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Qt in depth - presentation for Symbian expo 2009

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Comprehensive presentation about Qt with special focus on Symbian. Close to a training material so if you wanna know what Qt is, have a look at the ~150 slides....

Comprehensive presentation about Qt with special focus on Symbian. Close to a training material so if you wanna know what Qt is, have a look at the ~150 slides.

Held in www.see2009.org/ 27.10.2009

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    Qt in depth - presentation for Symbian expo 2009 Qt in depth - presentation for Symbian expo 2009 Presentation Transcript

    • Qt fireworks – demonstrating the power of Qt The Geeks from Nokia are: Kosonen, Viitanen, Tomuta, Riskedal 1
    • • Motivation 9:30 • Qt introduction 9:45 • Deep dive to Qt modules • Qt for Symbian 10:30 – 11:15 • Qt fireworks 11:15-12:00 2
    • From the scratch Time to laugh at Nokia engineers while they embarrass themselves… 3
    • Nov 2009 : get your Qt app running on more than + 130 000 000 smartphones! - Not to mention that Qt runs on all major desktop OSs as well 4
    • Part 1. The Motivation 5
    • 2010 : Back to the track – The Cross Platform Promise Increase Total Commit to Addressable Market Open Source Combine the Best of Lower Entry Barriers Both Worlds for Developers 6 6
    • Our Developer Offering: Elegantly connected services Services Level Apps Level Platform Level Nokia platforms Desktop OSs 7 7
    • Why Qt? What is Qt about? • QuickTime player? Programming language? A platform? Yet another runtime? • A new Japanese car model? Qt is Cross-platform application framework • Differentiated user experience across hardware platforms • Hybrid development: convergence of web and native applications • Cross-platform software across desktops and mobile devices. Qt supports major desktop OSs already and will extend it’s reach to Nokia platforms. • Qt is not a runtime – no perf issues or sandbox restrictions. You can stand out with your native development skills to fulfill the use cases offered by Qt. • Qt Mobility APIs will bring in the easy to use APIs for mobile use cases. Shorter time to market • Productive APIs and comprehensive documentation with great examples • Delivering functionality faster and maximizing efficiency by placing focus on innovation • All the great tools offered free of charge - commercial services available as well 8 8
    • Today : Qt is used already used everywhere! From embedded devices By companies to desktop applications from many industries 9
    • Qt: a cross-platform application and UI development framework http://qt.nokia.com 10
    • Nokia + Ovi Developer Story | 11 Simplified offering | Based on Qt The future offering will be based on Qt, the development tool globally used to build desktop apps – you may already know it. With the simplified toolchain you can tackle f.ex Maemo and Symbian based devices Develop on PC, Mac or Linux 11
    • Qt and Web is the way to go Web Web Runtime developers For native Qt UI Extensions Developers UI 85% of use cases ** Qt Engine Mobile Qt Mobility APIs Features Low level Native Native Native 15% of use Native access APIs APIs APIs cases ** Desktop Symbian Linux OSs S60 on Symbian maemo Platform Platform * Internal SAPIs, not for 3rd parties ** Not based in any realiable statistics ;) 12
    • Qt on Symbian path UI Qt Qt Qt Qt Engine with Mobility Qt Mobility Qt Mobility APIs rel 1 APIs Mobile Rel 2 Features Symbian C++ Symbian Symbian Low level C++ Symbian C++ Native access C++ Desktop OSs Nokia Symbian Symbian S60 on Symbian S60 on Symbian Platform Platform 13 2011
    • Qt Development Chain - maemo & Symbian Distribution Ovi Store Certification Symbian signed None - atleast yet… IDEs •Qt Creator •Qt Creator •Carbide Common offering •Mobility APIS •Mobility APIs SDKs Qt for Symbian platform Qt for maemo platform & Plugins Symbian SDKs Maemo SDKs Symbian Maemo 14
    • Maemo - Why should I care? • Coming from desktop? • The importance of mobile clients is widely recognized already – not gonna sell it here… • With Qt and Mobility APIs you can easily extend your application to cover smartphone features and utilize f.ex location, contacts, messaging etc. • With maemo and Symbian you can reach more than 100 million devices with your Qt application – already with Qt 4.6! • Maemo is and will be very important for Nokia – get a head start to maemo which we believe will be one of the most interesting platforms! • With Ovi store you have a ready channel to sell your application to hundreds of millions of users 15
    • Nov 2009 : get your Qt app running on more than + 130 000 000 smartphones! - Not to mention that Qt runs on all major desktop OSs as well 16
    • Part 2. The Explanation 17
    • Qt for Mobile Developers Qt Basics – Introduction 18
    • What is Qt? (1/2) • Qt (”cute”) is often referred to as a cross-platform GUI framework • Cross-platform GUI has been the driving force • Initially other modules did not even exist • However, nowadays Qt is much more than a plain GUI FW • Qt is a cross-platform C++ application development framework • Set of cross-platform APIs and • C++ class library • Development tools • Qt was originally designed for efficient creation of platform-independent desktop GUI programs • Developed by a Norwegian company called Trolltech, which has been part of Nokia since 2008 • Latest version is 4.6 (beta) • Qt provides native look-and-feel in all platforms • Implemented by relying on platform-specific APIs • Platform specialities isolated 19 http://qt.nokia.com
    • Qt is supported in wide range of platforms • Qt is currently ported to • Desktops: Windows, Linux (X11), Mac • Mobile: Windows CE, S60, and embedded Linux, e.g. Maemo One and unified Cross-Platform API Qt/Embedded Qt/X11 Qt/Win Qt/Mac Qt/WinCE Qt/S60 Linux 20
    • Qt Application Framework • Qt includes an intuitive C++ class library with a rich set of application build blocks • Qt goes beyond C++ in the areas of inter-object communication and flexibility for advanced GUI development. • Combining the speed of C++ with the flexibility of the Qt Object Model Qt provides both runtime efficiency and a high level of flexibility for GUI programming. • Qt goes beyond C++ to add the following features: • A very powerful mechanism for seamless object communication called signals and slots • Queryable and designable object properties • Powerful events and event filters • Contextual string translation for internationalization • Sophisticated interval driven timers that make it possible to elegantly integrate many tasks in an event-driven GUI • Hierarchical and queryable object trees that organize object ownership in a natural way • Guarded pointers (QPointer) that are automatically set to 0 when the referenced object is destroyed • A dynamic cast that works across library boundaries 21
    • Development Tools: Overview • Qt Creator: Cross-platform IDE • Qt Designer: GUI layout and forms builder • Qt Linguist: Internationalization toolset • Qt Assistant: Customizable documentation reader • qmake: Cross-platform build tool • Integration with Visual Studio® and Eclipse® IDEs • Carbide 2.0.2 for Qt for Symbian development 22 © 2008 Nokia V1-Filename.ppt / YYYY-MM-DD / Initials
    • Qt for Mobile Developers The developer offering for Symbian 23
