Package ch.bailu.gtk.gtk

Class SelectionModel

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.type.Interface
ch.bailu.gtk.gtk.SelectionModel
All Implemented Interfaces:
PointerInterface
public class SelectionModel extends Interface
`GtkSelectionModel` 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 [class@Gtk.SingleSelection], 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 item indicating if an item is
selected or not. This can be queried via [method@Gtk.SelectionModel.is_selected].
When the selected state of one or more items changes, the model will emit the
[signal@Gtk.SelectionModel::selection-changed] signal by calling the
[method@Gtk.SelectionModel.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
[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, `GtkSelectionModel`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.

https://docs.gtk.org/gtk4/iface.SelectionModel.html

  • Field Details

  • Constructor Details

  • Method Details

    • getClassHandler

      public static ClassHandler getClassHandler()

    • getSelection

      public 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 [method@Gtk.SelectionModel.is_selected] or if you are only
      interested in a few, consider [method@Gtk.SelectionModel.get_selection_in_range].
      Returns:
      a `GtkBitset` containing all the values currently selected in @model. If no items are selected, the bitset is empty. The bitset must not be modified.

    • getSelectionInRange

      public Bitset getSelectionInRange(int position, int n_items)
      Gets the set of selected items in a range.

      This function is an optimization for
      [method@Gtk.SelectionModel.get_selection] when you are only
      interested in part of the model's selected state. A common use
      case is in response to the [signal@Gtk.SelectionModel::selection-changed]
      signal.
      Parameters:
      position - start of the queired range
      n_items - number of items in the queried range
      Returns:
      A `GtkBitset` that matches the selection state for the given range with all other values being undefined. The bitset must not be modified.

    • isSelected

      public boolean isSelected(int position)
      Checks if the given item is selected.
      Parameters:
      position - the position of the item to query
      Returns:
      %TRUE if the item is selected

    • selectAll

      public boolean 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.

    • selectItem

      public boolean selectItem(int position, boolean unselect_rest)
      Requests to select an item in the model.
      Parameters:
      position - the position of the item to select
      unselect_rest - 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.

    • selectRange

      public boolean selectRange(int position, int n_items, boolean unselect_rest)
      Requests to select a range of items in the model.
      Parameters:
      position - the first item to select
      n_items - the number of items to select
      unselect_rest - 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.

    • selectionChanged

      public void selectionChanged(int position, int n_items)
      Helper function for implementations of `GtkSelectionModel`.

      Call this when a the selection changes to emit the
      [signal@Gtk.SelectionModel::selection-changed] signal.
      Parameters:
      position - the first changed item
      n_items - the number of changed items

    • setSelection

      public boolean setSelection(@Nonnull Bitset selected, @Nonnull 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:

      ```c
      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.

    • unselectAll

      public boolean 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.

    • unselectItem

      public boolean unselectItem(int 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.

    • unselectRange

      public boolean unselectRange(int position, int n_items)
      Requests to unselect a range of items in the model.
      Parameters:
      position - the first item to unselect
      n_items - 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.

    • onSelectionChanged

      public SignalHandler onSelectionChanged(SelectionModel.OnSelectionChanged signal)
      Connect to signal "selection-changed".
      See SelectionModel.OnSelectionChanged.onSelectionChanged(int, int) for signal description.
      Field SIGNAL_ON_SELECTION_CHANGED contains original signal name and can be used as resource reference.
      Parameters:
      signal - callback function (lambda).
      Returns:
      SignalHandler. Can be used to disconnect signal and to release callback function.

    • getTypeID

      public static long getTypeID()

    • getParentTypeID

      public static long getParentTypeID()

    • getTypeSize

      public static TypeSystem.TypeSize getTypeSize()

    • getParentTypeSize

      public static TypeSystem.TypeSize getParentTypeSize()

    • getInstanceSize

      public static int getInstanceSize()