Qt in Education

Hello,utcenter. I am reading the Qt3D Troubleshooting. In the last part, it suggests that I should delete the values in Windows registry @HKEY_CURRENT_USER\Software\Trolltech\OrganizationDefaults\Qt Plugin Cache 4.2.debug HKEY_CURRENT_USER\Software\Trolltech\OrganizationDefaults\Qt Plugin Cache 4.2.false@ But in my computer,the values read this: @Qt Plugin Cache 4.5.false Qt Plugin Cache 4.6.false Qt Plugin Cache 4.7.debug Qt Plugin Cache 4.7.false Qt Plugin Cache 4.8.debug Qt Plugin Cache 4.8.false @ Should I delete them all?

ThanQ very much you done a great job,it helps to Qt beginers

It is sometimes enlightening to open and read the generated code. In this case, take a look inside the generated ui.h file. The moc.cpp files are also interesting, but a bit harder to understand.

here they are: "Your text to link here...":https://sourceforge.net/projects/qtexamples/files/ sourceforge is unnecessarily complex...grandiose all 3 examples work but require a gunzip, tar xvf and execution (readme.txt file in each project ) sourceforge gurus advise..please The Lottery example will be changed to allow personal selection of 6 external values to run against 6 generated values

You could use a QListWidget to display items stored in a QStringList.

Attention:you must add glu.h or glut.h manually in you QtOpenGL file I think one must understand though only core code related to texture is showed. @#include <QtGui> #include <QtOpenGL> #include <glut.h> void GLwidget::loadTextures() { glEnable(GL_TEXTURE_2D); QImage text[3],buff[3]; if(!buff[0].load("./sun.bmp") ||!buff[1].load("./earth.bmp") ||!buff[2].load("./moon.bmp")){ printf("Load Image failed!\n"); } text[0] = QGLWidget::convertToGLFormat(buff[0]); text[1] = QGLWidget::convertToGLFormat(buff[1]); text[2] = QGLWidget::convertToGLFormat(buff[2]); glGenTextures(3,&texture[0]); glBindTexture( GL_TEXTURE_2D, texture[0] ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); glTexImage2D( GL_TEXTURE_2D, 0, 3, text[0].width(), text[0].height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, text[0].bits() ); glBindTexture( GL_TEXTURE_2D, texture[1] ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); glTexImage2D( GL_TEXTURE_2D, 0, 3, text[1].width(), text[1].height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, text[1].bits() ); glBindTexture( GL_TEXTURE_2D, texture[2] ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR ); glTexImage2D( GL_TEXTURE_2D, 0, 3, text[2].width(), text[2].height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, text[2].bits() ); }@ @ void GLwidget::paintGL() {GLUquadricObj *quadratic = gluNewQuadric(); glBindTexture(GL_TEXTURE_2D, texture[0]); //the same with texture[1],[2] glPushMatrix(); gluSphere(quadratic,sunRadius,100,100); glPopMatrix(); }@ @ void GLwidget::initializeGL(){ glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP); glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP); }@

Qt5.0 alpha can not run on windows. How to deal with it ?

@void GLWidget::mouseMoveEvent(QMouseEvent *event) { int dx = event->x() - lastPos.x(); int dy = event->y() - lastPos.y(); if (event->buttons() & Qt::LeftButton) { setXRotation(xRot + 8 * dy); setYRotation(yRot + 8 * dx); } else if (event->buttons() & Qt::RightButton) { setXRotation(xRot + 8 * dy); setZRotation(zRot + 8 * dx); } lastPos = event->pos(); } @ I delete the event->button() in mouseMoveEvent(), and it works. And I find that "event->buttons() & Qt::LeftButton " equals to "Qt::LeftArrow". Is it right? Edit: please wrap code sections in @ tags; Andre

Well, all is contained in the [[doc:QModelIndex]]. It contains row, column and parent item. These three together uniquely identify an item in an model. Edit: I happen to have the book here, but I can't quickly locate the exact snippet you're talking about.

