In my code I have additional thread for printing:
class PrintThread : public QThread {
public:
PrintThread(const QString& text, QPrinter* printer): mText(text), mPrinter(printer) {}
void run()
{
QTextDocument doc;
doc.setHtml(mText);
doc.print(mPrinter);
delete mPrinter;
}
private:
QString mText;
QPrinter *mPrinter;
};
Separate thread is needed to prevent GUI from freezing when printing to pdf.
Sometimes during printing I see such lines in console (many times repeated):
X Error: RenderBadGlyphSet (invalid GlyphSet parameter) 165
Extension: 148 (RENDER)
Minor opcode: 25 (RenderCompositeGlyphs32)
Resource id: 0×0
And any text in GUI disappears. What the problem and how to solve it? Thanks.
I'm using Qt 4.4.3
Thread is created here:
void MyClass::print() {
QPrinter *printer = new QPrinter;
printer->setOrientation(QPrinter::Landscape);
QPrintDialog dialog(printer);
if (dialog.exec() == QDialog::Accepted) {
QString text = dataForPrint();
mPrintThread = new PrintThread(text, printer);
connect(mPrintThread, SIGNAL(finished()), this, SLOT(onPrintingFinished()));
mPrintThread->start();
}
}
Related
I am using QGraphicsSvgItem subclass, that reads some content from a file, places content into a QDomDocument, does some initial processing, then sets the processed DOM onto a renderer.
During program processing, additional changes are required on a copy of pre-processed DOM, so the DOM is stored in class. After changes, the DOM is placed on renderer.
class MyGraphicsSvgItem : public QGraphicsSvgItem
{
public:
MyGraphicsSvgItem (QGraphicsItem *parent = 0):
QGraphicsSvgItem(parent),
_svgXML() {}
~MyGraphicsSvgItem () { delete renderer(); }
void CheckAndChangeSomeThings() {}
void LoadStuff (QString fileName)
{
QFile file(fileName);
file.open(QFile::ReadOnly | QFile::Text);
QTextStream in(&file);
QString svgContent = in.readAll();
file.close();
_svgXML.setContent(svgContent);
CheckAndChangeSomeThings(); // this modifies _svgXML
QByteArray _data = _svgXML.toByteArray();
setSharedRenderer(new QSvgRenderer(_data)); // very slow
}
void ChangeThingslater();
void ChangeSomeThingslater()
{
ChangeThingslater(); // this modifies _svgXML
renderer()->load(_svgXML.toByteArray()); // very slow - no file involved
}
protected:
QDomDocument _svgXML;
};
There seems to be a significant slow processing during the lines that assign the DOM to the renderer.
QByteArray _data = _svgXML.toByteArray();
setSharedRenderer(new QSvgRenderer(_data));
If I skip the DOM processing - if I set the renderer to the file - the code speeds up considerably:
Leaving all the code in, but replacing
setSharedRenderer(new QSvgRenderer(_data)); // VERY SLOW
with
setSharedRenderer(new QSvgRenderer(fileName)); // FAST
So it seems the bottleneck is loading the svg renderer from QByteArray.
I looked for alternatives... there is no mention of performance in documentation
QSvgRenderer::QSvgRenderer(const QString & filename, QObject * parent
= 0)
Constructs a new renderer with the given parent and loads the contents of the SVG file with the specified filename.
QSvgRenderer::QSvgRenderer(const QByteArray & contents, QObject *
parent = 0)
Constructs a new renderer with the given parent and loads
the SVG data from the byte array specified by contents.
QSvgRenderer::QSvgRenderer(QXmlStreamReader * contents, QObject *
parent = 0)
Constructs a new renderer with the given parent and loads
the SVG data using the stream reader specified by contents.
Looking in QXmlStreamReader Class, I find that its constructors are similar ! In addition, it says
In some cases it might also be a faster and more convenient alternative for use in applications that would otherwise use a DOM tree
I seem to be going in circles, and even though having already a well formed xml in the DOM, it seems I cannot take advantage of it !
What are my alternatives, to either loading the renderer from the pre-processed DOM, or to a different way of pre-processing the xml - using something other than DOM that the renderer can read fast ?
qt 4.8. c++
You can do all the DOM processing in a worker method that's executed on the thread queue using QtConcurrent::run.
