In my Qt 5.7.1 application I\'ve some buttons, I want to align button\'s icons to left and centre text, but there is no option in designer to do this.
I can
Simply specialize QPushButton
and override paintEvent
and sizeHint
, as proposed by cbuchart here. Then use it as a regular QPushButton
.
MyButton
declaration and implementation:mybutton.h:
#pragma once
#include
class MyButton : public QPushButton
{
public:
explicit MyButton(QWidget* parent = nullptr);
virtual ~MyButton();
void setPixmap(const QPixmap& pixmap);
virtual QSize sizeHint() const override;
protected:
virtual void paintEvent(QPaintEvent* e) override;
private:
QPixmap m_pixmap;
};
mybutton.cpp:
#include "mybutton.h"
#include
MyButton::MyButton(QWidget* parent) : QPushButton(parent)
{
}
MyButton::~MyButton()
{
}
QSize MyButton::sizeHint() const
{
const auto parentHint = QPushButton::sizeHint();
// add margins here if needed
return QSize(parentHint.width() + m_pixmap.width(), std::max(parentHint.height(), m_pixmap.height()));
}
void MyButton::setPixmap(const QPixmap& pixmap)
{
m_pixmap = pixmap;
}
void MyButton::paintEvent(QPaintEvent* e)
{
QPushButton::paintEvent(e);
if (!m_pixmap.isNull())
{
const int y = (height() - m_pixmap.height()) / 2; // add margin if needed
QPainter painter(this);
painter.drawPixmap(5, y, m_pixmap); // hardcoded horizontal margin
}
}
Here is an example where "Promote widget" feature in Qt Designer was used to create MyButton
from .ui files:
mainframe.ui:
MainWindow
0
0
400
300
MainWindow
-
Button
-
Other button
0
0
400
20
TopToolBarArea
false
MyButton
QPushButton
mybutton.h
mainwindow.h:
#pragma once
#include
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
Ui::MainWindow *ui;
};
mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QStyle* style = qApp->style();
// set buttons pixmaps:
ui->button1->setPixmap( style->standardPixmap(QStyle::SP_ComputerIcon) );
ui->button2->setPixmap( style->standardPixmap(QStyle::SP_TrashIcon) );
}
MainWindow::~MainWindow()
{
delete ui;
}
main.cpp:
#include "mainwindow.h"
#include
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
Results in:
QPushButton
(using QPushButton::setText
), you don't need to keep a reference to a mockup QLabel
to change button's text.