/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2006
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <QtGui/QPainter>
#include <QPrinter>
#include <QPrintDialog>

#include <stack>
#include <fstream>

#include <gecode/gist/treecanvas.hh>

#include <gecode/gist/nodevisitor.hh>
#include <gecode/gist/visualnode.hh>
#include <gecode/gist/drawingcursor.hh>

#include <gecode/search.hh>
#include <gecode/search/support.hh>

namespace Gecode { namespace Gist {

  TreeCanvas::TreeCanvas(Space* rootSpace, bool bab,
                         QWidget* parent, const Options& opt)
    : QWidget(parent)
    , mutex(QMutex::Recursive)
    , layoutMutex(QMutex::Recursive)
    , finishedFlag(false)
    , compareNodes(false), compareNodesBeforeFP(false)
    , autoHideFailed(true), autoZoom(false)
    , refresh(500), refreshPause(0), smoothScrollAndZoom(false)
    , moveDuringSearch(false)
    , zoomTimeLine(500)
    , scrollTimeLine(1000), targetX(0), sourceX(0), targetY(0), sourceY(0)
    , targetW(0), targetH(0), targetScale(0)
    , layoutDoneTimerId(0) {
      QMutexLocker locker(&mutex);
      curBest = (bab ? new BestNode(nullptr) : nullptr);
      if (rootSpace->status() == SS_FAILED) {
        if (!opt.clone)
          delete rootSpace;
        rootSpace = nullptr;
      } else {
        rootSpace = Gecode::Search::snapshot(rootSpace,opt);
      }
      na = new Node::NodeAllocator(bab);
      int rootIdx = na->allocate(rootSpace);
      assert(rootIdx == 0); (void) rootIdx;
      root = (*na)[0];
      root->layout(*na);
      root->setMarked(true);
      currentNode = root;
      pathHead = root;
      scale = LayoutConfig::defScale / 100.0;

      setAutoFillBackground(true);

      connect(&searcher, SIGNAL(update(int,int,int)), this,
                         SLOT(layoutDone(int,int,int)));
      connect(&searcher, SIGNAL(statusChanged(bool)), this,
              SLOT(statusChanged(bool)));

      connect(&searcher, SIGNAL(solution(const Space*)),
              this, SIGNAL(solution(const Space*)),
              Qt::BlockingQueuedConnection);
      connect(this, SIGNAL(solution(const Space*)),
              this, SLOT(inspectSolution(const Space*)));

      connect(&searcher, SIGNAL(moveToNode(VisualNode*,bool)),
              this, SLOT(setCurrentNode(VisualNode*,bool)),
              Qt::BlockingQueuedConnection);

      connect(&searcher, SIGNAL(searchFinished(void)), this, SIGNAL(searchFinished(void)));

      connect(&scrollTimeLine, SIGNAL(frameChanged(int)),
              this, SLOT(scroll(int)));
      scrollTimeLine.setCurveShape(QTimeLine::EaseInOutCurve);

      scaleBar = new QSlider(Qt::Vertical, this);
      scaleBar->setObjectName("scaleBar");
      scaleBar->setMinimum(LayoutConfig::minScale);
      scaleBar->setMaximum(LayoutConfig::maxScale);
      scaleBar->setValue(LayoutConfig::defScale);
      connect(scaleBar, SIGNAL(valueChanged(int)),
              this, SLOT(scaleTree(int)));
      connect(this, SIGNAL(scaleChanged(int)), scaleBar, SLOT(setValue(int)));
      connect(&searcher, SIGNAL(scaleChanged(int)),
              scaleBar, SLOT(setValue(int)));

      connect(&zoomTimeLine, SIGNAL(frameChanged(int)),
              scaleBar, SLOT(setValue(int)));
      zoomTimeLine.setCurveShape(QTimeLine::EaseInOutCurve);

      qRegisterMetaType<Statistics>("Statistics");
      update();
  }

  TreeCanvas::~TreeCanvas(void) {
    if (root) {
      DisposeCursor dc(root,*na);
      PreorderNodeVisitor<DisposeCursor>(dc).run();
    }
    delete na;
  }

