I have QWidget with button. When button is pressed, show new smaller window (Qwidget too). I want then new window is centered horizontal and veritcal on main window. Code which display new window is:
QWidget *wdg = new QWidget;
QPushButton *closeBtn = new QPushButton("Close");
QHBoxLayout *layout = new QHBoxLayout;
layout->addWidget(closeBtn);
wdg->setLayout(layout);
wdg->show();
wdg->resize(400,200);
Use the move slot. For example:
QPoint centerPoint = oldWidget->geometry()->center();
newWidget->adjustSize();
newWidget->move(centerPoint.x() - newWidget->width()/2, centerPoint.y() - newWidget->height()/2);
You may consider using frameGeometry() instead of geometry().
http://qt-project.org/doc/qt-5/application-windows.html#window-geometry
Hope that helps.
Related
I am trying to draw various shapes like rectangle, ellipse, text etc uisng QGraphicsView and QGraphicsScene. For that I am trying to create an interface where there will be a vertical layout and besides that there will be few buttons. On clicking those buttons, I can show various QGraphicsItem's on screen. I want to create this interface programatically but not using ui.
I tried and ended up this way.
I wanted buttons on the right side and verticalLayout on the left side and both should filled up the whole screen.
Here is my current implementation :
Widget::Widget(QWidget *parent)
: QWidget(parent)
, ui(new Ui::Widget)
{
ui->setupUi(this);
QGraphicsScene* scene = new QGraphicsScene(this);
QGraphicsView* view = new QGraphicsView(this);
view->setScene(scene);
QWidget* mainWidget = new QWidget(this);
QHBoxLayout *mainLayout = new QHBoxLayout();
QVBoxLayout *buttonLayout = new QVBoxLayout();
QVBoxLayout *vlayout2 = new QVBoxLayout();
vlayout2->addWidget(view);
QPushButton *btn1 = new QPushButton("Rectangle");
btn1->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
QPushButton *btn2 = new QPushButton("Ellipse");
btn2->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
QPushButton *btn3 = new QPushButton("Text");
btn3->setSizePolicy( QSizePolicy::Expanding, QSizePolicy::Preferred );
buttonLayout->addWidget(btn1);
buttonLayout->addWidget(btn2);
buttonLayout->addWidget(btn3);
buttonLayout->addStretch();
mainLayout->addLayout(buttonLayout);
mainLayout->addLayout(vlayout2);
mainWidget->setLayout(mainLayout);
}
Can anyone guide me ?
Actually, it should work with the hints given in my comments.
I made an MCVE to convince myself:
#include <QtWidgets>
int main(int argc, char **argv)
{
qDebug() << "Qt Version:" << QT_VERSION_STR;
QApplication app(argc, argv);
// setup GUI
QWidget qMain;
qMain.setWindowTitle("Test Box Layout");
qMain.resize(640, 320);
QHBoxLayout qHBox;
QVBoxLayout qVBoxBtns;
QPushButton qBtnRect("Rectangle");
qVBoxBtns.addWidget(&qBtnRect);
QPushButton qBtnCirc("Circle");
qVBoxBtns.addWidget(&qBtnCirc);
QPushButton qBtnText("Text");
qVBoxBtns.addWidget(&qBtnText);
qVBoxBtns.addStretch();
qHBox.addLayout(&qVBoxBtns);
QVBoxLayout qVBoxView;
QGraphicsView qView;
qVBoxView.addWidget(&qView, 1);
qHBox.addLayout(&qVBoxView, 1);
qMain.setLayout(&qHBox);
qMain.show();
// runtime loop
return app.exec();
}
Output:
Thus, there must be something else in OP's code…
Unfortunately, OP didn't expose an MCVE.
Thus, it's not clear how OP's Widget is instanced. Is it the widget which becomes the main window? Is there another widget where the Widget's instance becomes child of?
It's just guessing but the latter would explain what OP described.
To confirm my guess, I modified the above code a bit:
// setup GUI
QWidget qMain0; // main window widget
QWidget qMain(&qMain0); // child widget of main window widget
⋮
qMain.setLayout(&qHBox);
qMain0.show();
// runtime loop
return app.exec();
Please, note that qMain is now a child of qMain0 but there is no layout which adjusts the size of qMain when qMain0 is resized.
Hence, the size of view stays the initial size while the window is resized.
I'm trying to create a QScrollArea in a QTabWidget.