    • Qt for Symbian - Total Offering • http://qt.nokia.com - main place for Qt related development material • Qt for Symbian port – Qt 4.6 ported to S60 3rd Edition FP1 and FP2, 5th edition and also coming S60 platform editions. • Carbide.c++ 2.0.2 onwards supporting Qt development on Symbian. • Note : Qt creator will also support Symbian development • Fully integrated form editor (Qt Designer) • Wizards for creating new Qt projects and classes • Integrated .pro file editor • Automated build setup for moc, uic, and rcc • http://www.forum.nokia.com/Resources_and_Information/Tools/IDEs/Carbide.c++/ • Mobility APIs • http://labs.qt.nokia.com/page/Projects/QtMobility • And Their successor : Qt for S60 Mobile Extension • High abstraction level APIs making it possible to use most important services without using native Symbian C++ • Note : for a long time Qt developer will need Symbian APIs in specific use cases • Documents, examples, discussion board, wiki, Technical support, consultancy etc 24
    • Qt for Symbian Developer’s Library • After installing the ’Qt for Symbian Developer’s Library’ Carbide plugin you will see it in Carbide help (select Help->Help Contents from Carbide menu bar) • Note that the Qt Development User Guide that is ‘built-in’ with Carbide 2.0 is a separate library • The developers library contains the following sections • Legal notice & Release notes • Introduction to Qt • Introduction to S60 • Installation guide • Using Carbide.c++ • Qt for S60 guide • Qt-related books and URLs • Example ‘Qt for S60’ applications 25 http://library.forum.nokia.com/
    • ”smart installer” - Qt installer for Symbian The opportunity The problem The solution A Smart Installer tool that +130M Symbian devices Qt libraries need to be checks whether needed Qt could run cross-platform Qt post installed – most version is available on the applications already during consumers might not device – and if not, it will this year bother handle the installation Details •Nokia is working on a tool called Smart Installer for Symbian devices •The expected availability is 1Q 2010 •A piece of code is to be packaged together with the Qt application targeted for Symbian devices (when creating the .sis file) •The Smart Installer will download OTA the needed Qt version to the handset if it is not already present 26
    • Part 2.1 The In-depth Explanation 27
    • Tools – configure • configure is a tool for configuring Qt itself for the current platform • Compiles qmake • Executed only during Qt installation • Unless ready binaries are used (recommended) • Configure is platform independent – not Symbian specific qmake Qt Source Code configure Qt for specific platform 28
    • Building Qt Applications 1. qmake –project • Creates a Qt project file (.pro). This can also be created manually. 2. qmake • Uses the .pro file as input and produces platform-specific Makefile(s) • Generates make rules to invoke moc for project header files containing Q_OBJECT – as explained later 3. make • On Symbian make debug-winscw or make release-gcce • Compiles the program for the current platform • Executes also moc, uic and rcc qmake Project Platform Application qmake specific make -project information Binary file (.pro/.pri) Makefiles 29
    • Qt Creator Cross-Platform Qt IDE Introduction, Features & Benefits 30
    • What is Qt Creator? Lightweight, cross-platform IDE for Qt • Advanced C++ code editor • Integrated, context sensitive help system • Integrated visual debugger (based on gdb) • Integrated source code management • Project and build management tools • Integrated Qt development tools 31
    • What does Qt Creator provide? Lighting fast code Tailored to the needs Powerful C++ navigation tools of Qt cross-platform code editor developers 32
    • Tailored to the needs of Qt cross-platform developers Challenge • Qt is cross-platform, but IDEs/dev. environments are not • Can be difficult to get up with a new framework Solution • True cross-platform development environment for Qt • Integrated Qt-specific features (i.e. Signals & Slots) • Debugger aware of Qt class structures • New developers get productive sooner Visualizing Qt class structures in Debug mode. 33
    • Powerful C++ code editor Challenge • Writing elegant, correct code can be time consuming • Finding help often demands context switching Solution • Syntax highlighting and automatic code completion • Static code checking as you type • Context sensitive help • Code folding Code completion. • Parenthesis matching and parenthesis selection modes • Advanced editing capabilities like block selection Context-sensitive help. 34
    • Available as part of complete SDK Qt SDK Qt Development Tools Qt Libraries Qt Designer Qt Assistant Licensing Options: GUI Layout & Help file/documentation Forms Tool browser Commercial LGPL Qt Linguist qmake Translation/I18n Tool Cross-platform build tool 35
    • Qt Modules 36
    • Qt Modules • Cross-platform Qt consists of 12 modules • A little bit less than 700 API classes, all modules depend on QtCore • Additionally 3 platform specific modules: QAxContainer, QAxServer, QtDBus • Build Tools • Configure, Qmake, Moc, Uic and Rcc • Development Tools • Qt Creator, Qt Designer, Qt Assistant, Qt Linguist, Carbide • Enables pure Qt applications, but • Possibility to use platform APIs • Possibility to embed native elements, including UI widgets QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support QtGui QtSql QtXml QtNetwork QtScript Phonon QtCore 37
    • Qt for Symbian Platform - releases FINAL Beta based on QtXmlPatterns QtOpenGL Qt 4.6 October Tower July-09 QtSql Phonon QtWebkit based on 4.5 Garden P3-09 QtXml QtScript QtSvg based on 4.5 Pyramid P10 QtGUI *) QtCore QtNetwork QtTest Q3Support based on 4.4 http://pepper.troll.no/s60prereleases/ 38
    • Qt for Mobile Developers Qt Basics – Qt Core 39
    • Qt – Modules (Core) QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • Classes and methods for basic non-GUI functionality QtGui QtSql QtXml QtNetwork QtScript Phonon • Basic Type (Char, Date, Time, String) QtCore • File system access, Date and time handling • String handling, List and array handling • Threads and processes, Shared resources • Libraries and Plugins, Timers • Classes and methods for basic graphical elements • Point, Rectangle • Heart of the Qt object model, QObject • More information about Qt object model later on • QtCore do not depend on underlying window system 40
    • QObject Class Role • Heart of Qt's object model • Base class for all object classes • Provides object trees and object ownership • QObject's responsibility is to provide a central location for the most important concepts in Qt • Has three major responsibilities • Memory Management • Introspection • Event handling 41
    • Parent/Child Relationship • Each QObject instance may take a parent (argument for constructor) • Child informs its parent about its existence, upon which the parent adds it to its own list of children • If a widget object does not have a parent, it is a window • The parent does the following for its children: • Deletes them, when it is self deleted – • But, of course, is not able to set your own direct pointers to those children to NULL (if not using quarded pointers! • Hides and shows children, when hidden/shown itself • Enables and disables children when enabled or disabled itself • Note that a child may be explicitly hidden, although the parent is shown 42
    • Creating Objects • Objects inheriting from QObject are allocated on the heap using new • If a parent object is assigned, it takes ownership of the newly created object – and eventually calls delete • QLabel *label = new QLabel(”Some Text”, parent); • Objects not inheriting QObject are allocated on the stack, not the heap • QStringList list; • QColor color; • Exceptions • QFile and QApplication (inheriting QObject) are usually allocated on the stack • Modal dialogs are often allocated on the stack, too 43