  void
  TreeCanvas::addDoubleClickInspector(Inspector* i) {
    doubleClickInspectors.append(QPair<Inspector*,bool>(i,false));
  }

  void
  TreeCanvas::activateDoubleClickInspector(int i, bool active) {
    assert(i < doubleClickInspectors.size());
    doubleClickInspectors[i].second = active;
  }

  void
  TreeCanvas::addSolutionInspector(Inspector* i) {
    solutionInspectors.append(QPair<Inspector*,bool>(i,false));
  }

  void
  TreeCanvas::activateSolutionInspector(int i, bool active) {
    assert(i < solutionInspectors.size());
    solutionInspectors[i].second = active;
  }

  void
  TreeCanvas::addMoveInspector(Inspector* i) {
    moveInspectors.append(QPair<Inspector*,bool>(i,false));
  }

  void
  TreeCanvas::activateMoveInspector(int i, bool active) {
    assert(i < moveInspectors.size());
    moveInspectors[i].second = active;
  }

  void
  TreeCanvas::addComparator(Comparator* c) {
    comparators.append(QPair<Comparator*,bool>(c,false));
  }

  void
  TreeCanvas::activateComparator(int i, bool active) {
    assert(i < comparators.size());
    comparators[i].second = active;
  }

  void
  TreeCanvas::scaleTree(int scale0, int zoomx, int zoomy) {
    QMutexLocker locker(&layoutMutex);

    QSize viewport_size = size();
    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());

    if (zoomx==-1)
      zoomx = viewport_size.width()/2;
    if (zoomy==-1)
      zoomy = viewport_size.height()/2;

    int xoff = (sa->horizontalScrollBar()->value()+zoomx)/scale;
    int yoff = (sa->verticalScrollBar()->value()+zoomy)/scale;

    BoundingBox bb;
    scale0 = std::min(std::max(scale0, LayoutConfig::minScale),
                      LayoutConfig::maxScale);
    scale = (static_cast<double>(scale0)) / 100.0;
    bb = root->getBoundingBox();
    int w =
      static_cast<int>((bb.right-bb.left+Layout::extent)*scale);
    int h =
      static_cast<int>(2*Layout::extent+
        root->getShape()->depth()*Layout::dist_y*scale);

    sa->horizontalScrollBar()->setRange(0,w-viewport_size.width());
    sa->verticalScrollBar()->setRange(0,h-viewport_size.height());
    sa->horizontalScrollBar()->setPageStep(viewport_size.width());
    sa->verticalScrollBar()->setPageStep(viewport_size.height());
    sa->horizontalScrollBar()->setSingleStep(Layout::extent);
    sa->verticalScrollBar()->setSingleStep(Layout::extent);

    xoff *= scale;
    yoff *= scale;

    sa->horizontalScrollBar()->setValue(xoff-zoomx);
    sa->verticalScrollBar()->setValue(yoff-zoomy);

    emit scaleChanged(scale0);
    QWidget::update();
  }

  void
  TreeCanvas::update(void) {
    QMutexLocker locker(&mutex);
    layoutMutex.lock();
    if (root != nullptr) {
      root->layout(*na);
      BoundingBox bb = root->getBoundingBox();

      int w = static_cast<int>((bb.right-bb.left+Layout::extent)*scale);
      int h =
        static_cast<int>(2*Layout::extent+
          root->getShape()->depth()*Layout::dist_y*scale);
      xtrans = -bb.left+(Layout::extent / 2);

      QSize viewport_size = size();
      QAbstractScrollArea* sa =
        static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());
      sa->horizontalScrollBar()->setRange(0,w-viewport_size.width());
      sa->verticalScrollBar()->setRange(0,h-viewport_size.height());
      sa->horizontalScrollBar()->setPageStep(viewport_size.width());
      sa->verticalScrollBar()->setPageStep(viewport_size.height());
      sa->horizontalScrollBar()->setSingleStep(Layout::extent);
      sa->verticalScrollBar()->setSingleStep(Layout::extent);
    }
    if (autoZoom)
      zoomToFit();
    layoutMutex.unlock();
    QWidget::update();
  }

  void
  TreeCanvas::scroll(void) {
    QWidget::update();
  }

  void
  TreeCanvas::layoutDone(int w, int h, int scale0) {
    targetW = w; targetH = h; targetScale = scale0;

