Zooming scene Rect(Qt bug?)

[Bitto]

maverick_pol, please just send a compilable self-contained example, and the bug is likely to be revealed right away. It's hard to debug code that's translated to english.

[maverick_pol]

Hi,

I can't send you the code as I do not have permision to do so. I will send the (rectangle/size/etc) within 15 minutes.

Here it is:

The code I am using to print values:

// the given _rectangle for zooming
qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
m_view->fitInView(_rectangle,Qt::KeepAspectRatio); // or Qt::KeepAspectRatioBy expanding
// Scene rectangle	
_rectangle = m_view->sceneRect();	qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
// scene rectangle(from view)
_rectangle = m_scene->sceneRect();	qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
// view size
qDebug()<<m_view->size().height()<<m_view->size().width();
//view matrix
qDebug()<<m_view->matrix().m11()<<m_view->matrix().m12()<<m_view->matrix().m21()<<m_view->matrix().m22()<<m_view->matrix().det()<<m_view->matrix().dx()<<m_view->matrix().dy();

// the given _rectangle for zooming
qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
m_view->fitInView(_rectangle,Qt::KeepAspectRatio); // or Qt::KeepAspectRatioBy expanding
// Scene rectangle	
_rectangle = m_view->sceneRect();	qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
// scene rectangle(from view)
_rectangle = m_scene->sceneRect();	qDebug()<<(_rectangle.bottomLeft().rx())<<(_rectangle.bottomLeft().ry());
qDebug()<<(_rectangle.bottomRight().rx())<<(_rectangle.bottomRight().ry());
qDebug()<<(_rectangle.topLeft().rx())<<(_rectangle.topLeft().ry());
qDebug()<<(_rectangle.topRight().rx())<<(_rectangle.topRight().ry());
// view size
qDebug()<<m_view->size().height()<<m_view->size().width();
//view matrix
qDebug()<<m_view->matrix().m11()<<m_view->matrix().m12()<<m_view->matrix().m21()<<m_view->matrix().m22()<<m_view->matrix().det()<<m_view->matrix().dx()<<m_view->matrix().dy();

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HEre is the result:

-172 38
78 38
-172 -112
78 -112
-50 80
50 80
-50 50
50 50
-50 80
50 80
-50 50
50 50
660 1224
4.34667 0 0 4.34667 18.8935 0 0

QGraphicsScene::removeItem: item 01F45440's scene (00000000) is different from this scene (01AB88D8)

-51.3037 67.408
11.1963 67.408
-51.3037 29.908
11.1963 29.908
-50 80
50 80
-50 50
50 50
-50 80
50 80
-50 50
50 50
660 1224
17.3867 0 0 17.3867 302.296 0 0

QGraphicsScene::removeItem: item 01E9E968's scene (00000000) is different from this scene (01AB88D8)

-30.8857 57.2278
-15.2607 57.2278
-30.8857 47.8528
-15.2607 47.8528
-50 80
50 80
-50 50
50 50
-50 80
50 80
-50 50
50 50
660 1224
67.84 0 0 67.84 4602.27 0 0

QGraphicsScene::removeItem: item 01F78660's scene (00000000) is different from this scene (01AB88D8)

-19.487 52.5501
-15.5808 52.5501
-19.487 50.2064
-15.5808 50.2064
-50 80
50 80
-50 50
50 50
-50 80
50 80
-50 50
50 50
660 1224
271.36 0 0 271.36 73636.2 0 0

I have used zoom In 4 times here and after the second Zoom IN my widgets(created with m_view->viewport() as the parent) moved left. I tried to recreate the widgets after zooming In (removing items and addint them once again) that's why I get the "removeITem" warning.

Maverick

[wysota]

Looks like I was right from the very beginning - scene coordinates seem incorrect.

BTW. You could have formatted the output better, you know...

[maverick_pol]

Hi,

I will format the INPUT correctly. Sound good that you were right, but I still do not know what is the problem. Could you explain it to me?
When I use (scale() and fitInView() ) function the coordinates system changes, what kind of incorrectness you're seeing here?
I really appreciate your help in this thread.

Maverick

[wysota]

Take a look at the coordinates of the zooming rect, the scene and the view during first two zooms. If you have trouble, take a piece of paper and draw the rectangles, taking a closer look at how they intersect each other. Only during the last two sets of coordinates the zooming rectangle is smaller than the scene. A nice thing to have would be to know the bounding rect of all the items in the scene as well...

You should really try with a minimal compilable example as asked at the beginning... Or provide actual code - we won't steal it

[maverick_pol]

Hi,

Here is the piece of code I am using ( it's 100% what I have in my application(the part connected with gview framework).
After choosing the Zoom in from the Context menu and once again clicking left mouse button the rectangle appears and can be moved with the cursor and resized while pressing the right mouse button.
(There are 2 windows, the one with the gview is mine; other is not used)

My "Panels"(in the fungc class) should be at the same place while zooming, but are moving.
also in the begining(while zooming for first 2...4 times the center of the scene is zoomed not the rectangle).

If you have any ideas I would appreciate your help.

P.S. I have compiled/run this code using Qt 4.3.1 under win32

Maverick

[maverick_pol]

Hi guys,

Any ideas what can be the problem?(wrong zooming rectangle and moving Panels(labels))

Maverick

[pdolbey]

I'm not really a QGraphicsView expert and I've only got 4.2.1 at work so I had to hack out some of the hints, but you might find that the odd "update();" at the end of your zoomin, zoomout and mousemove routines might help a bit.

Pete

[maverick_pol]

all ideas are usefull.

I will try using "update()" and give you the result, but this probably will not solve all the problems.

Maverick