| Top | |
|
|
|
GtkSelectionModelGtkSelectionModel — An extension of the list model interface that handles selections |
| gboolean | gtk_selection_model_is_selected () |
| gboolean | gtk_selection_model_select_item () |
| gboolean | gtk_selection_model_unselect_item () |
| gboolean | gtk_selection_model_select_range () |
| gboolean | gtk_selection_model_unselect_range () |
| gboolean | gtk_selection_model_select_all () |
| gboolean | gtk_selection_model_unselect_all () |
| void | gtk_selection_model_query_range () |
| void | gtk_selection_model_selection_changed () |
GtkSelectionModel is an interface that extends the GListModel interface by adding support for selections. This support is then used by widgets using list models to add the ability to select and unselect various items.
GTK provides default implementations of the mode common selection modes such as GtkSingleSelection, so you will only need to implement this interface if you want detailed control about how selections should be handled.
A GtkSelectionModel supports a single boolean per row indicating if a row is selected
or not. This can be queried via gtk_selection_model_is_selected(). When the selected
state of one or more rows changes, the model will emit the
“selection-changed” signal by calling the
gtk_selection_model_selection_changed() function. The positions given in that signal
may have their selection state changed, though that is not a requirement.
If new items added to the model via the “items-changed” signal are selected
or not is up to the implementation.
Additionally, the interface can expose functionality to select and unselect items. If these functions are implemented, GTK's list widgets will allow users to select and unselect items. However, GtkSelectionModels are free to only implement them partially or not at all. In that case the widgets will not support the unimplemented operations.
When selecting or unselecting is supported by a model, the return values of the selection functions do NOT indicate if selection or unselection happened. They are only meant to indicate complete failure, like when this mode of selecting is not supported by the model.
Selections may happen asynchronously, so the only reliable way to find out when an item was selected is to listen to the signals that indicate selection.
gboolean gtk_selection_model_is_selected (GtkSelectionModel *model,guint position);
Checks if the given item is selected.
gboolean gtk_selection_model_select_item (GtkSelectionModel *model,guint position,gboolean exclusive);
Requests to select an item in the model.
gboolean gtk_selection_model_unselect_item (GtkSelectionModel *model,guint position);
Requests to unselect an item in the model.
gboolean gtk_selection_model_select_range (GtkSelectionModel *model,guint position,guint n_items,gboolean exclusive);
Requests to select a range of items in the model.
gboolean gtk_selection_model_unselect_range (GtkSelectionModel *model,guint position,guint n_items);
Requests to unselect a range of items in the model.
gboolean
gtk_selection_model_select_all (GtkSelectionModel *model);
Requests to select all items in the model.
gboolean
gtk_selection_model_unselect_all (GtkSelectionModel *model);
Requests to unselect all items in the model.
void gtk_selection_model_query_range (GtkSelectionModel *model,guint position,guint *start_range,guint *n_items,gboolean *selected);
This function allows to query the selection status of multiple elements at once. It is passed a position and returns a range of elements of uniform selection status.
If position
is greater than the number of items in model
, n_items
is set to 0.
Otherwise the returned range is guaranteed to include the passed-in position, so
n_items
will be >= 1.
Positions directly adjacent to the returned range may have the same selection status as the returned range.
This is an optimization function to make iterating over a model faster when few items are selected. However, it is valid behavior for implementations to use a naive implementation that only ever returns a single element.
void gtk_selection_model_selection_changed (GtkSelectionModel *model,guint position,guint n_items);
Helper function for implementations of GtkSelectionModel. Call this when a the selection changes to emit the ::selection-changed signal.
“selection-changed” signalvoid user_function (GtkSelectionModel *model, guint position, guint n_items, gpointer user_data)
Emitted when the selection state of some of the items in model
changes.
Note that this signal does not specify the new selection state of the items, they need to be queried manually. It is also not necessary for a model to change the selection state of any of the items in the selection model, though it would be rather useless to emit such a signal.
model |
||
position |
The first item that may have changed |
|
n_items |
number of items with changes |
|
user_data |
user data set when the signal handler was connected. |
Flags: Run Last