No problem. Glad to hear that your problem has been solved. Sometimes we overlook some simple things over and over again. Please mark your thread as solved next time.

Qt creator is an IDE (Integrated Development Environment) which helps you developing your applications. The sections, you are showing, are C++ source code presumably generated by the Qt creator based it templates. Q_OBJECT is required for the "Meta Object Compiler ":http://developer.qt.nokia.com/doc/qt-4.8/moc.html The "explicit statement is explained here":http://www.glenmccl.com/tip_023.htm for example. All see there is basic C++ code. It is recommended to have sufficient knowledge of C++ for using it with Qt. You might want to look for a C++ tutorial first, if you are lacking this knowledge. "One option for a tutorial.":http://www.cplusplus.com/doc/tutorial/ Please consult google search for others.

I dont know how exactly works the database naming on QML, i created a empty database, took his name and download a file with that name and put it into storage directory.

Hi, qBound() for QSize is not defined because it is not easily determined whether (20,10) is larger than (10, 20). You need to do the comparison dimension by dimension like that: @void PuzzleSizeWidget::setValue(const QSize &s) { // ... QSize newSize; newSize.setWidth(qBound(minimum().width(), s.width(), maximum().width()); newSize.setHeight(qBound(minimum().height(), s.width(), maximum().height()); // ... }@ or make use of QSize::boundedTo() and QSize::expandedTo(): @void PuzzleSizeWidget::setValue(const QSize &s) { // ... QSize newSize = s.expandedTo(minimum()).boundedTo(maximum()); // ... }@ Of course you could also just define qBound() for QSize: @QSize qBound(const QSize& min, const QSize& curr, const QSize& max) { return curr.boundedTo(max).expandedTo(min); }@ Hope that helps, good luck with your lab :)

Ok, this would work for now but if you find a better method please share :) this is my WorkerScript JS file "dbprocessor.js" @ var init = function(ids, overview) { // QML is ready var db = openDatabaseSync("QDeclarativeExampleDB", "1.0", "The Example QML SQL!", 1000000); db.transaction( function(tx) { // Create the database if it doesn't already exist tx.executeSql('CREATE TABLE IF NOT EXISTS Greeting(salutation TEXT, salutee TEXT)'); // Add (another) greeting row tx.executeSql('INSERT INTO Greeting VALUES(?, ?)', [ ids, overview ]); } ) } WorkerScript.onMessage = function(message) { // ... long-running operations and calculations are done here switch(message.msg) { case"init": WorkerScript.sendMessage({ 'reply': 'Done init'}); init(message.ids, message.overview); break; } @ And my main.qml file @import Qt 4.7 Rectangle { property bool done: false id: top width: 400 height: 400 property XmlListModel list: XmlListModel { id: xmlModel source: "http://www.example.com/data.xml" query: "/feed/xml/" XmlRole { name: "ids"; query: "id/string()" } XmlRole { name: "overview"; query: "description/string()" } } WorkerScript { id: werk source: "dbprocessor.js" onMessage: console.log(messageObject.reply) } Component { id: delegate Text { // or whatever item MouseArea { // Item click handler anchors.fill: parent onClicked: { console.log("clicked"); } // implement the click handler in the JavaScript } //Just to view data inserted text: ids Component.onCompleted:{ if(!done) { for(var i=0; i&lt; xmlModel.count; i++) werk.sendMessage({'msg': "init", 'ids': xmlModel.get(i).ids, 'overview': xmlModel.get(i).overview }); done = true; } } } } ListView { anchors.fill: parent model: top.list; delegate: delegate; } } @

Qt Quick is relatively new and undergoing many changes. Writing a book at this point in time may invalidate it very fast. I guess there would be books written, but may be after stabilization of the features.

This is the online resource for Qt Quick : http://developer.qt.nokia.com/doc/qt-4.7/qtquick.html