    QSize viewport_size = size();
    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());
    sa->horizontalScrollBar()->setRange(0,w-viewport_size.width());
    sa->verticalScrollBar()->setRange(0,h-viewport_size.height());

    if (layoutDoneTimerId == 0)
      layoutDoneTimerId = startTimer(15);
  }

  void
  TreeCanvas::statusChanged(bool finished) {
    if (finished) {
      update();
      centerCurrentNode();
    }
    emit statusChanged(currentNode, stats, finished);
  }

  void
  SearcherThread::search(VisualNode* n, bool all, TreeCanvas* ti) {
    node = n;

    depth = -1;
    for (VisualNode* p = n; p != nullptr; p = p->getParent(*ti->na))
      depth++;

    a = all;
    t = ti;
    start();
  }

  void
  SearcherThread::updateCanvas(void) {
    t->layoutMutex.lock();
    if (t->root == nullptr)
      return;

    if (t->autoHideFailed) {
      t->root->hideFailed(*t->na,true);
    }
    for (VisualNode* n = t->currentNode; n != nullptr; n=n->getParent(*t->na)) {
      if (n->isHidden()) {
        t->currentNode->setMarked(false);
        t->currentNode = n;
        t->currentNode->setMarked(true);
        break;
      }
    }

    t->root->layout(*t->na);
    BoundingBox bb = t->root->getBoundingBox();

    int w = static_cast<int>((bb.right-bb.left+Layout::extent)*t->scale);
    int h = static_cast<int>(2*Layout::extent+
                             t->root->getShape()->depth()
                              *Layout::dist_y*t->scale);
    t->xtrans = -bb.left+(Layout::extent / 2);

    int scale0 = static_cast<int>(t->scale*100);
    if (t->autoZoom) {
      QWidget* p = t->parentWidget();
      if (p) {
        double newXScale =
          static_cast<double>(p->width()) / (bb.right - bb.left +
                                             Layout::extent);
        double newYScale =
          static_cast<double>(p->height()) /
          (t->root->getShape()->depth() * Layout::dist_y + 2*Layout::extent);

        scale0 = static_cast<int>(std::min(newXScale, newYScale)*100);
        if (scale0<LayoutConfig::minScale)
          scale0 = LayoutConfig::minScale;
        if (scale0>LayoutConfig::maxAutoZoomScale)
          scale0 = LayoutConfig::maxAutoZoomScale;
        double scale = (static_cast<double>(scale0)) / 100.0;

        w = static_cast<int>((bb.right-bb.left+Layout::extent)*scale);
        h = static_cast<int>(2*Layout::extent+
                             t->root->getShape()->depth()*Layout::dist_y*scale);
      }
    }

    t->layoutMutex.unlock();
    emit update(w,h,scale0);
  }

  /// A stack item for depth first search
  class SearchItem {
  public:
    /// The node
    VisualNode* n;
    /// The currently explored child
    int i;
    /// The number of children
    int noOfChildren;
    /// Constructor
    SearchItem(VisualNode* n0, int noOfChildren0)
      : n(n0), i(-1), noOfChildren(noOfChildren0) {}
  };

  void
  SearcherThread::run(void) {
    {
      if (!node->isOpen())
        return;
      t->mutex.lock();
      emit statusChanged(false);

      unsigned int kids =
        node->getNumberOfChildNodes(*t->na, t->curBest, t->stats,
                                    t->c_d, t->a_d);
      if (kids == 0 || node->getStatus() == STOP) {
        t->mutex.unlock();
        updateCanvas();
        emit statusChanged(true);
        return;
      }

      std::stack<SearchItem> stck;
      stck.push(SearchItem(node,kids));
      t->stats.maxDepth =
        std::max(static_cast<long unsigned int>(t->stats.maxDepth),
                 static_cast<long unsigned int>(depth+stck.size()));

