[SOLVED] Resizable (by mouse) QFrame

[kripton]

Hi,
I'm trying to implement a QFrame that can be resized and dragged around using the mouse. Having googled around a bit and found nothing, I started to implement the thing a bit low-level. Dragging around is working, however resizing doesn't really work. Now before I put too much effort into that: Is there another way I could go? Maybe Qt does offer a widget that does just what I need but somehow I missed it?
Here's what I have up to now (a complete demo project can be uploaded if it helps):

EDIT: code removed, see my solution in later post

[steno]

Who is the parent to the resizableFrame? Is it in a layout, or maybe a central widget in a QMainWindow?

[kripton]

I'm currently developing it as the central widget in a QMainWindow but the usecase later will have another (not resizable) QFrame as parent. That one will be used in some kind of layout I yet need to think about :)
The inner (resizable) frames are not meant to be moved outside their parent QFrame.

Does it make any difference who/what the parent-object is?

[steno]

[quote author="kripton" date="1358957005"]Does it make any difference who/what the parent-object is?[/quote]

No it doesn't, it just gives me an idea of how you were using the widget. Setting the resizableFrame as a central widget actually puts the widget into a layout in the main window. Calling setGeometry on a widget in a layout is counter productive because the layout system will fight with you.

You can try calling updateGeometry(), and then in the sizeHint() function return a size bigger than it currently is to force it to grow.

[kripton]

Here's how it's solved (not actually hard, just needs a bit of thinking):
[code]#include "resizableframe.h"

#include <QDebug>

ResizableFrame::ResizableFrame(QWidget *parent) :
QFrame(parent)
{
setMouseTracking(true);
}

ResizableFrame::~ResizableFrame()
{
}

void ResizableFrame::mousePressEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton) {
dragStartPosition = event->pos();
dragStartGeometry = geometry();
}
}

void ResizableFrame::mouseMoveEvent(QMouseEvent *event)
{
if (!(event->buttons() & Qt::LeftButton)) {
// No drag, just change the cursor and return

    if (event->x() <= 3 && event->y() <= 3) {
        startPos = topleft;
        setCursor(Qt::SizeFDiagCursor);
    } else if (event->x() <= 3 && event->y() >= height() - 3) {
        startPos = bottomleft;
        setCursor(Qt::SizeBDiagCursor);
    } else if (event->x() >= width() - 3 && event->y() <= 3) {
        startPos = topright;
        setCursor(Qt::SizeBDiagCursor);
    } else if (event->x() >= width() - 3 && event->y() >= height() - 3) {
        startPos = bottomright;
        setCursor(Qt::SizeFDiagCursor);
    } else if (event->x() <= 3) {
        startPos = left;
        setCursor(Qt::SizeHorCursor);
    } else if (event->x() >= width() - 3) {
        startPos = right;
        setCursor(Qt::SizeHorCursor);
    } else if (event->y() <= 3) {
        startPos = top;
        setCursor(Qt::SizeVerCursor);
    } else if (event->y() >= height() - 3) {
        startPos = bottom;
        setCursor(Qt::SizeVerCursor);
    } else {
        startPos = move;
        setCursor(Qt::SizeAllCursor);
    }
    return;
}

switch (startPos) {
case topleft:
    setGeometry(dragStartGeometry.left() - (dragStartPosition.x() - event->x()),
                dragStartGeometry.top() - (dragStartPosition.y() - event->y()),
                dragStartGeometry.width() + (dragStartPosition.x() - event->x()),
                height() + (dragStartPosition.y() - event->y()));
    dragStartGeometry = geometry();
    break;

case bottomleft:
    setGeometry(dragStartGeometry.left() - (dragStartPosition.x() - event->x()),
                dragStartGeometry.top(),
                dragStartGeometry.width() + (dragStartPosition.x() - event->x()),
                event->y());
    dragStartGeometry = geometry();
    break;

case topright:
    setGeometry(dragStartGeometry.left(),
                dragStartGeometry.top() - (dragStartPosition.y() - event->y()),
                event->x(),
                height() + (dragStartPosition.y() - event->y()));
    dragStartGeometry = geometry();
    break;

case bottomright:
    setGeometry(dragStartGeometry.left(),
                dragStartGeometry.top(),
                event->x(),
                event->y());
    break;

case left:
    setGeometry(dragStartGeometry.left() - (dragStartPosition.x() - event->x()),
                dragStartGeometry.top(),
                dragStartGeometry.width() + (dragStartPosition.x() - event->x()),
                height());
    dragStartGeometry = geometry();
    break;

case right:
    setGeometry(dragStartGeometry.left(),
                dragStartGeometry.top(),
                event->x(),
                height());
    break;

case top:
    setGeometry(dragStartGeometry.left(),
                dragStartGeometry.top() - (dragStartPosition.y() - event->y()),
                dragStartGeometry.width(),
                height() + (dragStartPosition.y() - event->y()));
    dragStartGeometry = geometry();
    break;

case bottom:
    setGeometry(dragStartGeometry.left(),
                dragStartGeometry.top(),
                width(),
                event->y());
    break;

case move:
    setGeometry(dragStartGeometry.left() - (dragStartPosition.x() - event->x()),
                dragStartGeometry.top() - (dragStartPosition.y() - event->y()),
                width(),
                height());
    dragStartGeometry = geometry();
    break;

default:
    break;
}

}
[/code]

[tesmai4]

Thanks for posting reply for sharing purpose.
I tried using it, stuck at datatype of "startPos". Can you mention that?

[kripton]

True, you can't know that one. For completeness, here's the resizableframe.h file:
[code]
#ifndef RESIZABLEFRAME_H
#define RESIZABLEFRAME_H

#include <QFrame>
#include <QMouseEvent>

class ResizableFrame : public QFrame
{
Q_OBJECT

public:
explicit ResizableFrame(QWidget *parent = 0);
~ResizableFrame();

enum startPositions {topleft, left, bottomleft, bottom, bottomright, right, topright, top, move} startPositions;

protected:
void mousePressEvent(QMouseEvent event);
void mouseMoveEvent(QMouseEvent event);

private:
QPoint dragStartPosition;
QRect dragStartGeometry;
enum startPositions startPos;
};

#endif // RESIZABLEFRAME_H
[/code]