Issue with Qt Toolbar extension button - qt

Question

I have to add a toolbar in Qt like the Windows file system explorer one under menu bar (I'm under Windows 7) , that means when the window width is reduced, icons which don't have enough place to be displayed are automatically hidden and put into a drop down list (which is displayed when clicking to an arrow which appears to the toolbar's right side). I first copy paste a code that I found to the web :
#include <QApplication>
#include <QAction>
#include <QMainWindow>
#include <QLineEdit>
#include <QToolBar>
#include <QHBoxLayout>
void initWindow(QMainWindow* w);
int main(int argc, char *argv[])
{
Q_INIT_RESOURCE(application);
QApplication app(argc, argv);
QMainWindow mainWin;
initWindow(&mainWin);
mainWin.show();
return app.exec();
}
void initWindow(QMainWindow* w)
{
QLineEdit* searchBar = new QLineEdit;
QAction* newAct = new QAction(QIcon(":/images/new.png"), "&New", w);
newAct->setShortcuts(QKeySequence::New);
QAction* openAct = new QAction(QIcon(":/images/open.png"), "&Open...", w);
openAct->setShortcuts(QKeySequence::Open);
QAction* saveAct = new QAction(QIcon(":/images/save.png"), "&Save", w);
saveAct->setShortcuts(QKeySequence::Save);
QAction* cutAct = new QAction(QIcon(":/images/cut.png"), "Cu&t", w);
cutAct->setShortcuts(QKeySequence::Cut);
QAction* copyAct = new QAction(QIcon(":/images/copy.png"), "&Copy", w);
copyAct->setShortcuts(QKeySequence::Copy);
QAction* pasteAct = new QAction(QIcon(":/images/paste.png"), "&Paste", w);
pasteAct->setShortcuts(QKeySequence::Paste);
QToolBar* fileToolBar = w->addToolBar("File");
fileToolBar->addAction(newAct);
fileToolBar->addAction(openAct);
fileToolBar->addAction(saveAct);
QToolBar* editToolBar = w->addToolBar("Edit");
editToolBar->addAction(cutAct);
editToolBar->addAction(copyAct);
editToolBar->addAction(pasteAct);
editToolBar->addWidget(searchBar);
}
... but the problem is that code works only for toolbars into a QMainWindow (and add by using QMainWindow::addToolbar() method). But into the code which I'm working for I have to do that into a QWidget, not a QWindow. So I created a horizontal layout, I added several widget into it (a QLineEdit and several QAction) and it works fine for QAction but not for QLineEdit : When I click to the arrow, all hidden QAction are visibles but not QLineEdit. Here is my code :
#include <QApplication>
#include <QtGui/QWindow>
#include <QToolbar>
#include <QVBoxLayout>
#include <QMainWindow>
#include <QPushButton>
#include <QAction>
#include <QIcon>
#include <QLineEdit>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QWidget* w = new QWidget;
QHBoxLayout* tb1 = new QHBoxLayout;
tb1->addWidget(new QPushButton("item11"));
tb1->addWidget(new QPushButton("item12"));
tb1->addWidget(new QPushButton("item13"));
tb1->addWidget(new QPushButton("item14"));
QHBoxLayout* spacerLayout = new QHBoxLayout;
spacerLayout->addSpacerItem(new QSpacerItem(50, 20, QSizePolicy::MinimumExpanding,QSizePolicy::Fixed) );
spacerLayout->setAlignment(Qt::AlignJustify);
QWidget* sep = new QWidget;
QRect rect = sep->geometry();
rect.setWidth(0);
sep->setGeometry(rect);
QToolBar* tb3 = new QToolBar;
QLineEdit* searchBar = new QLineEdit;
QAction* item31 = new QAction(QIcon(":/images/cut.png"), "cut");
QAction* item32 = new QAction(QIcon(":/images/copy.png"), "copy");
QAction* item33 = new QAction(QIcon(":/images/open.png"), "open");
QAction* item34 = new QAction(QIcon(":/images/paste.png"), "past");
QAction* item35 = new QAction(QIcon(":/images/save.png"), "save");
tb3->addWidget(sep);
tb3->addWidget(searchBar);
tb3->addAction(item31);
tb3->addAction(item32);
tb3->addAction(item33);
tb3->addAction(item34);
tb3->addAction(item35);
QVBoxLayout* mainLayout = new QVBoxLayout;
QHBoxLayout* topLayout = new QHBoxLayout;
topLayout->addLayout(tb1);
topLayout->addLayout(spacerLayout);
topLayout->addWidget(tb3);
QHBoxLayout* bottomLayout = new QHBoxLayout;
bottomLayout->addWidget(new QPushButton);
mainLayout->addLayout(topLayout);
mainLayout->addLayout(bottomLayout);
w->setLayout(mainLayout);
w->show();
return app.exec();
}
These are screenshots of the result with the 2nd solution : I first launch application :
http://img4.hostingpics.net/pics/224120tb1.jpg
When I reduce its width, widgets which are to the right side disapeared. Then I click to the arrow to display them into the drop down list and they are all displayed except the QLineEdit :
http://img4.hostingpics.net/pics/903380tb2.jpg
Is someone here knows what the problem is ? Thanks.

Answer 1

Regrettably, tool bars only function correctly when embedded in a QMainWindow. The good news is that you can use a QMainWindow as if it were a widget. You can parent it to another widget, and then it won't be a standalone window. I've done this, and it works well. I was creating the objects using Qt Designer, and I had to remove the QMainWindow menu bar because Designer creates that automatically.
It's not an intuitive thing to do, but it works just fine, and it's a fairly easy change. A well-written comment explaining why you did that would probably be welcomed by anyone else reading the code in the future...

