
if ((si.nPos == si.nMin) && (wParam == NativeMethods.SB_PAGEUP || wParam == NativeMethods.SB_LINEUP))
{
return;
}
int msg = (style == NativeMethods.SBS_HORZ) ? NativeMethods.WM_HSCROLL : NativeMethods.WM_VSCROLL;
Misc.ProxySendMessage(parentHwnd, msg, (IntPtr)wParam, (IntPtr)(parentHwnd == _hwnd ? IntPtr.Zero : _hwnd));
}
// Check if a scroll bar is in a disabled state
internal static bool IsScrollBarWithThumb (IntPtr hwnd, int sbFlag)
{
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.cbSize = Marshal.SizeOf (si.GetType ());
si.fMask = NativeMethods.SIF_RANGE | NativeMethods.SIF_PAGE;
if (!Misc.GetScrollInfo(hwnd, sbFlag, ref si))
{
return false;
}
// Check for the min / max value
if (si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1)
{
// The scroll bar is enabled, check if we have a thumb
int idObject = sbFlag == NativeMethods.SB_VERT ? NativeMethods.OBJID_VSCROLL : sbFlag == NativeMethods.SB_HORZ ? NativeMethods.OBJID_HSCROLL : NativeMethods.OBJID_CLIENT;
NativeMethods.ScrollBarInfo sbi = new NativeMethods.ScrollBarInfo ();
sbi.cbSize = Marshal.SizeOf (sbi.GetType ());
// check that the 2 buttons can hold in the scroll bar
if (Misc.GetScrollBarInfo(hwnd, idObject, ref sbi))
{
// When the scroll bar is for a listbox within a combo and it is hidden, then
// GetScrollBarInfo returns true but the rectangle is boggus!
// 32 bits * 32 bits > 64 values
long area = (sbi.rcScrollBar.right - sbi.rcScrollBar.left) * (sbi.rcScrollBar.bottom - sbi.rcScrollBar.top);
if (area > 0 && area < 1000 * 1000)
{
NativeMethods.SIZE sizeArrow;
using (ThemePart themePart = new ThemePart(hwnd, "SCROLLBAR"))
{
sizeArrow = themePart.Size((int)ThemePart.SCROLLBARPARTS.SBP_ARROWBTN, 0);
}
bool fThumbVisible = false;
if (IsScrollBarVertical(hwnd, sbFlag))
{
fThumbVisible = (sbi.rcScrollBar.bottom - sbi.rcScrollBar.top >= 5 * sizeArrow.cy / 2);
}
else
{
fThumbVisible = (sbi.rcScrollBar.right - sbi.rcScrollBar.left >= 5 * sizeArrow.cx / 2);
}
return fThumbVisible;
}
}
}
return false;
}
// determine the number of lines that are visible in the Edit control.
// if there is no scrollbar then this is the actual number of lines displayed.
