QPainter hanging when taking webpage snapshot
-
Hi All,
We're using the following code to take a screenshot of a webpage:
@ QWebPage * page = mBrowser.page();
QImage screenshot(page->viewportSize(), QImage::Format_ARGB32);
QPainter paint(&screenshot);
page->currentFrame()->render(&paint);
paint.end();
screenshot.save("screenshot.png");@However, quite frequently, this block of code hangs. Using gdb, I've done a backtrace as follows. Does anyone have any clues as to why this may be occurring? Some sites this is occurring on include http://wordpress.tv/ and http://octodex.github.com
@Program received signal SIGINT, Interrupt.
qt_memfill32_sse2 (dest=0x7fffffff9650, value=4294967295, count=1280) at painting/qdrawhelper_sse2.cpp:269
269 case 0: do { _mm_stream_si128(dst128++, value128);
(gdb) up
#1 0x00007ffff52b92d8 in blend_color_generic (count=206, spans=<value optimized out>, userData=0x112e6e0)
at painting/qdrawhelper.cpp:3446
3446 op.funcSolid(dest, l, data->solid.color, spans->coverage);
(gdb) up
#2 0x00007ffff525dff7 in flushSpans (this=0xa4f7e0, a=<value optimized out>, b=<value optimized out>,
width=<value optimized out>, squareCap=<value optimized out>) at painting/qrasterizer.cpp:111
111 m_blend(m_spanCount, m_spans, m_data);
(gdb) up
#3 addSpan (this=0xa4f7e0, a=<value optimized out>, b=<value optimized out>, width=<value optimized out>,
squareCap=<value optimized out>) at painting/qrasterizer.cpp:105
105 flushSpans();
(gdb) up
#4 QRasterizer::rasterizeLine (this=0xa4f7e0, a=<value optimized out>, b=<value optimized out>,
width=<value optimized out>, squareCap=<value optimized out>) at painting/qrasterizer.cpp:882
882 Q16Dot16ToInt(Q16Dot16Multiply(rowHeight, coverage[i])));
(gdb) down
#3 addSpan (this=0xa4f7e0, a=<value optimized out>, b=<value optimized out>, width=<value optimized out>,
squareCap=<value optimized out>) at painting/qrasterizer.cpp:105
105 flushSpans();
(gdb) up
#4 QRasterizer::rasterizeLine (this=0xa4f7e0, a=<value optimized out>, b=<value optimized out>,
width=<value optimized out>, squareCap=<value optimized out>) at painting/qrasterizer.cpp:882
882 Q16Dot16ToInt(Q16Dot16Multiply(rowHeight, coverage[i])));
(gdb) up
#5 0x00007ffff529877e in QRasterPaintEngine::fillRect (this=0x139c6f0, r=..., data=0x112e6e0)
at painting/qpaintengine_raster.cpp:1899
1899 d->rasterizer->rasterizeLine(a, b, nr.height() / nr.width());
(gdb) up
#6 0x00007ffff5221037 in QPainter::fillRect (this=0x7fffffffcb50, r=..., brush=...)
at painting/qpainter.cpp:6961
6961 d->extended->fillRect(r, brush);
(gdb) up
#7 0x00007ffff67c6aab in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#8 0x00007ffff678b7cc in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#9 0x00007ffff66f3b11 in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#10 0x00007ffff6746880 in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#11 0x00007ffff6747414 in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#12 0x00007ffff663c17e in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#13 0x00007ffff6811c46 in ?? () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#14 0x00007ffff6811e76 in QWebFrame::render(QPainter*) () from /usr/lib64/libQtWebKit.so.4
(gdb) up
#15 0x0000000000411c20 in bricolage::WebCrawler::takeScreenshot (this=0x7fffffffe0f0)
at /data/bricolage/Code/Applications/Database/WebCrawlerCPP/src/WebCrawler.cpp:231
231 page->currentFrame()->render(&paint);@
-
Have tested http://wordpress.tv/ and http://octodex.github.com with my thumb-crawler on Linux x86_64 with Qt 4.7.1 & 4.8.2, no problem at all...
Are you using ubuntu? have you compiled Qt by yourself or is it default SDK installation?
