toAutoSpanColumns + navigation

[ghost]

We are in the process of upgrading from 1.31 => 4.8.7 (last version with BCB6 support - done but patched) => 6.3.
In 1.31 navigation like VK_LEFT honors toAutoSpanColumns ie if you are positioned right of a spanned cell and fires VK_LEFT => you will move to the first-spanned-cell. In 6.3 you end up in the last-spanned-cell and the cell-focus-rectangle disappears.

Dunno why this was dropped somewhere between 1.31 and 4.8.7...

[joachimmarder]

Dunno why this was dropped somewhere between 1.31 and 4.8.7...

Sorry, no. I took over the project with V5. And I personally never used spanned cells.

If you think this is a bug, could you please attach a sample project that allows to replicate the issue? Also a modified demo project would be fine.

[ghost]

Hmmm, I patch:ed 4.8.7 internally using code from 1.31 - I'll try to do the same for 6.3 and post a patch here (I guess you are allowed to use 1.31 code yes?)...

[joachimmarder]

(I guess you are allowed to use 1.31 code yes?)...

I think so, I guess it was published under the same license as the current version.

[ghost]

VK_{UP|DOWN|LEFT|RIGHT} should use the following 1.31 functions:

function TBaseVirtualTree.GetMergedColumn(Node: PVirtualNode; Column: TColumnIndex; ConsiderAllowFocus: bool): TColumnIndex;
// if auto column spanning is enabled and Column is merged look for the first non merged column, otherwise Column is returned
begin
  Result := Column;
  if (toAutoSpanColumns in FOptions.FAutoOptions) and Header.UseColumns then
    while (Result > NoColumn) and ColumnIsEmpty(Node, Result) do
      Result := FHeader.FColumns.GetPreviousVisibleColumn(Result, ConsiderAllowFocus);
end;

and

function TBaseVirtualTree.GetNextNonMergedColumn(Node: PVirtualNode; Column: TColumnIndex; ConsiderAllowFocus: bool): TColumnIndex;
// look for next visible non-merged column. if auto column spanning isn't enabled the function is equal GetNextVisibleColumn
begin
  Result := FHeader.FColumns.GetNextVisibleColumn(Column, ConsiderAllowFocus);
  if (toAutoSpanColumns in FOptions.FAutoOptions) and Header.UseColumns then
    while (Result >= 0) and (Result < Header.Columns.Count) and ColumnIsEmpty(Node, Result) do
      Result := FHeader.FColumns.GetNextVisibleColumn(Result, ConsiderAllowFocus);
end;

VK_LEFT and VK_RIGHT is simple; use the functions above to set FocusedColumn.

VK_UP and VK_DOWN is tricky; 1.31 mimics the navigation of excel (wider indicates span):

[ ][ ][5][ ][ ]
[4      ][ ][ ]
[ ][ ][3][ ][ ]
[ ][2   ][ ][ ]
[ ][ ][1][ ][ ]

Start position is 1 - VK_UP four time moves us to position 2-5. That is we need to keep track of the actual column. This was handled by FFocusedKeyColumn in 1.31:

FFocusedKeyColumn: Integer; // cache for FFocusedColumn when moving focus with the keyboard, used to get
                            // a correct behavior when using voAutoSpanColumns (i.e columns can be merged).

VK_LEFT and VK_RIGHT should use the functions above to set FocusedColumn (using FFocusedKeyColumn as parameter).

VK_LEFT/VK_RIGHT/MouseDown events updates FFocusedColumn => we must update FFocusedKeyColumn. The problem is all other places that updates FFocusedColumn; I'm not familiar enough with the code to determine where FFocusedKeyColumn updates should be placed...

[joachimmarder]

Would you mind attaching a sample project that makes it easy to test this behavior?

[joachimmarder]

Is there any news on this issue? If no sample project is supplied, I will close this issue sooner or later.

[sanjayssk]

Fixed. But found the same problem with VK_TAB forward and backward. However, that uses a completely different code by using a function pointer. Hence, making another issue for it and closing this issue.