In my app, i have several QDialog forms.
when i install and change translation of my app. MainWindow has been affected but all other dialogs didn't change to new Language.so,
how can i change all forms lang at runtime(dynamic)?
Please help me
void MainWindow::SetUILang()
{
QTranslator qtTranslator;
qtTranslator.load(QString("tr_fa"), "./Lang");
qApp->installTranslator(&qtTranslator);
ui->retranslateUi(this);
}
If you dynamically change the language on your application, a changeEvent of type QEvent::LanguageChange is emitted. You'll have to catch that and reset your texts everywhere (using the tr function)>
void myclass::changeEvent(QEvent *event) {
if (event->type() == QEvent::LanguageChange) {
// Set all texts
}
else {
QWidget::changeEvent(event);
}
}
Related
I have QGraphicsView, which has many QGraphicsItem. I am trying to create a right click menu on these QGraphicsItem. Right click menu has multiple options. But only 1st option works. It means, if I click on 2nd option, it does not work. If I change the sequence ( means 1st one will go to 2nd position, and 2nd one will come to 1st position ) then still 2nd one will not work.
bool myClass::eventFilter(QObject *watched, QEvent *event)
{
switch(event->type())
{
case QEvent::ContextMenu:
{
foreach(QGraphicsItem* pItem, _scene->items())
{
if(pItem->isUnderMouse())
{
QMouseEvent *mouseEvent = static_cast<QMouseEvent*> (event);
menu = new QMenu(this);
myMenu = menu->addMenu("Copy");
myMenu ->addAction(Name);
myMenu ->addAction(Address);
if(Name == menu->exec(mouseEvent->globalPos()))
{
// logic
}
if(Address == menu->exec(mouseEvent->globalPos()))
{
// logic
}
}
}
}
}
Always works only 1st mouse right click option. Why is so ?
The usual way to do something like this is to override the QGraphicsItem::mouseReleaseEvent() or QGraphicsItem::mousePressEvent() function of your item class.
This way, you won't have to do anything (no looping, etc...), it is already handled by the event loop.
Here you can find a simple example:
void MyItem::mouseReleaseEvent(QGraphicsSceneMouseEvent * event)
{
if(event->button() == Qt::RightButton)
{
QMenu my_menu;
// Build your QMenu the way you want
my_menu.addAction(my_first_action);
my_menu.addAction(my_second_action);
//...
my_menu.exec(event->globalPos());
}
}
From the Qt documentation:
Note that all signals are emitted as usual. If you connect a QAction to a slot and call the menu's exec(), you get the result both via the signal-slot connection and in the return value of exec().
You just need to QObject::connect() the QActions you added to the context menu to the proper slots (here goes the "logic") and the job is done.
If you prefer to check the returned value by yourself, you just have to get the returned QAction* once and for all (only one call to QMenu::exec()) and branch on it.
For example:
void MyItem::mouseReleaseEvent(QGraphicsSceneMouseEvent * event)
{
if(event->button() == Qt::RightButton)
{
QMenu my_menu;
// Build your QMenu the way you want
my_menu.addAction(my_first_action);
my_menu.addAction(my_second_action);
//...
QAction * triggered = my_menu.exec(event->globalPos());
if(triggered == my_first_action)
{
// Do something
}
else if(triggered == my_second_action)
{
// Do some other thing
}
//...
}
}
I would personnally prefer to stick with the signal-slot connections instead that manually handling the returned value, especially since each QAction is most likely to be already connected to its corresponding slot.
I am working on a Qt project consisting in a QMainWindow and multiple Qt and non-Qt classes. Many of them use QStrings with tr() that are translated with Qt Linguist. The language change (QTranslator load & install/QTranslator load & remove) is triggered by QActions in the app's menu.
I have read the official Qt documentation concerning dynamic translation, and it basically suggests the following overload:
void MainWindow::changeEvent(QEvent *event)
{
if (event->type() == QEvent::LanguageChange) {
titleLabel->setText(tr("Document Title"));
... // all my tr() QStrings here
okPushButton->setText(tr("&OK"));
} else
QWidget::changeEvent(event);
}
The problem I am facing is that the QStrings to translate are many (58 in QMainWindow alone), and several are filled at runtime as well, through user interaction; e. g. myFunction(a,b) below is called through a QPushButton:
void MainWindow::myFunction(MyClassA a, MyClassB b)
{
...
if(b.myCondition() == 0)
{
...
// below is the problem
myLabel->setText(myLabel->text() + QString("\n" + a->getName() + tr(" gagne ") + exp + tr(" points d'expérience")));
}
else
{
myLabel->setText(QString(tr("something else")));
}
...
}
So I hardly see how I can include this type of QString in the changeEvent() method above. What about the classes outside of MainWindow, which also have QStrings to translate but are not QWidget (so no changeEvent overload possible) ?
I have read that there's another way to use this method, with a UI form:
void MainWindow::changeEvent(QEvent* event)
{
if (event->type() == QEvent::LanguageChange)
{
ui.retranslateUi(this);
}
...