    • Memory Management • The ownership of all child QObjects is transferred to the parent • Automatic deletion by the parent • Allocated from the heap with new • Manual deletion won’t however cause double deletion because the child informs its parent of the deletion • All QObjects without a parent must be deleted manually • Stack allocation is a good option to avoid problems • Occasionally it may seem like Qt would hold some sort of automatic garbage collection but this is not true! • Always pay attention to ownerships and responsibilities! 44
    • Meta-Object System • Meta-object system extends C++ with dynamic features – similar to those in Java, for example • Dynamic features include • Mechanism to access any functions in the class • Also private ones • Used by signals and slots • Class information • Type without RTTI (Run-Time Type Information) • Information about base classes • Translate strings for internationalization • Dynamic properties 45
    • Signals and Slots • Observer pattern • Type-safe callbacks • More secure than callbacks, more flexible than virtual methods • Many-to-many relationship • Loose coupling between signals and slots • Implemented in QObject 46
    • Signals • A signal is a way to inform a possible observer that something of interest has happened inside the observed class • A QPushButton is clicked • An asynchronous service handler is finished • Value of QSlider is changed • Signals are member functions that are automatically implemented in the meta-object • Only the function declaration is provided by the developer • Signal is sent, or emitted, using the keyword emit • emit clicked(); • emit someSignal(7, “Hello”); //passing data in a connection 47
    • Slots • A slot is a function that is to be executed when a signal has been emitted. • (When QPushButton is pressed), close QDialog • (When service is ready), ask for the value and store it • (When QSLider value is changed), show a new value in QLCDNumber • A Slot function is a normal member function implemented by the developer 48
    • Signal and Slot Implementation class NewClass : public QObject { Q_OBJECT // Meta-object file needed // Code convention recommends Q_OBJECT use always, // otherwise qobject_cast fails signals: // Implementation in the meta-object void newSignal(int myInt, QString myString); public slots: // Slots are implemented as normal member functions void newSlot(int i, QString s); } 49
    • Signals and Slots connect(Object1, signal1, Object3, slot1) Object1 connect(Object1, signal2, Object3, slot2) Object3 signal1 signal1 signal2 signal2 slot1 slot2 connect(Object1, signal2, Object4, slot2) Object2 Object4 signal1 signal1 signal2 signal2 slot1 slot1 slot2 slot3 connect(Object2, signal1, Object4, slot1) 50
    • Qt for Symbian Event Handling Core cnt’d… 51
    • Event Handling in Brief • In Qt, events are objects that are delivered to event handling functions • Base class QEvent, subclasses like QMouseEvent, QKeyEvent, QTimerEvent • When an event occurs, Qt creates the event object and delivers the event to the particular QObject => QObject::event( QEvent& e ) • Does not handle the event, redelivers to a corresponding virtual event handler • Own virtual protected functions for different events 52
    • You Want to Have Your Widget to... • Respond to key presses, implement: void keyPressEvent(QKeyEvent&) • Use timer, implement: void timerEvent(QTimerEvent&) QObject • Respond to mouse presses, implement: event void mousePressEvent(QMouseEvent&) (QEvent&) • React to layout changes, implement: void resizeEvent(QResizeEvent&) void moveEvent(QMoveEvent&) MySubClass keyPressEvent • Etc. (QKeyEvent&) • Quite straightforward from the developer’s point of view! 53
    • Timer Events int QObject::startTimer ( int interval ) • Starts the timer, which will continuously send timer events at specified intervals (ms) • Returns the timer id • Stops when QObject::killTimer(id) is called • Class QTimer can also be used • Both repetitive and single-shot timer events • Emits signal timeout() when the timer expires • A zero-millisecond QTimer can be used to perform low-priority background tasks – compare to CIdle in S60/Symbian 54
    • Timers • QTimer is a class for executing functions at a later time. You create an instance of a QTimer and connect the signal timeout() to a slot containing the code you want to be executed. • Call setSingleShot() for a single-shot timer. • Finally, call start(int msec) on the timer to start it. • For a one-time non-cancellable single-shot timer: QTimer::singleShot(1000, this, SLOT(doit())) Example: StopWatch::StopWatch( QWidget* parent ) : QLabel( parent ) { QTimer* timer = new QTimer( this ); timer->start( 1000 ); connect( timer, SIGNAL( timeout() ), this, SLOT( shot() ) ); } void StopWatch::shot() { _secs += 1; QString str; str.sprintf("%d:%02d", _secs / 60, _secs % 60); setText( str ); http://qt.nokia.com/4.5/timers.html 55
    • Qt for Mobile Developers Qt Basics – Qt GUI 56
    • Qt GUI Classes • Extends QtCore with GUI functionality QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • UI application base class • UI components : set of widgets and dialogs QtGui QtSql QtXml QtNetwork QtScript Phonon • Widget layout management and classes for UI Events QtCore • All the UI components usually needed • Not enough? • Customized components can be done and integrated with Qt Creator • Provides rich set of GUI components and supporting functionality • Model-View-Controller (MVC) Item views • Styles – ensuring native or custom look and feel on target platforms • Font-aware layout system • Accessibility classes • Canvas component with Widget support 57
    • QApplication • Initializes application settings • Palette, font • Receives events from window system and dispatches them to widgets • Defines application’s look and feel • Provides localization of strings • Knows application’s windows • widgetAt() • Use global qApp pointer to access QApplication instance 58
    • Windows • Any widget is a window, unless it has a parent • In addition, Qt has QMainWindow class • Can be created with Qt Designer Menu bar Toolbars Dock widgets Central widget Status bar 59
    • Menus QAction *actionNew = new QAction(MainWindow); actionNew->setObjectName(QString::fromUtf8("actionNew")); QIcon icon; icon.addPixmap(QPixmap(QString::fromUtf8(":/:/images/images/file -16.png")), QIcon::Normal, QIcon::Off); actionNew->setIcon(icon); menubar->addAction(menuFile->menuAction()); // QMenuBar menuFile->addAction(actionNew); // QMenu QObject::connect(actionExit, SIGNAL(triggered()), MainWindow, SLOT(close())); 60
    • Toolbar • Create actions in the same way as to menus • Add actions to toolbars QToolBar *fileToolBar; fileToolBar = new QToolBar(MainWindow); fileToolBar->setObjectName( QString::fromUtf8("fileToolBar")); fileToolBar->addAction(actionOpen); 61
    • Display Widgets • Labels • Text Browsers • LCDNumbers • Progress Bar • ...and more 62
    • Input & Selection Widgets • Push buttons • Selection buttons • Text input • Line input • Plain text input • Plain & rich text input • Spin boxes • Dial • Scroll bars • Sliders 63
    • Group & Layout Widgets • Horizontal, vertical, grid layouts • Tab widgets, group boxes, etc. • Spacers Qt Designer Result 64
