GI.Gtk.Interfaces.SelectionModel

SelectionModel is an interface that extends the ListModel 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 most common selection modes such as SingleSelection, so you will only need to implement this interface if you want detailed control about how selections should be handled.

A SelectionModel supports a single boolean per item indicating if an item is selected or not. This can be queried via selectionModelIsSelected. When the selected state of one or more items changes, the model will emit the selectionChanged signal by calling the selectionModelSelectionChanged 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 itemsChanged signal are selected or not is up to the implementation.

Note that items added via itemsChanged may already be selected and no selectionChanged 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, 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.

Exported types

newtype SelectionModel

Memory-managed wrapper type.

Constructors

SelectionModel (ManagedPtr SelectionModel)

Instances

Eq SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

Methods

(==) :: SelectionModel -> SelectionModel -> Bool

(/=) :: SelectionModel -> SelectionModel -> Bool

GObject SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

ManagedPtrNewtype SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

Methods

toManagedPtr :: SelectionModel -> ManagedPtr SelectionModel

TypedObject SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

Methods

glibType :: IO GType

HasParentTypes SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

IsGValue (Maybe SelectionModel)

Convert SelectionModel to and from GValue. See toGValue and fromGValue.

Defined in GI.Gtk.Interfaces.SelectionModel

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe SelectionModel -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe SelectionModel)

type ParentTypes SelectionModel

Defined in GI.Gtk.Interfaces.SelectionModel

type ParentTypes SelectionModel = '[ListModel, Object]

class (GObject o, IsDescendantOf SelectionModel o) => IsSelectionModel o

Type class for types which can be safely cast to SelectionModel, for instance with toSelectionModel.

Instances

(GObject o, IsDescendantOf SelectionModel o) => IsSelectionModel o

Defined in GI.Gtk.Interfaces.SelectionModel

toSelectionModel :: (MonadIO m, IsSelectionModel o) => o -> m SelectionModel

Cast to SelectionModel, for types for which this is known to be safe. For general casts, use castTo.

Methods

Click to display all available methods, including inherited ones

Methods

bindProperty, bindPropertyFull, forceFloating, freezeNotify, getv, isFloating, isSelected, itemsChanged, notify, notifyByPspec, ref, refSink, runDispose, selectAll, selectItem, selectRange, selectionChanged, stealData, stealQdata, thawNotify, unref, unselectAll, unselectItem, unselectRange, watchClosure.

Getters

getData, getItem, getItemType, getNItems, getProperty, getQdata, getSelection, getSelectionInRange.

Setters

setData, setDataFull, setProperty, setSelection.

getSelection

selectionModelGetSelection

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> m Bitset

Returns: a Bitset containing all the values currently selected in model. If no items are selected, the bitset is empty. The bitset must not be modified.

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 selectionModelIsSelected or if you are only interested in a few consider selectionModelGetSelectionInRange.

getSelectionInRange

selectionModelGetSelectionInRange

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: start of the queired range

-> Word32

nItems: number of items in the queried range

-> m Bitset

Returns: A Bitset that matches the selection state for the given state with all other values being undefined. The bitset must not be modified.

Gets a set containing a set where the values in the range [position, position + n_items) match the selected state of the items in that range. All values outside that range are undefined.

This function is an optimization for selectionModelGetSelection when you are only interested in part of the model's selected state. A common use case is in response to the selectionChanged signal.

isSelected

selectionModelIsSelected

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the position of the item to query

-> m Bool

Returns: True if the item is selected

Checks if the given item is selected.

selectAll

selectionModelSelectAll

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean that all items are now selected.

Requests to select all items in the model.

selectItem

selectionModelSelectItem

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the position of the item to select

-> Bool

unselectRest: whether previously selected items should be unselected

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean the item was selected.

Requests to select an item in the model.

selectRange

selectionModelSelectRange

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the first item to select

-> Word32

nItems: the number of items to select

-> Bool

unselectRest: whether previously selected items should be unselected

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean the range was selected.

Requests to select a range of items in the model.

selectionChanged

selectionModelSelectionChanged

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the first changed item

-> Word32

nItems: the number of changed items

-> m ()

Helper function for implementations of SelectionModel. Call this when a the selection changes to emit the selectionChanged signal.

setSelection

selectionModelSetSelection

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Bitset

selected: bitmask specifying if items should be selected or unselected

-> Bitset

mask: bitmask specifying which items should be updated

-> m Bool

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.

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 code

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.

unselectAll

selectionModelUnselectAll

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean that all items are now unselected.

Requests to unselect all items in the model.

unselectItem

selectionModelUnselectItem

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the position of the item to unselect

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean the item was unselected.

Requests to unselect an item in the model.

unselectRange

selectionModelUnselectRange

Arguments

:: (HasCallStack, MonadIO m, IsSelectionModel a)

=> a

model: a SelectionModel

-> Word32

position: the first item to unselect

-> Word32

nItems: the number of items to unselect

-> m Bool

Returns: True if this action was supported and no fallback should be tried. This does not mean the range was unselected.

Requests to unselect a range of items in the model.

Signals

selectionChanged

type C_SelectionModelSelectionChangedCallback = Ptr () -> Word32 -> Word32 -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type SelectionModelSelectionChangedCallback

Arguments

 = Word32

position: The first item that may have changed

-> Word32

nItems: number of items with changes

-> IO ()

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.

afterSelectionModelSelectionChanged :: (IsSelectionModel a, MonadIO m) => a -> SelectionModelSelectionChangedCallback -> m SignalHandlerId

Connect a signal handler for the selectionChanged signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after selectionModel #selectionChanged callback

genClosure_SelectionModelSelectionChanged :: MonadIO m => SelectionModelSelectionChangedCallback -> m (GClosure C_SelectionModelSelectionChangedCallback)

Wrap the callback into a GClosure.

mk_SelectionModelSelectionChangedCallback :: C_SelectionModelSelectionChangedCallback -> IO (FunPtr C_SelectionModelSelectionChangedCallback)

Generate a function pointer callable from C code, from a C_SelectionModelSelectionChangedCallback.

noSelectionModelSelectionChangedCallback :: Maybe SelectionModelSelectionChangedCallback

A convenience synonym for Nothing :: Maybe SelectionModelSelectionChangedCallback.

onSelectionModelSelectionChanged :: (IsSelectionModel a, MonadIO m) => a -> SelectionModelSelectionChangedCallback -> m SignalHandlerId

Connect a signal handler for the selectionChanged signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on selectionModel #selectionChanged callback

wrap_SelectionModelSelectionChangedCallback :: SelectionModelSelectionChangedCallback -> C_SelectionModelSelectionChangedCallback

Wrap a SelectionModelSelectionChangedCallback into a C_SelectionModelSelectionChangedCallback.