Qt and C++: Add QLineEdit to QTabWidget - c++

I want to add a QLineEdit to a QTabWidget but I always get a
Segmentation fault, SIGSEGV
I did it the following way:
QHBoxLayout *layout = new QHBoxLayout;
QWidget *Tab = new QWidget(ui->tabWidget);
ui->tabWidget->addTab(Tab, "Tab1");
Tab->setLayout(layout);
QLineEdit *lE = new QLineEdit();
lE->setObjectName("Text");
lE->setText("Hello");
ui->tabWidget->widget(0)->layout()->addWidget(lE);
This way works for adding a QPushButton but somehow it doesn't work for a QLineEdit.

you can add a widget to a cell
example:
//
QWidget* pWidget = new QWidget();
QLineEdit* foo = new QLineEdit(this);
foo->setText("Edit");
QHBoxLayout* pLayout = new QHBoxLayout(pWidget);
pLayout->addWidget(foo);
pLayout->setAlignment(Qt::AlignCenter);
pLayout->setContentsMargins(0, 0, 0, 0);
pWidget->setLayout(pLayout);
this->ui->myTable->setCellWidget(1, 1, pWidget);

Related

Why HBoxLayout added in a QVBoxLayout turned out to display horizontally, but not vertically?

I want to make a QLable and a QComboBox display in one line (horizontal, let's name it as h_combination_1), and there are some similar layouts like this (e.g. h_combination_2, h_combination_3, and etc). Then I want to manage this combinations (h_combination_1..3) display vertially. But at last these combinations display horizontally, how strange it is! Could someone help me with this?
Here is the code:
void ThemeWidget::initLayout()
{
[..]
QHBoxLayout* themeLayout = new QHBoxLayout;
QLabel* themeLabel = new QLabel("Theme");
themeLayout->addWidget(themeLabel);
themeLayout->addWidget(cbox_theme);
QHBoxLayout* legendLayout = new QHBoxLayout;
QLabel* legendLabel = new QLabel("Legend");
themeLayout->addWidget(legendLabel);
themeLayout->addWidget(cbox_legend);
QHBoxLayout* animationLayout = new QHBoxLayout;
QLabel* animationLabel = new QLabel("Animation");
themeLayout->addWidget(animationLabel);
themeLayout->addWidget(cbox_animation);
antialiasCheckBox = new QCheckBox("Antialiasing");
[..]
QVBoxLayout* parametersLayout = new QVBoxLayout;
parametersLayout->addLayout(themeLayout);
parametersLayout->addLayout(legendLayout);
parametersLayout->addLayout(animationLayout);
parametersLayout->addWidget(antialiasCheckBox);
QWidget* paramsBox = new QWidget();
paramsBox->setLayout(parametersLayout);
gridLayout = new QGridLayout;
QHBoxLayout* layout = new QHBoxLayout;
layout->addLayout(gridLayout);
layout->addWidget(paramsBox);
this->setLayout(layout);
}
Here is a screenshot:
In the begining, I've just add the layout parametersLayout to layout, without binding it to a QWidget.
For example:
void ThemeWidget::initLayout()
{
[..]
QVBoxLayout* parametersLayout = new QVBoxLayout;
parametersLayout->addLayout(themeLayout);
parametersLayout->addLayout(legendLayout);
parametersLayout->addLayout(animationLayout);
parametersLayout->addWidget(antialiasCheckBox);
gridLayout = new QGridLayout;
QHBoxLayout* layout = new QHBoxLayout;
layout->addLayout(gridLayout);
layout->addWidget(parametersLayout);
this->setLayout(layout);
}
But it turned out just as same as binding parametersLayout to a QWidget.
The layoutItems in parametersLayout should be vertical, but there were not!
So I changed into the method I discribed in the details above, and the results was still the same.

How to reduce distance between widgets and window size with Qt?

