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qt-plugins/widgetstyle/boxshadowrenderer.h

98 lines
2.6 KiB
C++

/*
* Copyright (C) 2018 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#pragma once
// Qt
#include <QColor>
#include <QImage>
#include <QPoint>
#include <QSize>
class BoxShadowRenderer
{
public:
// Compiler generated constructors & destructor are fine.
/**
* Set the size of the box.
* @param size The size of the box.
**/
void setBoxSize(const QSize &size);
/**
* Set the radius of box' corners.
* @param radius The border radius, in pixels.
**/
void setBorderRadius(qreal radius);
/**
* Set the device pixel ratio of the resulting shadow texture.
* @param dpr The device pixel ratio.
**/
void setDevicePixelRatio(qreal dpr);
/**
* Add a shadow.
* @param offset The offset of the shadow.
* @param radius The blur radius.
* @param color The color of the shadow.
**/
void addShadow(const QPoint &offset, int radius, const QColor &color);
/**
* Render the shadow.
**/
QImage render() const;
/**
* Calculate the minimum size of the box.
*
* This helper computes the minimum size of the box so the shadow behind it has
* full its strength.
*
* @param radius The blur radius of the shadow.
**/
static QSize calculateMinimumBoxSize(int radius);
/**
* Calculate the minimum size of the shadow texture.
*
* This helper computes the minimum size of the resulting texture so the shadow
* is not clipped.
*
* @param boxSize The size of the box.
* @param radius The blur radius.
* @param offset The offset of the shadow.
**/
static QSize calculateMinimumShadowTextureSize(const QSize &boxSize, int radius, const QPoint &offset);
private:
QSize m_boxSize;
qreal m_borderRadius = 0.0;
qreal m_dpr = 1.0;
struct Shadow {
QPoint offset;
int radius;
QColor color;
};
QVector<Shadow> m_shadows;
};