    • Action Widgets • QMainWindow • Menus • Menu items • Inner menus • Mapped to Options menu in S60 builds • Tool bars • Tool bar items • Each menu or tool bar item is related to an Action (QAction) • Text, icon • Can be dragged from menu to toolbar • Can be the same in both 65
    • Dialogs • QInputDialog • Lets users provide one-line input • QMessageBox • Displays message and icon to user • QProgressDialog • Displays progress of lengthy operations to user • QDialog • Base class for all dialogs • QColorDialog • QFileDialog • QFontDialog 66
    • Geometry Mgmt with Layout managers Classes used QHBoxLayout, QVBoxLayout, QGridLayout, QStackedLayout Each widget should be added to a layout manager Layout managers may be nested QWidget *top = new QWidget; QLabel *nameLabel = new QLabel("Username:", top); QLineEdit *nameEdit = new QLineEdit(top); QLabel *passLabel = new QLabel("Password:", top); QLineEdit *passEdit = new QLineEdit(top); QVBoxLayout *vlay = new QVBoxLayout(top); QHBoxLayout *nameLayout = new QHBoxLayout; QHBoxLayout *passLayout = new QHBoxLayout; vlay->addLayout(nameLayout); vlay->addLayout(passLayout); nameLayout->addWidget(nameLabel); nameLayout->addWidget(nameEdit); passLayout->addWidget(passLabel); passLayout->addWidget(passEdit); top->show(); 67
    • Qt for Symbian Painting and Graphics Pipeline 68
    • Event Processing and Painting • Painting takes place when QWidget::paintEvent() function call is received by the application • Two ways to request repaint (QWidget member functions) • repaint() – causes immediate call to paintEvent() • Avoid • Use only in animations, where immediate repaint() needed • update() – causes a repaint event to be queued • Several update() calls are combined by Qt • Does not cause flickering 69
    • Basic Drawing QPainter QPaintEngine QPaintDevice • QPainter performs drawing operations • Specifies QPaintDevice instance to draw • QPaintDevice is an abstraction of 2D space that can be painted on (such as QBackingStoreDevice) • Drawing can be done on instances of QWidget, QPrinter, QPixmap, QImage, QPicture, QGLPixelBuffer, and QGLFrameBufferObject, in other words anything inheriting QPaintDevice 70
    • QPainter • Draw different shapes • Polygon, rectangle, ellipse, pie, line, arc, text • Specify pen width and style • Solid, dash, dot • Enable/disable antialiasing • Set brush • No brush, gradient color, texture • Use transformations • Translate, rotate, scale • Save and restore drawing context • QPainter settings 71
    • Added value to AVKON controls • Gradient colors • Transformations • Timed transformations, i.e., animations • Image composition • Color transparency, 8-bit alpha channel • Graphics view • With graphic items • With graphics widgets 72
    • Gradient Colors • Linear – Color interpolation between start and end points • Radial – Interpolation between focal and end points on a circle • Pattern can be repeated or reflected outside the end point • Conical – Counter-clockwise interpolation around a point QPainter p(this); QLinearGradient g(0, 0, 100, 100); g.setColorAt(0.0, Qt::white); g.setColorAt(1.0, Qt::blue); p.setBrush(g); p.drawRect(0, 0, 100, 100); • Also easy to add repeats and reflections, e.g.: QGradient::setSpread(QGradient::ReflectSpread); 73
    • Qt/S60 GUI Integration 74
    • Qt for Symbian Graphics View 75
    • Graphics View • Provides a surface for managing and interacting with number of custom-made 2D graphical items • Event propagation architecture provided • Allows precise double-precision interaction capabilities for the items on the scene • Items can handle key, mouse press, move, release and double click events • Tracks mouse movement • Uses Binary Space Partitioning tree to provide very fast item discovery • Items may be widgets • Fancy way to add transformations to the scene • Automatic collision detection • Main components • Graphics Item • Graphics Scene • Graphics View 76
    • Graphics Scene – QGraphicsScene • Container for item objects • Provides a fast interface for managing a large number of items • Propagates events to each item • Manages item state (selection, focus) QGraphicsScene scene; QGraphicsItem *rect = scene.addRect(QRectF(0, 0, 100, 100)); scene.addItem(newGraphicsItem); QGraphicsItem *item = scene.itemAt(50, 50); // item == rect 78
    • Graphics View - QGraphicsView • The view widget for displaying the contents of a QGraphicsScene • One scene may display on one or more graphics views • You can add a QGraphicsView directly from the UI Designer • Like an empty canvas for your Graphics Items • Convenient and efficient use of transformations • Uses QMatrix or QTransform • rotate() • scale() • translate() • shear() 79
    • Graphics View Usage • Create an instance of QGraphicsScene • Create a view to the scene using QGraphicsView, and insert it like any other widget into your layout • Create QGraphicsItems to the scene • For each item, set its position and other properties to your liking • Add each item with scene->addItem(item); • Optionally, create custom items by subclassing QGraphicsItem (or a subclass) • As a minimum, you need to implement boundingRect() and paint(QPainter*,const QStyleOptionGraphicsItem*,QWidget*) 80
    • Graphics View – QGraphicsItem • Graphical item on the screen • Several standard item classes exist: rectangle, ellipse, text • Items live in their own local coordinate system. • Coordinates are usually centered around its center point (0, 0), and this is also the center for all transformations. • Item features • Mouse press, move, release, double click, mouse hover event, wheel event, context menu events • Keyboard input focus, key events • Drag and drop • Grouping • Z-order • Collision detection • Set a shape for your items • Override collision detection function if needed 81
    • Animations • Single items can be animated by using a QGraphicsItemAnimation • QGraphicsItemAnimation can animate an item by interpolating the items position and transformation over a timeline QGraphicsItem* myitem = ...; QTimeLine* timeline = new QTimeLine(500); timeline->setFrameRange(0,100); QGraphicsItemAnimation* animation = new QGraphicsItemAnimation; animation->setItem(myitem); animation->setTimeLine(timeline); animation->setPosAt(0.0,QPointF(0.0,0.0)); animation->setPosAt(0.5,QPointF(100.0,100.0)); animation->setPosAt(1.0,QPointF(0.0,50.0)); timeline->start(); 82
    • Transformations • View can transform scene’s co-ordinate system • Implement slots, which implement the transformations • Slots connected to widgets signals • Easy to add transformations to graphic view items or to the whole view QTransform transform; transform.translate(50, 50); transform.rotate(45); transform.scale(0.5, 1.0); view.setTransform(transform); // Also available: view.rotate(45); 83
    • Qt for Symbian Animation framework 84
    • Animation Framework – new in Qt 4.6 • Helps build highly animated, high-performance GUIs without the hassle of managing complex structures, timers, and easing curves or state graphs • The framework makes it easy to animate any QObjects, including QWidgets, by allowing Qt properties to be animated. • Graphics views are not left out; one can animate QGraphicsWidgets and new QGraphicsObjects which inherit from QGraphicsItem (and thereby enable properties). • Animations are controlled using easing curves and can be grouped together. • The API is easy to grasp with functions such as start(), stop(), pause(), and currentTime(). • The animation framework also plugs into the new Qt Statemachine by allowing an animation to be played when transitions are triggered. The state machine framework is introduced in 4.6 85
