QWidgetAction ¶

概要 ¶

详细描述 ¶

应用程序中的大多数动作被表示成菜单项或工具栏按钮。不管怎样，更复杂的 Widget 有时是必要的。例如，文字处理程序缩放动作可以被变现使用 QComboBox 在 QToolBar ，呈现不同缩放级别的范围。 QToolBar 提供 insertWidget() as convenience function for inserting a single widget. However if you want to implement an action that uses custom widgets for visualization in multiple containers then you have to subclass QWidgetAction .

若 QWidgetAction is added for example to a QToolBar then createWidget() is called. Reimplementations of that function should create a new custom widget with the specified parent.

若动作从容器 Widget 中被移除则 deleteWidget() is called with the previously created custom widget as argument. The default implementation hides the widget and deletes it using deleteLater() .

If you have only one single custom widget then you can set it as default widget using setDefaultWidget() . That widget will then be used if the action is added to a QToolBar , or in general to an action container that supports QWidgetAction . If a QWidgetAction with only a default widget is added to two toolbars at the same time then the default widget is shown only in the first toolbar the action was added to. QWidgetAction takes over ownership of the default widget.

Note that it is up to the widget to activate the action, for example by reimplementing mouse event handlers and calling trigger() .

macOS : If you add a widget to a menu in the application’s menu bar on macOS, the widget will be added and it will function but with some limitations:

1. The widget is reparented away from the QMenu to the native menu view. If you show the menu in some other place (e.g. as a popup menu), the widget will not be there.

2. Focus/Keyboard handling of the widget is not possible.

3. Due to Apple’s design, mouse tracking on the widget currently does not work.

4. Connecting the triggered() signal to a slot that opens a modal dialog will cause a crash in macOS 10.4 (known bug acknowledged by Apple), a workaround is to use a QueuedConnection instead of a DirectConnection.

另请参阅

QAction QActionGroup QWidget

class QWidgetAction ( parent ) ¶

param parent

QObject

构造动作采用 parent .

PySide2.QtWidgets.QWidgetAction. createWidget ( parent ) ¶

参数

parent – QWidget

返回类型

QWidget

This function is called whenever the action is added to a container widget that supports custom widgets. If you don’t want a custom widget to be used as representation of the action in the specified parent widget then 0 should be returned.

另请参阅

deleteWidget()

PySide2.QtWidgets.QWidgetAction. createdWidgets ( ) ¶

返回类型

Returns the list of widgets that have been using createWidget() and are currently in use by widgets the action has been added to.

PySide2.QtWidgets.QWidgetAction. defaultWidget ( ) ¶

返回类型

QWidget

返回默认 Widget。

另请参阅

setDefaultWidget()

PySide2.QtWidgets.QWidgetAction. deleteWidget ( widget ) ¶

参数

widget – QWidget

This function is called whenever the action is removed from a container widget that displays the action using a custom widget previously created using createWidget() . The default implementation hides the widget and schedules it for deletion using deleteLater() .

另请参阅

createWidget()

PySide2.QtWidgets.QWidgetAction. releaseWidget ( widget ) ¶

参数

widget – QWidget

释放指定 widget .

Container widgets that support actions call this function when a widget action is removed.

另请参阅

requestWidget() deleteWidget() defaultWidget()

PySide2.QtWidgets.QWidgetAction. requestWidget ( parent ) ¶

参数

parent – QWidget

返回类型

QWidget

Returns a widget that represents the action, with the given parent .

Container widgets that support actions can call this function to request a widget as visual representation of the action.

另请参阅

releaseWidget() createWidget() defaultWidget()

PySide2.QtWidgets.QWidgetAction. setDefaultWidget ( w ) ¶

参数

w – QWidget

集 widget to be the default widget. The ownership is transferred to QWidgetAction . Unless createWidget() is reimplemented by a subclass to return a new widget the default widget is used when a container widget requests a widget through requestWidget() .

另请参阅

defaultWidget()