内容

• 公共类型
• 公共函数
• 公共变量
• 静态公共成员
• 详细描述

QStyleOptionGraphicsItem 类

QStyleOptionGraphicsItem class is used to describe the parameters needed to draw a QGraphicsItem . 更多...

头：	#include <QStyleOptionGraphicsItem>
qmake:	QT += widgets
Since:	Qt 4.2
继承：	QStyleOption

• 所有成员列表，包括继承成员
• 过时成员

公共类型

enum	StyleOptionType { Type }
enum	StyleOptionVersion { Version }

公共函数

	QStyleOptionGraphicsItem ()
	QStyleOptionGraphicsItem (const QStyleOptionGraphicsItem & other )

• 2 公共函数继承自 QStyleOption

公共变量

QRectF

exposedRect

• 8 public variables inherited from QStyleOption

静态公共成员

qreal

levelOfDetailFromTransform (const QTransform & worldTransform )

详细描述

QStyleOptionGraphicsItem class is used to describe the parameters needed to draw a QGraphicsItem .

For performance reasons, the access to the member variables is direct (i.e., using the . or -> operator). This low-level feel makes the structures straightforward to use and emphasizes that these are simply parameters.

对于可以如何使用样式选项的演示范例，见 样式 范例。

另请参阅 QStyleOption and QGraphicsItem::paint ().

成员类型文档编制

enum QStyleOptionGraphicsItem:: StyleOptionType

This enum is used to hold information about the type of the style option, and is defined for each QStyleOption 子类。

常量	值	描述
QStyleOptionGraphicsItem::Type	SO_GraphicsItem	提供样式选项的类型 ( SO_GraphicsItem 对于此类)。

类型内部使用通过 QStyleOption ，其子类，和 qstyleoption_cast () to determine the type of style option. In general you do not need to worry about this unless you want to create your own QStyleOption subclass and your own styles.

另请参阅 StyleOptionVersion .

enum QStyleOptionGraphicsItem:: StyleOptionVersion

This enum is used to hold information about the version of the style option, and is defined for each QStyleOption 子类。

常量	值	描述
QStyleOptionGraphicsItem::Version	1	1

版本的使用通过 QStyleOption 子类以实现扩展在不破坏兼容性的情况下。若使用 qstyleoption_cast (), you normally do not need to check it.

另请参阅 StyleOptionType .

成员函数文档编制

QStyleOptionGraphicsItem:: QStyleOptionGraphicsItem ()

构造 QStyleOptionGraphicsItem .

QStyleOptionGraphicsItem:: QStyleOptionGraphicsItem (const QStyleOptionGraphicsItem & other )

构造副本为 other .

[static] qreal QStyleOptionGraphicsItem:: levelOfDetailFromTransform (const QTransform & worldTransform )

Returns the level of detail from the worldTransform .

Its value represents the maximum value of the height and width of a unity rectangle, mapped using the worldTransform of the painter used to draw the item. By default, if no transformations are applied, its value is 1. If zoomed out 1:2, the level of detail will be 0.5, and if zoomed in 2:1, its value is 2.

该函数在 Qt 4.6 引入。

另请参阅 QGraphicsScene::minimumRenderSize ().

成员变量文档编制

QRectF QStyleOptionGraphicsItem:: exposedRect

This variable holds the exposed rectangle, in item coordinates

Make use of this rectangle to speed up item drawing when only parts of the item are exposed. If the whole item is exposed, this rectangle will be the same as QGraphicsItem::boundingRect ().

This member is only initialized for items that have the QGraphicsItem::ItemUsesExtendedStyleOption flag set.