    • Qt for Symbian Open GL 86
    • Qt – Modules (OpenGL) • Offers classes that make it easy to use OpenGL in Qt applications • Provides an OpenGL widget class that can be used just like any other Qt widget, except that it opens an OpenGL display buffer where you can use the OpenGL API to render the contents • Implemented as a platform-independent Qt/C++ wrapper around the platform- dependent GLX, WGL, or AGL C APIs • The functionality provided is very similar to Mark Kilgard's GLUT library, but with much more non-OpenGL-specific GUI functionality, i.e. the whole Qt API QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support QtGui QtSql QtXml QtNetwork QtScript Phonon QtCore 87
    • Qt Open GL/3D Classes •OpenGL is a standard API for rendering 3D graphics •Allows you to build your user interface in Qt, display and manipulate 3D model in OpenGL® •Integrates OpenGL canvas with Qt •Provides frame buffer and pixel buffer abstraction •Supports accelerating 2D painting with OpenGL •Mix 2D painting and 3D scenes 88
    • Qt for Symbian Declarative UI A peek to the future 89
    • Declarative UI Designer • For programmers and designers • expressive declaration language to allow describing how UI’s should look and behave instead of how they are constructed • Create state-of-the-art, visually appealing user interfaces • Utilizing declarative UI technology • Supports both visual and code editing • Target mobile/embedded and desktop platforms • Enabling transition and manipulation of individual component building blocks • Expose Qt objects and properties to JavaScript 90 Public
    • Traditional Qt User Interface 91 91
    • Red Rectangle with QML // grant access to basic elements import Qt 4.6 • QML = Qt Modeling Language • Inspired by Javascript // a red rectangle • Specify user interface declaratively Rectangle { • The “flow” of the application id: RedRectangle • QGraphicsView and QtScript below width: 400 • Qt Creator support height: 200 color: "red" } 92 92
    • Elements A Text Element over Traditional QPushButton an Image Element Elements are not restricted 93 93
    • Various Element Types 94 94
    • Script • An ECMAScript (Javascript) block can be the value of a property inside QML • Enables complex logic at QML level • Enables more advanced binding 95 95
    • Declarative UI - what else will there be • States • Transitions • Animations • With bindings to Qt C++ you can get access all the mobile features you need! 96
    • Qt for Mobile Developers Qt Advanced – Multimedia 97
    • Qt – Modules (Phonon) QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • Multimedia framework for audio and video content QtGui QtSql QtXml QtNetwork QtScript Phonon • Support playback of the most common formats QtCore • Media can be read from files or streamed over a network • It is just FW, backend provide the actual functionality • Windows: DirectX and DirectShow 9 or higher • Linux: GStreamer • Mac: QuickTime • S60: MMF Phonon::VideoPlayer *player = • Implementation in Qt for S60 beta new Phonon::VideoPlayer( • Based on three basic concepts Phonon::VideoCategory, • Media objects parentWidget); • Manages media sources player->play(url); • Media control: start, stop, pause etc • Sinks • Outputs media (video rendering to widget, audio to sound card) • Paths • Used to connect media objects and sinks • Enables media graphs 98
    • Architecture • Abstracts multimedia playback engines 99
    • Qt Convenience Classes • QMovie • QMovie class is a convenience class for playing movies with QImageReader • Incremental loading of animations or images • QLabel::setMovie() • QSound • Access to the platform audio facilities • Provides cross-platform sound support • On Microsoft Windows, the underlying multimedia system is used • Only the WAV format is supported for the sound files • On X11, the Network Audio System is used if available, otherwise all operations work silently • NAS supports WAV and AU files • On the Macintosh, all QuickTime-supported formats are supported • QVideoPlayer 100
    • Qt for Mobile Developers Qt Advanced – Databases 101
    • Qt – Modules (Sql) QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • Provides database integration to Qt applications • Divided to three layers QtGui QtSql QtXml QtNetwork QtScript Phonon 1. UI Layer • Provides classes to link the data from database to QtCore data-aware widgets • Designed to work with Qt's model/view framework 2. API layer • Provides Qt’s abstracted database-independent SQL API 3. Driver layer • Provides low-level bridge between the specific QSqlDatabase db = databases and the SQL API layer QSqlDatabase::database("sales"); • Uses driver plugins to communicate with the different QSqlQuery query databases ("SELECT Lastname, • Several drivers are supplied with Qt City FROM Names", db); 102
    • Connecting to a Database • Choose driver(s) to use in the static method QSqlDatabase::addDatabase(QString) Driver type Description QDB2 IBM DB2, v7.1 and higher QIBASE Borland Interbase Driver QMYSQL MySQL Driver QOCI Oracle Call Interface Driver QODBC ODBC Driver QPSQL PostgreSQL v6.x and v7.x FDriver QSQLITE SQLite version 3 or above QSQLITE2 SQLite version 2 QTDS Sybase Adaptive Server 103
    • Connecting Example QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL"); db.setHostName("bigblue"); db.setDatabaseName("flightdb"); db.setUserName("acarlson"); db.setPassword("1uTbSbAs"); bool ok = db.open(); if ( !ok ) qFatal() << "Error opening database: “ << db.lastError(); 104
    • Invoking SQL Queries • The class QSqlQuery can be used to run any SQL query • This includes select statements, insert statement, and even statements for creating new tables • To run a query, create an instance of QSqlQuery, and run the exec() method specifying the statement as a parameter: QSqlQuery query; if ( !query.exec( "SELECT name FROM author" ) ) ... • An optional argument can be given to the constructor specifying which database to use • Transaction support • QSqlDatabase::transaction(), QSqlDatabase::commit(), QSqlDatabase::rollback() 105
    • Qt for Mobile Developers Qt Advanced – XML 106
    • Qt – Modules (XML) QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support •QtXml • Provides C++ implementation of SAX and DOM QtGui QtSql QtXml QtNetwork QtScript Phonon style XML parsers • Provides a stream reader and writer for XML QtCore documents • XSLT support •QtXmlPatterns QXmlStreamReader xml; • XQuery support for Qt xml.addData( data ); while (!xml.atEnd()) • Simple SQL-like query language for traversing { XML documents xml.readNext(); ... • Can select and aggregate XML elements of // do processing interest and transform them for output as } XML or in some other format 107
    • XML APIs • Qt provides three different means of accessing XML data: • SAX (version 2), which provides a sequential view on the data using call backs • Stream Reader/Writer - also a sequential view, but control is in the app using a readNext() method - makes it easier to write recursive decent parsers • DOM (level 1 and 2), which provides a tree view on the data • In order to use the XML support, add QT += xml to your QMake files • Using SAX is easiest with QXmlDefaultHandler: class MyHandler :public QXmlDefaultHandler { ... } MyHandler handler; QXmlSimpleReader reader; reader.setContentHandler( &handler ); reader.setErrorHandler( &handler ); 108
    • Qt for Mobile Developers Qt Advanced – Networking 109