}
But this involves that I am using a UI form in my project, which I am not doing (all widgets are created in code).
I tried to export my MainWindow in a UI form, but when I try to include the generated header into the project, I get the following error:
ui_fenetreprincipale.h:32: error: qmainwindowlayout.h: No such file or directory
Thank you by advance for any suggestion to select the best way to translate my application.
Organize your code so that all the setting of translatable strings is done in one method in each class.
eg give every class that has translatable strings a setTrs() method that actually sets the strings.
class A
{
void setTrs()
{
okPushButton->setText(tr("&OK"));
}
}
//--------------
class B
{
int _trCond;
void myFunction(MyClassA a, MyClassB b)
{
_trCond = b.myCondition();
setTrs();
}
void setTrs()
{
if(_trCond == 0)
myLabel->setText(myLabel->text() + QString("\n" + a->getName() + tr(" gagne ") + exp + tr(" points d'expérience")));
else
myLabel->setText(QString(tr("something else")));
}
Then whenever the language for the application changes (eg connect to a menu entry selection, or MainWindow::event() or however the required language can change), you have to manually call the setTrs method of each of these objects
eg
void MainWindow::changeEvent(QEvent *event)
{
if (event->type() == QEvent::LanguageChange)
{
setTrs();
objA.setTrs();
objB.setTrs();
}
}
Even more elegant would be to store the objects in a QList and just iterate through it calling the setTrs method on each element in turn
I had the same problem, menus not translating, fixed completely by creating and installing the QTranslator...
QScopedPointer<QApplication> app(new QApplication(argc, argv));
QTranslator myappTranslator;
myappTranslator.load(QString("Languages/de"))
app->installTranslator(&myappTranslator);
...before creating and showing the main window...
MainWindow *mainWin;
mainWin = new MainWindow(&splash);
mainWin->show();
In our application that uses Qt 4 and supports touch input, we use the QFileDialog with the options QFileDialog::DontUseNativeDialog and QFileDialog::ExistingFiles.
The first is needed because we set our own stylesheet and that does not work with the native dialog. The second is for needed for selecting multiple files, which is what we want to do.
The problem ist that one can not select multiple files with touch input in the QFileDialog, because we have no "shift" or "ctrl"-key available. In Windows the problem is solved by adding checkboxes to the items. QFileDialog has no checkboxes.
I tried to manipulate the QFileDialog to make it displays check boxes for the items, but I failed.
I tried to exchanged the QFileSystemModel that is used by the underlying QTreeView and QListView, but this breaks the signal-slot connections between the model and the dialog. I could not find a way to restore them because they are burried deep in the private intestants of the dialog.
At this moment the only solution I can imagine is writing a whole new dialog, but I would like to avoid the effort.
So is there a way to add checkboxes to the QFileDialog model views ?
Do you have another idea how selecting multiple files could be made possible?
Is the problem fixed in Qt 5? We want to update anyway.
Thank you for your Help.
As I failed to add checkboxes to the item views, I implemented a "hacky" work-around. It adds an extra checkable button to the dialog that acts as a "ctrl"-key. When the button is checked, multiple files can be selected. The solution is a little bit ugly, because it relies on knowing the internals of the dialog, but it does the job.
So here is the code for the header ...
// file touchfiledialog.h
/*
Event filter that is used to add a shift modifier to left mouse button events.
This is used as a helper class for the TouchFileDialog
*/
class EventFilterCtrlModifier : public QObject
{
Q_OBJECT;
bool addCtrlModifier;
public:
EventFilterCtrlModifier( QObject* parent);
void setAddCtrlModifier(bool b);
protected:
virtual bool eventFilter( QObject* watched, QEvent* e);
};
/*
TouchDialog adds the possibility to select multiple files with touch input to the QFileDialog.
This is done by adding an extra button which can be used as control key replacement.
*/
class QTOOLS_API TouchFileDialog : public QFileDialog
{
Q_OBJECT
EventFilterCtrlModifier* listViewEventFilter;
EventFilterCtrlModifier* treeViewEventFilter;
bool initialized;
public:
TouchFileDialog( QWidget* parent);
protected:
virtual void showEvent( QShowEvent* e);
private slots:
void activateCtrlModifier(bool b);
private:
void initObjectsForMultipleFileSelection();
};
with the implementation ...
