Add full screen overlay for image display

CMakeLists.txt

@@ -77,6 +77,7 @@ set(SRC_FILES
     src/EmojiPickButton.cc
     src/EmojiProvider.cc
     src/ImageItem.cc
+    src/ImageOverlayDialog.cc
     src/TimelineItem.cc
     src/TimelineView.cc
     src/TimelineViewManager.cc
@@ -129,6 +130,7 @@ qt5_wrap_cpp(MOC_HEADERS
     include/EmojiPanel.h
     include/EmojiPickButton.h
     include/ImageItem.h
+    include/ImageOverlayDialog.h
     include/TimelineItem.h
     include/TimelineView.h
     include/TimelineViewManager.h

include/ImageOverlayDialog.h

@@ -0,0 +1,44 @@
+/*
+ * 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/>.
+ */
+
+#ifndef IMAGE_OVERLAY_DIALOG_H
+#define IMAGE_OVERLAY_DIALOG_H
+
+#include <QDialog>
+#include <QMouseEvent>
+#include <QPixmap>
+
+class ImageOverlayDialog : public QDialog
+{
+	Q_OBJECT
+public:
+	ImageOverlayDialog(QPixmap image, QWidget *parent = nullptr);
+
+protected:
+	void mousePressEvent(QMouseEvent *event) override;
+	void paintEvent(QPaintEvent *event) override;
+
+private:
+	void scaleImage(int width, int height);
+
+	QPixmap image_;
+
+	QRect content_;
+	QRect close_button_;
+};
+
+#endif  // IMAGE_OVERLAY_DIALOG_H

src/ImageItem.cc

@@ -23,6 +23,7 @@
 #include <QPixmap>
 
 #include "ImageItem.h"
+#include "ImageOverlayDialog.h"
 
 ImageItem::ImageItem(QSharedPointer<MatrixClient> client, const Event &event, const QString &body, const QUrl &url, QWidget *parent)
     : QWidget(parent)
@@ -121,10 +122,12 @@ void ImageItem::mousePressEvent(QMouseEvent *event)
 	auto point = event->pos();
 
 	// Click on the text box.
-	if (QRect(0, height_ - bottom_height_, width_, bottom_height_).contains(point))
+	if (QRect(0, height_ - bottom_height_, width_, bottom_height_).contains(point)) {
 		openUrl();
-	else
+	} else {
-		qDebug() << "Opening image overlay. Not implemented yet.";
+		auto image_dialog = new ImageOverlayDialog(image_, this);
+		image_dialog->show();
+	}
 }
 
 void ImageItem::resizeEvent(QResizeEvent *event)

src/ImageOverlayDialog.cc

@@ -0,0 +1,116 @@
+/*
+ * 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 "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();
+}
+
+// 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;
+
+	// FIXME: The main window needs double click to regain focus.
+	if (close_button_.contains(event->pos()))
+		close();
+}