DragWidget Class Reference

#include <dragwidget.h>

Inheritance diagram for DragWidget:

[legend]Collaboration diagram for DragWidget:

[legend]List of all members.

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Detailed Description

Definition at line 32 of file dragwidget.h.

Public Member Functions
	DragWidget (QWidget *parent=0)
	DragWidget (QWidget *parent=0)
	DragWidget (QWidget *parent=0)
Protected Member Functions
void	dragEnterEvent (QDragEnterEvent *event)
void	dropEvent (QDropEvent *event)
void	mousePressEvent (QMouseEvent *event)
void	dragEnterEvent (QDragEnterEvent *event)
void	dropEvent (QDropEvent *event)
void	dragMoveEvent (QDragMoveEvent *event)
void	dragEnterEvent (QDragEnterEvent *event)
void	dragMoveEvent (QDragMoveEvent *event)
void	dropEvent (QDropEvent *event)

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Constructor & Destructor Documentation

DragWidget::DragWidget

(

QWidget *

parent = 0

)

Definition at line 28 of file dragwidget.cpp.

References QWidget::move(), QWidget::QPixmap, QWidget::setAcceptDrops(), QWidget::setAttribute(), QFrame::setFrameStyle(), QWidget::setMinimumSize(), QLabel::setPixmap(), QWidget::show(), QFrame::StyledPanel, QFrame::Sunken, and Qt::WA_DeleteOnClose.

    : QFrame(parent)
{
    setMinimumSize(200, 200);
    setFrameStyle(QFrame::Sunken | QFrame::StyledPanel);
    setAcceptDrops(true);

    QLabel *boatIcon = new QLabel(this);
    boatIcon->setPixmap(QPixmap(":/images/boat.png"));
    boatIcon->move(20, 20);
    boatIcon->show();
    boatIcon->setAttribute(Qt::WA_DeleteOnClose);

    QLabel *carIcon = new QLabel(this);
    carIcon->setPixmap(QPixmap(":/images/car.png"));
    carIcon->move(120, 20);
    carIcon->show();
    carIcon->setAttribute(Qt::WA_DeleteOnClose);

    QLabel *houseIcon = new QLabel(this);
    houseIcon->setPixmap(QPixmap(":/images/house.png"));
    houseIcon->move(20, 120);
    houseIcon->show();
    houseIcon->setAttribute(Qt::WA_DeleteOnClose);
}

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DragWidget::DragWidget

(

QWidget *

parent = 0

)

DragWidget::DragWidget

(

QWidget *

parent = 0

)

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Member Function Documentation

void DragWidget::dragEnterEvent

(

QDragEnterEvent *

event

)

[protected, virtual]

This event handler is called when a drag is in progress and the mouse enters this widget. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDragEnterEvent

Reimplemented from QWidget.

Definition at line 54 of file dragwidget.cpp.

References QWidget::event(), and Qt::MoveAction.

{
    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
        if (event->source() == this) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else {
        event->ignore();
    }
}

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void DragWidget::dropEvent

(

QDropEvent *

event

)

[protected, virtual]

This event handler is called when the drag is dropped on this widget which are passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDropEvent

Reimplemented from QWidget.

Definition at line 68 of file dragwidget.cpp.

References QWidget::event(), QWidget::move(), Qt::MoveAction, QIODevice::ReadOnly, QWidget::setAttribute(), QLabel::setPixmap(), QWidget::show(), and Qt::WA_DeleteOnClose.

{
    if (event->mimeData()->hasFormat("application/x-dnditemdata")) {
        QByteArray itemData = event->mimeData()->data("application/x-dnditemdata");
        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
        
        QPixmap pixmap;
        QPoint offset;
        dataStream >> pixmap >> offset;

        QLabel *newIcon = new QLabel(this);
        newIcon->setPixmap(pixmap);
        newIcon->move(event->pos() - offset);
        newIcon->show();
        newIcon->setAttribute(Qt::WA_DeleteOnClose);

        if (event->source() == this) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else {
        event->ignore();
    }
}

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void DragWidget::mousePressEvent

(

QMouseEvent *

event

)

[protected, virtual]

This event handler, for event event, can be reimplemented in a subclass to receive mouse press events for the widget.