      VisualNode* sol = nullptr;
      int nodeCount = 0;
      t->stopSearchFlag = false;
      while (!stck.empty() && !t->stopSearchFlag) {
        if (t->refresh > 0 && nodeCount >= t->refresh) {
          node->dirtyUp(*t->na);
          updateCanvas();
          emit statusChanged(false);
          nodeCount = 0;
          if (t->refreshPause > 0)
            msleep(t->refreshPause);
        }
        SearchItem& si = stck.top();
        si.i++;
        if (si.i == si.noOfChildren) {
          stck.pop();
        } else {
          VisualNode* n = si.n->getChild(*t->na,si.i);
          if (n->isOpen()) {
            if (n->getStatus() == UNDETERMINED)
              nodeCount++;
            kids = n->getNumberOfChildNodes(*t->na, t->curBest, t->stats,
                                            t->c_d, t->a_d);
            if (t->moveDuringSearch)
              emit moveToNode(n,false);
            if (kids == 0) {
              if (n->getStatus() == SOLVED) {
                assert(n->hasCopy());
                emit solution(n->getWorkingSpace());
                n->purge(*t->na);
                sol = n;
                if (!a)
                  break;
              }
            } else {
              if ( n->getStatus() != STOP )
                stck.push(SearchItem(n,kids));
              else if (!a)
                break;
              t->stats.maxDepth =
                std::max(static_cast<long unsigned int>(t->stats.maxDepth),
                         static_cast<long unsigned int>(depth+stck.size()));
            }
          }
        }
      }
      node->dirtyUp(*t->na);
      t->stopSearchFlag = false;
      t->mutex.unlock();
      if (sol != nullptr) {
        t->setCurrentNode(sol,true,false);
      } else {
        t->setCurrentNode(node,true,false);
      }
    }
    updateCanvas();
    emit statusChanged(true);
    if (t->finishedFlag)
      emit searchFinished();
  }

  void
  TreeCanvas::searchAll(void) {
    QMutexLocker locker(&mutex);
    searcher.search(currentNode, true, this);
  }

  void
  TreeCanvas::searchOne(void) {
    QMutexLocker locker(&mutex);
    searcher.search(currentNode, false, this);
  }

  void
  TreeCanvas::toggleHidden(void) {
    QMutexLocker locker(&mutex);
    currentNode->toggleHidden(*na);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::hideFailed(void) {
    QMutexLocker locker(&mutex);
    currentNode->hideFailed(*na);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::unhideAll(void) {
    QMutexLocker locker(&mutex);
    QMutexLocker layoutLocker(&layoutMutex);
    currentNode->unhideAll(*na);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::toggleStop(void) {
    QMutexLocker locker(&mutex);
    currentNode->toggleStop(*na);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::unstopAll(void) {
    QMutexLocker locker(&mutex);
    QMutexLocker layoutLocker(&layoutMutex);
    currentNode->unstopAll(*na);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::timerEvent(QTimerEvent* e) {
    if (e->timerId() == layoutDoneTimerId) {
      if (!smoothScrollAndZoom) {
        scaleTree(targetScale);
      } else {
        zoomTimeLine.stop();
        int zoomCurrent = static_cast<int>(scale*100);
        int targetZoom = targetScale;
        targetZoom = std::min(std::max(targetZoom, LayoutConfig::minScale),
                              LayoutConfig::maxAutoZoomScale);
        zoomTimeLine.setFrameRange(zoomCurrent,targetZoom);
        zoomTimeLine.start();
      }
      QWidget::update();
      killTimer(layoutDoneTimerId);
      layoutDoneTimerId = 0;
    }
  }

  void
  TreeCanvas::zoomToFit(void) {
    QMutexLocker locker(&layoutMutex);
    if (root != nullptr) {
      BoundingBox bb;
      bb = root->getBoundingBox();
      QWidget* p = parentWidget();
      if (p) {
        double newXScale =
          static_cast<double>(p->width()) / (bb.right - bb.left +
                                             Layout::extent);
        double newYScale =
          static_cast<double>(p->height()) / (root->getShape()->depth() *
                                              Layout::dist_y +
                                              2*Layout::extent);
        int scale0 = static_cast<int>(std::min(newXScale, newYScale)*100);
        if (scale0<LayoutConfig::minScale)
          scale0 = LayoutConfig::minScale;
        if (scale0>LayoutConfig::maxAutoZoomScale)
          scale0 = LayoutConfig::maxAutoZoomScale;