    • Qt – Modules (Network) • Classes for writing TCP/IP clients and servers QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • Makes network programming easier and portable QtGui QtSql QtXml QtNetwork QtScript Phonon • Support for QtCore • Lower level protocols (TCP and UDP) and higher level application protocols (FTP and HTTP) • Seamless integration with progress widgets and any IO device • Host Name resolving services and URL parsing, SSL support and much more QHttp http; connect(http, SIGNAL(done(bool)), this, SLOT(done(bool))); http->get( “http://overtheair.org/amazingApi.jsp?action=doGreatThings”); void MyClass::done(bool error) { QString data = http->readAll(); //handle data } 110
    • Networking • Easy to use with high-level classes • QHttp (QNetworkRequest, QNetworkAccessManager, QNetworkReply) • In most cases, use WebKit directly • QFtp • QTcpServer • QTcpSocket • QUdpSocket • QNetworkProxy added in Qt 4.5 • Add network module to your project file • QT += network 111
    • Network Access • QNetworkAccessManager • Asynchronous API for sending and receiving data • Intuitive API for put/post/get/head • Modify or inspect headers in request and reply connect(manager, finished(QNetworkReply*)), this,SLOT(replyFinished(QNetworkReply*))); QNetworkRequest req(QUrl(“http://host.com/foo”)); manager->get(req); void replyFinished(QNetworkReply *reply) { //some checks to verify reply QByteArray data = reply->readAll(); } 112
    • Qt for Mobile Developers Qt Advanced – WebKit 113
    • Qt – Modules (WebKit) QtOpenGl QtSvg QtWebKit QtXmlPatterns Qt3Support • Classes for displaying and editing Web content QtGui QtSql QtXml QtNetwork QtScript Phonon • Web content can be enhanced with native controls QtCore • Based on open-source WebKit engine • Ported to use Qt • Rendering • Text Handling • Network Access • Integrated part of WebKit project, uses WebKit’s platform abstraction QWebView *view = new QWebView(parent); view->load(QUrl("http://qt.nokia.com/")); • Qt Style API to engine: view->show(); • QWebView, QWebPage and QWebFrame 114
    • Interact with Web Services • QtWebKit allows • Intuitive use of network resources • Exposing QWidget to HTML and QObject to JavaScript • Calling JavaScript from Qt and vice versa JS Qt OS specific APIs 115
    • QWebView and QWebPage classes • QWebView inherited from QWidget QWebView • Renders the content in QWebPage • Easy to embed wherever widget could be used QWebPage • QWebPage provides access to the document structure in a page QWebFrame • Frames • Navigation history • Undo/redo stack for editable content • Each QWebpage has one QWebFrame object as its main frame • HTML documents can be nested using frames 116
    • function setStatus() { Javascript twit.updateStatus( statusupdate.text ); } statusupdate.returnPressed.connect(this,setStatus); QWebFrame *frame = view->currentFrame(); //You can inject JavaScript to be executed frame->evaluateJavaScript(“myAmaging JS Stuff”); //You can expose any QObject to the web view MyQTwitter *twit = new MyQTwitter() frame->addToJavaScriptWindowObject(“twit”,twit); //do what ever you want with native APIs //that you can call directly from Qt CRRSensorApi::FindSensorsL(sensorList); 117
    • Exposing Widgets – 1(2) • WebKit can place QWidget’s in the web environment • Use HTML/script to control UI and infrastructure • Two approaches • Host widget inside web environment • Expose object to script environment • …or call script from C++ side • Why would you want to do this? • Simple updates (redeploy a script file) • Easy to reuse web design for Look & Feel • Easier interaction with web services 118
    • Exposing Widgets – 2(2) • Place QWidget in web environment • QWebPage::createPlugin() • QWebPluginFactory • <object type=“application/x-qt-plugin” classid=“MyNiceWidget” …> QObject* createPlugin(const QString &classid, const QUrl &url, const QStringList& paramNames, const QStringList &paramValues ) { if (classid==“MyNiceWidget”) return new MyNiceWidget; return 0; } 119
    • Work with Exposed Objects • QWebFrame::addToJavaScriptWindowObject • QObjects expose metaobject information • Properties can be read and altered • Slots can be called • Connect statements can be made frame->addToJavaScriptWindowObject(“twit”,twit); function setStatus() { twit.updateStatus( statusupdate.text ); } statusupdate.returnPressed.connect(this,setStatus); 120
    • Interoperating with JavaScript • Each web frame has a JS context • QWebFrame::evaluateJavaScript QWebFrame *frame = view->currentFrame(); frame->evaluateJavaScript(…) • Returns a variant QVariant value = frame->evaluateJavaScript(“1+1;”); // value.toInt() == 2; 121
    • Hybrid Development Approachability of Programming Environment Un at Are Easy ta a in WRT ab • Hybrid applications combine easily approachable web le technologies and powerful and scalable Qt C++ • Qt already includes a rich selection of features for web and Difficult Qt C++ Size of hybrid development Project Small Large • QtWebKit module: embed web content from servers, local files or application’s resources into Qt applications • QtScript module: make Qt applications scriptable Hybrid Applications • Both QtWebKit and QtScript provide a bridge between the Qt C++ Application JavaScript execution environment and the Qt object model, to allow for custom QObjects to be scripted. HTML, CSS, JavaScript • QtXMLPatterns module: shape and mash up XML date yielding HTML output • QNetworkAccessManager: interact with server side URL APIs Browser/ Standalone Web runtime Application *) Services written in Qt C++, Declarative UI, Access to Qt *) Planned future functionality 122 Public
    • Hybrid apps • So you can run JS and HTML inside Qt application… What are the differences when compared to a WRT widget? WRT Widget running on top of webkit Qt application Webkit QWebView running webkit Widgets HTML, CSS, Same HTML, CSS, JavaScript JavaScript Platform Services Native APIs Native APIs incl. Qt Mobility APIs Platform Services implementation Platform Services implementation 123
    • Webview Demo • Pure JS content run on top of Webkit • Demonstrates different applications & look and feel • BBC News • News (Iphone style) • Rock-Paper-Scissors • Tic-Tac-Toe • Calculator • Bubble • Statistics: • 300 lines of C++ code (flick support ~200 lines) • Size of .sis file: 20 kB • Development time: approx. 5 hours 124
    • Key selling points in the hybrid approach • No feature restrictions! • Portable where ever Qt is available (which is everywhere - soon) • Utilize web developer skills to make the apps • Qt native skills to implement”platform services” • Qt script generator http://labs.trolltech.com/page/Projects/QtScript/Generator • Mixing native and HTML UI • Interesting scenarious coming f.ex with Orbit widgets • Tools might be problematic (migrating web tools and native (Qt Creator)) • We can make hybrid approach even for compelling by providing ready framework where existing widgets can be plugged in 125
    • Part 3. Qt for Symbian Company Confidential 126 © 2009 Nokia V1-Filename.ppt / YYYY-MM-DD / Initials
    • Qt for Symbian Overview and tools 127
    • What is Qt for Symbian? • Qt APIs have been implemented on top of OpenC/Symbian APIs • The purpose is to have Qt programs running on the Symbian platform • Cross-platform applications • There will be a separate library called Orbit (built on top of Qt modules) which provides additional Symbian UI framework APIs in the future • Qt modules are compiled as Symbian DLLs and can be used in a Symbian environment as is • From the perspective of a developer, Qt can be considered as a set of libraries to use for UI implementation, otherwise it’s just Symbian development 128
