### Function

# Gtk TreeViewColumnDropFunc

since: 4.0

#### Declaration

    gboolean
    (* GtkTreeViewColumnDropFunc) (
      GtkTreeView* tree_view,
      GtkTreeViewColumn* column,
      GtkTreeViewColumn* prev_column,
      GtkTreeViewColumn* next_column,
      gpointer data
    )

#### Description [src]

Function type for determining whether `column` can be dropped in a particular spot (as determined by `prev_column` and `next_column`). In left to right locales, `prev_column` is on the left of the potential drop spot, and `next_column` is on the right. In right to left mode, this is reversed. This function should return `TRUE` if the spot is a valid drop spot. Please note that returning `TRUE` does not actually indicate that the column drop was made, but is meant only to indicate a possible drop spot to the user.

Available since: 4.0

#### Parameters

`tree_view`

  Type: `GtkTreeView`

  A `GtkTreeView`

  The data is owned by the caller of the function.

`column`

  Type: `GtkTreeViewColumn`

  The `GtkTreeViewColumn` being dragged.

  The data is owned by the caller of the function.

`prev_column`

  Type: `GtkTreeViewColumn`

  A `GtkTreeViewColumn` on one side of `column`.

  The data is owned by the caller of the function.

`next_column`

  Type: `GtkTreeViewColumn`

  A `GtkTreeViewColumn` on the other side of `column`.

  The data is owned by the caller of the function.

`data`

  Type: `gpointer`

  User data.

  The argument can be `NULL`.
  The data is owned by the caller of the function.

#### Return value

Type: `gboolean`

`TRUE`, if `column` can be dropped in this spot.