Issues writing a simple image viewer class

**Lykurg** · 26th March 2009, 22:07

Ok,

I don't have read all, but why do you want to do all the nasty work with the size thing by your own? Let Qt do the dirty work for you!

Since - I have said this this day already in an other post - QPixmap is a QPaintDevice use it! What I mean is:

store the given pixmap (gpm)
paint the gpm with transformations on a new pixmap (npm) you create
set this pixmap (npm) to the label

By doing so, you don't have to take care about all the layout stuff...

Lykurg

**ultim8** · 26th March 2009, 23:20

Originally Posted by Lykurg

Ok,

I don't have read all, but why do you want to do all the nasty work with the size thing by your own? Let Qt do the dirty work for you!

Since - I have said this this day already in an other post - QPixmap is a QPaintDevice use it! What I mean is:

store the given pixmap (gpm)
paint the gpm with transformations on a new pixmap (npm) you create
set this pixmap (npm) to the label

By doing so, you don't have to take care about all the layout stuff...
Lykurg

I've thought about that... but then I would have to store two copies of the image (one in my pixmap and one in the QLabel). Also I would have to copy the pixmap to the QLabel whenever I made a new transformation (I would imagine this would be an expensive operation if I were to animate my transformations).

By doing it in the method I'm attempting I don't have any of those issues. I store one pixmap... and I paint that one pixmap with the desired transformations onto the widget.

Instead of suggesting other options I would prefer some help with why my method is not working (unless people have suggestions that don't include QLabel

)

**ultim8** · 27th March 2009, 13:50

Turns out my issue was really trivial. When adding an image to a scroll area you need to call setWidgetResizable to true... otherwise the widget is never resized:

Qt Code:

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