path: root/src/object/sp-conn-end-pair.cpp

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * A class for handling connector endpoint movement and libavoid interaction.
 *
 * Authors:
 *   Peter Moulder <pmoulder@mail.csse.monash.edu.au>
 *   Michael Wybrow <mjwybrow@users.sourceforge.net>
 *   Abhishek Sharma
 *
 *    * Copyright (C) 2004-2005 Monash University
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */

#include <cstring>
#include <string>
#include <glibmm/stringutils.h>

#include "attributes.h"
#include "sp-conn-end.h"
#include "uri.h"
#include "display/curve.h"
#include "xml/repr.h"
#include "sp-path.h"
#include "sp-use.h"
#include "3rdparty/adaptagrams/libavoid/router.h"
#include "document.h"
#include "sp-item-group.h"


SPConnEndPair::SPConnEndPair(SPPath *const owner)
    : _path(owner)
    , _connRef(nullptr)
    , _connType(SP_CONNECTOR_NOAVOID)
    , _connCurvature(0.0)
    , _transformed_connection()
{
    for (unsigned handle_ix = 0; handle_ix <= 1; ++handle_ix) {
        this->_connEnd[handle_ix] = new SPConnEnd(owner);
        this->_connEnd[handle_ix]->_changed_connection
            = this->_connEnd[handle_ix]->ref.changedSignal()
            .connect(sigc::bind(sigc::ptr_fun(sp_conn_end_href_changed),
                                this->_connEnd[handle_ix], owner, handle_ix));
    }
}

SPConnEndPair::~SPConnEndPair()
{
    for (auto & handle_ix : this->_connEnd) {
        delete handle_ix;
        handle_ix = nullptr;
    }
}

void SPConnEndPair::release()
{
    for (auto & handle_ix : this->_connEnd) {
        handle_ix->_changed_connection.disconnect();
        handle_ix->_delete_connection.disconnect();
        handle_ix->_transformed_connection.disconnect();
        handle_ix->_group_connection.disconnect();
        g_free(handle_ix->href);
        handle_ix->href = nullptr;
        handle_ix->ref.detach();
    }

    // If the document is being destroyed then the router instance
    // and the ConnRefs will have been destroyed with it.
    const bool routerInstanceExists = (_path->document->getRouter() != nullptr);

    if (_connRef && routerInstanceExists) {
        _connRef->router()->deleteConnector(_connRef);
    }
    _connRef = nullptr;

    _transformed_connection.disconnect();
}

void sp_conn_end_pair_build(SPObject *object)
{
    object->readAttr(SPAttr::CONNECTOR_TYPE);
    object->readAttr(SPAttr::CONNECTION_START);
    object->readAttr(SPAttr::CONNECTION_START_POINT);
    object->readAttr(SPAttr::CONNECTION_END);
    object->readAttr(SPAttr::CONNECTION_END_POINT);
    object->readAttr(SPAttr::CONNECTOR_CURVATURE);
}


static void avoid_conn_transformed(Geom::Affine const */*mp*/, SPItem *moved_item)
{
    SPPath *path = SP_PATH(moved_item);
    if (path->connEndPair.isAutoRoutingConn()) {
        path->connEndPair.tellLibavoidNewEndpoints();
    }
}


void SPConnEndPair::setAttr(const SPAttr key, gchar const *const value)
{
    switch (key) {
    case SPAttr::CONNECTOR_TYPE:
        if (value && (strcmp(value, "polyline") == 0 || strcmp(value, "orthogonal") == 0)) {
            int new_conn_type = strcmp(value, "polyline") ? SP_CONNECTOR_ORTHOGONAL : SP_CONNECTOR_POLYLINE;

            if (!_connRef) {
                _connType = new_conn_type;
                Avoid::Router *router = _path->document->getRouter();
                _connRef = new Avoid::ConnRef(router);
                _connRef->setRoutingType(new_conn_type == SP_CONNECTOR_POLYLINE ?
                    Avoid::ConnType_PolyLine : Avoid::ConnType_Orthogonal);
                _transformed_connection = _path->connectTransformed(sigc::ptr_fun(&avoid_conn_transformed));
            } else if (new_conn_type != _connType) {
                _connType = new_conn_type;
                _connRef->setRoutingType(new_conn_type == SP_CONNECTOR_POLYLINE ?
                    Avoid::ConnType_PolyLine : Avoid::ConnType_Orthogonal);
                sp_conn_reroute_path(_path);
            }
        } else {
            _connType = SP_CONNECTOR_NOAVOID;

