How to "Re-Polish" QApplication with Same Style?

Upon my qt5 application's initialization, the QApplication instance is provided with a custom style class that inherits from QProxyStyle.

This class overwrites the void polish(QPalette &palette) function in order to change the general color scheme for the application.

For example:

#include "mycolormanager.h"

void MyStyle::polish(QPalette &palette) {
    palette.setBrush(QPalette::Window, MyColorManager::getWindowColor());
    palette.setColor(QPalette::WindowText, MyColorManager::getTextColor());
    palette.setColor(QPalette::Disabled, QPalette::WindowText, MyColorManager::getDisabledTextColor());
    palette.setColor(QPalette::Base, MyColorManager::getBaseColor());
    // etc...
}

However, I wish to allow users to customize the color scheme of the application. Once the user has selected new colors, I need someway to "reapply" the style, so the function can run again and obtain the new colors from the hypothetical "color manager" class.

How would this be done?

Solution

Instead you can call below static function and apply the desired palette.

void QApplication::setPalette(const QPalette &palette, const char *className = nullptr);

Create the new palette object after selecting the new color scheme and just pass it to above function. You can specify classname, if you want the change to apply for a specific widget.