probably a simple question: I just created a new project in Qt creator and I set it to use QWidget when I created it, now how do I get rid of the window that it automatically creates when I run it? I also created my own QWidget window which I want to be the only window.
#include "widget.h"
#include <QtGui>
Widget::Widget()
{
QWidget* window = new QWidget;
addBtn = new QPushButton("Add Module");
text = new QTextEdit();
text->setReadOnly(true);
QVBoxLayout* layout = new QVBoxLayout();
layout->addWidget(addBtn,5);
layout->addWidget(text);
window->setLayout(layout);
window->show();
}
Widget::~Widget()
{
}
#include <QtGui/QApplication>
#include "widget.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Widget w;
w.show();
return a.exec();
}
change it like this
Widget::Widget()
{
addBtn = new QPushButton("Add Module");
text = new QTextEdit();
text->setReadOnly(true);
QVBoxLayout* layout = new QVBoxLayout();
layout->addWidget(addBtn,5);
layout->addWidget(text);
this->setLayout(layout);
}
and try to have some time on look and try some of Qt Example (you can find it in Qt Creator)
and there is about 100 short video to learn quickly basic stuff on Qt
Qt is fun, enjoy it.
Related
I want to fit (child) widget into the parent widget size. So if the parent window is too small to display all the elements of the child widget the QScrollArea should appear otherwise it should be invisible.
I have attached the pictures for a better understanding.
The black box is where I want my scroll to appear. Since when we reduce the size of the window, sometimes you can't see the scroll bar (as displayed in the below picture) it doesn't look elegant enough for big projects.
Please help me with the same, thanks in advance.
Here's the sample code that I used for example:
int main(int argc, char *argv[]){
QApplication a(argc, argv);
QScrollPractice w;
QDialog * dlg = new QDialog();
//dlg->setGeometry(100, 100, 260, 260);
dlg->setMinimumSize(150, 200);
QScrollArea *scrollArea = new QScrollArea(dlg);
scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
scrollArea->setWidgetResizable(true);
//scrollArea->setGeometry(10, 10, 200, 200);
//scrollArea->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Ignored);
//QSizePolicy sizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
scrollArea->setSizePolicy(sizePolicy);
QWidget *widget = new QWidget(scrollArea);
scrollArea->setWidget(widget);
QVBoxLayout *layout = new QVBoxLayout(widget);
widget->setLayout(layout);
for (int i = 0; i < 10; i++)
{
QPushButton *button = new QPushButton(QString("%1").arg(i));
layout->addWidget(button);
}
dlg->show();
return a.exec();
}
Your Dialog is missing a layout as well. Thats the reason the scrollArea Widget isnt spread out across the dialog.
#include <QApplication>
#include <QDialog>
#include <QScrollArea>
#include <QVBoxLayout>
#include <QPushButton>
int main(int argc, char* argv[]){
QApplication a(argc, argv);
QDialog* dlg = new QDialog();
dlg->setMinimumSize(150, 200);
QScrollArea* scrollArea = new QScrollArea(dlg);
scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
scrollArea->setWidgetResizable(true);
QWidget* widget = new QWidget(scrollArea);
scrollArea->setWidget(widget);
QVBoxLayout* dlgLayout = new QVBoxLayout();
dlg->setLayout( dlgLayout );
dlgLayout->addWidget( scrollArea );
QVBoxLayout* layout = new QVBoxLayout(widget);
widget->setLayout(layout);
for (int i = 0; i < 10; i++)
{
QPushButton* button = new QPushButton(QString("%1").arg(i));
layout->addWidget(button);
}
dlg->show();
return a.exec();
}
I modified your code to make it run and compileable, also I added antoher QVBoxLayout and added it to the dialog. Then the scrollArea gets added to that Layout. Hope this helps.