            if (_connRef) {
                _connRef->router()->deleteConnector(_connRef);
                _connRef = nullptr;
                _transformed_connection.disconnect();
            }
        }
        break;
    case SPAttr::CONNECTOR_CURVATURE:
        if (value) {
            _connCurvature = g_strtod(value, nullptr);
            if (_connRef && _connRef->isInitialised()) {
                // Redraw the connector, but only if it has been initialised.
                sp_conn_reroute_path(_path);
            }
        }
        break;
    case SPAttr::CONNECTION_START:
        this->_connEnd[0]->setAttacherHref(value);
        break;
    case SPAttr::CONNECTION_START_POINT:
        this->_connEnd[0]->setAttacherSubHref(value);
        break;
    case SPAttr::CONNECTION_END:
        this->_connEnd[1]->setAttacherHref(value);
        break;
    case SPAttr::CONNECTION_END_POINT:
        this->_connEnd[1]->setAttacherSubHref(value);
        break;
    }
}

void SPConnEndPair::writeRepr(Inkscape::XML::Node *const repr) const
{
    char const * const attrs[] = {
        "inkscape:connection-start", "inkscape:connection-end"};
    char const * const point_attrs[] = {
        "inkscape:connection-start-point", "inkscape:connection-end-point"};
    for (unsigned handle_ix = 0; handle_ix < 2; ++handle_ix) {
        const Inkscape::URI* U = this->_connEnd[handle_ix]->ref.getURI();
        if (U) {
            auto str = U->str();
            repr->setAttribute(attrs[handle_ix], str);
        }
        const Inkscape::URI* P = this->_connEnd[handle_ix]->sub_ref.getURI();
        if (P) {
            auto str = P->str();
            repr->setAttribute(point_attrs[handle_ix], str);
        }
    }
    if (_connType == SP_CONNECTOR_POLYLINE || _connType == SP_CONNECTOR_ORTHOGONAL) {
        repr->setAttribute("inkscape:connector-curvature", Glib::Ascii::dtostr(_connCurvature));
        repr->setAttribute("inkscape:connector-type", _connType == SP_CONNECTOR_POLYLINE ? "polyline" : "orthogonal" );
    }
}

void SPConnEndPair::getAttachedItems(SPItem *h2attItem[2]) const {
    for (unsigned h = 0; h < 2; ++h) {
        auto obj = this->_connEnd[h]->ref.getObject();
        auto sub_obj = this->_connEnd[h]->sub_ref.getObject();

        if(sub_obj) {
            // For sub objects, we have to go fishing for the virtual/shadow
            // object which has the correct position for this use/symbol
            SPUse *use = dynamic_cast<SPUse *>(obj);
            if(use) {
                auto root = use->root();
                bool found = false;
                for (auto& child: root->children) {
                    if(!g_strcmp0(child.getAttribute("id"), sub_obj->getId())) {
                        h2attItem[h] = (SPItem *) &child;
                        found = true;
                    }
                }
                if(!found) {
                    g_warning("Couldn't find sub connector point!");
                }
            }
        } else {
            h2attItem[h] = obj;
        }

        // Deal with the case of the attached object being an empty group.
        // A group containing no items does not have a valid bbox, so
        // causes problems for the auto-routing code.  Also, since such a
        // group no longer has an onscreen representation and can only be
        // selected through the XML editor, it makes sense just to detach
        // connectors from them.
        if (SP_IS_GROUP(h2attItem[h])) {
            if (SP_GROUP(h2attItem[h])->getItemCount() == 0) {
                // This group is empty, so detach.
                sp_conn_end_detach(_path, h);
                h2attItem[h] = nullptr;
            }
        }
    }
}

void SPConnEndPair::getEndpoints(Geom::Point endPts[]) const
{
    SPCurve const *curve = _path->curveForEdit();
    SPItem *h2attItem[2] = {nullptr};
    getAttachedItems(h2attItem);
    Geom::Affine i2d = _path->i2doc_affine();