        if (!smoothScrollAndZoom) {
          scaleTree(scale0);
        } else {
          zoomTimeLine.stop();
          int zoomCurrent = static_cast<int>(scale*100);
          int targetZoom = scale0;
          targetZoom = std::min(std::max(targetZoom, LayoutConfig::minScale),
                                LayoutConfig::maxAutoZoomScale);
          zoomTimeLine.setFrameRange(zoomCurrent,targetZoom);
          zoomTimeLine.start();
        }
      }
    }
  }

  void
  TreeCanvas::centerCurrentNode(void) {
    QMutexLocker locker(&mutex);
    int x=0;
    int y=0;

    VisualNode* c = currentNode;
    while (c != nullptr) {
      x += c->getOffset();
      y += Layout::dist_y;
      c = c->getParent(*na);
    }

    x = static_cast<int>((xtrans+x)*scale); y = static_cast<int>(y*scale);

    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());

    x -= sa->viewport()->width() / 2;
    y -= sa->viewport()->height() / 2;

    sourceX = sa->horizontalScrollBar()->value();
    targetX = std::max(sa->horizontalScrollBar()->minimum(), x);
    targetX = std::min(sa->horizontalScrollBar()->maximum(),
                       targetX);
    sourceY = sa->verticalScrollBar()->value();
    targetY = std::max(sa->verticalScrollBar()->minimum(), y);
    targetY = std::min(sa->verticalScrollBar()->maximum(),
                       targetY);
    if (!smoothScrollAndZoom) {
      sa->horizontalScrollBar()->setValue(targetX);
      sa->verticalScrollBar()->setValue(targetY);
    } else {
      scrollTimeLine.stop();
      scrollTimeLine.setFrameRange(0,100);
      scrollTimeLine.setDuration(std::max(200,
        std::min(1000,
        std::min(std::abs(sourceX-targetX),
                 std::abs(sourceY-targetY)))));
      scrollTimeLine.start();
    }
  }

  void
  TreeCanvas::scroll(int i) {
    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());
    double p = static_cast<double>(i)/100.0;
    double xdiff = static_cast<double>(targetX-sourceX)*p;
    double ydiff = static_cast<double>(targetY-sourceY)*p;
    sa->horizontalScrollBar()->setValue(sourceX+static_cast<int>(xdiff));
    sa->verticalScrollBar()->setValue(sourceY+static_cast<int>(ydiff));
  }

  void
  TreeCanvas::inspectCurrentNode(bool fix, int inspectorNo) {
    QMutexLocker locker(&mutex);

    if (currentNode->isHidden()) {
      toggleHidden();
      return;
    }

    int failedInspectorType = -1;
    int failedInspector = -1;
    bool needCentering = false;
    try {
      switch (currentNode->getStatus()) {
      case UNDETERMINED:
          {
            unsigned int kids =
              currentNode->getNumberOfChildNodes(*na,curBest,stats,c_d,a_d);
            int depth = -1;
            for (VisualNode* p = currentNode; p != nullptr; p=p->getParent(*na))
              depth++;
            if (kids > 0) {
              needCentering = true;
              depth++;
            }
            stats.maxDepth =
              std::max(stats.maxDepth, depth);
            if (currentNode->getStatus() == SOLVED) {
              assert(currentNode->hasCopy());
              emit solution(currentNode->getWorkingSpace());
            }
            emit statusChanged(currentNode,stats,true);
            for (int i=0; i<moveInspectors.size(); i++) {
              if (moveInspectors[i].second) {
                failedInspectorType = 0;
                failedInspector = i;
                if (currentNode->getStatus() == FAILED) {
                  if (!currentNode->isRoot()) {
                    Space* curSpace =
                      currentNode->getSpace(*na,curBest,c_d,a_d);
                    moveInspectors[i].first->inspect(*curSpace);
                    delete curSpace;
                  }
                } else {
                  moveInspectors[i].first->
                    inspect(*currentNode->getWorkingSpace());
                }
                failedInspectorType = -1;
              }
            }
            if (currentNode->getStatus() == SOLVED) {
              currentNode->purge(*na);
            }
          }
          break;
      case FAILED:
      case STOP:
      case UNSTOP:
      case BRANCH:
      case SOLVED:
        {
          Space* curSpace;