You can use the QSvgRenderer directly in your item. Initialize it in the worker method, and load from QByteArray and not a file. You can then pass the renderer to the GUI thread and use it to render the graphics item by setting it on the QGraphicsSvgItem.
Caveats:
Since you create the renderer in a worker thread, you must move it to a null thread after you've done using it in the worker thread. Conversely, you must move it to the GUI thread once it has been received by the GUI thread.
Recall that moveToThread can only be called from the object's current thread, or any thread if thread() == 0.
In Qt 4.8, there's a bug in QGraphicsSvgItem::setSharedRenderer: it doesn't properly connect the renderer's repaintNeeded signal to its update method. The work around this to connect the signal manually to your own update slot.
This will prevent the GUI from getting blocked by the long processing.
Reentering the event loop, as you do, from within the item is a source of bugs and just a very bad idea from the design standpoint. Use the non-blocking API of the file dialog instead.
Below is an example that demonstrates this technique. It also displays a small spinner when the item is being loaded/processed. There's a simulated delay for this purpose.
#include <QGraphicsView>
#include <QGraphicsSvgItem>
#include <QGraphicsSceneMouseEvent>
#include <QFileDialog>
#include <QSvgRenderer>
#include <QDomDocument>
#include <QtConcurrentRun>
#include <QFutureWatcher>
#include <QThread>
#include <QApplication>
struct Thread : public QThread { using QThread::sleep; }; // Needed for Qt 4 only
class RendererGenerator {
QString m_fileName;
void process(QDomDocument &) {
Thread::sleep(3); /* let's pretend we process the DOM for a long time here */
}
QByteArray generate(const QByteArray & data) {
QDomDocument dom;
dom.setContent(data);
process(dom);
return dom.toByteArray();
}
public:
typedef QSvgRenderer * result_type;
RendererGenerator(const QString & fileName) : m_fileName(fileName) {}
QSvgRenderer * operator()() {
QFile file(m_fileName);
if (file.open(QIODevice::ReadOnly)) {
QByteArray data = file.readAll();
QScopedPointer<QSvgRenderer> renderer(new QSvgRenderer);
renderer->load(generate(data));
renderer->moveToThread(0);
return renderer.take();
}
return 0;
}
};
class UserSvgItem : public QGraphicsSvgItem {
Q_OBJECT
QSvgRenderer m_spinRenderer, * m_lastRenderer;
QScopedPointer<QSvgRenderer> m_renderer;
QFuture<QSvgRenderer*> m_future;
QFutureWatcher<QSvgRenderer*> m_watcher;
QGraphicsView * aView() const {
QList<QGraphicsView*> views = scene()->views();
return views.isEmpty() ? 0 : views.first();
}
Q_SLOT void update() { QGraphicsSvgItem::update(); }
void mousePressEvent(QGraphicsSceneMouseEvent * event) {
if (event->button() == Qt::LeftButton) askForFile();
}
void setRenderer(QSvgRenderer * renderer) {
if (m_lastRenderer) disconnect(m_lastRenderer, SIGNAL(repaintNeeded()), this, SLOT(update()));
setSharedRenderer(renderer);
m_lastRenderer = renderer;
connect(renderer, SIGNAL(repaintNeeded()), SLOT(update()));
if (aView()) aView()->centerOn(this);
}
void askForFile() {
QFileDialog * dialog = new QFileDialog(aView());
connect(dialog, SIGNAL(fileSelected(QString)), SLOT(loadFile(QString)));
dialog->setAcceptMode(QFileDialog::AcceptOpen);
dialog->setAttribute(Qt::WA_DeleteOnClose);
dialog->show();
}
Q_SLOT void loadFile(const QString & file) {
if (m_future.isRunning()) return;
setRenderer(&m_spinRenderer);
m_future = QtConcurrent::run(RendererGenerator(file));
m_watcher.setFuture(m_future);
}
Q_SLOT void rendererReady() {
m_renderer.reset(m_future.result());
m_renderer->moveToThread(thread());
setRenderer(m_renderer.data());
}
public:
UserSvgItem(const QString & fileName = QString(), QGraphicsItem *parent = 0) :
QGraphicsSvgItem(fileName, parent), m_lastRenderer(0) {
connect(&m_watcher, SIGNAL(finished()), SLOT(rendererReady()));
setFlags(QGraphicsItem::ItemClipsToShape);
setCacheMode(QGraphicsItem::NoCache);
}
void setWaitAnimation(const QByteArray & data) { m_spinRenderer.load(data); }
};
namespace {
const char svgCircle[] =
