Has anyone made scrollarea zoom with widget

  • The scrollarea works with a label, both scrolling and zooming. Using a widget it will scroll, but not zoom. The problem seems to be with:

    mageLabel->resize(scaleFactor * imageLabel->pixmap()->size());

    Widget does not resize.

    Has anyone found what changes must be made to widget to get it to work? Label has a method to set the contents scaleable, but widget has no such method.

  • Lifetime Qt Champion


    You should show the complete setup of your widgets.

  • Lifetime Qt Champion

    I assume its the scrollarea i help with so im pretty sure you are using a layout.
    When a QWidget is controlled by a layout,
    setGeometry and resize are ignore as layout controls sizes.
    You can however use
    setMinimumSize(QSize( w,h ) ) to make the widget be bigger.

  • @mrjj Thanks. I thought it had something to do with the layout. I changed the minimumSize from 20,000x10,000 to 200x100, all of the pixmap was visible and zooming worked, sorta--lost the scrollbars. However, headway has been made.

    In looking at the QLabel source, I noted that on line 1094 the pixmap is converted to an QImage object scaled and converted back to a pixmap. I am assuming that it was done for performance reasons.

  • @ofmrew Just a note for others interested in source code, use wobog because it will help you navigate through the code. Nice!

  • Hello Everyone,
    I'm learning Qt as a beginner, I stuck in one query that how can i set image in Scrollarea UI??

  • Lifetime Qt Champion

    Hi and welcome
    I you can place a QLabel on it and set its Pixmap property to an image.

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