If you create new widgets in the mousePressEvent() the mouseReleaseEvent() may not end up where you expect, depending on the underlying window system (or X11 window manager), the widgets' location and maybe more.

The default implementation implements the closing of popup widgets when you click outside the window. For other widget types it does nothing.

See also:

mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), event(), QMouseEvent, {Scribble Example}

Reimplemented from QWidget.

Definition at line 95 of file dragwidget.cpp.

References QPainter::begin(), QWidget::childAt(), QWidget::close(), Qt::CopyAction, QPainter::end(), QWidget::event(), QPainter::fillRect(), Qt::MoveAction, QLabel::pixmap(), QWidget::pos(), QPixmap::rect(), QDrag::setHotSpot(), QDrag::setMimeData(), QLabel::setPixmap(), QDrag::setPixmap(), QWidget::show(), QDrag::start(), and QIODevice::WriteOnly.

{
    QLabel *child = static_cast<QLabel*>(childAt(event->pos()));
    if (!child)
        return;

    QPixmap pixmap = *child->pixmap();

    QByteArray itemData;
    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
    dataStream << pixmap << QPoint(event->pos() - child->pos());

    QMimeData *mimeData = new QMimeData;
    mimeData->setData("application/x-dnditemdata", itemData);
        
    QDrag *drag = new QDrag(this);
    drag->setMimeData(mimeData);
    drag->setPixmap(pixmap);
    drag->setHotSpot(event->pos() - child->pos());

    QPixmap tempPixmap = pixmap;
    QPainter painter;
    painter.begin(&tempPixmap);
    painter.fillRect(pixmap.rect(), QColor(127, 127, 127, 127));
    painter.end();

    child->setPixmap(tempPixmap);

    if (drag->start(Qt::CopyAction | Qt::MoveAction) == Qt::MoveAction)
        child->close();
    else {
        child->show();
        child->setPixmap(pixmap);
    }
}

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void DragWidget::dragEnterEvent

(

QDragEnterEvent *

event

)

[protected, virtual]

This event handler is called when a drag is in progress and the mouse enters this widget. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDragEnterEvent

Reimplemented from QWidget.

void DragWidget::dropEvent

(

QDropEvent *

event

)

[protected, virtual]

This event handler is called when the drag is dropped on this widget which are passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDropEvent

Reimplemented from QWidget.

void DragWidget::dragMoveEvent

(

QDragMoveEvent *

event

)

[protected, virtual]

This event handler is called if a drag is in progress, and when any of the following conditions occurs: the cursor enters this widget, the cursor moves within this widget, or a modifier key is pressed on the keyboard while this widget has the focus. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDragMoveEvent

Reimplemented from QWidget.

Definition at line 77 of file dragwidget.cpp.

References QObject::children(), and QWidget::event().

{
    if (event->mimeData()->hasText()) {
        if (children().contains(event->source())) {
            event->setDropAction(Qt::MoveAction);
            event->accept();
        } else {
            event->acceptProposedAction();
        }
    } else {
        event->ignore();
    }
}

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void DragWidget::dragEnterEvent

(

QDragEnterEvent *

event

)

[protected, virtual]

This event handler is called when a drag is in progress and the mouse enters this widget. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDragEnterEvent

Reimplemented from QWidget.

void DragWidget::dragMoveEvent

(

QDragMoveEvent *

event

)

[protected, virtual]

This event handler is called if a drag is in progress, and when any of the following conditions occurs: the cursor enters this widget, the cursor moves within this widget, or a modifier key is pressed on the keyboard while this widget has the focus. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDragMoveEvent

Reimplemented from QWidget.

void DragWidget::dropEvent

(

QDropEvent *

event

)

[protected, virtual]

This event handler is called when the drag is dropped on this widget which are passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also:

QTextDrag, QImageDrag, QDropEvent

Reimplemented from QWidget.

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The documentation for this class was generated from the following files:

• examples/draganddrop/draggableicons/dragwidget.h
• examples/draganddrop/draggabletext/dragwidget.h
• examples/draganddrop/fridgemagnets/dragwidget.h
• examples/draganddrop/draggableicons/dragwidget.cpp
• examples/draganddrop/draggabletext/dragwidget.cpp
• examples/draganddrop/fridgemagnets/dragwidget.cpp

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