internal int LinesPerPage()
{
int linePerPage = 0;
if (Misc.IsBitSet(WindowStyle, NativeMethods.WS_VSCROLL))
{
// we call GetScrollInfo and return the size of the "page"
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo();
si.cbSize = System.Runtime.InteropServices.Marshal.SizeOf(typeof(NativeMethods.ScrollInfo));
si.fMask = NativeMethods.SIF_ALL;
bool ok = Misc.GetScrollInfo(WindowHandle, NativeMethods.SB_VERT, ref si);
linePerPage = ok ? si.nPage : 0;
if (IsMultiline && linePerPage <= 0)
{
linePerPage = 1;
}
}
else
{
NativeMethods.Win32Rect rect = new NativeMethods.Win32Rect();
if (Misc.GetClientRect(_hwnd, ref rect) && !rect.IsEmpty)
{
NativeMethods.SIZE size;
string s = new string('E', 1);
GetTextExtentPoint32(s, out size);
if (size.cy != 0)
{
linePerPage = (rect.bottom - rect.top) / size.cy;
}
}
}
return linePerPage;
}
// ------------------------------------------------------
//
// Internal Methods
//
// ------------------------------------------------------
#region Internal Methods
// Static implementation for the bounding rectangle. This is used by
// ElementProviderFromPoint to avoid to have to create for a simple
// boundary check
// param "item", ID for the scrollbar bit
// param "sbFlag", SBS_ WindowLong equivallent flag
static internal Rect GetBoundingRectangle(IntPtr hwnd, ProxyFragment parent, WindowsScrollBar.ScrollBarItem item, int sbFlag)
{
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.cbSize = Marshal.SizeOf (si.GetType ());
si.fMask = NativeMethods.SIF_RANGE;
// If the scroll bar is disabled, we cannot have a thumb and large Increment/Decrement)
bool fDisableScrollBar = !WindowsScrollBar.IsScrollBarWithThumb (hwnd, sbFlag);
if (fDisableScrollBar && (item == WindowsScrollBar.ScrollBarItem.LargeDecrement || item == WindowsScrollBar.ScrollBarItem.Thumb || item == WindowsScrollBar.ScrollBarItem.LargeDecrement))
{
return Rect.Empty;
}
// If fails assume that the hwnd is invalid
if (!Misc.GetScrollInfo(hwnd, sbFlag, ref si))
{
return Rect.Empty;
}
int idObject = sbFlag == NativeMethods.SB_VERT ? NativeMethods.OBJID_VSCROLL : sbFlag == NativeMethods.SB_HORZ ? NativeMethods.OBJID_HSCROLL : NativeMethods.OBJID_CLIENT;
NativeMethods.ScrollBarInfo sbi = new NativeMethods.ScrollBarInfo ();
sbi.cbSize = Marshal.SizeOf (sbi.GetType ());
if (!Misc.GetScrollBarInfo(hwnd, idObject, ref sbi))
{
return Rect.Empty;
}
if (parent != null && parent._parent != null)
{
//
// Builds prior to Vista 5359 failed to correctly account for RTL scrollbar layouts.
//
if ((Environment.OSVersion.Version.Major < 6) && (Misc.IsLayoutRTL(parent._parent._hwnd)))
{
// Right to left mirroring style
Rect rcParent = parent._parent.BoundingRectangle;
int width = sbi.rcScrollBar.right - sbi.rcScrollBar.left;
if (sbFlag == NativeMethods.SB_VERT)
{
int offset = (int)rcParent.Right - sbi.rcScrollBar.right;
sbi.rcScrollBar.left = (int)rcParent.Left + offset;
sbi.rcScrollBar.right = sbi.rcScrollBar.left + width;
}
else
{
int offset = sbi.rcScrollBar.left - (int)rcParent.Left;
sbi.rcScrollBar.right = (int)rcParent.Right - offset;
sbi.rcScrollBar.left = sbi.rcScrollBar.right - width;
}
}
}
// When the scroll bar is for a listbox within a combo and it is hidden, then
// GetScrollBarInfo returns true but the rectangle is boggus!
