breeze/kstyle/breezeblurhelper.cpp

//////////////////////////////////////////////////////////////////////////////
// breezeblurhelper.cpp
// handle regions passed to kwin for blurring
// -------------------
//
// SPDX-FileCopyrightText: 2018 Alex Nemeth <alex.nemeth329@gmail.com>
//
// Largely rewritten from Oxygen widget style
// SPDX-FileCopyrightText: 2007 Thomas Luebking <thomas.luebking@web.de>
// SPDX-FileCopyrightText: 2010 Hugo Pereira Da Costa <hugo.pereira@free.fr>
//
// SPDX-License-Identifier: MIT
//////////////////////////////////////////////////////////////////////////////

#include "breezeblurhelper.h"
#include "breezestyleconfigdata.h"

#include <KWindowEffects>

#include <QEvent>
#include <QVector>

namespace Breeze
{
    //___________________________________________________________
    BlurHelper::BlurHelper(QObject* parent):
        QObject(parent)
    {
    }

    //___________________________________________________________
    void BlurHelper::registerWidget(QWidget* widget)
    {
        // install event filter
        addEventFilter(widget);

        // schedule shadow area repaint
        update(widget);
    }

    //___________________________________________________________
    void BlurHelper::unregisterWidget(QWidget* widget)
    {
        // remove event filter
        widget->removeEventFilter(this);
    }

    //___________________________________________________________
    bool BlurHelper::eventFilter(QObject* object, QEvent* event)
    {
        switch (event->type()) {
            case QEvent::Hide:
            case QEvent::Show:
            case QEvent::Resize:
            {
                // cast to widget and check
                QWidget* widget(qobject_cast<QWidget*>(object));

                if (!widget)
                    break;

                update(widget);
                break;
            }

            default: break;
        }

        // never eat events
        return false;
    }

    //___________________________________________________________
    void BlurHelper::update(QWidget* widget) const
    {
        /*
        directly from bespin code. Supposedly prevent playing with some 'pseudo-widgets'
        that have winId matching some other -random- window
        */
        if (!(widget->testAttribute(Qt::WA_WState_Created) || widget->internalWinId()))
            return;

        widget->winId(); // force creation of the window handle
        KWindowEffects::enableBlurBehind(widget->windowHandle(), true);

        // force update
        if (widget->isVisible()) {
            widget->update();
        }
    }
}