    • Installing Qt for Symbian • The Qt modules’ source code, installation guide and a Windows installer are downloadable from http://qt.nokia.com • The Qt tools are compiled for Symbian platform • The Qt modules are compiled using Symbian build tools • As a result, a bunch of Qt*.dll and Qt*.lib files are produced into SDK emulator folders (epoc32) • For devices, pre-made .sisx files are provided • Qt libraries can currently only be compiled for devices using the RVCT tool chain 129
    • Installing Qt 4.6 beta to the device • Remember to have Symbian 3rd Edition FP1 or newer device • Not sure what device you have? Check out from http://www.forum.nokia.com/devices/ • Install the following • From Open C plugin (http://www.forum.nokia.com/openc) • pips_s60_1_6_SS.sis: Pips 1.6 • In [Symbian_SDK]nokia_pluginopencs60opencsis • openc_ssl_s60_1_6_SS.sis: Open C SSL 1.6 • In [Symbian_SDK]nokia_pluginopencs60opencsis • STDCPP_s60_1_6_SS.sis: STDCPP 1.6 • In [Symbian_SDK] nokia_pluginopencpps60opencppsis • qt_4_6_beta.sis: Qt for Symbian 4.6 beta • The Qt libraries, In the folder where you installed Qt • fluidlauncher.sis: Demo apps for Qt 4.6 beta • Demo applications • In the folder where you installed Qt, f.ex C:Qt4.6.0-beta • Yes, in the final version we will have a simpler solution ;) 130
    • ”smart installer” - Qt installer for Symbian The opportunity The problem The solution A Smart Installer tool that +130M Symbian devices Qt libraries need to be checks whether needed Qt could run cross-platform Qt post installed – most version is available on the applications already during consumers might not device – and if not, it will this year bother handle the installation Details •Nokia is working on a tool called Smart Installer for Symbian devices •The expected availability is 1Q 2010 •A piece of code is to be packaged together with the Qt application targeted for Symbian devices (when creating the .sis file) •The Smart Installer will download OTA the needed Qt version to the handset if it is not already present 131
    • Carbide.c++ 2.0 • Since version 2.0 all editions are free of charge • Qt for Symbian support! • New to Carbide? View the Getting Started with Carbide.c++ Express Screencast, which will take you through the basics of creating, building, and deploying your first application. • http://www.forum.nokia.com/info/sw.nokia.com/id/af80987a- a72d-44cf-bf00- 1926be01058c/Carbide_cpp_Getting_Started_v1_1_en.exe.html • Bug reports : Carbide Help menu, ”New Bug Report” 132
    • You can distribute Qt along with your application - Qt will be preinstalled in the coming Nokia devices! + Smart installer Company Confidential 133 © 2009 Nokia V1-Filename.ppt / YYYY-MM-DD / Initials
    • Part 4. The anatomy lesson Company Confidential 134 © 2009 Nokia V1-Filename.ppt / YYYY-MM-DD / Initials
    • Anatomy of a Qt app 135
    • Basic Project Structure • Project file • Headers • Sources • Resources • UI design files 136
    • First Qt Program #include <QtGui/QApplication> #include <QtGui/QLabel> int main(int argc, char* argv[]) { QApplication hwApp(argc, argv); QLabel hwLabel("Hello world"); // Widgets are not visible by default. // Alternatives: showMaximized(), showFullScreen() hwLabel.show(); return hwApp.exec(); } 137
    • qmake – example of .pro file Specifies for qmake that: • application is based on Qt and CONFIG += qt debug • debug information is needed HEADERS += hello.h SOURCES += hello.cpp SOURCES += main.cpp win32 { Platform specific conditions. This SOURCES += hellowin.cpp mechanism will be used to specify Symbian/S60 specific details, like } required capabilities, UIDs etc. unix { SOURCES += hellounix.cpp } !exists( main.cpp ) { error( "No main.cpp file found" ) } win32:debug { CONFIG += console } 138
    • Project File Structure CONFIG += qt debug HEADERS += hello.h SOURCES += hello.cpp SOURCES += main.cpp win32 { SOURCES += hellowin.cpp } unix { SOURCES += hellounix.cpp } Symbian { SOURCES += hellosymbian.cpp } !exists( main.cpp ) { error( "No main.cpp file found" ) } win32:debug { CONFIG += console } • You may also use flags in your code • Symbian features or changes flagged with Q_OS_SYMBIAN • S60 dependencies with Q_WS_S60 139
    • Building Qt Application on Symbian • In a normal Qt way for the Qt part: • qmake –project • qmake • Component description file created (bld.inf) • Project description file created (.mmp file) • Extension Makefiles created • Take care of executing moc, uic, rcc tools • Integrated like mifconv to the toolchain • Then, the actual compilation either with • Generated platform specific Makefile: make debug-winscw 140
    • Qt and Symbian OS Tool Chain Integration 141
    • Platform Security • Qt programs executed in processes with their own capabilities • Just like native programs • If a program accesses a protected Symbian/S60 API, it needs capabilities and/or secure/vendor IDs • Capabilities needed by native API calls easy to determine with Carbide.c++ capability scanner • PlatSecDiagnostics can be used to determine capabilities needed by Qt library APIs • Set PlatSecEnforcement OFF and diagnostics ON in the epoc32dataEPOC.INI file • Read possible platform security violations from %TEMP%EPOCWIND.out 142
    • MMP File Definitions in a .pro Project File • Everything you need in a Symbian OS MMP file, can be defined in the Qt .pro file • Symbian-specific extensions should be defined inside a special block as shown below TARGET = HelloWorld // Not Symbian-specific TEMPLATE = app // Not Symbian-specific symbian*:{ // LIBS-keyword as such is not Symbian-specific, but bitgdi library is LIBS += -lbitgdi ICON = ./images/myIcon.svg TARGET.UID2 = 0x100039CE TARGET.UID3 = 0xA000017F TARGET.SID = 0xA000017F TARGET.VID = 0x70000001 TARGET.CAPABILITY = NetworkServices // Qt app stack typically larger than 8kb TARGET.EPOCSTACKSIZE = 0x5000 // Min 128Kb, Max 16Mb TARGET.EPOCHEAPSIZE = “0x20000 0x1000000” } • This way the same .pro file would potentially work in other environments as well 143
    • make command Command Description make Creates abld and the project makefiles and builds debug build of the application for the emulator (winscw udeb). • Running make command calls bldmake and abld to build the Qt make debug Creates debug builds (winscw/gcce/armv5 udeb). make debug-winscw Creates winscw debug build. application for the S60 environment. make debug-gcce Creates gcce debug build. make debug-armv5 Creates armv5 debug build. make release Creates release builds (gcce/armv5 urel). make release-gcce Creates gcce release build. make release-armv5 Creates armv5 release build. make export Copies the exported files to their destination. make cleanexport Removes files created with make export. make mocclean Removes the header and source files created by the moc tool. make mocables Runs moc tool on necessary files. make clean Removes everything built with abld target, exported files and makefiles. make distclean As make clean, but also removes all Symbian specific files created with qmake. make confclean As make distclean, but also cleans everything generated by configure call. Note that this command is only available in the Qt root directory. make run Launches the application in the emulator. 145
