Graphics.UI.Gtk.ModelView.TreeSelection

The selection object for TreeView

Detail

The TreeSelection object is a helper object to manage the selection for a TreeView widget. The TreeSelection object is automatically created when a new TreeView widget is created, and cannot exist independentally of this widget. The primary reason the TreeSelection objects exists is for cleanliness of code and API. That is, there is no conceptual reason all these functions could not be methods on the TreeView widget instead of a separate function.

The TreeSelection object is gotten from a TreeView by calling treeViewGetSelection. It can be manipulated to check the selection status of the tree, as well as select and deselect individual rows. Selection is done completely on the TreeView side. As a result, multiple views of the same model can have completely different selections. Additionally, you cannot change the selection of a row on the model that is not currently displayed by the view without expanding its parents first.

One of the important things to remember when monitoring the selection of a view is that the "changed" signal is mostly a hint. That is, it may only emit one signal when a range of rows is selected. Additionally, it may on occasion emit a "changed" signal when nothing has happened (mostly as a result of programmers calling select_row on an already selected row).

Class Hierarchy

| GObject
| +----TreeSelection

Types

data TreeSelection

Instances

Eq TreeSelection

Methods

(==) :: TreeSelection -> TreeSelection -> Bool

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

Ord TreeSelection

Methods

compare :: TreeSelection -> TreeSelection -> Ordering

(<) :: TreeSelection -> TreeSelection -> Bool

(<=) :: TreeSelection -> TreeSelection -> Bool

(>) :: TreeSelection -> TreeSelection -> Bool

(>=) :: TreeSelection -> TreeSelection -> Bool

max :: TreeSelection -> TreeSelection -> TreeSelection

min :: TreeSelection -> TreeSelection -> TreeSelection

GObjectClass TreeSelection

Methods

toGObject :: TreeSelection -> GObject

unsafeCastGObject :: GObject -> TreeSelection

TreeSelectionClass TreeSelection

class GObjectClass o => TreeSelectionClass o

Instances

TreeSelectionClass TreeSelection

castToTreeSelection :: GObjectClass obj => obj -> TreeSelection

gTypeTreeSelection :: GType

toTreeSelection :: TreeSelectionClass o => o -> TreeSelection

data SelectionMode

Mode in which selections can be performed

• There is a deprecated entry SelectionExtended which should have the same value as SelectionMultiple. C2HS chokes on that construct.

Constructors

SelectionNone

SelectionSingle

SelectionBrowse

SelectionMultiple

Instances

Enum SelectionMode

Methods

succ :: SelectionMode -> SelectionMode

pred :: SelectionMode -> SelectionMode

toEnum :: Int -> SelectionMode

fromEnum :: SelectionMode -> Int

enumFrom :: SelectionMode -> [SelectionMode]

enumFromThen :: SelectionMode -> SelectionMode -> [SelectionMode]

enumFromTo :: SelectionMode -> SelectionMode -> [SelectionMode]

enumFromThenTo :: SelectionMode -> SelectionMode -> SelectionMode -> [SelectionMode]

Eq SelectionMode

Methods

(==) :: SelectionMode -> SelectionMode -> Bool

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

Show SelectionMode

Methods

showsPrec :: Int -> SelectionMode -> ShowS

show :: SelectionMode -> String

showList :: [SelectionMode] -> ShowS

type TreeSelectionCB = TreePath -> IO Bool

Callback type for a function that is called everytime the selection changes. This function is set with treeSelectionSetSelectFunction.

type TreeSelectionForeachCB = TreeIter -> IO ()

Callback function type for treeSelectionSelectedForeach.

Methods

treeSelectionSetMode :: TreeSelectionClass self => self -> SelectionMode -> IO ()

Set single or multiple choice.

treeSelectionGetMode :: TreeSelectionClass self => self -> IO SelectionMode

Gets the selection mode.

treeSelectionSetSelectFunction :: TreeSelectionClass self => self -> TreeSelectionCB -> IO ()

Set a callback function if selection changes.

• If set, this function is called before any node is selected or unselected, giving some control over which nodes are selected. The select function should return True if the state of the node may be toggled, and False if the state of the node should be left unchanged.

treeSelectionGetTreeView :: TreeSelectionClass self => self -> IO TreeView

Retrieve the TreeView widget that this TreeSelection works on.

treeSelectionGetSelected :: TreeSelectionClass self => self -> IO (Maybe TreeIter)

Retrieves the selection of a single choice TreeSelection.

treeSelectionSelectedForeach :: TreeSelectionClass self => self -> TreeSelectionForeachCB -> IO ()

Execute a function for each selected node.

• Note that you cannot modify the tree or selection from within this function. Hence, treeSelectionGetSelectedRows might be more useful.

treeSelectionGetSelectedRows

Arguments

:: TreeSelectionClass self

=> self

-> IO [TreePath]

returns a list containing a TreePath for each selected row.

Creates a list of paths of all selected rows.

• Additionally, if you are planning on modifying the model after calling this function, you may want to convert the returned list into a list of TreeRowReferences. To do this, you can use treeRowReferenceNew.
• Available since Gtk+ version 2.2

treeSelectionCountSelectedRows

Arguments

:: TreeSelectionClass self

=> self

-> IO Int

returns The number of rows selected.

Returns the number of rows that are selected.

• Available since Gtk+ version 2.2

treeSelectionSelectPath :: TreeSelectionClass self => self -> TreePath -> IO ()

Select a specific item by TreePath.

treeSelectionUnselectPath :: TreeSelectionClass self => self -> TreePath -> IO ()

Deselect a specific item by TreePath.

treeSelectionPathIsSelected :: TreeSelectionClass self => self -> TreePath -> IO Bool

Returns True if the row at the given path is currently selected.

treeSelectionSelectIter :: TreeSelectionClass self => self -> TreeIter -> IO ()

Select a specific item by TreeIter.

treeSelectionUnselectIter :: TreeSelectionClass self => self -> TreeIter -> IO ()

Deselect a specific item by TreeIter.

treeSelectionIterIsSelected :: TreeSelectionClass self => self -> TreeIter -> IO Bool

Returns True if the row at the given iter is currently selected.

treeSelectionSelectAll :: TreeSelectionClass self => self -> IO ()

Selects all the nodes. The tree selection must be set to SelectionMultiple mode.

treeSelectionUnselectAll :: TreeSelectionClass self => self -> IO ()

Unselects all the nodes.

treeSelectionSelectRange

Arguments

:: TreeSelectionClass self

=> self

-> TreePath

startPath - The initial node of the range.

-> TreePath

endPath - The final node of the range.

-> IO ()

Selects a range of nodes, determined by startPath and endPath inclusive. selection must be set to SelectionMultiple mode.

treeSelectionUnselectRange

Arguments

:: TreeSelectionClass self

=> self

-> TreePath

startPath - The initial node of the range.

-> TreePath

endPath - The initial node of the range.

-> IO ()

Unselects a range of nodes, determined by startPath and endPath inclusive.

• Available since Gtk+ version 2.2

Attributes

treeSelectionMode :: TreeSelectionClass self => Attr self SelectionMode

'mode' property. See treeSelectionGetMode and treeSelectionSetMode

Signals

treeSelectionSelectionChanged :: TreeSelectionClass self => Signal self (IO ())

Emitted whenever the selection has (possibly) changed. Please note that this signal is mostly a hint. It may only be emitted once when a range of rows are selected, and it may occasionally be emitted when nothing has happened.