CODEWITHSUNDEEP
c++qtdrag-and-dropqt5
sofname
sofname

Reputation: 441

Qt Drop event not firing

Drop event will not happen, although `setAcceptDrops' has been called. The following code is based on a widget project created with Qt 5.12.0. After adding in dropEvent() function the cpp file becomes

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug> // added

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setAcceptDrops(true); // added
}

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

// added; in .h it is in `protected:' section
void MainWindow::dropEvent(QDropEvent *event)
{
    qDebug() << "dropEvent";
}

What am I missing? I have been struggling for a few days... Thanks in advance.

Upvotes: 2

Views: 3827

Answers (2)

user20088022
user20088022

Reputation: 1

I had the same issue and found out what was causing it. In my case, it was because I was trying to drag and drop a file onto a QTextEdit widget instead of the MainWindow. As it turns out, nothing happens because the dragEnterEvent and dropEvent functions are defined for MainWindow and not for QTextEdit.

Upvotes: 0

eyllanesc
eyllanesc

Reputation: 244311

You have to overwrite the dragEnterEvent method that allow you to filter by the data type, by the source, by the type of action. In the following example, everything is accepted:

*.h

// ...
protected:
    void dropEvent(QDropEvent *event) override;
    void dragEnterEvent(QDragEnterEvent *event) override;
// ...

*.cpp

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setAcceptDrops(true); // added
}

// ...
void MainWindow::dropEvent(QDropEvent *event)
{
    qDebug() << "dropEvent" << event;
}
void MainWindow::dragEnterEvent(QDragEnterEvent *event)
{
    event->acceptProposedAction();
}

For more detail I recommend you read Drag and Drop.

Upvotes: 4

Related Questions