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Thread: Qmouseevent problem

  1. #1
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    Default Qmouseevent problem

    I read the documentation but couldn't figure out this constructor of QMouseevent
    QMouseEvent::QMouseEvent ( Type type, const QPoint & position, Qt::MouseButton button, Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers );

    I want to know what is meant by const QPoint& position in this case and what value should i provide to call the constructor

  2. #2
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    Default Re: Qmouseevent problem

    I read the documentation but couldn't figure out this constructor of QMouseevent
    what part of:
    The position is the mouse cursor's position relative to the receiving widget.
    didn't you understand?

    I want to know what is meant by const QPoint& position in this case and what value should i provide to call the constructor
    Unless you are overriding some low level Qt stuff, or some similar evil things, you should not have the need to construct your own mouse events - you should get them from the system.

    Maybe if you tell us what you want to achieve we can help you in the right direction.
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  3. The following user says thank you to high_flyer for this useful post:

    ready (21st March 2011)

  4. #3
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    Default Re: Qmouseevent problem

    actually I want to get mouse coordinate when I click in the picture that I loaded in my ui application using Qlabel

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    Default Re: Qmouseevent problem

    then you only need to overload the mouse event handler, or install and event filter on the QLabel.
    You do NOT need to create the mouse event object.
    ==========================signature=============== ==================
    S.O.L.I.D principles (use them!):
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    Do you write clean code? - if you are TDD'ing then maybe, if not, your not writing clean code.

  6. The following user says thank you to high_flyer for this useful post:

    ready (21st March 2011)

  7. #5
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    Default Re: Qmouseevent problem

    then you only need to overload the mouse event handler, or install and event filter on the QLabel.
    please elaborate your explanation .........
    how to install and event filter on the QLabel

  8. #6
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    Default Re: Qmouseevent problem

    ==========================signature=============== ==================
    S.O.L.I.D principles (use them!):
    https://en.wikipedia.org/wiki/SOLID_...iented_design)

    Do you write clean code? - if you are TDD'ing then maybe, if not, your not writing clean code.

  9. #7
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    Default Re: Qmouseevent problem

    I am getting really confused please help me how to install installEventFilter for Qlabel........
    I just want to get the co-ordinate in my lineedit when I click in qlabel

  10. #8
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    Default Re: Qmouseevent problem

    Which part of documentation is not clear to you ?
    In order to install event filter on a QLabel you need to call:
    Qt Code:
    1. MyClass * filterObject = new MyClass(); // MyClass is a subclass of QObject
    2. ...
    3. QLabel * label = new QLabel();
    4. label->installEventFilter(filterObject);
    To copy to clipboard, switch view to plain text mode 
    After that you will be able to catch all the events that goes to label object by reimplementing virtual bool eventFilter( QObject * obj, QEvent * ev ) in filterObject class:
    Qt Code:
    1. bool MyClass::eventFilter(QObject *obj, QEvent *event)
    2. {
    3. if (obj == label) {
    4. //... test if the event is MousePress and do something with it
    5. } else {
    6. // pass it to the parent class
    7. return QObject::eventFilter(obj, event);
    8. }
    9. }
    To copy to clipboard, switch view to plain text mode 
    I've almost copied the example from docs.

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