How to unblock signals when mouse button is down?

qwe3

Hi,

I would like to have QWidget with QGridLayout and many myButtons ( inherits QPushButton ) in it.

When I press random myButton, and still mouse button ( left ) will be down, and move to other button I would like to change color this two buttons.

But when I pressed left mouse button, my QWidget and my buttons don't get any signals ( like mousemoveenent or hover ). So when mouse button is down I can't do anything. Is there a solution to unblock signals?

mrjj

Hi
You could also just make a custom widget that paint the cells as you want.

#ifndef CELLWIDGET_H
#define CELLWIDGET_H

#include <QPainter>
#include <QResizeEvent>
#include <QWidget>
#include <QDebug>

struct Cell {
    QRect rect;
    QColor color{Qt::gray};
};

class CellWidget : public QWidget
{
    Q_OBJECT
    int numCols;
    int numRows;
    int cellWidth;
    int cellHeight;
    std::vector<Cell>Cells;
    bool pressed = false;
public:
    explicit CellWidget(QWidget *parent = nullptr, int nCols = 8, int nRows = 8 ) : QWidget(parent),
        numCols(nCols), numRows(nRows)
    {

    }

    void Layout() // calculate the cells
    {
        int y = 0;
        cellWidth = width() / numCols;
        cellHeight = height() / numRows;
        Cells.clear();
        Cell tmp;
        for (int rows = 0; rows < numRows; ++rows) {
            int x = 0;
            for (int cols = 0; cols < numCols; ++cols) {
                //qDebug() << "col=" << cols << "- row=" << rows;
                tmp.rect.setCoords(x, y, x + cellWidth, y + cellHeight);
                Cells.push_back(tmp);
                x += cellWidth;
            }
            y += cellHeight;
        }
    }
signals:
protected:

    virtual void mouseMoveEvent(QMouseEvent *event) override
    {
        if (pressed) {
            for (Cell &cell : Cells) { // find cell under mouse
                if (cell.rect.contains(event->pos()) ) {
                    cell.color = Qt::yellow;
                    update();
                    continue;
                }
            }

        }
    }

    virtual void paintEvent(QPaintEvent *) override
    {

        QPainter p(this);
        for (const Cell &cell : Cells) {
            p.setBrush( cell.color);
            p.drawRect( cell.rect ) ;
        }

    }

    virtual void resizeEvent(QResizeEvent *event) override
    {
        Layout();
    }

    virtual void mousePressEvent(QMouseEvent *) override
    {
        pressed = true;
    }
    virtual void mouseReleaseEvent(QMouseEvent *) override
    {
        pressed = false;
    }

};

#endif // CELLWIDGET_H

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SGaist

Hi,

Not to be picky but these are events, not signals. If you want your widgets to get all mouse related events you need to use mouseTracking.

qwe3

@SGaist My problem is like that:

https://stackoverflow.com/questions/46147290/pyqt5-check-if-mouse-is-held-down-in-enter-event

But I don't want use DragEvent

SGaist

Did you check my suggestion ?

qwe3

@SGaist I tried mouseTracking, but still don't get events when button is down.

Pl45m4

@qwe3

What you have done so far? How does your myButton class look like?

qwe3

@Pl45m4 I have a QWidget ( in this example MainWindow ) with QGridLayout on it. In this QGridLayout I have many clickableLabel ( I know that I told buttons, but it is very small change ). Now I would like to do:

In green X I pressed left mouse button ( don't release! ). Now I move mouse to other labels ( red arrows ) and in blue X I release left mouse button.

I would like to get:

So I would like to change color in this labels where I pressed mouse left button, released mouse left button and which were "on the move road".

Now my clickableLabel looks like this:

myLabel::myLabel(QWidget *parent): QLabel(parent)
{
    setMouseTracking(true);
   // this->setAttribute(Qt::WA_Hover, true);
}

void myLabel::mousePressEvent(QMouseEvent *event)
{
    isPressed = true;
    QLabel::mousePressEvent(event);
}

void myLabel::mouseReleaseEvent(QMouseEvent *event)
{
    QLabel::mouseReleaseEvent(event);
}

void myLabel::mouseMoveEvent(QMouseEvent *event)
{
    //qInfo()<<this;
    QLabel::mouseMoveEvent(event);
}

void myLabel::hoverEnter(QHoverEvent * event) {
    //qDebug() << Q_FUNC_INFO << this->objectName();

}
void myLabel::hoverLeave(QHoverEvent * event) {

    qDebug() << Q_FUNC_INFO << this->objectName();
}
void myLabel::hoverMove(QHoverEvent * event) {


    qDebug() << Q_FUNC_INFO << this;
    //if(isPressed)
        //setStyleSheet("QLabel {background:black}");
}

bool myLabel::event(QEvent * e)
{
    qInfo()<<e->type();
//    switch(e->type())
//    {
//    case QEvent::HoverEnter:
//        hoverEnter(static_cast<QHoverEvent*>(e));
//        return true;
//        break;
//    case QEvent::HoverLeave:
//        hoverLeave(static_cast<QHoverEvent*>(e));
//        return true;
//        break;
//    case QEvent::HoverMove:
//        hoverMove(static_cast<QHoverEvent*>(e));
//        return true;
//        break;
//    default:
//        break;
//    }
    return QWidget::event(e);
}

I know that I don't change color in this code above. This is code, which I present, what I tried ( setmousetracking, hovers ). I tried with qDebug().

mrjj

Hi
You could also just make a custom widget that paint the cells as you want.

#ifndef CELLWIDGET_H
#define CELLWIDGET_H

#include <QPainter>
#include <QResizeEvent>
#include <QWidget>
#include <QDebug>

struct Cell {
    QRect rect;
    QColor color{Qt::gray};
};

class CellWidget : public QWidget
{
    Q_OBJECT
    int numCols;
    int numRows;
    int cellWidth;
    int cellHeight;
    std::vector<Cell>Cells;
    bool pressed = false;
public:
    explicit CellWidget(QWidget *parent = nullptr, int nCols = 8, int nRows = 8 ) : QWidget(parent),
        numCols(nCols), numRows(nRows)
    {

    }

    void Layout() // calculate the cells
    {
        int y = 0;
        cellWidth = width() / numCols;
        cellHeight = height() / numRows;
        Cells.clear();
        Cell tmp;
        for (int rows = 0; rows < numRows; ++rows) {
            int x = 0;
            for (int cols = 0; cols < numCols; ++cols) {
                //qDebug() << "col=" << cols << "- row=" << rows;
                tmp.rect.setCoords(x, y, x + cellWidth, y + cellHeight);
                Cells.push_back(tmp);
                x += cellWidth;
            }
            y += cellHeight;
        }
    }
signals:
protected:

    virtual void mouseMoveEvent(QMouseEvent *event) override
    {
        if (pressed) {
            for (Cell &cell : Cells) { // find cell under mouse
                if (cell.rect.contains(event->pos()) ) {
                    cell.color = Qt::yellow;
                    update();
                    continue;
                }
            }

        }
    }

    virtual void paintEvent(QPaintEvent *) override
    {

        QPainter p(this);
        for (const Cell &cell : Cells) {
            p.setBrush( cell.color);
            p.drawRect( cell.rect ) ;
        }

    }

    virtual void resizeEvent(QResizeEvent *event) override
    {
        Layout();
    }

    virtual void mousePressEvent(QMouseEvent *) override
    {
        pressed = true;
    }
    virtual void mouseReleaseEvent(QMouseEvent *) override
    {
        pressed = false;
    }

};

#endif // CELLWIDGET_H

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Solved How to unblock signals when mouse button is down?