Errata

the solution presented in the back of the book for exercise on page 37 simply doesn't
work, and the program operates with all the same characteristics as before.

This could be caused by:
1. the fact that i'm running in Blackbox on a x86 Debian Linux machine
2. the language has changed so that a slider does send the signal valueChanged as the
slider is moved, and not just on the mouse release.

Programm qtscripple1.cpp:

the drawing QPainter object windowpainter has always the color white untill I resize
the window.

After creating a QPaint object and setting the size it works fine.

void ScribbleWindow::mouseMoveEvent(QMouseEvent* event)
{
//create a QPen object for setting the penwidth
QPen pen;
pen.setWidth(1);

//create a QPainter object for drawing onto the window
QPainter windowpainter;
//an another QPainter object for drawing into an off-screen pixmap
QPainter bufferpainter;

//start painting
windowpainter.begin(this); //this painter paints onto the window
bufferpainter.begin(&_buffer); //and this one paints in the buffer

//allocating the pen to both the window and the buffer
windowpainter.setPen(pen);
bufferpainter.setPen(pen);

//draw a line in both the window and the buffer
windowpainter.drawLine(_last, event->pos());
bufferpainter.drawLine(_last, event->pos());

//done with painting
windowpainter.end();
bufferpainter.end();

//remember the current mouse position
_last = event->pos();
}

I don't know if this problem is only on SunOs available.

Three of the lines of code to set the style do not compile:
QApplication::setStyle( new QWindowsStyle );
QWidgetListIt widgetlist_it( *widgetlist );
QObjectListIt objectlist_it( *objectlist );

The command-line switches to set the style have no effect.

This describes QDict, not QPtrDict. The heading and two references in the descriptive
paragraph should be changed.

The later QPtrDict paragraph (p.176) also has an error:
"This class is similar to QPtrDict..."
should be
"This class is similar to QDict..."

The 'dirlister.cpp' example will fail on WinXP Pro or WinNT (have not checked other
versions). It appears to me that if a command cannot be run from 'Start > Run'
dialog, it cannot be run from the QProcess.

EXISTING:------------------------------
#ifdef Q_WS_WIN
process->addArgument( "dir" );
#else

CHANGE TO:-----------------------------
#ifdef Q_WS_WIN
process->addArgument( "cmd.exe /C dir" );
#else

END Snippets -------------------------

I have found that my results look better if I comment out the line:
edit->append( "
" );
on page 270.

For more cmd.exe information, type 'cmd /?' at the dos prompt.

(Thanks to replies from Torbjorn Eriksson and Soeren Fietzke at the Trolltech
newsgroup)

QApplication::installGlobalEventFilter() should be
QApplication::installEventFilter();

According to TrollTech's documentation: "It's also possible to filter all events for
the entire application, by installing an event filter on QApplication."

moc -o moc_PizzaEntryTest.cpp PizzaEntry.cpp

should be...

moc -o moc_PizzaEntryTest.cpp PizzaEntry.h

When running this command on a Linux system with the g++ compiler(version 3.0.2), the following error is reported at the prompt:

PizzaEntryTest.cpp:0: Warning: No relevant classes found. No output generated.

All input files were double checked for mistakes( typos, syntax, etc.) and there were none. What is the problem? Why is the file
moc_PizzaEntryTest.cpp not included in the input for the g++ compiler
on line 3 at the top of the page?

This problem appears to be duplicated in the command list for
the Windows with Visual C++ option on the fifth line below the phrase "and for Windows with Visual C++" on the same page.