/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:FDL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Free Documentation License Usage
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file.  Please review the following information to ensure
** the GNU Free Documentation License version 1.3 requirements
** will be met: http://www.gnu.org/copyleft/fdl.html.
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
\page qdeclarativedebugging.html
\title Debugging QML

\section1 Logging

\c console.log can be used to print debugging information to the console. For example:

\qml
Rectangle {
    width: 200; height: 200
    MouseArea {
        anchors.fill: parent
        onClicked: console.log("clicked")
    }
}
\endqml

\section1 Debugging Transitions

When a transition doesn't look quite right, it can be helpful to view it in slow
motion to see what is happening more clearly. This functionality is supported
in the \l {QML Viewer} tool: to enable this,
click on the "Debugging" menu, then "Slow Down Animations".


\section1 Debugging module imports

The \c QML_IMPORT_TRACE environment variable can be set to enable debug output
from QML's import loading mechanisms. 

For example, for a simple QML file like this:

\qml
import QtQuick 1.0

Rectangle { width: 100; height: 100 }
\endqml

If you set \c {QML_IMPORT_TRACE=1} before running the \l {QML Viewer}
(or your QML C++ application), you will see output similar to this:

\code
QDeclarativeImportDatabase::addImportPath "/qt-sdk/imports" 
QDeclarativeImportDatabase::addImportPath "/qt-sdk/bin/QMLViewer.app/Contents/MacOS" 
QDeclarativeImportDatabase::addToImport 0x106237370 "." -1.-1 File as ""
QDeclarativeImportDatabase::addToImport 0x106237370 "Qt" 4.7 Library as ""
QDeclarativeImportDatabase::resolveType "Rectangle" = "QDeclarativeRectangle"
\endcode


\section1 Debugging with Qt Creator

\l{http://qt.nokia.com/products/developer-tools}{Qt Creator} provides built-in
support for QML debugging. QML projects and standalone C++ applications that
utilize QML can be debugged on desktops as well as on remote devices.
For more information, see the Qt Creator Manual.

*/