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#include "png_slave.h"
#include "thumbnailtool.h"
#include <qobject.h>
#include <qfile.h>
#include <qimage.h>
#include <qpixmap.h>
#include <qstring.h>
/*
* GPLv2 from kfile plugin
*/
PHUNK_VIEW_INTERFACE( "PNG", PNGSlave );
#define CHUNK_SIZE(data, index) ((data[index ]<<24) + (data[index+1]<<16) + \
(data[index+2]<< 8) + data[index+3])
#define CHUNK_TYPE(data, index) &data[index+4]
#define CHUNK_HEADER_SIZE 12
#define CHUNK_DATA(data, index, offset) data[8+index+offset]
/* TRANSLATOR QObject */
// known translations for common png keys
static const char* knownTranslations[]
#ifdef __GNUC__
__attribute__((unused))
#endif
= {
QT_TR_NOOP("Title"),
QT_TR_NOOP("Author"),
QT_TR_NOOP("Description"),
QT_TR_NOOP("Copyright"),
QT_TR_NOOP("Creation Time"),
QT_TR_NOOP("Software"),
QT_TR_NOOP("Disclaimer"),
QT_TR_NOOP("Warning"),
QT_TR_NOOP("Source"),
QT_TR_NOOP("Comment")
};
// and for the colors
static const char* colors[] = {
QT_TR_NOOP("Grayscale"),
QT_TR_NOOP("Unknown"),
QT_TR_NOOP("RGB"),
QT_TR_NOOP("Palette"),
QT_TR_NOOP("Grayscale/Alpha"),
QT_TR_NOOP("Unknown"),
QT_TR_NOOP("RGB/Alpha")
};
// and compressions
static const char* compressions[] =
{
QT_TR_NOOP("Deflate")
};
// interlaced modes
static const char* interlaceModes[] = {
QT_TR_NOOP("None"),
QT_TR_NOOP("Adam7")
};
static void read_comment( const QString& inf,
bool readComments, QString& str ) {
QFile f(inf);
f.open(IO_ReadOnly);
if (f.size() < 26) return;
// the technical group will be read from the first 26 bytes. If the file
// is smaller, we can't even read this.
uchar *data = new uchar[f.size()+1];
f.readBlock(reinterpret_cast<char*>(data), f.size());
data[f.size()]='\n';
// find the start
if (data[0] == 137 && data[1] == 80 && data[2] == 78 && data[3] == 71 &&
data[4] == 13 && data[5] == 10 && data[6] == 26 && data[7] == 10 )
{
// ok
// the IHDR chunk should be the first
if (!strncmp((char*)&data[12], "IHDR", 4))
{
// we found it, get the dimensions
ulong x,y;
x = (data[16]<<24) + (data[17]<<16) + (data[18]<<8) + data[19];
y = (data[20]<<24) + (data[21]<<16) + (data[22]<<8) + data[23];
uint type = data[25];
uint bpp = data[24];
// the bpp are only per channel, so we need to multiply the with
// the channel count
switch (type)
{
case 0: break; // Grayscale
case 2: bpp *= 3; break; // RGB
case 3: break; // palette
case 4: bpp *= 2; break; // grayscale w. alpha
case 6: bpp *= 4; break; // RGBA
default: // we don't get any sensible value here
bpp = 0;
}
str = QObject::tr("Dimensions: %1x%2\n" ).arg(x).arg(y);
str += QObject::tr("Depth: %1\n" ).arg(bpp);
str += QObject::tr("ColorMode: %1\n").arg(
(type < sizeof(colors)/sizeof(colors[0]))
? QObject::tr(colors[data[25]]) : QObject::tr("Unknown") );
str += QObject::tr("Compression: %1\n").arg(
(data[26] < sizeof(compressions)/sizeof(compressions[0]))
? QObject::tr(compressions[data[26]]) : QObject::tr("Unknown") );
str += QObject::tr("InterlaceMode: %1\n" ).arg(
(data[28] < sizeof(interlaceModes)/sizeof(interlaceModes[0]))
? QObject::tr(interlaceModes[data[28]]) : QObject::tr("Unknown"));
}
if ( readComments ) {
uint index = 8;
index += CHUNK_SIZE(data, index) + CHUNK_HEADER_SIZE;
while(index<f.size()-12)
{
while (index < f.size() - 12 &&
strncmp((char*)CHUNK_TYPE(data,index), "tEXt", 4))
{
if (!strncmp((char*)CHUNK_TYPE(data,index), "IEND", 4))
goto end;
index += CHUNK_SIZE(data, index) + CHUNK_HEADER_SIZE;
}
if (index < f.size() - 12)
{
// we found a tEXt field
// get the key, it's a null terminated string at the
// chunk start
uchar* key = &CHUNK_DATA(data,index,0);
int keysize=0;
for (;key[keysize]!=0; keysize++)
// look if we reached the end of the file
// (it might be corrupted)
if (8+index+keysize>=f.size())
goto end;
// the text comes after the key, but isn't null terminated
uchar* text = &CHUNK_DATA(data,index, keysize+1);
uint textsize = CHUNK_SIZE(data, index)-keysize-1;
// security check, also considering overflow wraparound from the addition --
// we may endup with a /smaller/ index if we wrap all the way around
uint firstIndex = (uint)(text - data);
uint onePastLastIndex = firstIndex + textsize;
if ( onePastLastIndex > f.size() || onePastLastIndex <= firstIndex)
goto end;
QByteArray arr(textsize);
arr = QByteArray(textsize).duplicate((const char*)text,
textsize);
str += QObject::tr(
QString(reinterpret_cast<char*>(key)),
QString(arr) );
index += CHUNK_SIZE(data, index) + CHUNK_HEADER_SIZE;
}
}
}
}
end:
delete[] data;
}
PNGSlave::PNGSlave()
: SlaveInterface("png")
{
}
PNGSlave::~PNGSlave() {
}
QString PNGSlave::iconViewName( const QString& path) {
QString str;
read_comment( path, false, str );
return str;
}
QString PNGSlave::fullImageInfo( const QString& path) {
QString str;
read_comment( path, true, str );
return str;
}
QPixmap PNGSlave::pixmap( const QString& path, int width, int height) {
QImage img; img.load( path );
if ( img.isNull() )
return QPixmap();
else
return ThumbNailTool::scaleImage( img, width,height );
}
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