public override AccessibleObject?Navigate(AccessibleNavigation navigationDirection)
{
if (Owner is null)
{
throw new InvalidOperationException(SR.DataGridViewCellAccessibleObject_OwnerNotSet);
}
if (Owner.OwningRow is null || Owner.DataGridView is null)
{
return(null);
}
switch (navigationDirection)
{
case AccessibleNavigation.Next:
return((Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) > 0)
? ParentPrivate?.GetChild(1) // go to the next sibling
: null);
case AccessibleNavigation.Down:
{
if (Owner.OwningRow.Index == Owner.DataGridView.Rows.GetLastRow(DataGridViewElementStates.Visible))
{
return(null);
}
int nextVisibleRow = Owner.DataGridView.Rows.GetNextRow(Owner.OwningRow.Index, DataGridViewElementStates.Visible);
int actualDisplayIndex = Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible, 0, nextVisibleRow);
if (Owner.DataGridView.ColumnHeadersVisible)
{
// Add 1 because the first child in the data grid view acc obj is the top row header acc obj
actualDisplayIndex++;
}
return(Owner.DataGridView.AccessibilityObject.GetChild(actualDisplayIndex)?.GetChild(0));
}
case AccessibleNavigation.Up:
{
if (Owner.OwningRow.Index == Owner.DataGridView.Rows.GetFirstRow(DataGridViewElementStates.Visible))
{
if (!Owner.DataGridView.ColumnHeadersVisible)
{
return(null);
}
// Return the top left header cell accessible object.
Debug.Assert(Owner.DataGridView.TopLeftHeaderCell.AccessibilityObject == Owner.DataGridView.AccessibilityObject.GetChild(0) !.GetChild(0));
return(Owner.DataGridView.AccessibilityObject.GetChild(0)?.GetChild(0));
}
else
{
int previousVisibleRow = Owner.DataGridView.Rows.GetPreviousRow(Owner.OwningRow.Index, DataGridViewElementStates.Visible);
int actualDisplayIndex = Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible, 0, previousVisibleRow);
if (Owner.DataGridView.ColumnHeadersVisible)
{
// Add 1 because the first child in the data grid view acc obj is the top row header acc obj
actualDisplayIndex++;
}
return(Owner.DataGridView.AccessibilityObject.GetChild(actualDisplayIndex)?.GetChild(0));
}
}
case AccessibleNavigation.Previous:
default:
return(null);
}
}
public override AccessibleObject Navigate(AccessibleNavigation navigationDirection)
{
Debug.Assert(Owner.DataGridView.RowHeadersVisible, "if the rows are not visible how did you get the row headers acc obj?");
switch (navigationDirection)
{
case AccessibleNavigation.Next:
if (Owner.OwningRow != null && Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) > 0)
{
// go to the next sibling
return(ParentPrivate.GetChild(1));
}
else
{
return(null);
}
case AccessibleNavigation.Down:
if (Owner.OwningRow == null)
{
return(null);
}
else
{
if (Owner.OwningRow.Index == Owner.DataGridView.Rows.GetLastRow(DataGridViewElementStates.Visible))
{
return(null);
}
else
{
int nextVisibleRow = Owner.DataGridView.Rows.GetNextRow(Owner.OwningRow.Index, DataGridViewElementStates.Visible);
int actualDisplayIndex = Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible, 0, nextVisibleRow);
if (Owner.DataGridView.ColumnHeadersVisible)
{
// + 1 because the first child in the data grid view acc obj is the top row header acc obj
return(Owner.DataGridView.AccessibilityObject.GetChild(1 + actualDisplayIndex).GetChild(0));
}
else
{
return(Owner.DataGridView.AccessibilityObject.GetChild(actualDisplayIndex).GetChild(0));
}
}
}
case AccessibleNavigation.Previous:
return(null);
case AccessibleNavigation.Up:
if (Owner.OwningRow == null)
{
return(null);
}
else
{
if (Owner.OwningRow.Index == Owner.DataGridView.Rows.GetFirstRow(DataGridViewElementStates.Visible))
{
if (Owner.DataGridView.ColumnHeadersVisible)
{
// Return the top left header cell accessible object.
Debug.Assert(Owner.DataGridView.TopLeftHeaderCell.AccessibilityObject == Owner.DataGridView.AccessibilityObject.GetChild(0).GetChild(0));
return(Owner.DataGridView.AccessibilityObject.GetChild(0).GetChild(0));
}
else
{
return(null);
}
}
else
{
int previousVisibleRow = Owner.DataGridView.Rows.GetPreviousRow(Owner.OwningRow.Index, DataGridViewElementStates.Visible);
int actualDisplayIndex = Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible, 0, previousVisibleRow);
if (Owner.DataGridView.ColumnHeadersVisible)
{
// + 1 because the first child in the data grid view acc obj is the top row header acc obj
return(Owner.DataGridView.AccessibilityObject.GetChild(actualDisplayIndex + 1).GetChild(0));
}
else
{
return(Owner.DataGridView.AccessibilityObject.GetChild(actualDisplayIndex).GetChild(0));
}
}
}
default:
return(null);
}
}
