text: /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is adapted from Qt Creator (replacing theme stuff by QColor)
  **
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU
  ** General Public License version 3 as published by the Free Software
  ** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
  ** included in the packaging of this file. Please review the following
  ** information to ensure the GNU General Public License requirements will
  ** be met: https://www.gnu.org/licenses/gpl-3.0.html.
  **
  ****************************************************************************/
  
  #include "icon.h"
  
  #include <QApplication>
  #include <QIcon>
  #include <QImage>
  #include <QMetaEnum>
  #include <QPainter>
  #include <QPaintEngine>
  #include <QWidget>
  
  namespace moveit_rviz_plugin {
  namespace utils {
  
  static const qreal PUNCH_EDGE_WIDTH = 0.5;
  static const qreal PUNCH_EDGE_INTENSITY = 0.6;
  
  static QPixmap maskToColorAndAlpha(const QPixmap& mask, const QColor& color) {
  	QImage result(mask.toImage().convertToFormat(QImage::Format_ARGB32));
  	result.setDevicePixelRatio(mask.devicePixelRatio());
  	QRgb* bits_start = reinterpret_cast<QRgb*>(result.bits());
  	const QRgb* bits_end = bits_start + result.width() * result.height();
  	const QRgb tint = color.rgb() & 0x00ffffff;
  	const QRgb alpha = QRgb(color.alpha());
  	for (QRgb* pixel = bits_start; pixel < bits_end; ++pixel) {
  		QRgb pixel_alpha = (((~*pixel) & 0xff) * alpha) >> 8;
  		*pixel = (pixel_alpha << 24) | tint;
  	}
  	return QPixmap::fromImage(result);
  }
  
  typedef QPair<QPixmap, QColor> MaskAndColor;
  using MasksAndColors = QList<MaskAndColor>;
  static MasksAndColors masksAndColors(const Icon& icon, int dpr) {
  	MasksAndColors result;
  	for (const IconMaskAndColor& i : icon) {
  		const QString& file_name = i.first;
  		const QColor color = i.second;
  		result.append(qMakePair(QPixmap(file_name), color));
  	}
  	return result;
  }
  
  static void smearPixmap(QPainter* painter, const QPixmap& pixmap, qreal radius) {
  	const qreal nagative = -radius - 0.01;  // Workaround for QPainter rounding behavior
  	const qreal positive = radius;
  	painter->drawPixmap(QPointF(nagative, nagative), pixmap);
  	painter->drawPixmap(QPointF(0, nagative), pixmap);
  	painter->drawPixmap(QPointF(positive, nagative), pixmap);
  	painter->drawPixmap(QPointF(positive, 0), pixmap);
  	painter->drawPixmap(QPointF(positive, positive), pixmap);
  	painter->drawPixmap(QPointF(0, positive), pixmap);
  	painter->drawPixmap(QPointF(nagative, positive), pixmap);
  	painter->drawPixmap(QPointF(nagative, 0), pixmap);
  }
  
  static QPixmap combinedMask(const MasksAndColors& masks, Icon::IconStyleOptions style) {
  	if (masks.count() == 1)
  		return masks.first().first;
  
  	QPixmap result(masks.first().first);
  	QPainter p(&result);
  	p.setCompositionMode(QPainter::CompositionMode_Darken);
  	auto mask_image = masks.constBegin();
  	mask_image++;
  	for (; mask_image != masks.constEnd(); ++mask_image) {
  		if (style & Icon::PUNCH_EDGES) {
  			p.save();
  			p.setOpacity(PUNCH_EDGE_INTENSITY);
  			p.setCompositionMode(QPainter::CompositionMode_Lighten);
  			smearPixmap(&p, maskToColorAndAlpha((*mask_image).first, Qt::white), PUNCH_EDGE_WIDTH);
  			p.restore();
  		}
  		p.drawPixmap(0, 0, (*mask_image).first);
  	}
  	p.end();
  	return result;
  }
  
  static QPixmap masksToIcon(const MasksAndColors& masks, const QPixmap& combinedMask, Icon::IconStyleOptions style) {
  	QPixmap result(combinedMask.size());
  	result.setDevicePixelRatio(combinedMask.devicePixelRatio());
  	result.fill(Qt::transparent);
  	QPainter p(&result);
  
