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QTreeWidget Class Reference

The QTreeWidget class provides a tree view that uses a predefined tree model. More...

#include <QTreeWidget>

Inherits QTreeView.

Writable Properties

Read-Only Properties

Public Functions

Public Slots

Signals

Static Public Members

Protected Functions

Protected Slots


Detailed Description

The QTreeWidget class provides a tree view that uses a predefined tree model.

The QTreeWidget class is a convenience class that provides a standard tree widget with a classic item-based interface similar to that used by the QListView class in Qt 3. This class is based on Qt's Model/View architecture and uses a default model to hold items, each of which is a QTreeWidgetItem.

Developers who do not need the flexibility of the Model/View framework can use this class to create simple hierarchical lists very easily. A more flexible approach involves combining a QTreeView with a standard item model. This allows the storage of data to be separated from its representation.

In its simplest form, a tree widget can be constructed in the following way:

        QTreeWidget *treeWidget;
        treeWidget = new QTreeWidget(this);

Before items can be added to the tree widget, the number of columns must be set with setColumnCount(). This allows each item to have one or more labels or other decorations. The number of columns in use can be found with the columnCount() function.

The tree can have a header that contains a section for each column in the widget. It is easiest to set up the labels for each section by supplying a list of strings with setHeaderLabels(), but a custom header can be constructed with a QTreeWidgetItem and inserted into the tree with the setHeaderItem() function.

The items in the tree can be sorted by column according to a predefined sort order. If sorting is enabled, the user can sort the items by clicking on a column header. Sorting can be enabled or disabled by calling setSortingEnabled(). The isSortingEnabled() function indicates whether sorting is enabled.

See also Model/View Programming and QTreeWidgetItem.


Property Documentation

columnCount : int

This property holds the number of columns displayed in the tree widget.

Access functions:

sortingEnabled : bool

This property holds whether the items in the tree widget can be sorted by clicking on the header.

Access functions:

topLevelItemCount : int

This property holds the number of top-level items.

Access functions:


Member Function Documentation

QTreeWidget::QTreeWidget ( QWidget * parent = 0 )

Constructs a tree widget with the given parent.

QTreeWidget::~QTreeWidget ()

Destroys the tree widget and all its items.

void QTreeWidget::aboutToShowContextMenu ( QMenu * menu, QTreeWidgetItem * item, int column )   [signal]

This signal is emitted when the tree widget is about to show a context menu specified by menu. The menu is actived for the specified item and column.

void QTreeWidget::appendTopLevelItem ( QTreeWidgetItem * item )

Appends the item as a top-level item in the widget.

See also insertToplevelItem().

void QTreeWidget::clear ()   [slot]

Clears the tree widget by removing all of its items and selections.

void QTreeWidget::clicked ( QTreeWidgetItem * item, int column, Qt::MouseButton button, Qt::KeyboardModifiers modifiers )   [signal]

void QTreeWidget::closeItem ( const QTreeWidgetItem * item )   [slot]

Closes the item. This causes the tree containing the item's children to be collapsed.

void QTreeWidget::closePersistentEditor ( QTreeWidgetItem * item, int column = 0 )

Closes the persistent editor for the item in the given column.

This function has no effect if no persistent editor is open for this combination of item and column.

void QTreeWidget::collapsed ( QTreeWidgetItem * item )   [signal]

This signal is emitted when the specified item is collapsed so that none of its children are displayed.

See also isItemOpen().

void QTreeWidget::currentChanged ( QTreeWidgetItem * current, QTreeWidgetItem * previous )   [signal]

This signal is emitted when the current item changes. The current item is specified by current, and this replaces the previous current item.

QTreeWidgetItem * QTreeWidget::currentItem () const

Returns the current item in the tree widget.

See also setCurrentItem().

void QTreeWidget::doubleClicked ( QTreeWidgetItem * item, int column, Qt::MouseButton button, Qt::KeyboardModifiers modifiers )   [signal]

void QTreeWidget::ensureVisible ( const QTreeWidgetItem * item )   [slot]

Ensures that the item is visible, scrolling the view if necessary.

void QTreeWidget::expanded ( QTreeWidgetItem * item )   [signal]

This signal is emitted when the specified item is expanded so that all of its children are displayed.

See also isItemOpen().

