/// <summary>
/// Override of WndProc to handle the context menu or column resize on column headers.
/// Necessary because ListView eats almost all mouse events, and does not provide any that can be used to handling right
/// clicks in the header.
/// Also couldn't use class wizard to handle WM_NOTIFY because it won't add HDN_ITEMCLICKA and HDN_DIVIDERDBLCLICKW
/// </summary>
/// <param name="m">The Windows Message to process</param>
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_CONTEXTMENU:
Point pointClicked = PointToClient(MousePosition);
int index = GetColumnIndexFromMousePosition(pointClicked);
if (index >= 0)
{
OnColumnRightClick(index, pointClicked);
}
break;
case WM_NOTIFY:
var nm = (NMHDR)m.GetLParam(typeof(NMHDR));
// Notification names: standard, ANSI (A), and Unicode (W)
const int HDN_FIRST = 0 - 300;
const int HDN_DIVIDERDBLCLICKA = HDN_FIRST - 5;
const int HDN_DIVIDERDBLCLICKW = HDN_FIRST - 25;
// Handle notifications for header column divider
if (nm.code == HDN_DIVIDERDBLCLICKA || nm.code == HDN_DIVIDERDBLCLICKW)
{
// nmheader.iItem is in the original column order, but the resizes are done in display order.
var nmheader = (NMHEADER)m.GetLParam(typeof(NMHEADER));
int inDisplayOrder = m_orderForColumnsDisplay[nmheader.iItem];
m_bv.AdjustColumnWidthToMatchContents(inDisplayOrder);
}
// Handle all other notifications
else
{
base.WndProc(ref m);
}
break;
default:
base.WndProc(ref m);
break;
}
}
const int NM_LCLICKUP = NM_FIRST - 16; // Left Click Mouse Up
/// ------------------------------------------------------------------------------------
/// <summary>
/// Overrides <see cref="M:System.Windows.Forms.Control.WndProc(System.Windows.Forms.Message@)"/>.
/// </summary>
/// <param name="m">The Windows <see cref="T:System.Windows.Forms.Message"/> to process.</param>
/// ------------------------------------------------------------------------------------
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_NOTIFY:
Win32.NMHEADER nmhdr = (Win32.NMHEADER)m.GetLParam(typeof(Win32.NMHEADER));
switch (nmhdr.hdr.code)
{
case HDN_DIVIDERDBLCLICKW: // double-click on line between column headers.
// adjust width of column to match item of greatest length.
m_bv.AdjustColumnWidthToMatchContents(nmhdr.iItem);
break;
default:
base.WndProc(ref m);
break;
}
//Debug.WriteLine("DhListView.WndProc: WM_NOTIFY code = " + nmhdr.hdr.code);
switch (nmhdr.hdr.code)
{
case HDN_BEGINTRACKA:
case HDN_BEGINTRACKW:
if (m_bv.m_xbv.Vc.HasSelectColumn)
{
int iCol = nmhdr.iItem;
// We want to prevent the user from resizing the checkbox column (LT-3938)
if (iCol == 0)
{
m.Result = (IntPtr)1; // Disable tracking.
}
}
m_suppressColumnWidthChanges = true;
break;
case HDN_ITEMDBLCLICKW: // double-click on line between items collapses it.
// However, we never get this notification, because we're not treating the
// column headers as buttons. Sigh.
break;
case HDN_ENDTRACK:
m_bv.AdjustColumnWidths(true);
m_suppressColumnWidthChanges = false;
break;
case HDN_ITEMCHANGED:
// No longer needed. HDN_DIVIDERDBLCLICKW above helps to
// avoid the the problem of someone double-clicking the
// separator and messing up the check mark column irretrievably.
if (!m_suppressColumnWidthChanges && !m_fInAdjustWidth)
{
m_bv.AdjustColumnWidths(true);
}
break;
case NM_RCLICK:
// HDN_ITEMCLICK never shows up for a right click, although it does for a
// left click.
// NM_RCLICK shows up okay, but gives no useful information for where the
// right click occurred! We have to get the current mouse position, and
// compare it to the column boundaries across the window.
Point pt_rclick = this.PointToClient(Control.MousePosition);
int icol_rclick = GetColumnIndexFromMousePosition(pt_rclick);
if (icol_rclick >= 0)
{
OnColumnRightClick(icol_rclick, pt_rclick);
return;
}
break;
case HDN_ENDDRAG:
// We don't have a new display order until AFTER the HDN_ENDDRAG event.
// so flag for further handling (on NM_CLICKUP).
m_fColumnDropped = true; // flag for further handling during NM_LCLICKUP.
return;
case NM_LCLICKUP:
// first handle the special case where the user may have dragged and dropped
// something into the location of the "select column".
if (m_bv.m_xbv.Vc.HasSelectColumn &&
m_fColumnDropped && this.ColumnOrdersOutOfSync)
{
this.MaintainSelectColumnPosition();
}
// if displayed columns are (still) out of sync with Columns collection,
// then we re-sync with that reordering and let the browse view know the new order.
if (m_fColumnDropped && this.ColumnOrdersOutOfSync)
{
this.OnColumnDisplayReordered();
// reset our drag-n-drop event flag.
m_fColumnDropped = false;
}
return;
default:
break;
}
break;
default:
base.WndProc(ref m);
break;
}
}
