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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QObject
com.trolltech.qt.gui.QImageIOPlugin
public abstract class QImageIOPlugin
The QImageIOPlugin
class defines an interface for writing an image format plugin. QImageIOPlugin
is a factory for creating QImageIOHandler
objects, which are used internally by QImageReader
and QImageWriter
to add support for different image formats to Qt.
Writing an image I/O plugin is achieved by subclassing this base class, reimplementing the pure virtual functions capabilities()
, create()
, and keys()
, and exporting the class with the Q_EXPORT_PLUGIN2() macro. See How to Create Qt Plugins for details.
An image format plugin can support three capabilities: reading (CanRead
), writing (CanWrite
) and incremental reading (CanReadIncremental
). Reimplement capabilities()
in you subclass to expose the capabilities of your image format.
create()
should create an instance of your QImageIOHandler
subclass, with the provided device and format properly set, and return this handler. You must also reimplement keys()
so that Qt knows which image formats your plugin supports.
Different plugins can support different capabilities. For example, you may have one plugin that supports reading the GIF format, and another that supports writing. Qt will select the correct plugin for the job, depending on the return value of capabilities()
. If several plugins support the same capability, Qt will select one arbitrarily.
QImageIOHandler
, and How to Create Qt Plugins.
Nested Class Summary | |
---|---|
static class |
QImageIOPlugin.Capabilities
This is a flags class for com.trolltech.qt.gui.QImageIOPlugin.Capability |
static class |
QImageIOPlugin.Capability
This enum describes the capabilities of a QImageIOPlugin . |
Nested classes/interfaces inherited from class com.trolltech.qt.QtJambiObject |
---|
QtJambiObject.QPrivateConstructor |
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter |
---|
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I> |
Constructor Summary | |
---|---|
|
QImageIOPlugin()
Constructs an image plugin with the given parent. |
|
QImageIOPlugin(QObject parent)
Constructs an image plugin with the given parent. |
protected |
QImageIOPlugin(QtJambiObject.QPrivateConstructor p)
This method is internal to Qt Jambi. |
Method Summary | |
---|---|
long |
__qt_cast_to_QAbstractFactory(long ptr)
This method is internal to Qt Jambi. |
long |
__qt_cast_to_QAbstractImageIOHandlerFactory(long ptr)
This method is internal to Qt Jambi. |
abstract QImageIOPlugin.Capabilities |
capabilities(QIODevice device,
QByteArray format)
Returns the capabilities on the plugin, based on the data in device and the format format. |
abstract QImageIOHandler |
create(QIODevice device,
QByteArray format)
Creates and returns a QImageIOHandler subclass, with device and format set. |
static QImageIOPlugin |
fromNativePointer(QNativePointer nativePointer)
|
abstract java.util.List<java.lang.String> |
keys()
Returns the list of image keys this plugin supports. |
Methods inherited from class com.trolltech.qt.core.QObject |
---|
blockSignals, childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, signalsBlocked, startTimer, thread, timerEvent, toString, userProperty |
Methods inherited from class com.trolltech.qt.QtJambiObject |
---|
disableGarbageCollection, dispose, disposed, equals, finalize, nativeId, nativePointer, reassignNativeResources, reenableGarbageCollection, setJavaOwnership, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
---|
__qt_signalInitialization, disconnect, disconnect, signalSender |
Methods inherited from class java.lang.Object |
---|
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
---|
public QImageIOPlugin()
public QImageIOPlugin(QObject parent)
protected QImageIOPlugin(QtJambiObject.QPrivateConstructor p)
Method Detail |
---|
public abstract QImageIOPlugin.Capabilities capabilities(QIODevice device, QByteArray format)
QImageIOHandler
supports the BMP format, and the data in the device starts with the characters "BM", this function should return CanRead
. If format is "bmp" and the handler supports both reading and writing, this function should return CanRead
| CanWrite
.
public abstract QImageIOHandler create(QIODevice device, QByteArray format)
QImageIOHandler
subclass, with device and format set. The format must come from the list returned by keys()
. Format names are case sensitive. keys()
.
create
in interface QAbstractImageIOHandlerFactoryInterface
public abstract java.util.List<java.lang.String> keys()
These keys are usually the names of the image formats that are implemented in the plugin (e.g., "jpg" or "gif").
capabilities()
.
keys
in interface QAbstractFactoryInterface
keys
in interface QAbstractImageIOHandlerFactoryInterface
public static QImageIOPlugin fromNativePointer(QNativePointer nativePointer)
public long __qt_cast_to_QAbstractImageIOHandlerFactory(long ptr)
__qt_cast_to_QAbstractImageIOHandlerFactory
in interface QAbstractImageIOHandlerFactoryInterface
public long __qt_cast_to_QAbstractFactory(long ptr)
__qt_cast_to_QAbstractFactory
in interface QAbstractFactoryInterface
|
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