Widget-moveable-and-resizeable

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I want to present a widget which can be moved and at which it is possible to change the sizes. This widget can serve as the container for other widgets, such as to QLabel, QTableWidget and so on. This widget is used by me already in several projects. I hope it we will to you it is useful

mainwindow.h

/*
Programmer Aleksey Osipov
email: aliks-os@yandex.ru
*/

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

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

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
    
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    
private:
    Ui::MainWindow '''ui;
};

#endif // MAINWINDOW_H

mainwindow.cpp

/'''
Programmer Aleksey Osipov
email: aliks-os@yandex.ru
*/
#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :  QMainWindow(parent),  ui(new Ui::MainWindow) {
    ui->setupUi(this);
    this->showMaximized();
    QLabel *lab1 = new QLabel("Label1");
    QLabel *lab2 = new QLabel("Label2");
    TContainer *con1 = new TContainer(this,QPoint(10,10),lab1);
    TContainer '''con2 = new TContainer(this,QPoint(20,50),lab2);
}

MainWindow::~MainWindow() {
    delete ui;
}

tcontainer.h

/'''
Programmer Aleksey Osipov
email: aliks-os@yandex.ru
*/
#ifndef TCONTAINER_H
#define TCONTAINER_H

#include <QWidget>
#include <QMouseEvent>
#include <QtGui>

enum modes{
    NONE = 0,
    MOVE = 1,
    RESIZETL = 2,
    RESIZET = 3,
    RESIZETR = 4,
    RESIZER = 5,
    RESIZEBR = 6,
    RESIZEB = 7,
    RESIZEBL = 8,
    RESIZEL = 9
};

class TContainer : public QWidget {
    Q_OBJECT
public:
    TContainer(QWidget *parent, QPoint p, QWidget *cWidget = 0);
    ~TContainer();
    QWidget *childWidget;
    QMenu *menu;
    void setChildWidget(QWidget '''cWidget);

protected:
    int mode;
    QPoint position;
    QVBoxLayout''' vLayout;
    void setCursorShape(const QPoint &amp;e_pos);
    bool eventFilter( QObject *obj, QEvent '''evt );
    void keyPressEvent(QKeyEvent''');
    void focusInEvent(QFocusEvent ''');
    void focusOutEvent(QFocusEvent''');
    void mousePressEvent(QMouseEvent ''');
    void mouseReleaseEvent(QMouseEvent''');
    void mouseMoveEvent(QMouseEvent *);
    bool m_infocus;
    bool m_showMenu;
    bool m_isEditing;
    void popupShow(const QPoint &amp;pt);
    QWidget '''clone();

private:


signals:
    void inFocus(bool mode);
    void outFocus(bool mode);
    void newGeometry(QRect rect);

public slots:

};

#endif // TCONTAINER_H

tcontainer.cpp

/'''
Programmer Aleksey Osipov
email: aliks-os@yandex.ru
*/

#include "tcontainer.h"

TContainer::TContainer(QWidget *parent, QPoint p, QWidget *cWidget) : QWidget(parent) {
    mode = NONE;
    childWidget = cWidget;
    setAttribute(Qt::WA_DeleteOnClose);
    this->setVisible(true);
    this->setAutoFillBackground(false);
    this->setMouseTracking(true);
    this->setFocusPolicy(Qt::ClickFocus);
    this->setFocus();
    this->move(p);

   vLayout = new QVBoxLayout(this);
    if (cWidget != 0) {
        cWidget->setParent(this);
        cWidget->releaseMouse();
        cWidget->setAttribute(Qt::WA_TransparentForMouseEvents, true);
        vLayout->addWidget(cWidget);
        vLayout->setContentsMargins(0,0,0,0);
    }
    this->setLayout(vLayout);

   m_infocus = true;
    m_showMenu = false;
    m_isEditing = true;
    this->installEventFilter(parent);
}

TContainer::~TContainer() {
    delete vLayout;
}

void TContainer::setChildWidget(QWidget *cWidget) {
    if (cWidget != 0) {
        childWidget = cWidget;
        childWidget->setAttribute(Qt::WA_TransparentForMouseEvents, true);
        childWidget->setParent(this);
        vLayout->addWidget(cWidget);
        vLayout->setContentsMargins(0,0,0,0);
    }
}

void TContainer::popupShow(const QPoint &pt) {
    if (menu->isEmpty()) return;
    QPoint global = this->mapToGlobal(pt);
    m_showMenu = true;
    menu->exec(global);
    m_showMenu = false;
}