What I currently have:
What I want:
For those unable to view the images; the widgets are spread out by some sort of margin between them. I would like to keep them as close as possible. How can I squeeze the widgets closer together?
I have already tried:
setFixedSize(sizeHint()); and setSizeConstraint(QLayout::SetFixedSize); on the main window, layouts, and widget object. Nothing seems to work.
As an extra, I would also appreciate this:
(having the label get even closer to the lineEdit)
I am using Windows and Qt 5.11.1, 64-bits.
The window constructor code:
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
widget = new QWidget();
label = new QLabel(tr("Enter your name:"));
nameLine = new QLineEdit;
nameLine->setMinimumWidth(250);
label->setBuddy(nameLine);
okButton = new QPushButton (tr("Ok"));
clearButton = new QPushButton (tr("Clear"));
connect(okButton, SIGNAL(clicked()), this, SLOT(message()));
connect(clearButton, SIGNAL(clicked()), this, SLOT(clear()));
QGridLayout *grid = new QGridLayout;
grid->addWidget(label,0,0);
grid->addWidget(nameLine,1,0);
grid->addWidget(okButton,0,1);
grid->addWidget(clearButton,1,1);
widget->setLayout(grid);
setWindowTitle(tr("Leo v0.0"));
setCentralWidget(widget);
}
A possible solution is to establish a QVBoxLayout with addStretch():
QVBoxLayout *vlay = new QVBoxLayout;
QGridLayout *grid = new QGridLayout;
grid->addWidget(label, 0, 0);
grid->addWidget(nameLine, 1, 0);
grid->addWidget(okButton, 0, 1);
grid->addWidget(clearButton, 1, 1);
vlay->addLayout(grid);
vlay->addStretch();
widget->setLayout(vlay);
setCentralWidget(widget);

QT dynamically generate label, LineEdit, Button

I want to do serial communication in the QT inside, according to the number of serial ports to dynamically generate label, LineEdit, Button, and these three buttons can pull down the scroll bar when the size of the interface, how to do well, I write this below is dead of.
The effect of encapsulation into a method
The interface was washed last
Define QGridLayout insude QScrollArea. And add your new widgets into
that layout in code. QGridLayout::addWidget
Define table where you will show several widgets in table cells. That real complicated way.
void BaseUi::BaseScrollArea()
{
QScrollArea *pArea = new QScrollArea();
QWidget *pWidget = new QWidget();
pWidget->setStyleSheet("QWidget" "{background:white;}");
m_vbox_layout = new QVBoxLayout();
m_vbox_layout->addSpacerItem(new QSpacerItem(100, 30,
QSizePolicy::Expanding, QSizePolicy::Expanding));
pWidget->setLayout(m_vbox_layout);
pArea->setWidget(pWidget);
pArea->setWidgetResizable(true);
m_main_layout = new QVBoxLayout();
m_main_layout->addWidget(pArea);
}
void BaseUi::addAutoRecordUi(QString lab_neme, QString ledit_name)
{
QWidget *page = new QWidget;
QGridLayout *layout = new QGridLayout(page);
QLabel *label = new QLabel;
label->setText(lab_neme);
label->setFont(font());
QLineEdit *ledit = new QLineEdit;
ledit->setText(ledit_name);
ledit->setFont(font());
layout->addWidget(label, 0, 1);
layout->addWidget(ledit, 0, 2);
page->setLayout(layout);
m_vbox_layout->insertWidget(m_vbox_layout->count()-1, page);
}
void BaseUi::addMulRecordUi(QString lab_neme, QString ledit_name, QString
but_name)
{
QWidget *page = new QWidget;
QGridLayout *layout = new QGridLayout(page);
QLabel *label = new QLabel;
label->setText(lab_neme);
label->setFont(font());
QLineEdit *ledit = new QLineEdit;
ledit->setText(ledit_name);
ledit->setFont(font());
QPushButton *but = new QPushButton(but_name);
but->setFont(font());
layout->addWidget(label, 0, 1);
layout->addWidget(ledit, 0, 2);
layout->addWidget(but, 0, 3);
page->setLayout(layout);
m_vbox_layout->insertWidget(m_vbox_layout->count()-1, page);
}

