matrixion/src/ImageOverlayDialog.cc

/*
 * nheko Copyright (C) 2017  Konstantinos Sideris <siderisk@auth.gr>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <QDebug>
#include <QPainter>
#include <QTimer>

#include "ImageOverlayDialog.h"

ImageOverlayDialog::ImageOverlayDialog(QPixmap image, QWidget *parent)
    : QDialog{parent}
    , image_{image}
{
	setMouseTracking(true);
	setModal(false);

	setWindowFlags(windowFlags() | Qt::FramelessWindowHint);

	setAttribute(Qt::WA_NoSystemBackground, true);
	setAttribute(Qt::WA_TranslucentBackground, true);
	setAttribute(Qt::WA_DeleteOnClose, true);

	setWindowState(Qt::WindowFullScreen);

	raise();

	connect(this, SIGNAL(closing()), this, SLOT(closeDialog()));
}

void ImageOverlayDialog::closeDialog()
{
	QTimer::singleShot(100, this, &ImageOverlayDialog::reject);
}

// TODO: Move this into Utils
void ImageOverlayDialog::scaleImage(int max_width, int max_height)
{
	if (image_.isNull())
		return;

	auto width_ratio = (double)max_width / (double)image_.width();
	auto height_ratio = (double)max_height / (double)image_.height();

	auto min_aspect_ratio = std::min(width_ratio, height_ratio);

	int final_width = 0;
	int final_height = 0;

	if (min_aspect_ratio > 1) {
		final_width = image_.width();
		final_height = image_.height();
	} else {
		final_width = image_.width() * min_aspect_ratio;
		final_height = image_.height() * min_aspect_ratio;
	}

	image_ = image_.scaled(final_width, final_height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
}

void ImageOverlayDialog::paintEvent(QPaintEvent *event)
{
	Q_UNUSED(event);

	QPainter painter(this);
	painter.setRenderHint(QPainter::Antialiasing);

	// Full screen overlay.
	painter.fillRect(rect(), QColor(55, 55, 55, 170));

	// Left and Right margins
	int outer_margin = rect().width() * 0.12;
	int buttonSize = 36;
	int margin = outer_margin * 0.1;

	int max_width = rect().width() - 2 * outer_margin;
	int max_height = rect().height();

	scaleImage(max_width, max_height);

	int diff_x = max_width - image_.width();
	int diff_y = max_height - image_.height();

	content_ = QRect(outer_margin + diff_x / 2, diff_y / 2, image_.width(), image_.height());
	close_button_ = QRect(rect().width() - margin - buttonSize, margin, buttonSize, buttonSize);

	// Draw main content_.
	painter.drawPixmap(content_, image_);

	// Draw top right corner X.
	QPen pen;
	pen.setCapStyle(Qt::RoundCap);
	pen.setWidthF(5);
	pen.setColor("gray");

	auto center = close_button_.center();

	painter.setPen(pen);
	painter.drawLine(center - QPointF(15, 15), center + QPointF(15, 15));
	painter.drawLine(center + QPointF(15, -15), center - QPointF(15, -15));
}

void ImageOverlayDialog::mousePressEvent(QMouseEvent *event)
{
	if (event->button() != Qt::LeftButton)
		return;

	if (close_button_.contains(event->pos()))
		emit closing();
	else if (!content_.contains(event->pos()))
		emit closing();
}