selected in model. If no items are selected, the bitset is empty. The bitset must not be modified.
gtk.selection_model_mixin
Module for [SelectionModel] interface mixin
Templates 2
tmplSelectionModelT()
[gtk.selection_model.SelectionModel] is an interface that add support for selection to list models.
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 most common selection modes such as [gtk.single_selection.SingleSelection], so you will only need to implement this interface if you want detailed control about how selections should be handled.
A [gtk.selection_model.SelectionModel] supports a single boolean per item indicating if an item is selected or not. This can be queried via [gtk.selection_model.SelectionModel.isSelected]. When the selected state of one or more items changes, the model will emit the signal@Gtk.SelectionModel::selection-changed signal by calling the [gtk.selection_model.SelectionModel.selectionChanged] 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 signal@Gio.ListModel::items-changed signal are selected or not is up to the implementation.
Note that items added via signal@Gio.ListModel::items-changed may already be selected and no signal@Gtk.SelectionModel::selection-changed will be emitted for them. So to track which items are selected, it is necessary to listen to both signals.
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, [gtk.selection_model.SelectionModel]s 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.
Functions
gtk.bitset.Bitset getSelection()
Gets the set containing all currently selected items in the model.
This function may be slow, so if you are only interested in single item, consider using [gtk.selection_model.SelectionModel.isSelected] or if you are only interested in a few, consider [gtk.selection_model.SelectionModel.getSelectionInRange].
Returns
a [gtk.bitset.Bitset] containing all the values currently
gtk.bitset.Bitset getSelectionInRange(uint position, uint nItems)
Gets the set of selected items in a range.
This function is an optimization for [gtk.selection_model.SelectionModel.getSelection] when you are only interested in part of the model's selected state. A common use case is in response to the signalGtk.SelectionModel::selection-changed signal.
Parameters
position | start of the queried range |
nItems | number of items in the queried range |
Returns
A [gtk.bitset.Bitset] that matches the selection state
for the given range with all other values being undefined. The bitset must not be modified.
bool isSelected(uint position)
Checks if the given item is selected.
Parameters
position | the position of the item to query |
Returns
true if the item is selected
bool selectAll()
Requests to select all items in the model.
Returns
true if this action was supported and no fallback should be
tried. This does not mean that all items are now selected.
bool selectItem(uint position, bool unselectRest)
Requests to select an item in the model.
Parameters
position | the position of the item to select |
unselectRest | whether previously selected items should be unselected |
Returns
true if this action was supported and no fallback should be
tried. This does not mean the item was selected.
bool selectRange(uint position, uint nItems, bool unselectRest)
Requests to select a range of items in the model.
Parameters
position | the first item to select |
nItems | the number of items to select |
unselectRest | whether previously selected items should be unselected |
Returns
true if this action was supported and no fallback should be
tried. This does not mean the range was selected.
void selectionChanged(uint position, uint nItems)
Helper function for implementations of [gtk.selection_model.SelectionModel].
Call this when the selection changes to emit the signalGtk.SelectionModel::selection-changed signal.
Parameters
position | the first changed item |
nItems | the number of changed items |
bool setSelection(gtk.bitset.Bitset selected, gtk.bitset.Bitset mask)
Make selection changes.
This is the most advanced selection updating method that allows the most fine-grained control over selection changes. If you can, you should try the simpler versions, as implementations are more likely to implement support for those.
Requests that the selection state of all positions set in mask be updated to the respective value in the selected bitmask.
In pseudocode, it would look something like this:
for (i = 0; i < n_items; i++)
{
// don't change values not in the mask
if (!gtk_bitset_contains (mask, i))
continue;
if (gtk_bitset_contains (selected, i))
select_item (i);
else
unselect_item (i);
}
gtk_selection_model_selection_changed (model,
first_changed_item,
n_changed_items);mask and selected must not be modified. They may refer to the same bitset, which would mean that every item in the set should be selected.
Parameters
selected | bitmask specifying if items should be selected or unselected |
mask | bitmask specifying which items should be updated |
Returns
true if this action was supported and no fallback should be
tried. This does not mean that all items were updated according to the inputs.
bool unselectAll()
Requests to unselect all items in the model.
Returns
true if this action was supported and no fallback should be
tried. This does not mean that all items are now unselected.
bool unselectItem(uint position)
Requests to unselect an item in the model.
Parameters
position | the position of the item to unselect |
Returns
true if this action was supported and no fallback should be
tried. This does not mean the item was unselected.
bool unselectRange(uint position, uint nItems)
Requests to unselect a range of items in the model.
Parameters
position | the first item to unselect |
nItems | the number of items to unselect |
Returns
true if this action was supported and no fallback should be
tried. This does not mean the range was unselected.
gulong connectSelectionChanged(T)(T callback, Flag!"After" after = No.After) if (isCallable!T
&& is(ReturnType!T == void)
&& (Parameters!T.length < 1 || (ParameterStorageClassTuple!T[0] == ParameterStorageClass.none && is(Parameters!T[0] == uint)))
&& (Parameters!T.length < 2 || (ParameterStorageClassTuple!T[1] == ParameterStorageClass.none && is(Parameters!T[1] == uint)))
&& (Parameters!T.length < 3 || (ParameterStorageClassTuple!T[2] == ParameterStorageClass.none && is(Parameters!T[2] : gtk.selection_model.SelectionModel)))
&& Parameters!T.length < 4)
Connect to SelectionChanged signal.
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.
Parameters
callback | signal callback delegate or function to connect void callback(uint position, uint nItems, gtk.selection_model.SelectionModel selectionModel) position The first item that may have changed (optional) nItems number of items with changes (optional) selectionModel the instance the signal is connected to (optional) |
after | Yes.After to execute callback after default handler, No.After to execute before (default) |
Returns
Signal ID
tmplSelectionModelGidBuilderT()