Add widgets into a QTabWidget

Can I add some widgets like QLabel and QPushButton into a QTabWidget?
Actually, I want to do something like this:
I'm using C++ and Qt.
Thanks
It's possible, just use QTabWidget::setCornerWidget.
Quick example:
QWidget* pTabCornerWidget = new QWidget(this);
QLabel* pLabelTime = new QLabel(pTabCornerWidget);
pLabelTime->setText("10:22:20");
QPushButton* pButton = new QPushButton(pTabCornerWidget);
pButton->setText("?");
pButton->setMaximumSize(QSize(25, 25));
QHBoxLayout* pHLayout = new QHBoxLayout(pTabCornerWidget);
pHLayout->addWidget(pLabelTime);
pHLayout->addWidget(pButton);
mUI.tabWidget->setCornerWidget(pTabCornerWidget, Qt::TopRightCorner);
If you want do this stuff, I recommend you use QTabBar instead of QTabWidget. For example, your code can be (remember, that it's just a very simple example):
// Here some first widget
QWidget *wid1 = new QWidget(this);
QHBoxLayout *wid1Lay = new QHBoxLayout(wid1);
wid1Lay->addWidget(new QLabel(tr("Widget1")));
// Here some second widget
QWidget *wid2 = new QWidget(this);
QHBoxLayout *wid2Lay = new QHBoxLayout(wid2);
wid2Lay->addWidget(new QLabel(tr("Widget2")));
// Here some third widget
QWidget *wid3 = new QWidget(this);
QHBoxLayout *wid3Lay = new QHBoxLayout(wid3);
wid3Lay->addWidget(new QLabel(tr("Widget3")));
// Here your Tab bar with only bars
QTabBar *bar = new QTabBar(this);
bar->addTab("One");
bar->addTab("Two");
bar->addTab("Three");
// Here some label (for example, current time) and button
QLabel *lab = new QLabel(tr("Some text"), this);
QPushButton *but = new QPushButton(tr("Push"), this);
// Main layouts
QVBoxLayout *vLay = new QVBoxLayout(ui->centralWidget);
QHBoxLayout *hLay = new QHBoxLayout();
vLay->addLayout(hLay);
hLay->addWidget(bar);
// Spacer for expanding left and right sides
hLay->addItem(new QSpacerItem(0, 0, QSizePolicy::Expanding, QSizePolicy::Minimum));
hLay->addWidget(lab);
hLay->addWidget(but);
vLay->addWidget(wid1);
vLay->addWidget(wid2);
vLay->addWidget(wid3);
// Some simple connect with lambda for navigation
connect(bar, &QTabBar::currentChanged, [=] (int index) {
wid1->setVisible(false);
wid2->setVisible(false);
wid3->setVisible(false);
switch(index) {
case 0: wid1->setVisible(true);
break;
case 1: wid2->setVisible(true);
break;
case 2: wid3->setVisible(true);
break;
default:{}
}
});
emit bar->currentChanged(0);

check QCheckBox in QVboxLayout of QStackedWidget

i have a QstackedWidget and i add QHboxLayout and QVBoxLayout to it, in my vertical layout i add 3 QCheckBox, and i add this layout with two spacer for left and right side to it, then i push this new layout with two spacer for top and bottom in horizontal layout, now i want to check if this QCheckBoxes are checked or not, but i don't know how to check this.
here is my code :
QVBoxLayout *center = new QVBoxLayout();
QVBoxLayout *main = new QVBoxLayout();
QHBoxLayout *middle = new QHBoxLayout();
QSpacerItem *topspacer = new QSpacerItem(14, 24, QSizePolicy::Fixed, QSizePolicy::Fixed);
QSpacerItem *buttom = new QSpacerItem(4, 4, QSizePolicy::Expanding, QSizePolicy::Expanding);
QSpacerItem *left = new QSpacerItem(4, 4, QSizePolicy::Expanding, QSizePolicy::Expanding);
QSpacerItem *right = new QSpacerItem(4, 4, QSizePolicy::Expanding, QSizePolicy::Expanding);
middle->addItem(left);
middle->addLayout(center);
middle->addItem(right);
center->addWidget(checkBoxEvent(QString::fromStdString("Analyze events")));
center->addWidget(checkBoxEvent(QString::fromStdString("Edit Tracks")));
center->addWidget(checkBoxEvent(QString::fromStdString("Analyze players")));
main->addItem(topspacer);
main->addLayout(middle);
main->addItem(buttom);
Qwidget *m_page = new Qwidget();
m_page->setLayout(main);
m_stackedWidget->addWidget(m_page);
i tried this code for accessing to elements but i get segmentation fault:
for(int i = 0; i < m_stackedWidget->widget(2)->layout()->count(); i++)
if(dynamic_cast<QPushButton*>( m_stackedWidget->widget(2)->layout()->itemAt(i) )->isChecked())
this items are added to m_stackedWidget[1]