Answer 2

Thank you for your answer, I tried to test with a QMainWindow but it completely messed up the layout on which I worked and as it's a complex window (a lot of people worked on it in the past) and I have to finish my work soon I preferred to try a new approach. So after some research on the web I found that it's possible to do that I want even if the toolbar is not into a QMainWindow, but I have to replace all QWidget's that I want to have into QToolBar by a class which derived of QWidgetAction's, and instantiate them into QWidgetAction::createWidget() method. So I did this code which works correctly :
main.cpp :
#include <QApplication>
#include <QtGui/QWindow>
#include <QToolbar>
#include <QVBoxLayout>
#include <QMainWindow>
#include <QPushButton>
#include <QAction>
#include <QIcon>
#include <QLineEdit>
#include <QSlider>
#include <QVariant>
#include <QCheckBox>
#include <QWidgetAction>
#include "QMyWidgetAction.h"
void test2(QApplication& app);
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
test2(app);
return app.exec();
}
void test2(QApplication& app)
{
QWidget* w = new QWidget;
QHBoxLayout* l1 = new QHBoxLayout;
l1->addWidget(new QPushButton("item11"));
l1->addWidget(new QPushButton("item12"));
l1->addWidget(new QPushButton("item13"));
l1->addWidget(new QPushButton("item14"));
QHBoxLayout* l2 = new QHBoxLayout;
l2->addSpacerItem(new QSpacerItem(50, 20, QSizePolicy::MinimumExpanding,QSizePolicy::Fixed) );
l2->setAlignment(Qt::AlignJustify);
QHBoxLayout* l3 = new QHBoxLayout;
QToolBar* tb = new QToolBar;
l3->addWidget(tb);
QAction* item31 = new QAction(QIcon(":/images/cut.png"), "cut");
QAction* item32 = new QAction(QIcon(":/images/copy.png"), "copy");
QAction* item33 = new QAction(QIcon(":/images/open.png"), "open");
QAction* item34 = new QAction(QIcon(":/images/paste.png"), "past");
QAction* item35 = new QAction(QIcon(":/images/save.png"), "save");
QLineEdit* searchBar = new QLineEdit;
QMyWidgetAction* widgetAction = new QMyWidgetAction(tb);
QLineEditAction* lineEditAction = new QLineEditAction(tb);
tb->addSeparator();
tb->addWidget(searchBar);
tb->addAction(item31);
tb->addAction(item32);
tb->addAction(item33);
tb->addAction(item34);
tb->addAction(item35);
tb->addAction(widgetAction);
tb->addAction(lineEditAction);
QVBoxLayout* mainLayout = new QVBoxLayout;
QHBoxLayout* topLayout = new QHBoxLayout;
topLayout->addLayout(l1);
topLayout->addLayout(l2);
topLayout->addLayout(l3);
QHBoxLayout* bottomLayout = new QHBoxLayout;
bottomLayout->addWidget(new QPushButton);
mainLayout->addLayout(topLayout);
mainLayout->addLayout(bottomLayout);
w->setLayout(mainLayout);
w->show();
}
QMyWidgetAction.h :
#ifndef QMAYAWIDGETACTION_H
#define QMAYAWIDGETACTION_H
#include <QObject>
#include <QWidget>
#include <QWidgetAction>
class QLineEdit;
class QMyWidgetAction : public QWidgetAction
{
Q_OBJECT
public:
QMyWidgetAction(QWidget* parent);
QWidget* createWidget(QWidget* parent);
};
class QLineEditAction : public QWidgetAction
{
Q_OBJECT
public:
QLineEditAction(QWidget* parent);
QWidget* createWidget(QWidget* parent);
protected slots:
virtual void searchTextChanged(const QString& text);
private:
QLineEdit* fWidget;
};
#endif // QMAYAWIDGETACTION_H
QMyWidgetAction.cpp :
#include <QApplication>
#include <QtGui/QWindow>
#include <QToolbar>
#include <QVBoxLayout>
#include <QMainWindow>
#include <QPushButton>
#include <QAction>
#include <QIcon>
#include <QLineEdit>
#include <QSlider>
#include <QVariant>
#include <QCheckBox>
#include <QWidgetAction>
#include "QMyWidgetAction.h"
QMyWidgetAction::QMyWidgetAction(QWidget* parent)
: QWidgetAction(parent)
{
}
QWidget* QMyWidgetAction::createWidget(QWidget* parent)
{
QPushButton* widget = new QPushButton("bouton", parent);
widget->setMinimumSize(100, 30);
return widget;
}
QLineEditAction::QLineEditAction(QWidget* parent)
: QWidgetAction(parent)
{
}
QWidget* QLineEditAction::createWidget(QWidget* parent)
{
fWidget = new QLineEdit(parent);
connect(fWidget, SIGNAL(textChanged(QString)), this, SLOT(searchTextChanged(QString)));
fWidget->setMinimumSize(100, 30);
return fWidget;
}
void QLineEditAction::searchTextChanged(const QString& text)
{
fWidget->setMinimumWidth(fWidget->minimumWidth() + 10);
}
So now here is what I get when I reduce the window width :
So the result is correct (and controls works, I tested them), but now I would like to know if it's possible to display the extension list horizontally instead of vertically ? (I mean "past" action at the right of "open" action, "save" action at the right of past action etc.) Thanks for your help.