Versions :
Qt 5.15.0
Qt creator 4.12.4
MSVC2019 64 bits
First of all, I've created the QTabWidget :
tabWidget = new QTabWidget(this);
tabWidget->setGeometry(10, 15, 1200, 665);
tabWidget->setStyleSheet("font-size : 15px");
tab1Content = new QWidget(tabWidget); tabWidget->addTab(tab1Content, "tab1");
tab2Content = new QWidget(tabWidget); tabWidget->addTab(tab2Content, "tab2");
tab3Content = new QWidget(tabWidget); tabWidget->addTab(tab3Content, "tab3");
tab4Content = new QWidget(tabWidget); tabWidget->addTab(tab4Content, "tab4");
I can add
tabWidget->setEnable(true);
And for all tabs, 0 <= i < tabWidget.count
tabWidget->setTabEnabled(i, true);
Click to change tab doesn't work : https://i.stack.imgur.com/8r1Jg.png
Strange thing : color looks like enabled but i can only change tabs with ← → and when i lost tabWidget focus by clicking on an other thing outside the tabWidget, i can't regain focus.
So i've created temporary button to change tabs and linked to tabWidget like that :
connect(changeTab, &QPushButton::clicked, [&]() {onChangeTab();});
void MainWindow::onChangeTab() {
tabWidget->setCurrentIndex(tabWidget->currentIndex() >= tabWidget->count() - 1 ? 0 : tabWidget->currentIndex() + 1);
}
It works well.
Thus, I've start to create the QScrollArea :
First, it doesn't work, so I've tried to found sth on internet :
QScrollArea not working as expected with QWidget and QVBoxLayout
My result : https://i.stack.imgur.com/jvVol.png
I cannot click on a single button and i can't scroll...
And if i try to force scroll like this, it doesn't scroll
scrollArea->scroll(0, 50);
Last thing, there isn't infinite loop or dead lock things because all things around this cursed tabWidget and scroll Area work perfectly.
I don't know why these objects "don't answer" if somedoby had this kind of experiment could you help me please ?
Thank you very much in advance.
try this code
#include "widget.h"
#include<QTabWidget>
#include<QLabel>
#include<QVBoxLayout>
#include<QScrollArea>
Widget::Widget(QWidget *parent)
: QWidget(parent)
{
QTabWidget *tabWidget = new QTabWidget(this);
tabWidget->setGeometry(10, 15, 1200, 665);
tabWidget->setStyleSheet("font-size : 15px");
QWidget * tab1Content = new QWidget;
//preparing tab1content ( e.g.)
QVBoxLayout * verticalLayout = new QVBoxLayout;
// adding items to vertical layout
for(int i=0;i<100;i++)
verticalLayout->addWidget(new QLabel(QString::number(i)));
// set this vertical layout inside tab1content
tab1Content->setLayout(verticalLayout);
// create new scroll area ...
QScrollArea * scroll = new QScrollArea;
// ... and add tab1content in scroll area
scroll->setWidget(tab1Content);
// and finally add scroll area inside tabwidget
tabWidget->addTab(scroll,"tab1");
QWidget * tab2Content = new QWidget; tabWidget->addTab(tab2Content, "tab2");
QWidget * tab3Content = new QWidget; tabWidget->addTab(tab3Content, "tab3");
QWidget * tab4Content = new QWidget; tabWidget->addTab(tab4Content, "tab4");
}
Widget::~Widget()
{
}
To my custom widget, inherited from QWidget, I have added a QScrollArea like this:
MainWindow::MainWindow(QWidget *parent) :
QWidget(parent)//MainWindow is a QWidget
{
auto *scrollArea = new QScrollArea(this);
auto *widget = new QWidget(this);
widget->setStyleSheet("background-color:green");
scrollArea->setWidget(widget);
scrollArea->setWidgetResizable(true);
scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
QVBoxLayout *parentLayout = new QVBoxLayout(widget);
this->setStyleSheet("background-color:blue");
for(int i=0;i<12;i++){
QHBoxLayout* labelLineEdit = f1();
parentLayout->addStretch(1);
parentLayout->addLayout(labelLineEdit);
}
parentLayout->setContentsMargins(0,0,40,0);
}
QHBoxLayout* MainWindow::f1()
{
QHBoxLayout *layout = new QHBoxLayout;
QLabel *label = new QLabel("Movie");
label->setStyleSheet("background-color:blue;color:white");
label->setMinimumWidth(300);
label->setMaximumWidth(300);
layout->addWidget(label);
QLineEdit *echoLineEdit = new QLineEdit;
echoLineEdit->setMaximumWidth(120);
echoLineEdit->setMaximumHeight(50);
echoLineEdit->setMinimumHeight(50);
echoLineEdit->setStyleSheet("background-color:white");
layout->addWidget(echoLineEdit);
layout->setSpacing(0);
return layout;
}
This produces a window which looks like this:
The problem is, that I want the scrollArea to occupy the entire window, but it does not. It also doesn't get resized when I resize the window.
