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GtkTreeView drag-and-dropGtkTreeView drag-and-drop — Interfaces for drag-and-drop support in GtkTreeView |
GtkTreeDragSource is implemented by GtkListStore, GtkTreeModelFilter, GtkTreeModelSort and GtkTreeStore.
GtkTreeDragDest is implemented by GtkListStore and GtkTreeStore.
GTK+ supports Drag-and-Drop in tree views with a high-level and a low-level API.
The low-level API consists of the GTK+ DND API, augmented by some treeview
utility functions: gtk_tree_view_set_drag_dest_row(),
gtk_tree_view_get_drag_dest_row(), gtk_tree_view_get_dest_row_at_pos(),
gtk_tree_view_create_row_drag_icon(), gtk_tree_set_row_drag_data() and
gtk_tree_get_row_drag_data(). This API leaves a lot of flexibility, but
nothing is done automatically, and implementing advanced features like
hover-to-open-rows or autoscrolling on top of this API is a lot of work.
On the other hand, if you write to the high-level API, then all the bookkeeping of rows is done for you, as well as things like hover-to-open and auto-scroll, but your models have to implement the GtkTreeDragSource and GtkTreeDragDest interfaces.
gboolean gtk_tree_drag_source_drag_data_delete (GtkTreeDragSource *drag_source,GtkTreePath *path);
Asks the GtkTreeDragSource to delete the row at path
, because
it was moved somewhere else via drag-and-drop. Returns FALSE
if the deletion fails because path
no longer exists, or for
some model-specific reason. Should robustly handle a path
no
longer found in the model!
gboolean gtk_tree_drag_source_drag_data_get (GtkTreeDragSource *drag_source,GtkTreePath *path,GtkSelectionData *selection_data);
Asks the GtkTreeDragSource to fill in selection_data
with a
representation of the row at path
. selection_data->target
gives
the required type of the data. Should robustly handle a path
no
longer found in the model!
drag_source |
||
path |
row that was dragged |
|
selection_data |
a GtkSelectionData to fill with data from the dragged row |
gboolean gtk_tree_drag_source_row_draggable (GtkTreeDragSource *drag_source,GtkTreePath *path);
Asks the GtkTreeDragSource whether a particular row can be used as the source of a DND operation. If the source doesn’t implement this interface, the row is assumed draggable.
gboolean gtk_tree_drag_dest_drag_data_received (GtkTreeDragDest *drag_dest,GtkTreePath *dest,GtkSelectionData *selection_data);
Asks the GtkTreeDragDest to insert a row before the path dest
,
deriving the contents of the row from selection_data
. If dest
is
outside the tree so that inserting before it is impossible, FALSE
will be returned. Also, FALSE may be returned if the new row is
not created for some model-specific reason. Should robustly handle
a dest
no longer found in the model!
gboolean gtk_tree_drag_dest_row_drop_possible (GtkTreeDragDest *drag_dest,GtkTreePath *dest_path,GtkSelectionData *selection_data);
Determines whether a drop is possible before the given dest_path
,
at the same depth as dest_path
. i.e., can we drop the data in
selection_data
at that location. dest_path
does not have to
exist; the return value will almost certainly be FALSE if the
parent of dest_path
doesn’t exist, though.
gboolean gtk_tree_set_row_drag_data (GtkSelectionData *selection_data,GtkTreeModel *tree_model,GtkTreePath *path);
Sets selection data of target type GTK_TREE_MODEL_ROW. Normally used
in a drag_data_get handler.
gboolean gtk_tree_get_row_drag_data (GtkSelectionData *selection_data,GtkTreeModel **tree_model,GtkTreePath **path);
Obtains a tree_model
and path
from selection data of target type
GTK_TREE_MODEL_ROW. Normally called from a drag_data_received handler.
This function can only be used if selection_data
originates from the same
process that’s calling this function, because a pointer to the tree model
is being passed around. If you aren’t in the same process, then you'll
get memory corruption. In the GtkTreeDragDest drag_data_received handler,
you can assume that selection data of type GTK_TREE_MODEL_ROW is
in from the current process. The returned path must be freed with
gtk_tree_path_free().
selection_data |
||
tree_model |
a GtkTreeModel. |
[nullable][optional][transfer none][out] |
path |
row in |
[nullable][optional][out] |
struct GtkTreeDragSourceIface {
/* VTable - not signals */
gboolean (* row_draggable) (GtkTreeDragSource *drag_source,
GtkTreePath *path);
gboolean (* drag_data_get) (GtkTreeDragSource *drag_source,
GtkTreePath *path,
GtkSelectionData *selection_data);
gboolean (* drag_data_delete) (GtkTreeDragSource *drag_source,
GtkTreePath *path);
};
Asks the GtkTreeDragSource whether a particular row can be used as the source of a DND operation. |
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Asks the GtkTreeDragSource to fill in selection_data with a representation of the row at path. |
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Asks the GtkTreeDragSource to delete the row at path, because it was moved somewhere else via drag-and-drop. |
struct GtkTreeDragDestIface {
/* VTable - not signals */
gboolean (* drag_data_received) (GtkTreeDragDest *drag_dest,
GtkTreePath *dest,
GtkSelectionData *selection_data);
gboolean (* row_drop_possible) (GtkTreeDragDest *drag_dest,
GtkTreePath *dest_path,
GtkSelectionData *selection_data);
};
Asks the GtkTreeDragDest to insert a row before the path dest, deriving the contents of the row from selection_data. |
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Determines whether a drop is possible before the given dest_path, at the same depth as dest_path. |