public override AccessibleObject Navigate(AccessibleNavigation navdir)
{
TreeNavigation navAction;
switch (navdir)
{
case AccessibleNavigation.Down:
navAction = TreeNavigation.NextSibling;
break;
case AccessibleNavigation.FirstChild:
navAction = TreeNavigation.FirstChild;
break;
case AccessibleNavigation.LastChild:
navAction = TreeNavigation.LastChild;
break;
case AccessibleNavigation.Up:
navAction = TreeNavigation.PreviousSibling;
break;
case AccessibleNavigation.Left:
navAction = TreeNavigation.Left;
break;
case AccessibleNavigation.Next:
navAction = TreeNavigation.Down;
break;
case AccessibleNavigation.Previous:
navAction = TreeNavigation.Up;
break;
case AccessibleNavigation.Right:
navAction = TreeNavigation.Right;
break;
default:
return null;
}
AccessibleObject retVal = null;
var tree = myCtl.Tree;
var colPerm = myCtl.ColumnPermutation;
if (colPerm != null
&& myDisplayColumn >= colPerm.VisibleColumnCount)
{
// Handle a stale object so the rest of this doesn't crash
return null;
}
var target = tree.GetNavigationTarget(navAction, myRow, myDisplayColumn, colPerm);
if (target.IsValid)
{
var nativeColumn = target.Column;
var settings = AccItemSettings.None;
if (colPerm != null)
{
nativeColumn = colPerm.GetNativeColumn(nativeColumn);
if (colPerm.GetPermutedColumn(nativeColumn) == -1)
{
settings |= AccItemSettings.HiddenItem;
}
}
var newInfo = tree.GetItemInfo(target.Row, nativeColumn, true);
retVal = new AccPrimaryItem(myCtl, target.Row, nativeColumn, target.Column, settings, ref newInfo);
}
return retVal;
}
/// <summary>
/// Return either a Cell or Column object, depending on the branch settings
/// </summary>
/// <param name="ctl">The parent control</param>
/// <param name="baseRow">The row coordinate</param>
/// <param name="nativeBaseColumn">The column coordinate for the owning branch</param>
/// <param name="localColumn">The native column offset</param>
/// <param name="returnColumn">Return an AccColumn object if this is true, otherwise return the AccPrimaryItem directly</param>
/// <returns>An AccSimpleCell or AccColumn</returns>
public static AccessibleObject GetColumnObject(
VirtualTreeControl ctl, int baseRow, int nativeBaseColumn, int localColumn, bool returnColumn)
{
// Note: if this logic changes, corresponding change should be made to IsSimpleItem below.
Debug.Assert(localColumn > 0);
AccessibleObject retVal = null;
var tree = ctl.Tree;
var info = tree.GetItemInfo(baseRow, nativeBaseColumn, false);
var mcBranch = info.Branch as IMultiColumnBranch;
if (mcBranch != null)
{
var simpleCell = true;
var useColInfo = false;
var nativeColumn = nativeBaseColumn + localColumn;
var displayColumn = nativeColumn;
var colPerm = ctl.myColumnPermutation;
var settings = AccItemSettings.None;
if (colPerm != null)
{
displayColumn = colPerm.GetPermutedColumn(nativeColumn);
if (displayColumn == -1)
{
displayColumn = 0;
settings |= AccItemSettings.HiddenItem;
}
}
var style = mcBranch.ColumnStyles(localColumn);
var colInfo = new VirtualTreeItemInfo();
style = mcBranch.ColumnStyles(localColumn);
switch (style)
{
case SubItemCellStyles.Expandable:
// Use a simple cell unless the item is expandable. An item
// in an expandable column cannot have subitems, so
// we will not need a column object for this purpose.
simpleCell = !info.Branch.IsExpandable(info.Row, localColumn);
break;
case SubItemCellStyles.Mixed:
case SubItemCellStyles.Complex:
colInfo = tree.GetItemInfo(baseRow, nativeColumn, true);
if (colInfo.Column == 0)
{
var columns = (0 == (info.Branch.Features & BranchFeatures.JaggedColumns))
? mcBranch.ColumnCount
: mcBranch.GetJaggedColumnCount(info.Row);
// The data is provided by a different branch. The item is simple only
// if the branch has one unexpandable item and no sub items.
if (!(colInfo.Branch.VisibleItemCount == 1 &&
!colInfo.Branch.IsExpandable(0, 0) &&
(localColumn < columns ||
(null != (colInfo.Branch as IMultiColumnBranch) &&
0 == tree.GetSubItemCount(baseRow, nativeColumn)))))
{
simpleCell = false;
}
useColInfo = true;
}
else if (style == SubItemCellStyles.Mixed)
{
goto case SubItemCellStyles.Expandable;
}
break;
}
if (simpleCell)
{
if (useColInfo)
{
retVal = new AccSimpleCell(ctl, baseRow, displayColumn, nativeColumn, settings, ref colInfo);
}
else
{
var cellInfo = tree.GetItemInfo(baseRow, nativeColumn, true);
if (!cellInfo.Blank)
{
retVal = new AccSimpleCell(ctl, baseRow, displayColumn, nativeColumn, settings, ref cellInfo);
}
}
}
else if (returnColumn)
{
if (useColInfo)
{
retVal = new AccColumn(ctl, baseRow, displayColumn, nativeColumn, settings, ref colInfo);
}
else
{
var cellInfo = tree.GetItemInfo(baseRow, nativeBaseColumn + localColumn, true);
retVal = new AccColumn(ctl, baseRow, displayColumn, nativeColumn, settings, ref cellInfo);
}
}
else
{
if (useColInfo)
{
retVal = new AccPrimaryItem(ctl, baseRow, displayColumn, nativeColumn, settings, ref colInfo);
}
else
{
var cellInfo = tree.GetItemInfo(baseRow, nativeBaseColumn + localColumn, true);
retVal = new AccPrimaryItem(ctl, baseRow, displayColumn, nativeColumn, settings, ref cellInfo);
}
}
}
return retVal;
}