  	for (MasksAndColors::const_iterator mask_image = masks.constBegin(); mask_image != masks.constEnd(); ++mask_image) {
  		if (style & Icon::PUNCH_EDGES && mask_image != masks.constBegin()) {
  			// Punch a transparent outline around an overlay.
  			p.save();
  			p.setOpacity(PUNCH_EDGE_INTENSITY);
  			p.setCompositionMode(QPainter::CompositionMode_DestinationOut);
  			smearPixmap(&p, maskToColorAndAlpha((*mask_image).first, Qt::white), PUNCH_EDGE_WIDTH);
  			p.restore();
  		}
  		p.drawPixmap(0, 0, maskToColorAndAlpha((*mask_image).first, (*mask_image).second));
  	}
  
  	if (style & Icon::DROP_SHADOW) {
  		const QPixmap shadow_mask = maskToColorAndAlpha(combinedMask, Qt::black);
  		p.setCompositionMode(QPainter::CompositionMode_DestinationOver);
  		p.setOpacity(0.05);
  		p.drawPixmap(QPointF(0, -0.501), shadow_mask);
  		p.drawPixmap(QPointF(-0.501, 0), shadow_mask);
  		p.drawPixmap(QPointF(0.5, 0), shadow_mask);
  		p.drawPixmap(QPointF(0.5, 0.5), shadow_mask);
  		p.drawPixmap(QPointF(-0.501, 0.5), shadow_mask);
  		p.setOpacity(0.2);
  		p.drawPixmap(0, 1, shadow_mask);
  	}
  
  	p.end();
  
  	return result;
  }
  
  static QPixmap combinedPlainPixmaps(const QVector<IconMaskAndColor>& images) {
  	QPixmap result(images.first().first);
  	auto pixmap = images.constBegin();
  	pixmap++;
  	for (; pixmap != images.constEnd(); ++pixmap) {
  		const QPixmap overlay((*pixmap).first);
  		result.paintEngine()->painter()->drawPixmap(0, 0, overlay);
  	}
  	return result;
  }
  
  Icon::Icon() {}
  
  Icon::Icon(std::initializer_list<IconMaskAndColor> args, Icon::IconStyleOptions style)
    : QVector<IconMaskAndColor>(args), m_style(style) {}
  
  Icon::Icon(const QString& imageFileName) : m_style(NONE) {
  	append({ imageFileName, QColor() });
  }
  
  QIcon Icon::icon() const {
  	if (isEmpty()) {
  		return QIcon();
  	} else if (m_style == NONE) {
  		return QIcon(combinedPlainPixmaps(*this));
  	} else {
  		QIcon result;
  		const int max_dpr = qRound(qApp->devicePixelRatio());
  		for (int dpr = 1; dpr <= max_dpr; dpr++) {
  			const MasksAndColors masks = masksAndColors(*this, dpr);
  			const QPixmap combined_mask = combinedMask(masks, m_style);
  			result.addPixmap(masksToIcon(masks, combined_mask, m_style));
  
  			const QColor disabled_color = QColor::fromRgba(0x60a4a6a8);
  			result.addPixmap(maskToColorAndAlpha(combined_mask, disabled_color), QIcon::Disabled);
  		}
  		return result;
  	}
  }
  
  QPixmap Icon::pixmap() const {
  	if (isEmpty()) {
  		return QPixmap();
  	} else if (m_style == NONE) {
  		return combinedPlainPixmaps(*this);
  	} else {
  		const MasksAndColors masks = masksAndColors(*this, qRound(qApp->devicePixelRatio()));
  		const QPixmap combined_mask = combinedMask(masks, m_style);
  		return masksToIcon(masks, combined_mask, m_style);
  	}
  }
  
  QString Icon::imageFileName() const {
  	return first().first;
  }
  
  QIcon Icon::sideBarIcon(const Icon& classic, const Icon& flat) {
  	return flat.icon();
  }
  
  QIcon Icon::modeIcon(const Icon& classic, const Icon& flat, const Icon& flatActive) {
  	QIcon result = sideBarIcon(classic, flat);
  	result.addPixmap(flatActive.pixmap(), QIcon::Active);
  	return result;
  }
  
  QIcon Icon::combinedIcon(const QList<QIcon>& icons) {
  	QIcon result;
  	QWindow* window = QApplication::allWidgets().first()->windowHandle();
  	for (const QIcon& icon : icons)
  		for (const QIcon::Mode mode : { QIcon::Disabled, QIcon::Normal })
  			for (const QSize& size : icon.availableSizes(mode))
  				result.addPixmap(icon.pixmap(window, size, mode), mode);
  	return result;
  }
  }  // namespace utils
  }  // namespace moveit_rviz_plugin
  