QList<QTreeWidgetItem *> QTreeWidget::findItems ( const QString & text, QAbstractItemModel::MatchFlags flags = QAbstractItemModel::MatchDefault ) const

Returns a list of items that match the given text, using the criteria given by the flags (see QAbstractItemModel::MatchFlags).

QTreeWidgetItem * QTreeWidget::headerItem () const

Returns the item used for the tree widget's header.

See also setHeaderItem().

int QTreeWidget::indexOfTopLevelItem ( QTreeWidgetItem * item )

Returns the index of the given top-level item, or -1 if the item cannot be found.

void QTreeWidget::insertTopLevelItem ( int index, QTreeWidgetItem * item )

Inserts the item at index in the top level in the view.

See also appendToplevelItem().

bool QTreeWidget::isItemHidden ( const QTreeWidgetItem * item ) const

Returns true if the item is explicitly hidden, otherwise returns false.

bool QTreeWidget::isItemOpen ( const QTreeWidgetItem * item ) const

Returns true if the given item is open; otherwise returns false.

bool QTreeWidget::isItemVisible ( const QTreeWidgetItem * item ) const

Returns true if the item is in the viewport; otherwise returns false.

bool QTreeWidget::isSelected ( const QTreeWidgetItem * item ) const

Returns true if the item is selected and not-hidden and does not have hidden parents; otherwise returns false.

void QTreeWidget::itemChanged ( QTreeWidgetItem * item, int column )   [signal]

This signal is emitted when the contents of the column in the specified item changes.

void QTreeWidget::itemEntered ( QTreeWidgetItem * item, int column, Qt::MouseButton button, Qt::KeyboardModifiers modifiers )   [signal]

void QTreeWidget::keyPressed ( QTreeWidgetItem * item, int column, Qt::Key key, Qt::KeyboardModifiers modifiers )   [signal]

void QTreeWidget::openItem ( const QTreeWidgetItem * item )   [slot]

Opens the item. This causes the tree containing the item's children to be expanded.

void QTreeWidget::openPersistentEditor ( QTreeWidgetItem * item, int column = 0 )

Opens a persistent editor for the item in the given column.

void QTreeWidget::pressed ( QTreeWidgetItem * item, int column, Qt::MouseButton button, Qt::KeyboardModifiers modifiers )   [signal]

void QTreeWidget::returnPressed ( QTreeWidgetItem * item, int column )   [signal]

This signal is emitted when the return key is pressed inside the widget.

The specified item and column had the focus when the return key was pressed. If no item had the focus, item is 0 and column is -1.

See also keyPressed().

QList<QTreeWidgetItem *> QTreeWidget::selectedItems () const

Returns a list of all selected non-hidden items.

void QTreeWidget::selectionChanged ()   [signal]

This signal is emitted when the selection changes in the tree widget. The current selection can be found with selectedItems().

void QTreeWidget::setCurrentItem ( QTreeWidgetItem * item )

Sets the current item in the tree widget.

See also currentItem().

void QTreeWidget::setHeaderItem ( QTreeWidgetItem * item )

Sets the header item for the tree widget. The label for each column in the header is supplied by the corresponding label in the item.

See also headerItem().

void QTreeWidget::setHeaderLabels ( const QStringList & labels )

Adds a column in the header for each item in the labels list, and sets the label for each column.

void QTreeWidget::setItemHidden ( const QTreeWidgetItem * item, bool hide )

Hides the given item if hide is true; otherwise shows the item.

void QTreeWidget::setSelected ( const QTreeWidgetItem * item, bool select )

If select is true, the given item is selected; otherwise it is deselected.

void QTreeWidget::sortItems ( int column, Qt::SortOrder order )

Sorts the items in the widget in the specified order by the values in the given column.

void QTreeWidget::sortItems ( int column )   [slot]

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Sorts all items in the widget by the values in the given column. The items are sorted in the order given by the sort indicator in the header.

QTreeWidgetItem * QTreeWidget::takeTopLevelItem ( int index )

Removes the top-level item at the given index in the tree and returns it, otherwise returns 0;

QTreeWidgetItem * QTreeWidget::topLevelItem ( int index ) const

Returns the top level item at the given index, or 0 if the item does not exist.


Copyright © 2004 Trolltech Trademarks
Qt 4.0.0-b1