//---------------------------------------------------------------------------
/*
QtArrowItem, an arrow QGraphicsItem
Copyright (C) 2012-2015 Richel Bilderbeek
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/>.
*/
//---------------------------------------------------------------------------
//From http://www.richelbilderbeek.nl/CppQtArrowItem.htm
//---------------------------------------------------------------------------
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Weffc++"
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#include "qtarrowitem.h"
#include <cassert>
#include <cmath>
#include <boost/math/constants/constants.hpp>
#include <QCursor>
#include <QGraphicsScene>
#include <QGraphicsSceneMouseEvent>
#include <QKeyEvent>
#include <QPainter>
#include "geometry.h"
#include "trace.h"
#pragma GCC diagnostic pop
const double ribi::QtArrowItem::m_click_easy_width = 10.0;
ribi::QtArrowItem::QtArrowItem(
const double x1,
const double y1,
const bool tail,
const double x2,
const double y2,
const bool head,
QGraphicsItem* parent)
: QGraphicsLineItem(x1,y1,x2,y2,parent),
m_signal_item_requests_scene_update{},
m_arrow_head_clicking_distance(20.0),
m_focus_pen(QPen(Qt::DashLine)),
m_head(head),
m_pen(QPen(QColor(0,0,0))),
m_tail(tail)
{
this->setFlags(
QGraphicsItem::ItemIsFocusable
| QGraphicsItem::ItemIsMovable
| QGraphicsItem::ItemIsSelectable
);
//Allow mouse tracking
this->setAcceptHoverEvents(true);
assert(this->line().p1() == QPointF(x1,y1));
assert(this->line().p2() == QPointF(x2,y2));
}
QRectF ribi::QtArrowItem::boundingRect() const
{
return shape().boundingRect();
}
std::string ribi::QtArrowItem::GetVersion() noexcept
{
return "1.2";
}
std::vector<std::string> ribi::QtArrowItem::GetVersionHistory() noexcept
{
return {
"2012-11-18: version 1.0: initial version",
"2012-11-20: version 1.1: mouse cursor changes its shape when moving over this item",
"2012-12-19: version 1.2: allow changing pens"
};
}
void ribi::QtArrowItem::hoverEnterEvent(QGraphicsSceneHoverEvent *)
{
this->setCursor(QCursor(Qt::PointingHandCursor));
}
void ribi::QtArrowItem::keyPressEvent(QKeyEvent *event)
{
switch (event->key())
{
case Qt::Key_F1:
case Qt::Key_1:
case Qt::Key_T:
case Qt::Key_Minus:
m_tail = !m_tail;
this->update();
break;
case Qt::Key_F2:
case Qt::Key_2:
case Qt::Key_H:
case Qt::Key_Plus:
m_head = !m_head;
this->update();
break;
default:
break;
}
QGraphicsLineItem::keyPressEvent(event);
m_signal_item_requests_scene_update(this);
}
void ribi::QtArrowItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
m_signal_item_requests_scene_update(this);
QGraphicsLineItem::mouseMoveEvent(event);
}
void ribi::QtArrowItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
if (event->modifiers() & Qt::ShiftModifier)
{
if ((event->pos() - this->line().p1()).manhattanLength() < m_arrow_head_clicking_distance)
{
m_tail = !m_tail;
this->update();
}
else if ((event->pos() - this->line().p2()).manhattanLength() < m_arrow_head_clicking_distance)
{
m_head = !m_head;
this->update();
}
}
}
void ribi::QtArrowItem::paint(QPainter* painter, const QStyleOptionGraphicsItem *, QWidget *)
{
painter->setRenderHint(QPainter::Antialiasing);
if (this->isSelected() || this->hasFocus())
{
painter->setPen(m_focus_pen);
}
else
{
painter->setPen(m_pen);
}
painter->drawLine(this->line());
const double pi{boost::math::constants::pi<double>()};
//The angle from tail to head
double angle{Geometry().GetAngleClockScreen(line().dx(),line().dy())};
if (line().dy() >= 0.0) angle = (1.0 * pi) + angle;
const double sz{10.0}; //pixels
if (m_tail)
{
const QPointF p0{this->line().p1()};
const QPointF p1{
p0 + QPointF(
std::sin(angle + pi + (pi * 0.1)) * sz,
-std::cos(angle + pi + (pi * 0.1)) * sz)};
const QPointF p2
= p0 + QPointF(
std::sin(angle + pi - (pi * 0.1)) * sz,
-std::cos(angle + pi - (pi * 0.1)) * sz);
painter->drawPolygon(QPolygonF() << p0 << p1 << p2);
}
if (m_head)
{
const QPointF p0 = this->line().p2();
const QPointF p1
= p0 + QPointF(
std::sin(angle + 0.0 + (pi * 0.1)) * sz,
-std::cos(angle + 0.0 + (pi * 0.1)) * sz);
const QPointF p2
= p0 + QPointF(
std::sin(angle + 0.0 - (pi * 0.1)) * sz,
-std::cos(angle + 0.0 - (pi * 0.1)) * sz);
painter->drawPolygon(QPolygonF() << p0 << p1 << p2);
}
}
void ribi::QtArrowItem::SetArrowHeadClickingDistance(const double manhattan_distance) noexcept
{
m_arrow_head_clicking_distance = manhattan_distance;
}
void ribi::QtArrowItem::SetHeadPos(const double x, const double y) noexcept
{
if (line().x2() != x || line().y2() != y)
{
QLineF line = this->line();
line.setP2(QPointF(x,y));
this->setLine(line);
this->update();
}
}
void ribi::QtArrowItem::SetTailPos(const double x, const double y) noexcept
{
if (line().x1() != x || line().y1() != y)
{
QLineF line = this->line();
line.setP1(QPointF(x,y));
this->setLine(line);
this->update();
}
}
QPainterPath ribi::QtArrowItem::shape() const
{
//Thanks to norobro for posting this code at
//http://www.qtcentre.org/threads/49201-Increase-margin-for-detecting-tooltip-events-of-QGraphicsLineItem
QPainterPath path;
QPainterPathStroker stroker;
path.moveTo(line().p1());
path.lineTo(line().p2());
stroker.setWidth(m_click_easy_width);
return stroker.createStroke(path);
}
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