PySide6.QtGui.QDrag

class QDrag

The QDrag class provides support for MIME-based drag and drop data transfer. More…

Synopsis

Methods

• def __init__()

• def defaultAction()

• def dragCursor()

• def exec()

• def exec_()

• def hotSpot()

• def mimeData()

• def pixmap()

• def setDragCursor()

• def setHotSpot()

• def setMimeData()

• def setPixmap()

• def source()

• def supportedActions()

• def target()

Signals

• def actionChanged()

• def targetChanged()

Static functions

• def cancel()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

Drag and drop is an intuitive way for users to copy or move data around in an application, and is used in many desktop environments as a mechanism for copying data between applications. Drag and drop support in Qt is centered around the QDrag class that handles most of the details of a drag and drop operation.

The data to be transferred by the drag and drop operation is contained in a QMimeData object. This is specified with the setMimeData() function in the following way:

drag = QDrag(self)
mimeData = QMimeData()
mimeData.setText(commentEdit.toPlainText())
drag.setMimeData(mimeData)

Note that setMimeData() assigns ownership of the QMimeData object to the QDrag object. The QDrag must be constructed on the heap with a parent QObject to ensure that Qt can clean up after the drag and drop operation has been completed.

A pixmap can be used to represent the data while the drag is in progress, and will move with the cursor to the drop target. This pixmap typically shows an icon that represents the MIME type of the data being transferred, but any pixmap can be set with setPixmap() . The cursor’s hot spot can be given a position relative to the top-left corner of the pixmap with the setHotSpot() function. The following code positions the pixmap so that the cursor’s hot spot points to the center of its bottom edge:

drag.setHotSpot(QPoint(drag.pixmap().width()/2,
                        drag.pixmap().height()))

Note

On X11, the pixmap may not be able to keep up with the mouse movements if the hot spot causes the pixmap to be displayed directly under the cursor.

The source and target widgets can be found with source() and target() . These functions are often used to determine whether drag and drop operations started and finished at the same widget, so that special behavior can be implemented.

QDrag only deals with the drag and drop operation itself. It is up to the developer to decide when a drag operation begins, and how a QDrag object should be constructed and used. For a given widget, it is often necessary to reimplement mousePressEvent() to determine whether the user has pressed a mouse button, and reimplement mouseMoveEvent() to check whether a QDrag is required.

See also

Drag and Drop QClipboard QMimeDataDraggable Icons ExampleDraggable Text ExampleDrop Site Example

__init__(dragSource)

Parameters:

dragSource – QObject

Constructs a new drag object for the widget specified by dragSource.

actionChanged(action)

Parameters:

action – DropAction

This signal is emitted when the action associated with the drag changes.

See also

targetChanged()

static cancel()

Cancels a drag operation initiated by Qt.

Note

This is currently implemented on Windows and X11.

See also

exec()

defaultAction()

Return type:

DropAction

Returns the default proposed drop action for this drag operation.

See also

exec() supportedActions()

dragCursor(action)

Parameters:

action – DropAction

Return type:

QPixmap

Returns the drag cursor for the action.

See also

setDragCursor()

exec([supportedActions=Qt.MoveAction])

Parameters:

supportedActions – Combination of DropAction

Return type:

DropAction

Starts the drag and drop operation and returns a value indicating the requested drop action when it is completed. The drop actions that the user can choose from are specified in supportedActions. The default proposed action will be selected among the allowed actions in the following order: Move, Copy and Link.

Note

On Linux and macOS, the drag and drop operation can take some time, but this function does not block the event loop. Other events are still delivered to the application while the operation is performed. On Windows, the Qt event loop is blocked during the operation.

See also

cancel()

exec(supportedActions, defaultAction)

Parameters:

• supportedActions – Combination of DropAction

• defaultAction – DropAction

Return type:

DropAction

Starts the drag and drop operation and returns a value indicating the requested drop action when it is completed. The drop actions that the user can choose from are specified in supportedActions.

The defaultDropAction determines which action will be proposed when the user performs a drag without using modifier keys.

Note

On Linux and macOS, the drag and drop operation can take some time, but this function does not block the event loop. Other events are still delivered to the application while the operation is performed. On Windows, the Qt event loop is blocked during the operation. However, exec() on Windows causes processEvents() to be called frequently to keep the GUI responsive. If any loops or operations are called while a drag operation is active, it will block the drag operation.

exec_([supportedActions=Qt.MoveAction])

Parameters:

supportedActions – Combination of DropAction

Return type:

DropAction

exec_(arg__1, arg__2)

Parameters:

• arg__1 – Combination of DropAction

• arg__2 – DropAction

Return type:

DropAction

hotSpot()

Return type:

QPoint

Returns the position of the hot spot relative to the top-left corner of the cursor.

See also

setHotSpot()

mimeData()

Return type:

QMimeData

Returns the MIME data that is encapsulated by the drag object.

See also

setMimeData()

pixmap()

Return type:

QPixmap

Returns the pixmap used to represent the data in a drag and drop operation.

See also

setPixmap()

setDragCursor(cursor, action)

Parameters:

• cursor – QPixmap

• action – DropAction

Sets the drag cursor for the action. This allows you to override the default native cursors. To revert to using the native cursor for action pass in a null QPixmap as cursor.

Note: setting the drag cursor for IgnoreAction may not work on all platforms. X11 and macOS has been tested to work. Windows does not support it.

See also

dragCursor()

setHotSpot(hotspot)

Parameters:

hotspot – QPoint

Sets the position of the hot spot relative to the top-left corner of the pixmap used to the point specified by hotspot.

Note

on X11, the pixmap may not be able to keep up with the mouse movements if the hot spot causes the pixmap to be displayed directly under the cursor.

See also

hotSpot()

setMimeData(data)

Parameters:

data – QMimeData

Sets the data to be sent to the given MIME data. Ownership of the data is transferred to the QDrag object.

See also

mimeData()

setPixmap(arg__1)

Parameters:

arg__1 – QPixmap

Sets pixmap as the pixmap used to represent the data in a drag and drop operation. You can only set a pixmap before the drag is started.

See also

pixmap()

source()

Return type:

QObject

Returns the source of the drag object. This is the widget where the drag and drop operation originated.

supportedActions()

Return type:

Combination of DropAction

Returns the set of possible drop actions for this drag operation.

See also

exec() defaultAction()

target()

Return type:

QObject

Returns the target of the drag and drop operation. This is the widget where the drag object was dropped.

targetChanged(newTarget)

Parameters:

newTarget – QObject

This signal is emitted when the target of the drag and drop operation changes, with newTarget the new target.

See also

target() actionChanged()