Graphics.UI.Gtk.ModelView.TreeSortable

The interface for sortable models used by TreeView

Detail

TreeSortable is an interface to be implemented by tree models which support sorting. The TreeView uses the methods provided by this interface to sort the model. As of now, only the TreeModelSort proxy supports the sortable interface. Thus, in order to enable sortable columns in a TreeView, it is necessary to wrap a ListStore or TreeStore model in a TreeModelSort.

A TreeViewColumn can be sorted by the user though clicking into the column's header. The rows in the view will then be sorted by the sorting function set for that column. Specifically, a set of sorting functions must be set using the interface provided in this module. Each sorting function is associated with a SortColumnId, which is some positive number. A tree view column is then associated with the sorting function by passing the SortColumnId to treeViewColumnSetSortColumnId. There exists one special SortColumnId, namely treeSortableDefaultSortColumnId for which a default sorting function can be set. If no such function is set, the order of the rows is the order in which they are stored in the model.

Class Hierarchy

| GInterface
| +----TreeSortable

Types

data TreeSortable

Instances

Eq TreeSortable

Ord TreeSortable

GObjectClass TreeSortable

TreeSortableClass TreeSortable

class GObjectClass o => TreeSortableClass o

Instances

TreeSortableClass TreeModelSort

TreeSortableClass TreeSortable

TreeSortableClass (TypedTreeModelSort row)

castToTreeSortable :: GObjectClass obj => obj -> TreeSortable

gTypeTreeSortable :: GType

toTreeSortable :: TreeSortableClass o => o -> TreeSortable

type SortColumnId = Int

ID number of a sort column.

• A SortColumnId is a logical number to which a sorting function can be associated. The number does not have to coincide with any column number.

Constants

treeSortableDefaultSortColumnId :: SortColumnId

A special SortColumnId to indicated that the default sorting function is used.

Methods

treeSortableGetSortColumnId

Arguments

:: TreeSortableClass self

=> self

-> IO (SortType, Bool, SortColumnId)

(type, columnSet, sortColumnId) returns True in columnSet if sortColumnId is not treeSortableDefaultSortColumnId. The type value indicates increasing or decreasing ordering.

Query the sort column id that is currently in use. The return value may be the special constant treeSortableDefaultSortColumnId in which case the returned Boolean flag is False.

treeSortableSetSortColumnId

Arguments

:: TreeSortableClass self

=> self

-> SortColumnId

sortColumnId - the sort column id to set

-> SortType

order - The sort order of the column

-> IO ()

Sets the current sort column to be sortColumnId. The sortable will resort itself to reflect this change, after emitting a sortColumnChanged signal. If sortColumnId is treeSortableDefaultSortColumnId, then the default sort function will be used, if it is set. Note that this function is mainly used by the view and that the user program should simply set the SortColumnId of the TreeViewColumns.

treeSortableSetSortFunc

Arguments

:: TreeSortableClass self

=> self

-> SortColumnId

sortColumnId - the sort column id to set the function for

-> (TreeIter -> TreeIter -> IO Ordering)

sortFunc - The comparison function

-> IO ()

Sets the comparison function used when sorting to be sortFunc. If the current sort column id of self is the same as sortColumnId, then the model will sort using this function.

treeSortableSetDefaultSortFunc

Arguments

:: TreeSortableClass self

=> self

-> Maybe (TreeIter -> TreeIter -> IO Ordering)

sortFunc - The comparison function or Nothing to use default comparison function.

-> IO ()

Sets the default comparison function used when sorting to be sortFunc. If the current sort column id of self is treeSortableDefaultSortColumnId then the model will sort using this function.

| If sortFunc is Nothing, then there will be no default comparison function. This means that once the model has been sorted, it can't go back to the default state. In this case, when the current sort column id of sortable is TreeSortableDefaultSortColumnId, the model will be unsorted.

treeSortableHasDefaultSortFunc

Arguments

:: TreeSortableClass self

=> self

-> IO Bool

returns True, if the model has a default sort function

Returns True if the model has a default sort function. This is used primarily by TreeViewColumns in order to determine if a model has a default ordering or if the entries are retrieved in the sequence in which they are stored in the model.

treeSortableSortColumnChanged :: TreeSortableClass self => self -> IO ()

Emits a sortColumnChanged signal on the model.

Signals

sortColumnChanged :: TreeSortableClass self => Signal self (IO ())