Interfaces for drag-and-drop support in GtkTreeView
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 <gtk-tree-drag-source> and
<gtk-tree-drag-dest> interfaces.
<gtk-tree-drag-source>) (path <gtk-tree-path>) (selection_data <gtk-selection-data>) ⇒ (ret bool)Asks the
<gtk-tree-drag-source>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
- a
<gtk-tree-drag-source>- path
- row that was dragged
- selection-data
- a
<gtk-selection-data>to fill with data from the dragged row- ret
- ‘
#t’ if data of the required type was provided
<gtk-tree-drag-source>) (path <gtk-tree-path>) ⇒ (ret bool)Asks the
<gtk-tree-drag-source>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.
- drag-source
- a
<gtk-tree-drag-source>- path
- row on which user is initiating a drag
- ret
- ‘
#t’ if the row can be dragged
<gtk-selection-data>) (tree_model <gtk-tree-model>) (path <gtk-tree-path>) ⇒ (ret bool)Sets selection data of target type ‘GTK_TREE_MODEL_ROW’. Normally used in a drag_data_get handler.
- selection-data
- some
<gtk-selection-data>- tree-model
- a
<gtk-tree-model>- path
- a row in tree-model
- ret
- ‘
#t’ if the<gtk-selection-data>had the proper target type to allow us to set a tree row