QTableWidget fails to display column/row content correctly after MainWindow resize

Simula

OS: Win10 64
Qt: 5.14.2
IDE: VS2019
Hi,

I needed to implement the QTableWidget where I can drag and drop files. So made my own QDropTableWidget that inherits from QTableWidget where I then implemented dragEnterEvent(),
dragLeaveEvent(), and dropEvent().

I then placed a QTableWidget inside the layout with QDesigner and promoted it to QDropTableWidget and now I'm able to drop files inside the widget and populate the table this way.

However now I have a weird issue where the table stops displaying some rows or columns after I resize the MainWindow (and horizontal layout containing the table).
In only resets after I manually resize columns on the table. I tried to update,repain refresh table->viewPort() but the issue remains.

Here are the pictures of before and after resize:

https://imgur.com/a/Hqk7w4C

Header
```
#ifndef DROPAREA_H
#define DROPAREA_H

    #include <QTableWidget>
 
    class QMimeData;
 
    class QDropTableWidget : public QTableWidget 
    {
    	Q_OBJECT
 
     	public:
     		QDropTableWidget(QWidget *parent = 0);
 
    	public slots:
    		void clear();
 
    	signals:
    		void changed(const QMimeData *mimeData = 0);
    		void dropped(const QMimeData *mimeData = 0);
            void test(const QMimeData *mimeData);
            void OnDrop(QStringList list, int row);
 
 
    	protected:
    		void dragEnterEvent(QDragEnterEvent *event);
    		void dragMoveEvent(QDragMoveEvent *event);
    		void dragLeaveEvent(QDragLeaveEvent *event);
    		void dropEvent(QDropEvent *event);
            void resizeEvent(QResizeEvent *event) override;
 
    	private:
    		QTableWidget *tablewidget;
    };
 
    #endif

source

#include <QtGui>
    #include "qdroptablewidget.h"
    #include <qheaderview.h>
 
    QDropTableWidget::QDropTableWidget(QWidget *parent) : QTableWidget(parent) 
    {
    	//set widget default properties:
    	setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
    	setEditTriggers(QAbstractItemView::NoEditTriggers);
    	setDragDropMode(QAbstractItemView::DropOnly);
    	setAlternatingRowColors(true);
    	setShowGrid(true);
    	setWordWrap(false);
 
        QHeaderView *vh = this->verticalHeader();
        vh->setSectionResizeMode(QHeaderView::Fixed);
        vh->setDefaultSectionSize(20);
 
        setSelectionBehavior(QAbstractItemView::SelectRows);
        //setUpdatesEnabled( true ) ;
 
 
 
}
 
    void QDropTableWidget::dragEnterEvent(QDragEnterEvent *event) {
 
    	event->acceptProposedAction();
    	emit changed(event->mimeData());
    }
 
    void QDropTableWidget::dragMoveEvent(QDragMoveEvent *event) {
    	event->acceptProposedAction();
    }
 
    void QDropTableWidget::dropEvent(QDropEvent *event) 
    {
 
     	event->acceptProposedAction();
        int row = this->rowAt(event->pos().y());
 
        QStringList list;
 
          if (event->mimeData()->hasUrls())
             {
                foreach (QUrl url, event->mimeData()->urls()) 
                {
 
                 printf("%s\n",url.toString().toStdString().c_str());
                 list.push_back(url.toLocalFile());
 
               }              
             }
 
     	//emit dropped(event->mimeData());
     	emit OnDrop(list, row);
 
 
        //emit (event->mimeData());
    }
 
    void QDropTableWidget::dragLeaveEvent(QDragLeaveEvent *event) 
    {
    	event->accept();
    }
 
    void QDropTableWidget::clear() 
    {
    	emit changed();
    }
 
 
 
 
 
void QDropTableWidget::resizeEvent(QResizeEvent *event)
{
    QWidget::resizeEvent(event);
 
 
   viewport()->update();
   viewport()->repaint();
}

On drop event

void MainWindow::DropToPlayList(QStringList list, int row)  // row is the location of the row where the files are dropped
{
 if (row < 0)
     row = 0;
 
         for (int c=0;c<list.count();c++)
             {
                 ui.tablePlaylist->insertRow(row+c);
 
                 // create all items for the row
                 uint32_t duration = 0;
                 for (int i=0;i<ui.tablePlaylist->columnCount();i++)
                     {
                      ui.tablePlaylist->setItem(row+c,i, new QTableWidgetItem("")); // create all column items for row
                     }
 
 
                  ui.tablePlaylist->item(row+c,COLUMN_START_TIME)->setText("00:00:00:00");
                  ui.tablePlaylist->item(row+c,COLUMN_DURATION)->setText("duration");
                  ui.tablePlaylist->item(row+c,COLUMN_TITLE)->setText("title");
                  ui.tablePlaylist->item(row+c,COLUMN_LOCATION)->setText("location");
                  ui.tablePlaylist->item(row+c,COLUMN_CATEGORY)->setText("category");
 
            }
 
}

This only happens on promoted table widget. If I use ordinary QTableWidget resize works fine but I can't drag and drop files on to it.

Christian Ehrlicher

@Simula said in QTableWidget fails to display column/row content correctly after MainWindow resize:

QWidget::resizeEvent(event);

You must call the base class.

Simula

That was short, precise and correct.

This has been bugging me for a month. I can't believe I missed it.

Thank you.

Christian Ehrlicher

@Simula Then please mark the topic as solved :)