// file touchfiledialog.cpp
#include "touchfiledialog.h"
EventFilterCtrlModifier::EventFilterCtrlModifier(QObject* parent)
: QObject(parent)
, addCtrlModifier(false)
{
}
void EventFilterCtrlModifier::setAddCtrlModifier(bool b)
{
addCtrlModifier = b;
}
bool EventFilterCtrlModifier::eventFilter(QObject* watched, QEvent* e)
{
QEvent::Type type = e->type();
if( type == QEvent::MouseButtonPress || type == QEvent::MouseButtonRelease)
{
if( addCtrlModifier)
{
QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(e);
// Create and post a new event with ctrl modifier if the event does not already have one.
if( !mouseEvent->modifiers().testFlag(Qt::ControlModifier))
{
QMouseEvent* newEventWithModifier = new QMouseEvent(
type,
mouseEvent->pos(),
mouseEvent->globalPos(),
mouseEvent->button(),
mouseEvent->buttons(),
mouseEvent->modifiers() | Qt::ControlModifier
);
QCoreApplication::postEvent(watched, newEventWithModifier);
return true; // absorb the original event
}
}
}
return false;
}
//#######################################################################################
TouchFileDialog::TouchFileDialog(QWidget* parent)
: QFileDialog(parent)
, listViewEventFilter(NULL)
, treeViewEventFilter(NULL)
, initialized(false)
{
}
void TouchFileDialog::showEvent(QShowEvent* e)
{
// install objects that are needed for multiple file selection if needed
if( !initialized)
{
if( fileMode() == QFileDialog::ExistingFiles)
{
initObjectsForMultipleFileSelection();
}
initialized = true;
}
QFileDialog::showEvent(e);
}
void TouchFileDialog::initObjectsForMultipleFileSelection()
{
// install event filter to item views that are used to add ctrl modifiers to mouse events
listViewEventFilter = new EventFilterCtrlModifier(this);
QListView* listView = findChild<QListView*>();
listView->viewport()->installEventFilter(listViewEventFilter);
treeViewEventFilter = new EventFilterCtrlModifier(this);
QTreeView* treeView = findChild<QTreeView*>();
treeView->viewport()->installEventFilter(treeViewEventFilter);
QGridLayout* dialogLayout = static_cast<QGridLayout*>(layout()); // Ugly because it makes assumptions about the internals of the QFileDialog
QPushButton* pushButtonSelectMultiple = new QPushButton(this);
pushButtonSelectMultiple->setText(tr("Select multiple"));
pushButtonSelectMultiple->setCheckable(true);
connect( pushButtonSelectMultiple, SIGNAL(toggled(bool)), this, SLOT(activateCtrlModifier(bool)));
dialogLayout->addWidget(pushButtonSelectMultiple, 2, 0);
}
void ZFFileDialog::activateCtrlModifier(bool b)
{
listViewEventFilter->setAddCtrlModifier(b);
treeViewEventFilter->setAddCtrlModifier(b);
}
The TouchFileDialog installs an event filter to the item views that will add a ControlModifier to the mouse events of the views when the corresponging button in the dialog is checked.
Feel free to post other solutions, because this is somewhat improvised.
I have wrote an application in Qt/c++ on OSX. When quitting the app, I'm catching the closeevent to display dialog box
void MainUI::closeEvent (QCloseEvent *event)
{
if( DeviceUnplugged == false) {
ExitDialog = new DialogExit;
ExitDialog->exec();
if(ExitDialog->result() == QDialog::Accepted) {
m_device.CloseDevice();
event->accept();
}
else {
event->ignore();
}
}
}
The dialog box is correctly displayed when closing using the red cross or using the menu "quit".
but when I'm closing the app using the right click on the icon in the dock, the dialog box appears twice the close event is called twice.
Any idea why ?
Yes, I think it is normal for Mac, at least I had this in my Qt application, too (only on Mac).
I used the following workaround:
void MainUI::closeEvent (QCloseEvent *event)
{
if (m_closing)
{
event->accept();
return;
}
if( DeviceUnplugged == false) {
ExitDialog = new DialogExit;
ExitDialog->exec();
if(ExitDialog->result() == QDialog::Accepted) {
m_device.CloseDevice();
m_closing = true;
event->accept();
}
else {
event->ignore();
}
}
}
By default, boolean variable m_closing should be initialized by false of course in your class. This way second time nothing will be done (processing will be skipped). This worked for me.
Looks like this is a QT bug:
See: https://bugreports.qt.io/browse/QTBUG-43344
Also had this problem when using qt-5.6_4 ,
In my case it happened when using CMD+Q but didn't happen when using the red x button.
Used a similar patch.
I avoided accept or ignore since this is a bug and I don't think we should "talk to it" :-)
Instead I simply return when called more then once.
static int numCalled = 0;
if (numCalled++ >= 1)
return;
When I have changeEvent(QEvent* event) with receive type event->type() == QEvent::LanguageChange, how can I get information about what the new language is in my app?
Qt don't have any object to represent application langugae. So you should implement it yorself.
Usually changeEvent(QEvent* event) with type QEvent::LanguageChange was caused by installTranslator(QTranslator*) so you should know witch langugae you loaded to translator and store it locally.
You can compare the translated string with its known translations:
void changeEvent(QEvent *event)
{
if (event->type() == QEvent::LanguageChange) {
QString translated = QCoreApplication::translate("some context", "Button");
if (translated == "Button")
// language is English
else if (translated == "Кнопка")
// language is Russian
...
}
}