How could I use the QColorDialog inside another widget not as a separate dialog?

Question

I would like to use QColorDialog not as a dialog window but as a widget which I could insert into a layout. (More specifically as a custom sub menu in a context menu)

I looked into the QColorDialog sourcecode, and I could probably copy over a part of the internal implementation of the QColorDialog to achieve this, but is there a cleaner way to do this? I am using Qt 4.5.1...

Solution 1

If there's a way to do this cleanly, I'm not aware of it. As I see it, you have a couple of options:

• Subclass it and copy the code that actually constructs the widget, making edits to remove the part that creates the dialog window and replace it with some other container.
• If you're not dead-set on using that particular dialog, the color triangle widget from qt solutions might work, because it isn't a dialog window. You can find it at http:// doc.trolltech.com/solutions/4/qtcolortriangle/qtcolortriangle.html (remove the space from the link)

Solution 2

QColorDialog is a dialog which means IT IS a widget. All you need to do is set a few window flags and drop it into your layout as you wish. Here is a (tested) example:

#include <QApplication>
#include <QMainWindow>
#include <QColorDialog>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    /* setup a quick and dirty window */
    QMainWindow app;
    app.setGeometry(250, 250, 600, 400);

    QColorDialog *colorDialog = new QColorDialog(&app);
    /* set it as our widiget, you can add it to a layout or something */
    app.setCentralWidget(colorDialog);
    /* define it as a Qt::Widget (SubWindow would also work) instead of a dialog */
    colorDialog->setWindowFlags(Qt::Widget);
    /* a few options that we must set for it to work nicely */
    colorDialog->setOptions(
                /* do not use native dialog */
                QColorDialog::DontUseNativeDialog
                /* you don't need to set it, but if you don't set this
                    the "OK" and "Cancel" buttons will show up, I don't
                    think you'd want that. */
                | QColorDialog::NoButtons
    );

    app.show();
    return a.exec();
}

Solution 3

You can do it clean in a very simple way by setting right window flags.

QColorDialog8 colorDialog = new ....
colorDialog->setWindowFlags(Qt::SubWindow);

Solution 4

You might want to look at some Qt Solutions, which will do at least part of what you want. For example, see the Color Picker solution, which they note is now available as an LGPL-licensed library also.

As an alternative (and probably less-supported) approach, I recall some work in the Qt-Labs about embedding Qt widgets, including QDialogs, into a QGraphicsScene. You could potentially do so, then change the view on your graphics scene so that only the portion of the color picker dialog you are interested in was visible to the user. It sounds very hackish, however.

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Comments

[metal]

Worked like a charm for me. See my answer below for some further hints about making it work in a menu.

[Wiz]

Just a note that your modified code is no longer Qt4 as this question is tagged with.

[metal]

Right. Besides the connect() calls which require a slightly different syntax to use lambdas for the slots, do you notice any other incompatibilities?