"<svg height=\"100\" width=\"100\"><circle cx=\"50\" cy=\"50\" r=\"40\" stroke=\"black\" stroke-width=\"3\" fill=\"red\" /></svg>";
const char svgRectangle[] =
"<svg width=\"400\" height=\"110\"><rect width=\"300\" height=\"100\" style=\"fill:rgb(0,0,255);stroke-width:3;stroke:rgb(0,0,0)\"></svg>";
const char svgThrobber[] =
"<svg width=\"16\" height=\"16\" viewBox=\"0 0 300 300\" xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\"><path d=\"M 150,0 a 150,150 0 0,1 106.066,256.066 l -35.355,-35.355 a -100,-100 0 0,0 -70.711,-170.711 z\" fill=\"#3d7fe6\"><animateTransform attributeName=\"transform\" attributeType=\"XML\" type=\"rotate\" from=\"0 150 150\" to=\"360 150 150\" begin=\"0s\" dur=\"1s\" fill=\"freeze\" repeatCount=\"indefinite\" /></path></svg>";
void write(const char * str, const QString & fileName) {
QFile out(fileName);
if (out.open(QIODevice::WriteOnly | QIODevice::Truncate)) out.write(str);
}
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
write(svgRectangle, "rectangle.svg"); // Put svg resources into the working directory
write(svgCircle, "circle.svg");
QGraphicsScene scene;
UserSvgItem item("circle.svg");
QGraphicsView view(&scene);
scene.addItem(&item);
item.setWaitAnimation(QByteArray::fromRawData(svgThrobber, sizeof(svgThrobber)-1));
view.show();
return app.exec();
}
#include "main.moc"
I would like to create a program that shows a question with some answers to the user. My application uses 3 forms: Main Menu, Login Menu and Game Form, and all inherit from an abstract class called Form; I do this because it allows the use of the factory method, which it create a new window when a signal GoFw is emitted by the actual form.
The "loop" that shows the windows is the following: MainMenu -> LoginMenu -> GameForm -> MainMenu...
The problem is when the game is finished (e.g. the count of remaining questions is zero) the GameForm emits the signal GoFw but the application crashes after the show() method (I could see a white window with no buttons before the crash).
The debugger show a messagebox with this error:
The inferior stopped because it triggered an exception.
Stopped in thread 0 by: Exception at 0x723f7b93, code: 0xc0000005: read access
violation at: 0x0, flags=0x0 (first chance).
and QtCreator opens a file called: Disassembler(QHash::findNode)
This is the code of the factory method:
void FormFactory::Init(int formType)
{
///if formType == 1 MainMenu is showed
if(formType == MAIN_MENU_TYPE)
{
//inizializza il puntatore
actualForm = new MainMenu();
}
///else if is == 2 show ProfileMenu
else if(formType == PROFILE_MENU_TYPE)
{
actualForm = new LoginMenu();
}
///else if == 3 show GameForm
else if(formType == GAME_FORM_TYPE)
{
actualForm = new GameForm();
}
///else if there is no match launch an exception
else
throw UnexpectedIdEx();
connect(actualForm, SIGNAL(GoFw(int)), this, SLOT(DisplayForm(int)));
}
void FormFactory::DisplayForm(int i)
{
Reset();
Init(i);
///show the form pointed by actualform
actualForm->show();
}
void FormFactory::Reset()
{
disconnect(actualForm, SIGNAL(GoFw(int)), this, SLOT(DisplayForm(int)));
///if actualform is actually pointing to a form, delete it and set actualForm to zero
if(actualForm!=0)
delete actualForm;
actualForm = 0;
}
And the code of MainMenu.cpp is
MainMenu::MainMenu()
{
setUpGui();
}
void MainMenu::setUpGui()
{
playButton = new QPushButton(tr("Play"));
infoButton = new QPushButton(tr("Info"));
quitButton = new QPushButton(tr("Exit"));
///connect the clicked signal to the related slot
connect(infoButton, SIGNAL(clicked()), this, SLOT(info()));
connect(quitButton, SIGNAL(clicked()), this, SLOT(quit()));
connect(playButton, SIGNAL(clicked()), this, SLOT(emitSig()));
///create the vertical layout
QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(playButton);
layout->addWidget(infoButton);
layout->addWidget(quitButton);
setLayout(layout);
setWindowTitle(tr("Menu Principale"));
}
void MainMenu::emitSig()
{
emit GoFw(2);
}
Thank you all for your help,
Luca
I'd suggest rethink your solution, it seems you overcomplicated it with the factory method.