How could I fix this?
The problem is, that I want the scrollArea to occupy the entire
window, but it does not. It also doesn't get resized when I resize the window.
The reason is that you have not set any kind of layout to manage the positioning of your QScrollArea widget itself, so it is just being left to its own devices (and therefore it just chooses a default size-and-location for itself and stays at that size-and-location).
A simple fix would be to add these lines to the bottom of your MainWindow constructor:
QBoxLayout * mainLayout = new QVBoxLayout(this);
mainLayout->setMargin(0);
mainLayout->addWidget(scrollArea);
I have created a simple QHBoxLayout (horizontal) that is pushed to the bottom of the QVBoxLayout (Vertical) and it contains two buttons. See code:
QWidget* create_ver_and_horizontal_box() {
QWidget* temp = new QWidget();
// Add buttons to the horizontal box
QHBoxLayout* hbox = new QHBoxLayout();
QPushButton *ok = new QPushButton("OK");
QPushButton *cancel = new QPushButton("Cancel");
hbox->addWidget(ok);
hbox->addWidget(cancel);
// Create a vertical box and add the horizontal box to
// the end of it
QVBoxLayout* vbox = new QVBoxLayout();
vbox->addStretch(1);
vbox->addLayout(hbox);
// set the layout and return
temp->setLayout(vbox);
return temp;
}
and the resulting UI is the following.
But when I add the QWidget temp to be the parent of the QHBoxLayout, like so:
// Add buttons to the horizontal box
QHBoxLayout* hbox = new QHBoxLayout(temp);
This is what I get:
I want to understand what is going on here. And in which cases I want the QWidget to be the parent of a layout or any other QWidget(s) and in which cases I don't the containing QWidget to be the parent of the containing QWidgets. For example, I could've added temp to be the parent of the two Push buttons but I didn't. What is the implication of not adding vs adding.
Thanks,
QHBoxLayout* hbox = new QHBoxLayout(temp);
is equivalent to
QHBoxLayout* hbox = new QHBoxLayout();
temp->setLayout(hbox);
I.e. you are making the horizontal layout responsible for temp.
The call to setLayout(vbox) should have generated a runtime warning message, that temp already has a layout, hinting at that.
Since you want the vertical layout to be responsible for that widget, either keep the temp->setLayout(vbox) or pass temp to the constructor of QVBoxLayout.
I am trying to create an expandable Qt dialog application. The main layout is a QVBoxLayout. The top part has two views and a QPushButtonbutton. Clicking button will unfold the bottom widget which is initially hidden. In the bottom widget, there is another push button, which could fold (hide) the bottom widget. When the bottom widget fold/unfold, I expect the size of the dialog size to change as well.
But for some reason, the dialog size only increases when the bottom widget is unfolded. And never shrink back to (200, 100). Is there anything I missed?
Environment: Qt Creator 3.6.1; Based on Qt5.6.0 (MSVC2013 32bit); build on Mar 14 2016; revision d502727b2c
The code I am using :
Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
QTreeView *tree = new QTreeView;
QTableView *table = new QTableView;
QPushButton *button_show = new QPushButton;
button_show->setText(tr("Show hidden panel"));
QHBoxLayout *layout_top = new QHBoxLayout;
layout_top->addWidget(tree);
layout_top->addWidget(table);
layout_top->addWidget(button_show);
QHBoxLayout *layout_bottom = new QHBoxLayout;
QTextEdit *editor = new QTextEdit;
QPushButton *button_hide = new QPushButton;
button_hide->setText(tr("Hide the bottom panel"));
g_pEditor = editor;
layout_bottom->addWidget(editor);
layout_bottom->addWidget(button_hide);
QWidget *panel = new QWidget;
panel->setLayout(layout_bottom);
QVBoxLayout *layout_main = new QVBoxLayout;
layout_main->addLayout(layout_top);
layout_main->addWidget(panel);
setLayout(layout_main);
panel->hide();
connect(button_show, &QPushButton::clicked
, panel
, [=]()
{
panel->setVisible(true);
button_show->setEnabled(false);
resize(200, 200);// not really working, the dialog size is able to increase without calling resize()
});
connect(button_hide, &QPushButton::clicked, panel, [=]()
{
panel->hide();
button_show->setEnabled(true);
resize(200,100);// does not shrink the dialog size*
});
resize(200,100);
}
Thanks for your help :)
Your should try setFixedSize(w, h) instead. This sets both, the minimum and the maximum size to (w, h). "This will override the default size constraints set by QLayout."