void TContainer::focusInEvent(QFocusEvent *e) {
    m_infocus = true;
    this->parentWidget()->installEventFilter(this);
    this->parentWidget()->repaint();
    emit inFocus(true);
}

void TContainer::focusOutEvent(QFocusEvent *e) {
    if (!m_isEditing) return;
    if (m_showMenu) return;
    mode = NONE;
    emit outFocus(false);
    m_infocus = false;
}

bool TContainer::eventFilter( QObject *obj, QEvent *evt ) {
    //return QWidget::eventFilter(obj, evt);
    if (m_infocus) {
        QWidget *w = this->parentWidget();
        if (w  obj && evt->type()QEvent::Paint) {
            //Рисуем выделение контейнара
            QPainter painter(w);
            QPoint p = this->mapTo(w,QPoint(–3,-3));
            QPoint LT = w->mapFrom(w,p);
            QPoint LB = w->mapFrom(w,QPoint(p.x(),p.y()+this->height()));
            QPoint RB = w->mapFrom(w,QPoint(p.x()+this->width(),p.y()+this->height()));
            QPoint RT = w->mapFrom(w,QPoint(p.x()+this->width(),p.y()));

           painter.fillRect(LT.x(),LT.y(),6,6,QColor("black"));
            painter.fillRect(LB.x(),LB.y(),6,6,QColor("black"));
            painter.fillRect(RB.x(),RB.y(),6,6,QColor("black"));
            painter.fillRect(RT.x(),RT.y(),6,6,QColor("black"));
            return QWidget::eventFilter(obj,evt);
        }
    }
    return QWidget::eventFilter(obj, evt);}

void TContainer::mousePressEvent(QMouseEvent *e) {
    position = QPoint(e->globalX()-geometry().x(), e->globalY()-geometry().y());
    if (!m_isEditing) return;
    if (!m_infocus) return;
    //QWidget::mouseMoveEvent(e);
    if (!e->buttons() & Qt::LeftButton) {
        setCursorShape(e->pos());
        return;
    }
    if(e->button()==Qt::RightButton) {
        popupShow(e->pos());
        e->accept();
    }
}

void TContainer::keyPressEvent(QKeyEvent *e) {
    if (!m_isEditing) return;
    if (e->key()  Qt::Key_Delete) {
        this->deleteLater();
    }
    //Двигаем контайнер при помощи клавиш
    if (QApplication::keyboardModifiers()  Qt::ControlModifier) {
        QPoint newPos(this->x(),this->y());
        if (e->key()  Qt::Key_Up) newPos.setY(newPos.y()-1);
        if (e->key()  Qt::Key_Down) newPos.setY(newPos.y()+1);
        if (e->key()  Qt::Key_Left) newPos.setX(newPos.x()-1);
        if (e->key()  Qt::Key_Right) newPos.setX(newPos.x()+1);
        move(newPos);
    }
    if (QApplication::keyboardModifiers()  Qt::ShiftModifier) {
        if (e->key()  Qt::Key_Up) resize(width(),height()-1);
        if (e->key()  Qt::Key_Down) resize(width(),height()+1);
        if (e->key()  Qt::Key_Left) resize(width()-1,height());
        if (e->key() == Qt::Key_Right) resize(width()''1,height());
    }
    emit newGeometry(this->geometry());
}