Just use 3 variables for the forms, do the "new" operation once for each, and use show() / hide() methods depending on your signals.
To answer to the crash problem, one reason i see is because you do "delete" in the slot.
From Qt doc:
Warning: Deleting a QObject while pending events are waiting to be delivered can cause a crash. You must not delete the QObject directly if it exists in a different thread than the one currently executing. Use deleteLater() instead, which will cause the event loop to delete the object after all pending events have been delivered to it.
I've been struggling with a really strange behavior that I do not manage to resolve on my own, so here I am.
I'm creating an GUI for a console application which works great. The user can either select a file to be loaded or reload a previous selected file. Those two actions are handled with two different slots. I'm handling errors in the file's format with exceptions and it worked great in the console version, but for the GUI not too well for the moment...
When an error is thrown in the openFile slot, the catch block makes his work and the method is stopped as expected BUT then the other slot is being called unexpectedly. I have no idea why and so have no idea how to correct that behavior.
Here's the relevant code :
void Loader::openSourceFile()
{
fileName = QFileDialog::getOpenFileName(myWindow, tr("Select source file"), QString(), tr("Text files (*.txt)"));
try{
parseSourceFile();
} catch(MyException &e)
{
QString msg = QString(e.what());
myWindow->alertUser(msg);
return;
}
}
void Loader::reloadSourceFile()
{
try{
parseSourceFile();
} catch(MyException &e)
{
QString msg = QString(e.what());
myWindow->alertUser(msg);
return;
}
}
the context of use :
myLoader = new Loader(this);
menuTop = menuBar()->addMenu(tr("&File"));
//open source file
openAction = new QAction(QIcon(":images/document.png"), tr("&Open"), this);
connect(openAction, SIGNAL(triggered()), myLoader, SLOT(openSourceFile()));
menuTop->addAction(openAction);
//reload source file
reloadAction = new QAction(QIcon(":images/reload.png"), tr("&Reload"), this);
connect(openAction, SIGNAL(triggered()), myLoader, SLOT(reloadSourceFile()));
menuTop->addAction(reloadAction);
Note : after heavy debugging, I found that one function in the moc file of that class is being called after the execution of the catch block :
void Loader::qt_static_metacall(QObject *_o, QMetaObject::Call _c, int _id, void **_a)
{
if (_c == QMetaObject::InvokeMetaMethod) {
Q_ASSERT(staticMetaObject.cast(_o));
Loader *_t = static_cast<Loader *>(_o);
switch (_id) {
case 0: _t->openSourceFile(); break;
case 1: _t->reloadSourceFile(); break;
default: ;
}
}
Q_UNUSED(_a);
}
it is called with _id = 1 which explain the undesired execution of the other slot. But why this happens ??? Does anybody could explain how this can be avoided ? I've already made my own application class derived from qApplication and override notify() but that does not change anything.
Should:
reloadAction = new QAction(QIcon(":images/reload.png"), tr("&Reload"), this);
connect(openAction, SIGNAL(triggered()), myLoader, SLOT(reloadSourceFile()));
menuTop->addAction(reloadAction);
be:
reloadAction = new QAction(QIcon(":images/reload.png"), tr("&Reload"), this);
connect(reloadAction, SIGNAL(triggered()), myLoader, SLOT(reloadSourceFile()));
// ^^^^^^^^^^^^
menuTop->addAction(reloadAction);
I had a segmentation fault when using my new Qt Widget with Qt Designer 4.6. The problem arise when trying to preview the new widget.
when using gdb I found that the problem is in qdesigner_internal::WidgetFactory::applyStyleToTopLevel:
Program received signal SIGSEGV, Segmentation fault.
qdesigner_internal::WidgetFactory::applyStyleToTopLevel (style=0x0, widget=0x1829df0) at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/widgetfactory.cpp:777
777 /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/widgetfactory.cpp: No such file or directory.
