I want to create a custom title bar in qt

Question

I want to create a custom title bar in qt.

So I looked up some examples and followed them. Here is the code that applies the example.

Widget header file :

#include <QWidget>
#include <QMouseEvent>

class KcWdTitlebar :public QWidget
{
private:
    QWidget *m_parent;
    QPoint m_pCursor;

public:
    KcWdTitlebar( QWidget *parent) ;

protected:
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
};

Widget cpp :

KcWdTitlebar::KcWdTitlebar(QWidget *parent ) :m_parent(parent)
{
    QLabel *title = new QLabel(parent->windowTitle());
    QPushButton *pPB = new QPushButton ("x");

    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->addWidget(title);
    layout->addWidget(pPB);

    connect(pPB,SIGNAL(clicked()),parent,SLOT(close()));
}

void KcWdTitlebar::mousePressEvent(QMouseEvent *event)
{
    if(event->button() == Qt::LeftButton)
    {
        m_pCursor = event->globalPos() - geometry().topLeft();
        event->accept();
    }
}

void KcWdTitlebar::mouseMoveEvent(QMouseEvent *event)
{
    if(event->buttons() & Qt::LeftButton)
    {
        m_parent->move(event->globalPos() - m_pCursor);
        event->accept();
    }
}

mainwindow header :

#include <QMainWindow>
#include "KcWdTitlebar.h"

namespace Ui {
class mainwindow;
}

class mainwindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit mainwindow(QWidget *parent = 0);
    ~mainwindow();

private:
    KcWdTitlebar *m_title;
    Ui::mainwindow *ui;
};

mainwidow cpp :

mainwindow::mainwindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::mainwindow)
{
    ui->setupUi(this);
    m_title = new KcWdTitlebar(this);
    ui->verticalLayout->addWidget(m_title);

}

When I run this code, Clicking and dragging the KcWdTitle portion will cause the mainwindow to follow further than the point I clicked.

What parts of the code should I fix?

I hope everyone can understand my English.

Answer 1

You need to change mousePressEvent() to subtract the MainWindow geometry instead of the title bar's geometry.

Change:

m_pCursor = event->globalPos() - geometry().topLeft();

To this:

m_pCursor = event->globalPos() - m_parent->geometry().topLeft();