everyone! I try to set a click property to a QMediaPlayer Element, but I can not find the mode to make it, and if I try to put a button in front to Video, the button puts behind to video, even with
button->raise();
videoWidget->lower();
And If I put a Button to fullscreen the screen turns in black and don't shows the video
this id the code of the video player
QMediaPlayer *player = new QMediaPlayer(this);
QVideoWidget *vw = new QVideoWidget(this);
QMediaPlaylist *PlayList = new QMediaPlaylist(this);
PlayList->addMedia(QUrl::fromLocalFile("/home/user/Videos/video.mp4"));
PlayList->setPlaybackMode(QMediaPlaylist::Loop);
QVBoxLayout *layout = new QVBoxLayout;
layout->addWidget(vw);
player->setVideoOutput(vw);
player->setPlaylist(PlayList);
vw->setGeometry(0,0,800,480);
vw->show();
player->play();
One possible solution is to create a widget where the QVideoWidget is placed through a layout, the button is also added and we change the position through the resizeEvent() event.
#include <QApplication>
#include <QMediaPlayer>
#include <QMediaPlaylist>
#include <QPushButton>
#include <QUrl>
#include <QVBoxLayout>
#include <QVideoWidget>
#include <QDebug>
class VideoWidgetButton: public QWidget{
QPushButton *btn;
QVideoWidget *vw;
QMediaPlayer *player;
public:
VideoWidgetButton(QWidget *parent=Q_NULLPTR):QWidget(parent){
setLayout(new QVBoxLayout);
layout()->setContentsMargins(0, 0, 0, 0);
vw = new QVideoWidget(this);
btn = new QPushButton(this);
btn->setIcon(QIcon(":/icons/tux.jpeg"));
btn->resize(QSize(128, 128));
btn->setIconSize(QSize(128, 128));
connect(btn, &QPushButton::clicked, [](){
qDebug()<<"clicked";
});
layout()->addWidget(vw);
player = new QMediaPlayer(this);
player->setVideoOutput(vw);
QMediaPlaylist *playList = new QMediaPlaylist(this);
playList->addMedia(QUrl("qrc:/video/SampleVideo_1280x720_1mb.mp4"));
playList->setPlaybackMode(QMediaPlaylist::Loop);
player->setPlaylist(playList);
player->play();
}
protected:
void resizeEvent(QResizeEvent *ev){
btn->move(rect().bottomRight()-btn->rect().bottomRight());
return QWidget::resizeEvent(ev);
}
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
VideoWidgetButton w;
w.resize(640, 480);
w.show();
return a.exec();
}
The complete example can be found in the following link.
I would like to use a custom made QWidget in one row of a QFormLayout. The code below presents a form layout in which the first row has a a QLineEdit and the second line has a custom made widget:
The problem is that the custom made widget is not vertically aligned. How to align it vertically?
project.pro:
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = CustomLineEdit
TEMPLATE = app
SOURCES += main.cpp
main.cpp
#include <QApplication>
#include <QHBoxLayout>
#include <QFormLayout>
#include <QLineEdit>
#include <QPushButton>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget w;
QFormLayout *formLayout = new QFormLayout(&w);
QLineEdit *leUser = new QLineEdit;
QWidget *widget = new QWidget;
QHBoxLayout *hLayout = new QHBoxLayout(widget);
hLayout->addWidget(leUser);
hLayout->addWidget(new QPushButton);
formLayout->addRow("Text:", new QLineEdit);
formLayout->addRow("User:", widget);
w.show();
return a.exec();
}
This is because of margins. Just add followed line:
QHBoxLayout *hLayout = new QHBoxLayout(widget);
hLayout->setMargin(0); //this line
I have a QT main window and on top of this I want to add a widget ( containing buttons), as similar to image below.
If I add a dock widget , it is added in separate row, but not added as overlay on existing main window.
Any inputs ?
The easiest is to set your overlay widget's parent to be the main window. But because it will not be in any layout you have to take care of its geometry yourself. In case you want to have multiple overlays, the last added will be the top most.