    for (unsigned h = 0; h < 2; ++h) {
        if (h2attItem[h]) {
            endPts[h] = h2attItem[h]->getAvoidRef().getConnectionPointPos();
        } else if (!curve->is_empty()) {
            if (h == 0) {
                endPts[h] = *(curve->first_point()) * i2d;
            } else {
                endPts[h] = *(curve->last_point()) * i2d;
            }
        }
    }
}

gdouble SPConnEndPair::getCurvature() const
{
    return _connCurvature;
}

SPConnEnd** SPConnEndPair::getConnEnds()
{
    return _connEnd;
}

bool SPConnEndPair::isOrthogonal() const
{
    return _connType == SP_CONNECTOR_ORTHOGONAL;
}


static void redrawConnectorCallback(void *ptr)
{
    auto path = static_cast<SPPath *>(ptr);
    if (path->document == nullptr) {
        // This can happen when the document is being destroyed.
        return;
    }
    sp_conn_redraw_path(path);
}

void SPConnEndPair::rerouteFromManipulation()
{
    sp_conn_reroute_path_immediate(_path);
}


// Called from SPPath::update to initialise the endpoints.
void SPConnEndPair::update()
{
    if (_connType != SP_CONNECTOR_NOAVOID) {
        g_assert(_connRef != nullptr);
        if (!_connRef->isInitialised()) {
            _updateEndPoints();
            _connRef->setCallback(&redrawConnectorCallback, _path);
        }
    }
}

void SPConnEndPair::_updateEndPoints()
{
    Geom::Point endPt[2];
    getEndpoints(endPt);

    Avoid::Point src(endPt[0][Geom::X], endPt[0][Geom::Y]);
    Avoid::Point dst(endPt[1][Geom::X], endPt[1][Geom::Y]);

    _connRef->setEndpoints(src, dst);
}


bool SPConnEndPair::isAutoRoutingConn() const
{
    return _connType != SP_CONNECTOR_NOAVOID;
}

void SPConnEndPair::makePathInvalid()
{
    g_assert(_connRef != nullptr);

    _connRef->makePathInvalid();
}


// Redraws the curve along the recalculated route
// Straight or curved
void recreateCurve(SPCurve *curve, Avoid::ConnRef *connRef, const gdouble curvature)
{
    g_assert(connRef != nullptr);

    bool straight = curvature<1e-3;

    Avoid::PolyLine route = connRef->displayRoute();
    if (!straight) route = route.curvedPolyline(curvature);
    connRef->calcRouteDist();

    curve->reset();

    curve->moveto( Geom::Point(route.ps[0].x, route.ps[0].y) );
    int pn = route.size();
    for (int i = 1; i < pn; ++i) {
        Geom::Point p(route.ps[i].x, route.ps[i].y);
        if (straight) {
            curve->lineto( p );
        } else {
            switch (route.ts[i]) {
                case 'M':
                    curve->moveto( p );
                    break;
                case 'L':
                    curve->lineto( p );
                    break;
                case 'C':
                    g_assert( i+2<pn );
                    curve->curveto( p, Geom::Point(route.ps[i+1].x, route.ps[i+1].y),
                            Geom::Point(route.ps[i+2].x, route.ps[i+2].y) );
                    i+=2;
                    break;
            }
        }
    }
}


void SPConnEndPair::tellLibavoidNewEndpoints(bool const processTransaction)
{
    if (_connRef == nullptr || !isAutoRoutingConn()) {
        // Do nothing
        return;
    }
    makePathInvalid();

    _updateEndPoints();
    if (processTransaction) {
        _connRef->router()->processTransaction();
    }
    return;
}


bool SPConnEndPair::reroutePathFromLibavoid()
{
    if (_connRef == nullptr || !isAutoRoutingConn()) {
        // Do nothing
        return false;
    }

    SPCurve *curve = _path->curve();

    recreateCurve(curve, _connRef, _connCurvature);

    Geom::Affine doc2item = _path->i2doc_affine().inverse();
    curve->transform(doc2item);

    return true;
}


/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :