QXbmHandler Class Reference

#include <qxbmhandler_p.h>

Inheritance diagram for QXbmHandler:

Public Functions
bool	canRead () const
	Returns true if an image can be read from the device (i. More...
QByteArray	name () const
	Use format() instead. More...
QVariant	option (ImageOption option) const
	Returns the value assigned to option as a QVariant. More...
	QXbmHandler ()
bool	read (QImage *image)
	Read an image from the device, and stores it in image. More...
void	setOption (ImageOption option, const QVariant &value)
	Sets the option option with the value value. More...
bool	supportsOption (ImageOption option) const
	Returns true if the QImageIOHandler supports the option option; otherwise returns false. More...
bool	write (const QImage &image)
	Writes the image image to the assigned device. More...
Public Functions inherited from QImageIOHandler
virtual int	currentImageNumber () const
	For image formats that support animation, this function returns the sequence number of the current image in the animation. More...
virtual QRect	currentImageRect () const
	Returns the rect of the current image. More...
QIODevice *	device () const
	Returns the device currently assigned to the QImageIOHandler. More...
QByteArray	format () const
	Returns the format that is currently assigned to QImageIOHandler. More...
virtual int	imageCount () const
	For image formats that support animation, this function returns the number of images in the animation. More...
virtual bool	jumpToImage (int imageNumber)
	For image formats that support animation, this function jumps to the image whose sequence number is imageNumber. More...
virtual bool	jumpToNextImage ()
	For image formats that support animation, this function jumps to the next image. More...
virtual int	loopCount () const
	For image formats that support animation, this function returns the number of times the animation should loop. More...
virtual int	nextImageDelay () const
	For image formats that support animation, this function returns the number of milliseconds to wait until reading the next image. More...
	QImageIOHandler ()
	Constructs a QImageIOHandler object. More...
void	setDevice (QIODevice *device)
	Sets the device of the QImageIOHandler to device. More...
void	setFormat (const QByteArray &format)
	Sets the format of the QImageIOHandler to format. More...
void	setFormat (const QByteArray &format) const
	Sets the format of the QImageIOHandler to format. More...
virtual	~QImageIOHandler ()
	Destructs the QImageIOHandler object. More...

Static Public Functions
static bool	canRead (QIODevice *device)

Private Types
enum	State { Ready, ReadHeader, Error }

Private Functions
bool	readHeader ()

Properties
QString	fileName
int	height
State	state
int	width

Additional Inherited Members
Public Types inherited from QImageIOHandler
enum	ImageOption {   Size, ClipRect, Description, ScaledClipRect,   ScaledSize, CompressionRatio, Gamma, Quality,   Name, SubType, IncrementalReading, Endianness,   Animation, BackgroundColor, ImageFormat }
	This enum describes the different options supported by QImageIOHandler. More...
Protected Functions inherited from QImageIOHandler
	QImageIOHandler (QImageIOHandlerPrivate &dd)
	Constructs a QImageIOHandler object, using the private member dd. More...
Protected Variables inherited from QImageIOHandler
QScopedPointer< QImageIOHandlerPrivate >	d_ptr

Detailed Description

Definition at line 62 of file qxbmhandler_p.h.

Enumerations

State

enum QXbmHandler::State

private

Enumerator
Ready
ReadHeader
Error

Definition at line 80 of file qxbmhandler_p.h.

               {
        Ready,
        ReadHeader,
        Error
    };

Constructors and Destructors

QXbmHandler()

QXbmHandler::QXbmHandler

(

)

Definition at line 257 of file qxbmhandler.cpp.

    : state(Ready)
{
}

Functions

canRead() [1/2]

bool QXbmHandler::canRead ( ) const

virtual

Returns true if an image can be read from the device (i.

e., the image format is supported, the device can be read from and the initial header information suggests that the image can be read); otherwise returns false.

When reimplementing canRead(), make sure that the I/O device (device()) is left in its original state (e.g., by using peek() rather than read()).

See also

read(), QIODevice::peek()

Implements QImageIOHandler.

Definition at line 271 of file qxbmhandler.cpp.

Referenced by createReadHandlerHelper().

{
    if (state == Ready && !canRead(device()))
        return false;

    if (state != Error) {
        setFormat("xbm");
        return true;
    }

    return false;
}

canRead() [2/2]

bool QXbmHandler::canRead ( QIODevice *  device )

static

Definition at line 284 of file qxbmhandler.cpp.

{
    QImage image;

    // it's impossible to tell whether we can load an XBM or not when
    // it's from a sequential device, as the only way to do it is to
    // attempt to parse the whole image.
    if (device->isSequential())
        return false;

    qint64 oldPos = device->pos();
    bool success = read_xbm_image(device, &image);
    device->seek(oldPos);

    return success;
}

name()

QByteArray QXbmHandler::name ( ) const

virtual

Use format() instead.

Reimplemented from QImageIOHandler.

Definition at line 354 of file qxbmhandler.cpp.

{
    return "xbm";
}

option()

QVariant QXbmHandler::option ( ImageOption  option ) const

virtual

Returns the value assigned to option as a QVariant.

The type of the value depends on the option. For example, option(Size) returns a QSize variant.

See also

setOption(), supportsOption()

Reimplemented from QImageIOHandler.

Definition at line 332 of file qxbmhandler.cpp.

{
    if (option == Name) {
        return fileName;
    } else if (option == Size) {
        if (state == Error)
            return QVariant();
        if (state == Ready && !const_cast<QXbmHandler*>(this)->readHeader())
            return QVariant();
        return QSize(width, height);
    } else if (option == ImageFormat) {
        return QImage::Format_MonoLSB;
    }
    return QVariant();
}

read()

bool QXbmHandler::read ( QImage *  image )

virtual

Read an image from the device, and stores it in image.

Returns true if the image is successfully read; otherwise returns false.

For image formats that support incremental loading, and for animation formats, the image handler can assume that image points to the previous frame.

See also

canRead()

Implements QImageIOHandler.

Definition at line 301 of file qxbmhandler.cpp.

{
    if (state == Error)
        return false;
    
    if (state == Ready && !readHeader()) {
        state = Error;
        return false;
    }

    if (!read_xbm_body(device(), width, height, image)) {
        state = Error;
        return false;
    }

    state = Ready;
    return true;
}

readHeader()

bool QXbmHandler::readHeader ( )

private

Definition at line 262 of file qxbmhandler.cpp.

Referenced by option(), and read().

{
    state = Error;
    if (!read_xbm_header(device(), width, height))
        return false;
    state = ReadHeader;
    return true;
}

setOption()

void QXbmHandler::setOption ( ImageOption  option, const QVariant &  value  )

virtual

Sets the option option with the value value.

See also

option(), ImageOption

Reimplemented from QImageIOHandler.

Definition at line 348 of file qxbmhandler.cpp.

{
    if (option == Name)
        fileName = value.toString();
}

supportsOption()

bool QXbmHandler::supportsOption ( ImageOption  option ) const

virtual

Returns true if the QImageIOHandler supports the option option; otherwise returns false.

For example, if the QImageIOHandler supports the Size option, supportsOption(Size) must return true.

See also

setOption(), option()

Reimplemented from QImageIOHandler.

Definition at line 325 of file qxbmhandler.cpp.

{
    return option == Name
        || option == Size
        || option == ImageFormat;
}

write()

bool QXbmHandler::write ( const QImage &  image )

virtual

Writes the image image to the assigned device.

Returns true on success; otherwise returns false.

The default implementation does nothing, and simply returns false.

Reimplemented from QImageIOHandler.

Definition at line 320 of file qxbmhandler.cpp.

{
    return write_xbm_image(image, device(), fileName);
}

Properties

fileName

QString QXbmHandler::fileName

private

Definition at line 88 of file qxbmhandler_p.h.

Referenced by option(), setOption(), and write().

height

int QXbmHandler::height

private

Definition at line 87 of file qxbmhandler_p.h.

Referenced by option(), read(), and readHeader().

state

State QXbmHandler::state

private

Definition at line 85 of file qxbmhandler_p.h.

Referenced by canRead(), option(), read(), and readHeader().

width

int QXbmHandler::width

private

Definition at line 86 of file qxbmhandler_p.h.

Referenced by option(), read(), and readHeader().

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The documentation for this class was generated from the following files:

• /src/gui/image/qxbmhandler_p.h
• /src/gui/image/qxbmhandler.cpp