/*
	Copyright 2006-2026 The QElectroTech Team
	This file is part of QElectroTech.

	QElectroTech 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.

	QElectroTech 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 QElectroTech.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef QET_STYLE_H
#define QET_STYLE_H

#include <QHash>
#include <QIcon>
#include <QProxyStyle>

/**
	@brief The QETStyle class
	A proxy over the running widget style that gives icons a hover state.

	QToolButton, QTabBar and item views ask the application style for the
	QIcon::Active pixmap of an icon while the mouse is over it. Every
	built-in style returns the icon unchanged for that mode, so only the
	button frame changes on hover, and on a dark palette Fusion's frame is
	too faint to see (GitHub #870). This proxy answers QIcon::Active for
	line-art icons with the icon tinted in the palette's highlight color,
	lightened when needed to reach 3:1 on a button face, so the icon
	itself changes on both light and dark palettes. Colored icons keep
	their colors. Every other mode is left to the base style.

	Fusion also asks for QIcon::Active for the icon of a highlighted menu
	item and paints it on the highlight bar, where the hover tint would
	vanish. The generated pixmap is cached per icon and cannot tell a
	menu from a toolbar, so drawControl(CE_MenuItem) hands the base style
	an icon whose Active pixmap is the icon in the highlighted-text color.
*/
class QETStyle : public QProxyStyle
{
	Q_OBJECT

	public:
		explicit QETStyle(QStyle *base);
		~QETStyle() override = default;

		QPixmap generatedIconPixmap(QIcon::Mode mode,
		                            const QPixmap &pixmap,
		                            const QStyleOption *option) const override;
		void drawControl(ControlElement element,
		                 const QStyleOption *option,
		                 QPainter *painter,
		                 const QWidget *widget = nullptr) const override;

		/// True when fewer than a fifth of the visible pixels are saturated.
		static bool isLineArt(const QImage &image);
		/// The highlight color, lightened until it reads at 3:1 on a button.
		static QColor hoverColor(const QPalette &palette);
		/// pixmap with every pixel set to color, alpha kept.
		static QPixmap tinted(const QPixmap &pixmap, const QColor &color);

	private:
		QIcon menuIcon(const QIcon &icon, const QPalette &palette, int size, qreal dpr) const;
		mutable QHash<QString, QIcon> menu_icons_;
};

#endif