in /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/widgetfactory.cpp
(gdb) bt
#0 qdesigner_internal::WidgetFactory::applyStyleToTopLevel (style=0x0, widget=0x1829df0) at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/widgetfactory.cpp:777
#1 0x00007ffff7475bed in qdesigner_internal::QDesignerFormBuilder::createPreview (fw=, styleName=..., appStyleSheet=..., deviceProfile=, scriptErrors=
0x7fffffffbee0, errorMessage=0x7fffffffc3f0) at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/qdesigner_formbuilder.cpp:404
#2 0x00007ffff7476773 in qdesigner_internal::QDesignerFormBuilder::createPreview (fw=0x0, styleName=..., appStyleSheet=..., deviceProfile=..., errorMessage=0x0)
at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/qdesigner_formbuilder.cpp:439
#3 0x00007ffff7532b27 in qdesigner_internal::PreviewManager::createPreview (this=0x837f20, fw=0x1879200, pc=..., deviceProfileIndex=-1, errorMessage=0x7fffffffc3f0, initialZoom=-1)
at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/previewmanager.cpp:686
#4 0x00007ffff75343cf in qdesigner_internal::PreviewManager::showPreview (this=0x837f20, fw=0x1879200, pc=..., deviceProfileIndex=-1, errorMessage=0x7fffffffc3f0)
at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/previewmanager.cpp:760
#5 0x00007ffff753472f in qdesigner_internal::PreviewManager::showPreview (this=0x837f20, fw=0x1879200, style=..., deviceProfileIndex=-1, errorMessage=0x7fffffffc3f0)
at /var/tmp/qt-x11-src-4.6.0/tools/designer/src/lib/shared/previewmanager.cpp:659
because a null pointer was passed there:
void WidgetFactory::applyStyleToTopLevel(QStyle *style, QWidget *widget)
{
const QPalette standardPalette = style->standardPalette();
if (widget->style() == style && widget->palette() == standardPalette)
return;
//....
}
I'm new in Qt and this is my first custom widget. does anybody have a clue for solving this.
here is my widget code
MBICInput::MBICInput(QWidget *parent) : QStackedWidget(parent){
displayPage = new QWidget();
displayPage->setObjectName(QString::fromUtf8("displayPage"));
inputLB = new QLabel(displayPage);
inputLB->setObjectName(QString::fromUtf8("inputLabel"));
inputLB->setCursor(QCursor(Qt::PointingHandCursor));
addWidget(displayPage);
EditPage = new QWidget();
EditPage->setProperty("EditInputLine", QVariant(true));
EditPage->setObjectName(QString::fromUtf8("EditPage"));
inputInput = new QLineEdit(EditPage);
inputInput->setGeometry(QRect(5, 10, 231, 25));
inputInput->setObjectName(QString::fromUtf8("input"));
addWidget(EditPage);
_animation = new QString("");
_message = new QString("Message");
_validator = new QRegExpValidator(QRegExp("[a-zA-Z]+"), this);
}
MBICInput::~MBICInput() {
}
QValidator::State MBICInput::validate(QString &text, int &pos) const{
return _validator->validate(text, pos);
}
void MBICInput::paintEvent(QPaintEvent *) {
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
}
QSize MBICInput::minimumSizeHint() const{
return QSize(200, 40);
}
QSize MBICInput::sizeHint() const{
return QSize(200, 40);
}
void MBICInput::setAnimation(const QString &animation){
*_animation = animation;
update();
}
QString MBICInput::animation() const{
return *_animation;
}
void MBICInput::setMessage(const QString &message){
*_message = message;
update();
}
QString MBICInput::message() const{
return *_message;
}
void MBICInput::mousePressEvent(QMouseEvent *event){
if(currentIndex()==0){
setCurrentIndex(1);
}else{
setCurrentIndex(0);
}
update();
}
In the applyStyleToTopLevel function, you are using the widget pointers without verifying it's a valid pointer. So when doing widget->style with a NULL widget pointer it will crash.
Just for information I just compiled the same code under the Qt version 4.5.3-9 and it worked just fine with the 4.5 designer. may be it's a Qt 4.6 bug...
I'm having problem (basically, I'm confused.) while trying to create a worker thread for my wxWidgets GUI application that WILL MODIFY one of the GUI property itself. (In this case, wxTextCtrl::AppendText).
