Move qt-ui to desktop-widgets

Since we have now destkop and mobile versions, 'qt-ui' was a very
poor name choice for a folder that contains only destkop-enabled
widgets.

Also, move the graphicsview-common.h/cpp to subsurface-core because
it doesn't depend on qgraphicsview, it merely implements all the
colors that we use throughout Subsurface, and we will use colors on both
desktop and mobile versions

Same thing applies for metrics.h/cpp

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

desktop-widgets/starwidget.cpp

@@ -0,0 +1,164 @@
+#include "starwidget.h"
+#include "metrics.h"
+#include <QSvgRenderer>
+#include <QMouseEvent>
+#include "simplewidgets.h"
+
+QImage StarWidget::activeStar;
+QImage StarWidget::inactiveStar;
+
+const QImage& StarWidget::starActive()
+{
+	return activeStar;
+}
+
+const QImage& StarWidget::starInactive()
+{
+	return inactiveStar;
+}
+
+QImage focusedImage(const QImage& coloredImg)
+{
+	QImage img = coloredImg;
+	for (int i = 0; i < img.width(); ++i) {
+		for (int j = 0; j < img.height(); ++j) {
+			QRgb rgb = img.pixel(i, j);
+			if (!rgb)
+				continue;
+
+			QColor c(rgb);
+			c = c.dark();
+			img.setPixel(i, j, c.rgb());
+		}
+	}
+
+	return img;
+}
+
+
+int StarWidget::currentStars() const
+{
+	return current;
+}
+
+void StarWidget::mouseReleaseEvent(QMouseEvent *event)
+{
+	if (readOnly) {
+		return;
+	}
+
+	int starClicked = event->pos().x() / defaultIconMetrics().sz_small + 1;
+	if (starClicked > TOTALSTARS)
+		starClicked = TOTALSTARS;
+
+	if (current == starClicked)
+		current -= 1;
+	else
+		current = starClicked;
+
+	Q_EMIT valueChanged(current);
+	update();
+}
+
+void StarWidget::paintEvent(QPaintEvent *event)
+{
+	QPainter p(this);
+	QImage star = hasFocus() ? focusedImage(starActive()) : starActive();
+	QPixmap selected = QPixmap::fromImage(star);
+	QPixmap inactive = QPixmap::fromImage(starInactive());
+	const IconMetrics& metrics = defaultIconMetrics();
+
+
+	for (int i = 0; i < current; i++)
+		p.drawPixmap(i * metrics.sz_small + metrics.spacing, 0, selected);
+
+	for (int i = current; i < TOTALSTARS; i++)
+		p.drawPixmap(i * metrics.sz_small + metrics.spacing, 0, inactive);
+
+	if (hasFocus()) {
+		QStyleOptionFocusRect option;
+		option.initFrom(this);
+		option.backgroundColor = palette().color(QPalette::Background);
+		style()->drawPrimitive(QStyle::PE_FrameFocusRect, &option, &p, this);
+	}
+}
+
+void StarWidget::setCurrentStars(int value)
+{
+	current = value;
+	update();
+	Q_EMIT valueChanged(current);
+}
+
+StarWidget::StarWidget(QWidget *parent, Qt::WindowFlags f) : QWidget(parent, f),
+	current(0),
+	readOnly(false)
+{
+	int dim = defaultIconMetrics().sz_small;
+
+	if (activeStar.isNull()) {
+		QSvgRenderer render(QString(":star"));
+		QPixmap renderedStar(dim, dim);
+
+		renderedStar.fill(Qt::transparent);
+		QPainter painter(&renderedStar);
+
+		render.render(&painter, QRectF(0, 0, dim, dim));
+		activeStar = renderedStar.toImage();
+	}
+	if (inactiveStar.isNull()) {
+		inactiveStar = grayImage(activeStar);
+	}
+	setFocusPolicy(Qt::StrongFocus);
+}
+
+QImage grayImage(const QImage& coloredImg)
+{
+	QImage img = coloredImg;
+	for (int i = 0; i < img.width(); ++i) {
+		for (int j = 0; j < img.height(); ++j) {
+			QRgb rgb = img.pixel(i, j);
+			if (!rgb)
+				continue;
+
+			QColor c(rgb);
+			int gray = 204 + (c.red() + c.green() + c.blue()) / 15;
+			img.setPixel(i, j, qRgb(gray, gray, gray));
+		}
+	}
+
+	return img;
+}
+
+QSize StarWidget::sizeHint() const
+{
+	const IconMetrics& metrics = defaultIconMetrics();
+	return QSize(metrics.sz_small * TOTALSTARS + metrics.spacing * (TOTALSTARS - 1), metrics.sz_small);
+}
+
+void StarWidget::setReadOnly(bool r)
+{
+	readOnly = r;
+}
+
+void StarWidget::focusInEvent(QFocusEvent *event)
+{
+	setFocus();
+	QWidget::focusInEvent(event);
+}
+
+void StarWidget::focusOutEvent(QFocusEvent *event)
+{
+	QWidget::focusOutEvent(event);
+}
+
+void StarWidget::keyPressEvent(QKeyEvent *event)
+{
+	if (event->key() == Qt::Key_Up || event->key() == Qt::Key_Right) {
+		if (currentStars() < TOTALSTARS)
+			setCurrentStars(currentStars() + 1);
+	} else if (event->key() == Qt::Key_Down || event->key() == Qt::Key_Left) {
+		if (currentStars() > 0)
+			setCurrentStars(currentStars() - 1);
+	}
+}