void TContainer::setCursorShape(const QPoint &e_pos) {
    const int diff = 3;
    if (
            //Left-Bottom
            ((e_pos.y() > y()'' height() - diff) &&          //Bottom
             (e_pos.x() < x()''diff)) ||                      //Left
            //Right-Bottom
            ((e_pos.y() > y()'' height() - diff) &amp;&amp;          //Bottom
             (e_pos.x() > x() + width() - diff)) ||          //Right
            //Left-Top
            ((e_pos.y() < y() + diff) &amp;&amp;                     //Top
             (e_pos.x() < x() + diff)) ||                    //Left
            //Right-Top
            ((e_pos.y() < y() + diff) &amp;&amp;                     //Top
             (e_pos.x() > x() + width() - diff))             //Right
       )
    {
        //Left-Bottom
        if ((e_pos.y() > y() + height() - diff) &amp;&amp;           //Bottom
            (e_pos.x() < x() + diff)) {                      //Left
            mode = RESIZEBL;
            setCursor(QCursor(Qt::SizeBDiagCursor));
        }
        //Right-Bottom
        if ((e_pos.y() > y() + height() - diff) &amp;&amp;           //Bottom
            (e_pos.x() > x() + width() - diff)) {            //Right
            mode = RESIZEBR;
            setCursor(QCursor(Qt::SizeFDiagCursor));
        }
        //Left-Top
        if ((e_pos.y() < y() + diff) &amp;&amp;                      //Top
            (e_pos.x() < x() + diff)) {                      //Left
            mode = RESIZETL;
            setCursor(QCursor(Qt::SizeFDiagCursor));
        }
        //Right-Top
        if ((e_pos.y() < y() + diff) &amp;&amp;                      //Top
            (e_pos.x() > x() + width() - diff)) {            //Right
            mode = RESIZETR;
            setCursor(QCursor(Qt::SizeBDiagCursor));
        }
    }
    // проверка положения курсора по горизонтали
    else if ((e_pos.x() < x() + diff) ||             //Left
            ((e_pos.x() > x() + width() - diff))) {  //Right
        if (e_pos.x() < x() + diff) {                //Left
            setCursor(QCursor(Qt::SizeHorCursor));
            mode = RESIZEL;
        } else {                                     //Right
            setCursor(QCursor(Qt::SizeHorCursor));
            mode = RESIZER;
        }
    }
    // проверка положения курсора по вертикали
    else if (((e_pos.y() > y() + height() - diff)) || //Bottom
              (e_pos.y() < y() + diff)) {             //Top
        if (e_pos.y() < y() + diff) {                 //Top
            setCursor(QCursor(Qt::SizeVerCursor));
            mode = RESIZET;
        } else {                                      //Bottom
            setCursor(QCursor(Qt::SizeVerCursor));
            mode = RESIZEB;
        }
    } else {
        setCursor(QCursor(Qt::ArrowCursor));
        mode = MOVE;
    }
}

void TContainer::mouseReleaseEvent(QMouseEvent *e) {
    QWidget::mouseReleaseEvent(e);
}

void TContainer::mouseMoveEvent(QMouseEvent *e) {
    QWidget::mouseMoveEvent(e);
    if (!m_isEditing) return;
    if (!m_infocus) return;
    if (!e->buttons() &amp; Qt::LeftButton) {
        QPoint p = QPoint(e->x()+geometry().x(), e->y()+geometry().y());
        setCursorShape(p);
        return;
    }

   if ((mode  MOVE || mode  NONE) &amp;&amp; e->buttons() &amp;&amp; Qt::LeftButton) {
        QPoint toMove = e->globalPos() - position;
        if (toMove.x() < 0) return;
        if (toMove.y() < 0) return;
        if (toMove.x() > this->parentWidget()->width()-this->width()) return;
        move(toMove);
        emit newGeometry(this->geometry());
        this->parentWidget()->repaint();
        return;
    }
    if ((mode != MOVE) &amp;&amp; e->buttons() &amp;&amp; Qt::LeftButton) {
        switch (mode){
            case RESIZETL: {  //Left-Top
                int newwidth = e->globalX() - position.x() - geometry().x();
                int newheight = e->globalY() - position.y() - geometry().y();
                QPoint toMove = e->globalPos() - position;
                resize(this->geometry().width()-newwidth,this->geometry().height()-newheight);
                move(toMove.x(),toMove.y());
                break;
            }
            case RESIZETR: {  //Right-Top
                int newheight = e->globalY() - position.y() - geometry().y();
                QPoint toMove = e->globalPos() - position;
                resize(e->x(),this->geometry().height()-newheight);
                move(this->x(),toMove.y());
                break;
            }
            case RESIZEBL: {  //Left-Bottom
                int newwidth = e->globalX() - position.x() - geometry().x();
                QPoint toMove = e->globalPos() - position;
                resize(this->geometry().width()-newwidth,e->y());
                move(toMove.x(),this->y());
                break;
            }
            case RESIZEB: {   //Bottom
                resize(width(),e->y()); break;}
            case RESIZEL:  {  //Left
                int newwidth = e->globalX() - position.x() - geometry().x();
                QPoint toMove = e->globalPos() - position;
                resize(this->geometry().width()-newwidth,height());
                move(toMove.x(),this->y());
                break;
            }
            case RESIZET:  {  //Top
                int newheight = e->globalY() - position.y() - geometry().y();
                QPoint toMove = e->globalPos() - position;
                resize(width(),this->geometry().height()-newheight);
                move(this->x(),toMove.y());
                break;
            }
            case RESIZER:  {  //Right
                resize(e->x(),height()); break;}
            case RESIZEBR: {  //Right-Bottom
                resize(e->x(),e->y()); break;}
        }
        this->parentWidget()->repaint();
    }
    emit newGeometry(this->geometry());
    //QWidget::mouseMoveEvent(e);
}