Getting problem in drag and drop of thumbnail image inside the image view?

amarism

I want to use drag and drop event inside my project. Where I have a list widget as( Thumbnails). and I want to drag an image from the thumbnail and drop inside the grid layout as (QVTKOpenGlWidget). I will make a file QOpenGLWidgetDrag.cpp and inherit this QOpenGlWidget.cpp.

QOpenGLWidgetDrag.h

class QvtkOpenGLWidgetdrag : public QOpenGLWidget
{
	Q_OBJECT
public:
	explicit QvtkOpenGLWidgetdrag(QWidget *parent = nullptr);

protected:
	void dropEvent(QDropEvent *event) override ;
	//QvtkOpenGLWidgetdrag * New();
	void dragEnterEvent(QDragEnterEvent *event) override;
	void paintGL() override;

private:
	QPixmap m_pixmap;
};

QOpenGLWidgetDrag.cpp

void QvtkOpenGLWidgetdrag::dragEnterEvent(QDragEnterEvent *event)
{
	QOpenGLWidget::dragEnterEvent(event);
	event->accept();
}

void QvtkOpenGLWidgetdrag::dropEvent(QDropEvent *event)
{
	const QMimeData *mimeData = event->mimeData();

	if (mimeData->hasFormat("application/x-qabstractitemmodeldatalist")) {
		QByteArray encoded = mimeData->data("application/x-qabstractitemmodeldatalist");
		QDataStream stream(&encoded, QIODevice::ReadOnly);

		while (!stream.atEnd()) {
			int row;
			int col;
			QMap<int, QVariant> roleDataMap;


			stream >> row >> col >> roleDataMap;

			// QString name = roleDataMap.value(0).toString();
			QIcon icon = roleDataMap.value(1).value<QIcon>();

			m_pixmap = icon.pixmap(icon.availableSizes().first());

			update();
		}
	}
	else {
		event->ignore();
	}
}

void QvtkOpenGLWidgetdrag::paintGL()
{
	QPainter painter(this);

	painter.drawPixmap(500, 250, m_pixmap);
}

I will ask the same question in stack overflow also. link:-https://stackoverflow.com/questions/51966584/qt-drag-and-drop-image-from-thumbnail-to-gridlayout-qvtkopenglwidget

But this one code not reflecting anything inside my project.

Please help me

Thanks in advance

anil_arise

I think you can get idea from this sample code. its works on drag and drop...

QListWidget *listWidget = new QListWidget;
listWidget->setAcceptDrops(true);
listWidget->setDragEnabled(true);
listWidget->setDragDropMode(QAbstractItemView::InternalMove);
listWidget->setDropIndicatorShown(true);
listWidget->setUpdatesEnabled(true);

QStringList img_list; // list of path of all images
img_list<<":/images/red.jpg";
img_list<<":/images/green.jpg";

for(int i=0;i<img_list.size();i++)
{
    QListWidgetItem *item=new QListWidgetItem;
    item->setIcon(QIcon(img_list.at(i)));
    listWidget->insertItem(i,item);
    listWidget->setCurrentRow(i);
}
listWidget->show();

amarism

@anil_arise Sorry I m not getting this one code

anil_arise

@amarism you checked it or not this Git code

amarism

@anil_arise this one working inside the QT but when the same thing i will apply inside my project it will not working.
So, Now my question is can i write this one code inside the my mainwindow.cpp file insist of making new file .

anil_arise

@amarism your code is working just change this line
painter.drawPixmap(500, 250, m_pixmap); beccause out of range
use in widget range
painter.drawPixmap(100, 100, m_pixmap);

amarism

@anil_arise still this one not working

anil_arise

@amarism can you show your widget structure. where are you design.?

amarism

@anil_arise I have added new file as QvtkOpenGLWidgetDrag.cpp/.h and inherit the QOpenGLWidget and i will displaying everything through mainwindiw.cpp. So, I will add the drag class inside the mainwindow.h. But were i will calling this file QvtkOpenGLWidgetDrag.cpp/.h throung mainwindow.cpp

anil_arise

@amarism when your are create and initialize your widget in mainwindow.cpp

example
auto *viewTopLeft = new OpenGlWidget(this);
layoutGrid->addWidget(viewTopLeft, 0, 0);

amarism

@anil_arise I will directly create view port through Qt. statistically creating port not dynamically

anil_arise

@amarism @amarism it should be create dynamically. and add to layout

amarism

@anil_arise everything i am take as a static inside the QT so how i am going to create dynamically on view port. inside the view port i am added slider also

anil_arise

@amarism Again I said ,create and initialization of these 4 widgets you can use dynamically in your project. you can also add slider dynamically.

amarism

@anil_arise Can i do the same thing in statically or not

anil_arise

@amarism No , How can you connect your statically created OpenGlWidget to dynamically created OpenGlWidget class..
try this mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <openglwidget.h>
#include <QSlider>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
auto *viewTopLeft = new OpenGlWidget(this);
auto *viewTopRight = new OpenGlWidget(this);
auto *viewBottomLeft = new OpenGlWidget(this);
auto *viewBottomRight = new OpenGlWidget(this);

ui->listWidget->addItem(new QListWidgetItem(QIcon(":/images/red.jpg"), tr("Item 1")));
ui->listWidget->addItem(new QListWidgetItem(QIcon(":/images/green.jpg"), tr("Item 2")));
ui->listWidget->addItem(new QListWidgetItem(QIcon(":/images/stop.png"), tr("Item 3")));
ui->listWidget->setViewMode(QListWidget::IconMode);
ui->listWidget->setIconSize(QSize(50, 50));
ui->listWidget->setGridSize(QSize(65, 65));
ui->listWidget->setMaximumWidth(100); //already set by statically


QSlider *slider1=new QSlider;
slider1->setRange(0,100);
slider1 ->setOrientation(Qt::Horizontal);
QSlider *slider2=new QSlider;
slider2->setRange(0,100);
slider2 ->setOrientation(Qt::Horizontal);
QSlider *slider3=new QSlider;
slider3->setRange(0,100);
slider3 ->setOrientation(Qt::Horizontal);
QSlider *slider4=new QSlider;
slider4->setRange(0,100);
slider4 ->setOrientation(Qt::Horizontal);

ui->gridLayout->addWidget(viewTopLeft, 0, 0);
ui->gridLayout->addWidget(viewTopRight, 0, 1);
ui->gridLayout->addWidget(slider1, 1, 0);
ui->gridLayout->addWidget(slider2, 1, 1);
ui->gridLayout->addWidget(viewBottomLeft, 2, 0);
ui->gridLayout->addWidget(viewBottomRight, 2, 1);
ui->gridLayout->addWidget(slider3, 3, 0);
ui->gridLayout->addWidget(slider4, 3, 1);

}

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

amarism

@anil_arise This one all are there in my ui just can i write only drag n drop event

anil_arise

@amarism just replace your static openGLWidget with thisss

auto *viewTopLeft = new OpenGlWidget(this);
auto *viewTopRight = new OpenGlWidget(this);
auto *viewBottomLeft = new OpenGlWidget(this);
auto *viewBottomRight = new OpenGlWidget(this);

amarism

@anil_arise But how i will set the position for every view port

anil_arise

@amarism by using LAYOUT