/**************************************************************************** ** ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:FDL$ ** Commercial Usage ** Licensees holding valid Qt Commercial licenses may use this file in ** accordance with the Qt Commercial License Agreement provided with the ** Software or, alternatively, in accordance with the terms contained in a ** written agreement between you and Nokia. ** ** GNU Free Documentation License ** 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. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** $QT_END_LICENSE$ ** ****************************************************************************/ /*! \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 Qt 4.7 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. */