flameshot/src/tools/arrow/arrowtool.cpp

// SPDX-License-Identifier: GPL-3.0-or-later
// SPDX-FileCopyrightText: 2017-2019 Alejandro Sirgo Rica & Contributors

#include "arrowtool.h"
#include <cmath>

namespace {
const int ArrowWidth = 10;
const int ArrowHeight = 18;

QPainterPath getArrowHead(QPoint p1, QPoint p2, const int thickness)
{
    QLineF base(p1, p2);
    // Create the vector for the position of the base  of the arrowhead
    QLineF temp(QPoint(0, 0), p2 - p1);
    int val = ArrowHeight + thickness * 4;
    if (base.length() < val) {
        val = static_cast<int>(base.length() + thickness * 2);
    }
    temp.setLength(base.length() + thickness * 2 - val);
    // Move across the line up to the head
    QPointF bottomTranslation(temp.p2());

    // Rotate base of the arrowhead
    base.setLength(ArrowWidth + thickness * 2);
    base.setAngle(base.angle() + 90);
    // Move to the correct point
    QPointF temp2 = p1 - base.p2();
    // Center it
    QPointF centerTranslation((temp2.x() / 2), (temp2.y() / 2));

    base.translate(bottomTranslation);
    base.translate(centerTranslation);

    QPainterPath path;
    path.moveTo(p2);
    path.lineTo(base.p1());
    path.lineTo(base.p2());
    path.lineTo(p2);
    return path;
}

// gets a shorter line to prevent overlap in the point of the arrow
QLine getShorterLine(QPoint p1, QPoint p2, const int thickness)
{
    QLineF l(p1, p2);
    int val = ArrowHeight + thickness * 4;
    if (l.length() < val) {
        val = static_cast<int>(l.length() + thickness * 2);
    }
    l.setLength(l.length() + thickness * 2 - val);
    return l.toLine();
}

} // unnamed namespace

ArrowTool::ArrowTool(QObject* parent)
  : AbstractTwoPointTool(parent)
{
    setPadding(ArrowWidth / 2);
    m_supportsOrthogonalAdj = true;
    m_supportsDiagonalAdj = true;
}

QIcon ArrowTool::icon(const QColor& background, bool inEditor) const
{
    Q_UNUSED(inEditor)
    return QIcon(iconPath(background) + "arrow-bottom-left.svg");
}
QString ArrowTool::name() const
{
    return tr("Arrow");
}

ToolType ArrowTool::nameID() const
{
    return ToolType::ARROW;
}

QString ArrowTool::description() const
{
    return tr("Set the Arrow as the paint tool");
}

CaptureTool* ArrowTool::copy(QObject* parent)
{
    ArrowTool* tool = new ArrowTool(parent);
    copyParams(this, tool);
    return tool;
}

void ArrowTool::copyParams(const ArrowTool* from, ArrowTool* to)
{
    AbstractTwoPointTool::copyParams(from, to);
    to->m_arrowPath = this->m_arrowPath;
}

void ArrowTool::process(QPainter& painter, const QPixmap& pixmap)
{
    Q_UNUSED(pixmap)
    painter.setPen(QPen(color(), thickness()));
    painter.drawLine(
      getShorterLine(points().first, points().second, thickness()));
    m_arrowPath = getArrowHead(points().first, points().second, thickness());
    painter.fillPath(m_arrowPath, QBrush(color()));
}

void ArrowTool::pressed(const CaptureContext& context)
{
    Q_UNUSED(context)
}

void ArrowTool::drawObjectSelection(QPainter& painter)
{
    int offset =
      thickness() <= 1 ? 1 : static_cast<int>(round(thickness() / 2 + 0.5));

    // get min and max arrow pos
    int min_x = points().first.x();
    int min_y = points().first.y();
    int max_x = points().first.x();
    int max_y = points().first.y();
    for (int i = 0; i < m_arrowPath.elementCount(); i++) {
        QPointF pt = m_arrowPath.elementAt(i);
        if (static_cast<int>(pt.x()) < min_x) {
            min_x = static_cast<int>(pt.x());
        }
        if (static_cast<int>(pt.y()) < min_y) {
            min_y = static_cast<int>(pt.y());
        }
        if (static_cast<int>(pt.x()) > max_x) {
            max_x = static_cast<int>(pt.x());
        }
        if (static_cast<int>(pt.y()) > max_y) {
            max_y = static_cast<int>(pt.y());
        }
    }

    // get min and max line pos
    int line_pos_min_x =
      std::min(std::min(points().first.x(), points().second.x()), min_x);
    int line_pos_min_y =
      std::min(std::min(points().first.y(), points().second.y()), min_y);
    int line_pos_max_x =
      std::max(std::max(points().first.x(), points().second.x()), max_x);
    int line_pos_max_y =
      std::max(std::max(points().first.y(), points().second.y()), max_y);

    QRect rect = QRect(line_pos_min_x - offset,
                       line_pos_min_y - offset,
                       line_pos_max_x - line_pos_min_x + offset * 2,
                       line_pos_max_y - line_pos_min_y + offset * 2);
    drawObjectSelectionRect(painter, rect);
}