So far, I have 2 source files and 2 header files for the wx program itself (excluding my own libs, MySQL lib, etc), say MainDlg.cpp which contains a derived class of wxFrame called 'MainDlg' and MainForm.cpp which contains a derived class of wxApp called 'MainForm'.
MainForm.cpp
#include "MainHeader.h" // contains multiple header files
IMPLEMENT_APP(MainForm)
bool MainForm::OnInit()
{
MainDlg *Server = new MainDlg(wxT("App Server 1.0"), wxDEFAULT_FRAME_STYLE - wxRESIZE_BORDER - wxMAXIMIZE_BOX);
Editor->Show();
return true;
}
MainDlg.cpp:
#include "MainHeader.h"
BEGIN_EVENT_TABLE(MainDlg, wxFrame)
EVT_BUTTON(6, MainDlg::StartServer)
EVT_BUTTON(7, MainDlg::StopServer)
END_EVENT_TABLE()
CNETServerConnection *cnServCon;
std::string ServerIP, DBHost, DBUser, DBName, DBPass;
int UserCapacity, DBPort, ServerPort;
MYSQL *sqlhnd;
MainDlg::MainDlg(const wxString &title, long style) : wxFrame(NULL, wxID_ANY, title, wxDefaultPosition, wxSize(301, 230), style)
{
cnServCon = new CNETServerConnection(100);
this->InitializeComponent();
}
void MainDlg::InitializeComponent()
{
this->SetTitle(wxT("App Server 1.0"));
this->SetSize(396, 260);
this->SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_3DFACE));
this->Centre();
statBox = new wxTextCtrl(this, 4, wxT("Welcome to AppServer 1.0\n\n"), wxPoint(10, 10), wxSize(371, 141), wxTE_MULTILINE | wxTE_READONLY);
//.................................
}
void MainDlg::StartServer(wxCommandEvent &event)
{
this->startBtn->Enable(false);
this->AppendStatus(wxT("\nLoading server configuration... "));
//.................................
this->AppendStatus(wxT("OK\n\nServer ready!\n\n"));
// When the server is ready, I need to run a thread
// that will update the statBox (through AppendStatus func or wxTextCtrl::AppendText directly)
// regularly without interrupting the GUI itself.
// Because the thread will contain a while-loop
// to make the program keep receiving message from clients.
this->startBtn->Hide();
this->stopBtn->Show();
this->cmdBtn->Enable();
this->cmdBox->Enable();
}
void MainDlg::StopServer(wxCommandEvent &event)
{
//...................................
}
void MainDlg::AppendStatus(const wxString &message)
{
statBox->AppendText(message);
}
// Well, here is the function I'd like to run in a new thread
void MainDlg::ListenForMessages()
{
int MsgSender = 0;
while(1)
{
if(!cnServCon->GetNewMessage())
continue;
if(MsgSender = cnServCon->GetJoiningUser())
this->AppendStatus(wxT("Someone connected to the server."));
}
}
I also found an usage example of wxThread from Simple example of threading in C++:
class MessageThread : public wxThread
{
private:
MessageThread(const MessageThread ©);
public:
MessageThread() : wxThread(wxTHREAD_JOINABLE)
{
}
void *Entry(void)
{
// My works goes here
return;
}
};
wxThread *CreateThread()
{
wxThread *_hThread = new MessageThread();
_hThread->Create();
_hThread->Run();
return _hThread;
}
But I don't know how to associate it with my program and make it able to modify my GUI property (statBox).
Any kind of help would be appreciated! :)
Thanks.
The easiest is to create an event type id, and use a wxCommandEvent using the type id, set its string member ("evt.SetText"), and send the event to one of your windows (using AddPendingEvent). In the handler of that event, you can then call AppendText on your control using the text you sent (evt.GetText), because you are in the GUI thread by then.
// in header
DECLARE_EVENT_TYPE(wxEVT_MY_EVENT, -1)
// in cpp file
DEFINE_EVENT_TYPE(wxEVT_MY_EVENT)
// the event macro used in the event table. id is the window id you set when creating
// the `wxCommandEvent`. Either use -1 or the id of some control, for example.
EVT_COMMAND(window-id, event-id, handler-function)
Here is an overview how it works: Custom Events.