    • Symbian Extensions to Project Files • A Qt application on Symbian, is a Symbian application written in Qt running on S60 devices. • All statements that are in a Symbian project defined in the mmp file are defined in the project file when creating application with Qt in the S60 environment. Executing qmake overrides all changes made manually to the mmp file. • Trick : if you really need to have manual changes put the file as read only! • Target type is specified using TEMPLATE and CONFIG variables in the .pro file. • TEMPLATE = app value maps to target type EXE in MMP file, • TEMPLATE = lib, CONFIG variable is used to distinguish between lib and dll target types. • Name of application executable – use TARGET statement in .pro file (maps to TARGET in MMP file). Example: TARGET = QtS60HelloWorld • Symbian specific definitions in the project file should be separated from other definitions using a Symbian keyword. Example: symbian: { TARGET.UID2 = 0x100039CE TARGET.UID3 = 0xA000017F } 146
    • Symbian Extensions to Project Files • Some other examples of Symbian specific keywords: • TARGET.SID = 0xA000017F • TARGET.VID = 0x70000001 • TARGET.EPOCSTACKSIZE = 0x5000 // 20kb • TARGET.EPOCHEAPSIZE = 0x20000 0x1000000 // Min 128kb, Max 16Mb • TARGET.CAPABILITY = NetworkServices • The DEFINES keyword can be used to add MACRO statements to the mmp file. • QMAKE_CXXFLAGS can be used for setting compiler-specific options. The keyword is followed by the specific compiler: QMAKE_CXXFLAGS.CW += -O2 QMAKE_CXXFLAGS.ARMCC += -O0 147
    • Symbian extensions to project files • RSS_RULES keyword for adding information to the _reg.rss file • BLD_INF_RULES keyword for adding information to the bld.inf file • Bunch of other extensions can be found in the Qt for S60 documentation – see more in: http://library.forum.nokia.com/topic/Qt_for_S60_Developers_Library/GUID- 97A34C6E-9F2B-4743-86F8-563362F7047A_cover.html • And http://pepper.troll.no/s60prereleases/doc/qmake-variable-reference.html 148
    • Libraries • Some libraries are automatically added to the mmp file when generating the file. These libraries are: • libc, libm, euser, libdl and QtCore, • static library libcrt0 for QtCore applications, • static library qtmain for QtGui applications, • QtGui, avkon, eikcore, eiksrv, ws32, apparc, cone, eikcoctl, bafl and efsrv for QtGui applicaitons. • Qt libraries are added to the project file using the QT variable: QT += network • If other platform-specific libraries need to be added to the project, this can be done by adding the LIBS variable to the project file with the appropriate library name preceded with a ‘–l’ prefix: LIBS += -lbitgdi –lfbscli 149
    • Platform Security cnt’d • Qt programs executed in processes with their own capabilities • Just like native programs • If a program accesses a protected Symbian/S60 API, it needs capabilities and/or secure/vendor IDs • Capabilities needed by native API calls easy to determine with Carbide.c++ capability scanner • PlatSecDiagnostics can be used to determine capabilities needed by Qt library APIs • Set PlatSecEnforcement OFF and diagnostics ON in the epoc32dataEPOC.INI file • Read possible platform security violations from %TEMP%EPOCWIND.out 150
    • 151
    • Part 5. Go Nuts - Mixing Qt with Symbian C++ 152
    • Qt and Symbian mixed 153
    • Go nuts and mix Qt with Symbian APIs • As Qt is not a runtime you can always use native apps to fill the gaps • Mobility APIs progressing and removing the need for many cases 154
    • Exceptions/Leaves • Isolate all leaving Symbian OS code from Qt code • Trap all leaving functions and return error code to Qt … or … • Use the global conversion macros and functions provided by the Qt for Symbian release int PainterWrapper::ConstructPainter() { TRAPD(error, activePainter = CActivePainter::NewL()); return error; } // …or something like… HBufC* buf=0; // this will throw a std::bad_alloc because we've asked for too much memory QT_TRANSLATE_SYMBIAN_LEAVE_TO_EXCEPTION(buf = HBufC::NewL(100000000)); 155
    • Separating Qt and Symbian implementations 1/2 • Symbian code should be separated from Qt code so that it can be replaced with another platform-specific code when changing the platform. Private implementation (aka pimpl) is an idiom that is used in Qt, and it can be utilised to separate platform-specific code — different platforms have different implementations of the private class. Binary compatibility can be retained with this idiom. • The idea of cross-platform implementation is to have the public interface of the class the same for all platforms; the private implementation can then be platform specific. 156
    • Separating Qt and Symbian implementations 2/2 • The main principles for private implementation are: • The public class has to have a pointer to the private class AOWrapper::AOWrapper(QObject *parent) : QObject(parent) { d_ptr = new AOWrapperPrivate(this); } • The constructor of the private class creates a pointer to the public class passed as a parameter: AOWrapperPrivate::AOWrapperPrivate(AOWrapper *wrapper) : q_ptr(wrapper) { } • The q_ptr pointer can be used to refer to the public class from the private class and the d_ptr pointer can be used to refer to the private class from the public class. • For examples of using the private implementation you can have a look f.ex at the Mobile Extensions 157
    • Private Implementation • The problem: Maintaining Binary Compatibility • Adding, removing or reordering members in public classes would break binary compatibility • Different implementations of the same class in different platforms • Need a way to hide implementational details from the class header • Private Implementation, P-IMPL, is a general design pattern providing a solution for this problem • Used throughout Qt with a few exceptions • QColor, QModellndex, QMatrix, Q*Event 158
    • Private Implementation in General // a.hh // a.hh // a.cpp class A { struct D; struct D { ... int x; private: class A { int y; int x; ... }; int y; private: ... }; D* d_ptr; }; 159
    • Hiding Platform Dependencies 160
    • Qt and Active Objects • Active scheduler is created when the S60 GUI Framework is initialized in s60main • Happens before main() in your Qt application is called • How to use Qt and Active Objects: • An example application exists: http://www.forum.nokia.com/info/sw.nokia.com/id/63313e06-8fd7-4a68-8610- 80dd7ee22745/Qt_for_S60_Examples.html • And also documentation: http://www.forum.nokia.com/info/sw.nokia.com/id/c41e7898-2dd8-4f23-a629- d27727519ffa/Qt_for_S60_Developers_Library.html 161
    • Separating Symbian specific implementation • When you need to write Symbian specific code use the following macro #if defined(Q_OS_SYMBIAN) #include <e32std.h> #endif • One good way to separate Symbian code is to have in in a separate DLL (plugin) 162
    • Lucian – the floor is yours • Please take it… 163
    • Part 6. Closing Please take my business card! ;) 164
    • We’ll be making it easy for you • All you need is Qt creator – no SDKs ;) • Integrated with Remote Device Access (RDA) - you don’t even need a device ;) • http://www.forum.nokia.com/rda • No promises here about dates or months yet… Combine hybrid framework with this one – isn’t it creepy how easy we can make it for you? 165 http://www.youtube.com/watch?v=TmFn90Zx2oo
    • Nokia + Ovi Developer Story | 167 Nokia native dev offering, redefined 1= Nokia cross-platform SDKs that you’ll love – with a money back guarantee (as it’s free) 2= Ovi APIs. Amazing features in your apps – take the Ovi social network to be a part of your solution 3= Ovi Store. Sell your app to hundreds of millions 167
    • http://qt.nokia.com/ http://qt.nokia.com/ Thank you very ma ny! Questions? pekka.kosonen@n okia.com Company Confidential 168 168 Slides will be available in http://www.slideshare.net/pkosonen © 2009 Nokia V1-Filename.ppt / YYYY-MM-DD / Initials
    • Fireworks! • Espen 169