// 32 bits * 32 bits > 64 values
//
// Note that this test must come after the rectangle has been normalized for RTL or it will fail
//
long area = (sbi.rcScrollBar.right - sbi.rcScrollBar.left) * (sbi.rcScrollBar.bottom - sbi.rcScrollBar.top);
if (area <= 0 || area > 1000 * 1000)
{
// Ridiculous value assume error
return Rect.Empty;
}
if(WindowsScrollBar.IsScrollBarVertical(hwnd, sbFlag))
{
return GetVerticalScrollbarBitBoundingRectangle(hwnd, item, sbi);
}
else
{
return GetHorizontalScrollbarBitBoundingRectangle(hwnd, item, sbi);
}
}
// Scroll control by a given amount
static private bool ScrollCursor(IntPtr hwnd, ScrollAmount amount, int sbFlag, bool fForceResults)
{
// Check Param
if (amount == ScrollAmount.NoAmount)
{
return true;
}
if (!Scrollable(hwnd, sbFlag))
{
return false;
}
// Get Max & min
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.fMask = NativeMethods.SIF_ALL;
si.cbSize = Marshal.SizeOf (si.GetType ());
// if no scroll bar return false
// on Win 6.0 success is false
// on other system check through the scroll info is a scroll bar is there
if ((!Misc.GetScrollInfo(hwnd, sbFlag, ref si) ||
!((si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1))))
{
return false;
}
// Get Action to perform
int nAction;
if (sbFlag == NativeMethods.SB_HORZ)
{
switch (amount)
{
case ScrollAmount.SmallDecrement :
nAction = NativeMethods.SB_LINELEFT;
break;
case ScrollAmount.LargeDecrement :
nAction = NativeMethods.SB_PAGELEFT;
break;
case ScrollAmount.SmallIncrement :
nAction = NativeMethods.SB_LINERIGHT;
break;
case ScrollAmount.LargeIncrement :
nAction = NativeMethods.SB_PAGERIGHT;
break;
default :
return false;
}
}
else
{
switch (amount)
{
case ScrollAmount.SmallDecrement :
nAction = NativeMethods.SB_LINEUP;
break;
case ScrollAmount.LargeDecrement :
nAction = NativeMethods.SB_PAGEUP;
break;
case ScrollAmount.SmallIncrement :
nAction = NativeMethods.SB_LINEDOWN;
break;
case ScrollAmount.LargeIncrement :
nAction = NativeMethods.SB_PAGEDOWN;
break;
default :
return false;
}
}
// Set position
int wParam = NativeMethods.Util.MAKELONG (nAction, 0);
int message = sbFlag == NativeMethods.SB_HORZ ? NativeMethods.WM_HSCROLL : NativeMethods.WM_VSCROLL;
int result = Misc.ProxySendMessageInt(hwnd, message, (IntPtr)wParam, IntPtr.Zero);
return result == 0 || fForceResults;
}
private bool SetScrollPercent(double fScrollPos, int sbFlag, int cPelsAll, out int delta)
{
// in case of early exit no move
delta = 0;
// Check param
if ((int)fScrollPos == (int)ScrollPattern.NoScroll)
{
return true;
}
if (fScrollPos < 0 || fScrollPos > 100)
{
throw new ArgumentOutOfRangeException(sbFlag == NativeMethods.SB_HORZ ? "horizontalPercent" : "verticalPercent", SR.Get(SRID.ScrollBarOutOfRange));
}
int scrollBar = sbFlag == NativeMethods.SB_HORZ ? NativeMethods.OBJID_HSCROLL : NativeMethods.OBJID_VSCROLL;
NativeMethods.ScrollBarInfo scrollBarInfo = new NativeMethods.ScrollBarInfo();
scrollBarInfo.cbSize = Marshal.SizeOf(scrollBarInfo.GetType());
if (!Misc.GetScrollBarInfo(_hwnd, scrollBar, ref scrollBarInfo) ||
(scrollBarInfo.scrollBarInfo & NativeMethods.STATE_SYSTEM_INVISIBLE) != 0 ||
(scrollBarInfo.scrollBarInfo & NativeMethods.STATE_SYSTEM_UNAVAILABLE) != 0)
{
return false;
}
// Get scroll range
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo (); // this is used all over
si.cbSize = Marshal.SizeOf (si.GetType ());
si.fMask = NativeMethods.SIF_ALL;
// if no scroll bar return false
// on Win 6.0 success is false
// on other system check through the scroll info is a scroll bar is there
if (!Misc.GetScrollInfo(_hwnd, sbFlag, ref si) ||
!((si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1)))
{
return false;
}
// calculate user-requested thumb position
int deltaPage = (si.nPage > 0) ? si.nPage - 1 : 0;
int future = (int) Math.Round (((si.nMax - deltaPage) - si.nMin) * fScrollPos / 100.0 + si.nMin);
// 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
delta = (future - si.nPos) * (cPelsAll / (si.nMax + 1 - si.nMin));
return true;
}
// Request to scroll a control horizontally or vertically by a specified amount.
