QT GraphicsView Help

[mistertoony]

Qt will automatically add a scrollbar if the QGraphicsScene/View is too big for the current window. In your example, you would either want to move your horizontal labels inside the scene so that they get scrolled too, or you would have to subclass the scrollbar so that when it moved your label would change.

mAx

the above example is a QWT plot. when you say that Qt will automatically add a scrollbar in the GraphicsScene/View is too big, did you mean that this was also true for QWT. because the QWT plot appears to stay in a fixed restraints without a scrollbar.

[maxpower]

I am talking about QGraphicsScene/View. I have no idea about qwt.

mAx

[Uwe]

Have a look at the realtime example, that is included in the Qwt package. It shows how to add scrollbars to a plot. ( they appear, when you zoom in. ). Guess you can copy and use the ScrollZoomer class, like it is.

Instead of scrollbars you could also use wheels, what is demonstated in the eventfilter example. Another option for navigation is panning (QwtPlotPanner). The bode example shows how to combine zooming and panning.

HTH,
Uwe

[mistertoony]

has anyone done plotting with QPolygonF or QPainterPath? i am having trouble understanding the coordinate system. for instance, if i use the following function:

void QPainterPath::lineTo ( qreal x, qreal y )

lineTo(1,4); how does this actually work? because it seems to be upside or something?

[aamer4yu]

did u use moveTo() before lineTo() ??

[mistertoony]

did u use moveTo() before lineTo() ??

yes i did. does the QGraphicsScene rely on the cartesian coordinate system? because something is really messed up.

[aamer4yu]

may be you are confusing the cordinate systems...
cartesian systems start from bottom left.... while painting in devices has a cordinate system starting from top left

i guess u r getting the result upside down on Y axis ??