#include <QApplication>
#include <QtGui>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QMainWindow *window = new QMainWindow();
QWidget *centralWiddget = new QWidget();
window->setCentralWidget(centralWiddget);
QVBoxLayout *layout = new QVBoxLayout(centralWiddget);
QPushButton *button = new QPushButton("Button in a layout");
layout->addWidget(button);
QPushButton *overlayButton = new QPushButton("Button overlay");
overlayButton->setParent(window);
overlayButton->setGeometry(40, 40, 120, 30)
window->show();
return app.exec();
}
You should look into using QStackedLayout to so this.
I'm try to create a GUI application.
The main window, a QMainWindow, contains 9 labels with fixed size and also the size of the main window.
I tried to make it programmatically without Qt GUI Designer. The project is built without error but I cannot see any label nor layout shown on the main window. it's just blank.
Here is my source code:
WCwindow::WCwindow()
{
// initialize widgets with text
CAM111 = new QLabel("CAM 01");
CAM121 = new QLabel("CAM 02");
CAM131 = new QLabel("CAM 03");
CAM211 = new QLabel("CAM 04");
CAM221 = new QLabel("CAM 05");
CAM231 = new QLabel("CAM 06");
CAM311 = new QLabel("CAM 07");
CAM321 = new QLabel("CAM 08");
CAM331 = new QLabel("CAM 09");
CAM111->setFixedSize(wcW,wcH);
CAM121->setFixedSize(wcW,wcH);
CAM131->setFixedSize(wcW,wcH);
CAM211->setFixedSize(wcW,wcH);
CAM221->setFixedSize(wcW,wcH);
CAM231->setFixedSize(wcW,wcH);
CAM311->setFixedSize(wcW,wcH);
CAM321->setFixedSize(wcW,wcH);
CAM331->setFixedSize(wcW,wcH);
QGridLayout *layout = new QGridLayout;
layout->addWidget(CAM111,0,0);
layout->addWidget(CAM121,0,1);
layout->addWidget(CAM131,0,2);
layout->addWidget(CAM211,1,0);
layout->addWidget(CAM221,1,1);
layout->addWidget(CAM231,1,2);
layout->addWidget(CAM311,2,0);
layout->addWidget(CAM321,2,1);
layout->addWidget(CAM331,2,2);
setLayout(layout);
setWindowTitle("Camera Window");
setFixedSize(1000, 800);
}
of course, the class is initialized and evoked in main.cpp:
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
WCwindow *WCwin = new WCwindow;
WCwin->show();
return app.exec();
}
what kind of bug am I having??
The code below works fine. The problem was in the code you weren't showing. When you use a QMainWindow, as you've eventually admitted to doing, you need to set its centralWidget with a new widget that you construct.
// main.cpp
#include <QVector>
#include <QMainWindow>
#include <QLabel>
#include <QGridLayout>
#include <QApplication>
class WCwindow : public QMainWindow
{
public:
WCwindow();
private:
QVector<QLabel*> cams;
QLabel* cam(int r, int c) const {
return cams[r*3 + c];
}
};
WCwindow::WCwindow()
{
QGridLayout *layout = new QGridLayout;
for (int i = 1; i < 10; ++ i) {
QLabel * const label = new QLabel(QString("CAM %1").arg(i, 2, 10, QLatin1Char('0')));
label->setFixedSize(200, 50);
layout->addWidget(label, (i-1) / 3, (i-1) % 3);
cams << label;
}
QWidget * central = new QWidget();
setCentralWidget(central);
centralWidget()->setLayout(layout);
setWindowTitle("Camera Window");
setFixedSize(1000, 800);
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
WCwindow win;
win.show();
return app.exec();
}
Is WCwindow a subclass of QMainWindow? In that case i would advise to remove the layout from your window in the GUI editor by clicking the "break layout" button in the top bar, then use the following:
//setup all your labels and layout ...
//creating a QWidget, and setting the WCwindow as parent
QWidget * widget = new QWidget(this);
//set the gridlayout for the widget
widget->setLayout(layout);
//setting the WCwindow's central widget
setCentralWidget(widget);