static private bool SetScrollPercent(IntPtr hwnd, double fScrollPos, int sbFlag, out bool forceResults)
{
forceResults = false;
// Check param
if ((int)fScrollPos == (int)ScrollPattern.NoScroll)
{
return true;
}
if (!Scrollable(hwnd, sbFlag))
{
return false;
}
if (fScrollPos < 0 || fScrollPos > 100)
{
throw new ArgumentOutOfRangeException(sbFlag == NativeMethods.SB_HORZ ? "horizontalPercent" : "verticalPercent", SR.Get(SRID.ScrollBarOutOfRange));
}
// Get Max & min
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.fMask = NativeMethods.SIF_ALL;
si.cbSize = Marshal.SizeOf(si.GetType ());
// if no scroll bar return false
// on Win 6.0 success is false
// on other system check through the scroll info is a scroll bar is there
if (!Misc.GetScrollInfo(hwnd, sbFlag, ref si) ||
!((si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1)))
{
return false;
}
// Set position
int delta = (si.nPage > 0) ? si.nPage - 1 : 0;
int newPos = (int) Math.Round (((si.nMax - delta) - si.nMin) * fScrollPos / 100.0 + si.nMin);
// No move, exit
if (newPos == si.nPos)
{
return true;
}
si.nPos = newPos;
forceResults = true;
int message = sbFlag == NativeMethods.SB_HORZ ? NativeMethods.WM_HSCROLL : NativeMethods.WM_VSCROLL;
int wParam = NativeMethods.Util.MAKELONG(NativeMethods.SB_THUMBPOSITION, si.nPos);
bool fRet = Misc.ProxySendMessageInt(hwnd, message, (IntPtr)wParam, IntPtr.Zero) == 0;
if (fRet && Misc.GetScrollInfo(hwnd, sbFlag, ref si) && si.nPos != newPos)
{
// [....] treeview has some problems. The first is that the SendMessage with WM_HSCROLL/WM_VSCROLL
// with SB_THUMBPOSITION is not moving the scroll position. The second problem is that SetScrollInfo()
// lose the theming for the scroll bars and it really does not move the scroll position. The
// scrollbars change but it does not scroll the treeview control.
int prevPos = newPos;
ScrollAmount prevAmount = si.nPos > newPos ? ScrollAmount.SmallDecrement : ScrollAmount.SmallIncrement;
do
{
ScrollAmount amount = si.nPos > newPos ? ScrollAmount.SmallDecrement : ScrollAmount.SmallIncrement;
// If we were moving in one direction and overshoot, break to prevent getting into infant loop.
// If ScrollCursor() can not set the new position, also break to prevent infant loop.
if (prevAmount != amount || prevPos == si.nPos)
{
break;
}
prevPos = si.nPos;
fRet = ScrollCursor(hwnd, amount, sbFlag, forceResults);
} while (fRet && Misc.GetScrollInfo(hwnd, sbFlag, ref si) && si.nPos != newPos);
}
return fRet;
}
// View Size
static private double ScrollViewSize(IntPtr hwnd, int sbFlag)
{
// Get scroll range and page size
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.cbSize = Marshal.SizeOf (si.GetType ());
si.fMask = NativeMethods.SIF_RANGE | NativeMethods.SIF_PAGE;
if (!Misc.GetScrollInfo(hwnd, sbFlag, ref si) || (si.nMax == si.nMin))
{
return 100.0;
}
else
{
// "+1" because nPage can be 0 to nMax-nMin+1
int nPage = si.nPage > 0 ? si.nPage : 1;
return (100.0 * nPage) / (si.nMax + 1 - si.nMin);
}
}
// ------------------------------------------------------
//
// Private Methods
//
// ------------------------------------------------------
// Retrieve the scrollbar position in the [0..100]% range
static private double GetScrollInfo(IntPtr hwnd, int sbFlag)
{
// check if there is a scrollbar
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.fMask = NativeMethods.SIF_ALL;
si.cbSize = Marshal.SizeOf (si.GetType ());
if (Misc.GetScrollInfo(hwnd, sbFlag, ref si))
{
if (si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1)
{
int delta;
// NOTE:
// Proportional scrollbars have a few key values: min, max, page, and current.
