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com.trolltech.qt.gui
Enum QGraphicsView.OptimizationFlag

java.lang.Object
  extended by java.lang.Enum<QGraphicsView.OptimizationFlag>
      extended by com.trolltech.qt.gui.QGraphicsView.OptimizationFlag
All Implemented Interfaces:
QtEnumerator, java.io.Serializable, java.lang.Comparable<QGraphicsView.OptimizationFlag>
Enclosing class:
QGraphicsView

public static enum QGraphicsView.OptimizationFlag
extends java.lang.Enum<QGraphicsView.OptimizationFlag>
implements QtEnumerator

This enum describes flags that you can enable to improve rendering performance in QGraphicsView. By default, none of these flags are set. Note that setting a flag usually imposes a side effect, and this effect can vary between paint devices and platforms.


Enum Constant Summary
DontAdjustForAntialiasing
          Disables QGraphicsView's antialiasing auto-adjustment of exposed areas.
DontClipPainter
          QGraphicsView sometimes clips the painter when rendering the scene contents.
DontSavePainterState
          When rendering, QGraphicsView protects the painter state (see QPainter::save()) when rendering the background or foreground, and when rendering each item.
 
Method Summary
static QGraphicsView.OptimizationFlags createQFlags(QGraphicsView.OptimizationFlag... values)
           
static QGraphicsView.OptimizationFlag resolve(int value)
           
 int value()
          This function should return an integer value for the enum values of the enumeration that implements this interface.
static QGraphicsView.OptimizationFlag valueOf(java.lang.String name)
          Returns the enum constant of this type with the specified name.
static QGraphicsView.OptimizationFlag[] values()
          Returns an array containing the constants of this enum type, in the order they are declared.
 
Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 

Enum Constant Detail

DontClipPainter

public static final QGraphicsView.OptimizationFlag DontClipPainter

QGraphicsView sometimes clips the painter when rendering the scene contents. This can generally improve performance (e.g., rendering only small parts of a large pixmap), and protects against rendering mistakes (e.g., drawing outside bounding rectangles, or outside the exposed area). In some situations, however, the painter clip can slow down rendering; especially when all painting is restricted to inside exposed areas. By enabling this flag, QGraphicsView will completely disable its implicit clipping. Note that rendering artifacts from using a semi-transparent foreground or background brush can occur if clipping is disabled.


DontSavePainterState

public static final QGraphicsView.OptimizationFlag DontSavePainterState

When rendering, QGraphicsView protects the painter state (see QPainter::save()) when rendering the background or foreground, and when rendering each item. This allows you to leave the painter in an altered state (i.e., you can call QPainter::setPen() or QPainter::setBrush() without restoring the state after painting). However, if the items consistently do restore the state, you should enable this flag to prevent QGraphicsView from doing the same.


DontAdjustForAntialiasing

public static final QGraphicsView.OptimizationFlag DontAdjustForAntialiasing

Disables QGraphicsView's antialiasing auto-adjustment of exposed areas. Items that render antialiased lines on the boundaries of their QGraphicsItem::boundingRect() can end up rendering parts of the line outside. To prevent rendering artifacts, QGraphicsView expands all exposed regions by 2 pixels in all directions. If you enable this flag, QGraphicsView will no longer perform these adjustments, minimizing the areas that require redrawing, which improves performance. A common side effect is that items that do draw with antialiasing can leave painting traces behind on the scene as they are moved.

Method Detail

values

public static QGraphicsView.OptimizationFlag[] values()
Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
for (QGraphicsView.OptimizationFlag c : QGraphicsView.OptimizationFlag.values())
    System.out.println(c);

Returns:
an array containing the constants of this enum type, in the order they are declared

valueOf

public static QGraphicsView.OptimizationFlag valueOf(java.lang.String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:
name - the name of the enum constant to be returned.
Returns:
the enum constant with the specified name
Throws:
java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
java.lang.NullPointerException - if the argument is null

value

public int value()
Description copied from interface: QtEnumerator
This function should return an integer value for the enum values of the enumeration that implements this interface.

Specified by:
value in interface QtEnumerator

createQFlags

public static QGraphicsView.OptimizationFlags createQFlags(QGraphicsView.OptimizationFlag... values)

resolve

public static QGraphicsView.OptimizationFlag resolve(int value)

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