valentina/src/libs/vwidgets/global.cpp

/************************************************************************
 **
 **  @file
 **  @author Roman Telezhynskyi <dismine(at)gmail.com>
 **  @date   14 6, 2017
 **
 **  @brief
 **  @copyright
 **  This source code is part of the Valentina project, a pattern making
 **  program, whose allow create and modeling patterns of clothing.
 **  Copyright (C) 2017 Valentina project
 **  <https://gitlab.com/smart-pattern/valentina> All Rights Reserved.
 **
 **  Valentina 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.
 **
 **  Valentina 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 Valentina.  If not, see <http://www.gnu.org/licenses/>.
 **
 *************************************************************************/

#include "global.h"
#include "../vmisc/def.h"
#include "../vmisc/vabstractapplication.h"

#include <QBitmap>
#include <QGraphicsItem>
#include <QGraphicsScene>
#include <QGraphicsSceneMouseEvent>
#include <QGraphicsView>

const qreal minVisibleFontSize = 5;

extern auto qt_regionToPath(const QRegion &region) -> QPainterPath;

inline auto DefPointRadiusPixel() -> qreal
{
    return (VAbstractApplication::VApp()->Settings()->GetLineWidth() + 0.8) / 25.4 * PrintDPI;
}

//---------------------------------------------------------------------------------------------------------------------
auto SceneScale(QGraphicsScene *scene) -> qreal
{
    qreal scale = 1;

    if (scene)
    {
        const QList<QGraphicsView *> views = scene->views();
        if (not views.isEmpty())
        {
            scale = views.constFirst()->transform().m11();
        }
    }

    return scale;
}

//---------------------------------------------------------------------------------------------------------------------
auto PointRect(qreal radius) -> QRectF
{
    QRectF rec = QRectF(0, 0, radius * 2, radius * 2);
    rec.translate(-rec.center().x(), -rec.center().y());
    return rec;
}

//---------------------------------------------------------------------------------------------------------------------
auto ScaledRadius(qreal scale) -> qreal
{
    qreal scaledRadius = DefPointRadiusPixel();
    if (scale > 1)
    {
        scaledRadius = qMax(DefPointRadiusPixel() / 96, DefPointRadiusPixel() / scale);
    }
    return scaledRadius;
}

//---------------------------------------------------------------------------------------------------------------------
void ScaleCircleSize(QGraphicsEllipseItem *item, qreal scale)
{
    SCASSERT(item != nullptr)

    item->setRect(PointRect(ScaledRadius(scale)));
}

//---------------------------------------------------------------------------------------------------------------------
auto ScaleWidth(qreal width, qreal scale) -> qreal
{
    if (scale > 1)
    {
        width = qMax(0.01, width / scale);
    }
    return width;
}

//---------------------------------------------------------------------------------------------------------------------
auto ItemShapeFromPath(const QPainterPath &path, const QPen &pen) -> QPainterPath
{
    // We unfortunately need this hack as QPainterPathStroker will set a width of 1.0
    // if we pass a value of 0.0 to QPainterPathStroker::setWidth()
    const qreal penWidthZero = qreal(0.00000001);

    if (path == QPainterPath() || pen == Qt::NoPen)
    {
        return path;
    }
    QPainterPathStroker ps;
    ps.setCapStyle(pen.capStyle());
    if (pen.widthF() <= 0.0)
    {
        ps.setWidth(penWidthZero);
    }
    else
    {
        ps.setWidth(pen.widthF());
    }
    ps.setJoinStyle(pen.joinStyle());
    ps.setMiterLimit(pen.miterLimit());
    QPainterPath p = ps.createStroke(path);
    p.addPath(path);
    return p;
}

//---------------------------------------------------------------------------------------------------------------------
auto PixmapToPainterPath(const QPixmap &pixmap) -> QPainterPath
{
    if (not pixmap.isNull())
    {
        QBitmap mask = pixmap.mask();
        if (not mask.isNull())
        {
            return qt_regionToPath(QRegion(mask));
        }
    }

    return {};
}

//---------------------------------------------------------------------------------------------------------------------
void GraphicsItemHighlightSelected(const QRectF &boundingRect, qreal itemPenWidth, QPainter *painter,
                                   const QStyleOptionGraphicsItem *option)
{
    const QRectF murect = painter->transform().mapRect(QRectF(0, 0, 1, 1));
    if (qFuzzyIsNull(qMax(murect.width(), murect.height())))
    {
        return;
    }

    const QRectF mbrect = painter->transform().mapRect(boundingRect);
    if (qMin(mbrect.width(), mbrect.height()) < qreal(1.0))
    {
        return;
    }

    const qreal pad = itemPenWidth / 2;

    const qreal penWidth = 0; // cosmetic pen

    const QColor fgcolor = option->palette.windowText().color();
    const QColor bgcolor( // ensure good contrast against fgcolor
        fgcolor.red() > 127 ? 0 : 255, fgcolor.green() > 127 ? 0 : 255, fgcolor.blue() > 127 ? 0 : 255);

    painter->setPen(QPen(bgcolor, penWidth, Qt::SolidLine));
    painter->setBrush(Qt::NoBrush);
    painter->drawRect(boundingRect.adjusted(pad, pad, -pad, -pad));

    painter->setPen(QPen(option->palette.windowText(), 0, Qt::DashLine));
    painter->setBrush(Qt::NoBrush);
    painter->drawRect(boundingRect.adjusted(pad, pad, -pad, -pad));
}

//---------------------------------------------------------------------------------------------------------------------
auto IsSelectedByReleaseEvent(QGraphicsItem *item, QGraphicsSceneMouseEvent *event) -> bool
{
    SCASSERT(item != nullptr)
    return event->button() == Qt::LeftButton && event->type() != QEvent::GraphicsSceneMouseDoubleClick &&
           item->contains(event->pos());
}