//
// Min and max represent the endpoints of the scrollbar; page is the side of the thumb,
// and current is the position of the leading edge of the thumb (top for a vert scrollbar).
//
// Because of this arrangment, current can't be any value between min and max, it's actually
// confied to min...(max-page)+1. That +1 is a quirk of the scrollbar's internal logic.
//
// For example, in an edit in notepad, these might be:
// min = 0
// max = 33 (~total lines in file)
// current = { any value from 0 .. 12 inclusive }
// page = 22
//
// Most controls just let the scrollbar do all the proportional logic: they pass the incoming
// values from the scroll messages (eg as a reuslt of dragging with a mouse or from UIA's SetValue)
// straight down to the scrollbar APIs.
//
// RichEdit is different: it does its own extra 'validation', and limits the current value to
// (max-page) - without that +1.
//
// The end result of this is that it's not possible using UIA to scroll a richedit to the max value:
// the richedit is exposing (implicitly through the scrollbar APIs) a max value one higher than the
// max value that it will actually allow.
string classname = Misc.GetClassName(hwnd);
if (classname.ToLower(System.Globalization.CultureInfo.InvariantCulture).Contains("richedit"))
{
delta = (si.nPage > 0) ? si.nPage : 0;
}
else
{
delta = (si.nPage > 0) ? si.nPage - 1 : 0;
}
return 100.0 * (si.nPos - si.nMin) / ((si.nMax - delta) - si.nMin);
}
}
return (double)ScrollPattern.NoScroll;
}
// Finds if a control can be scrolled
static internal bool Scrollable (IntPtr hwnd, int sbFlag)
{
int style = Misc.GetWindowStyle(hwnd);
if ((sbFlag == NativeMethods.SB_HORZ && !Misc.IsBitSet(style, NativeMethods.WS_HSCROLL)) ||
(sbFlag == NativeMethods.SB_VERT && !Misc.IsBitSet(style, NativeMethods.WS_VSCROLL)))
{
return false;
}
if (!Misc.IsEnabled(hwnd))
{
return false;
}
// Check if the scroll info shows the scroll bar as enabled.
bool scrollBarEnabled = false;
NativeMethods.ScrollBarInfo sbi = new NativeMethods.ScrollBarInfo();
sbi.cbSize = Marshal.SizeOf(sbi.GetType());
int scrollBarObjectId =
(sbFlag == NativeMethods.SB_VERT) ? NativeMethods.OBJID_VSCROLL : NativeMethods.OBJID_HSCROLL;
if (Misc.GetScrollBarInfo(hwnd, scrollBarObjectId, ref sbi))
{
scrollBarEnabled =
!Misc.IsBitSet(sbi.scrollBarInfo, NativeMethods.STATE_SYSTEM_UNAVAILABLE);
}
if (!scrollBarEnabled)
{
return false;
}
// Get scroll range
NativeMethods.ScrollInfo si = new NativeMethods.ScrollInfo ();
si.cbSize = Marshal.SizeOf (si.GetType ());
si.fMask = NativeMethods.SIF_ALL;
if (!Misc.GetScrollInfo(hwnd, sbFlag, ref si))
{
return false;
}
return (si.nMax != si.nMin && si.nPage != si.nMax - si.nMin + 1);
}
//------------------------------------------------------
//
// 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.Get(SRID.RangeValueMax));
}
else if (pos < si.nMin)
{
throw new ArgumentOutOfRangeException("value", val, SR.Get(SRID.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, on occasion the result will be different to given value
// a-jeanp: I played a lot to figure out what it is not the case.
// I am giving up and issuing instead a second call with a 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);
}
}
}