          if (fix) {
            if (currentNode->isRoot() && currentNode->getStatus() == FAILED)
              break;
            curSpace = currentNode->getSpace(*na,curBest,c_d,a_d);
            if (currentNode->getStatus() == SOLVED &&
                curSpace->status() != SS_SOLVED) {
              // in the presence of weakly monotonic propagators, we may have
              // to use search to find the solution here
              assert(curSpace->status() == SS_BRANCH &&
                     "Something went wrong - probably an incorrect brancher");
              Space* dfsSpace = Gecode::dfs(curSpace);
              delete curSpace;
              curSpace = dfsSpace;
            }
          } else {
            if (currentNode->isRoot())
              break;
            VisualNode* p = currentNode->getParent(*na);
            curSpace = p->getSpace(*na,curBest,c_d,a_d);
            switch (curSpace->status()) {
            case SS_SOLVED:
            case SS_FAILED:
              break;
            case SS_BRANCH:
              curSpace->commit(*p->getChoice(),
                               currentNode->getAlternative(*na));
              break;
            default:
              GECODE_NEVER;
            }
          }

          if (inspectorNo==-1) {
            for (int i=0; i<doubleClickInspectors.size(); i++) {
              if (doubleClickInspectors[i].second) {
                failedInspectorType = 1;
                failedInspector = i;
                doubleClickInspectors[i].first->inspect(*curSpace);
                failedInspectorType = -1;
              }
            }
          } else {
            failedInspectorType = 1;
            failedInspector = inspectorNo;
            doubleClickInspectors[inspectorNo].first->inspect(*curSpace);
            failedInspectorType = -1;
          }
          delete curSpace;
        }
        break;
      }
    } catch (Exception& e) {
      switch (failedInspectorType) {
      case 0:
        qFatal("Exception in move inspector %d: %s.\n Stopping.",
               failedInspector, e.what());
        break;
      case 1:
        qFatal("Exception in double click inspector %d: %s.\n Stopping.",
               failedInspector, e.what());
        break;
      default:
        qFatal("Exception: %s.\n Stopping.", e.what());
        break;
      }
    }

    currentNode->dirtyUp(*na);
    update();
    if (needCentering)
      centerCurrentNode();
  }

  void
  TreeCanvas::inspectBeforeFP(void) {
    inspectCurrentNode(false);
  }

  void
  TreeCanvas::labelBranches(void) {
    QMutexLocker locker(&mutex);
    currentNode->labelBranches(*na,curBest,c_d,a_d);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }
  void
  TreeCanvas::labelPath(void) {
    QMutexLocker locker(&mutex);
    currentNode->labelPath(*na,curBest,c_d,a_d);
    update();
    centerCurrentNode();
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::inspectSolution(const Space* s) {
    int failedInspectorType = -1;
    int failedInspector = -1;
    try {
      Space* c = nullptr;
      for (int i=0; i<solutionInspectors.size(); i++) {
        if (solutionInspectors[i].second) {
          if (c == nullptr)
            c = s->clone();
          failedInspectorType = 1;
          failedInspector = i;
          solutionInspectors[i].first->inspect(*c);
          failedInspectorType = -1;
        }
      }
      delete c;
    } catch (Exception& e) {
      switch (failedInspectorType) {
      case 0:
        qFatal("Exception in move inspector %d: %s.\n Stopping.",
               failedInspector, e.what());
        break;
      case 1:
        qFatal("Exception in solution inspector %d: %s.\n Stopping.",
               failedInspector, e.what());
        break;
      default:
        qFatal("Exception: %s.\n Stopping.", e.what());
        break;
      }
    }
  }

  void
  TreeCanvas::stopSearch(void) {
    stopSearchFlag = true;
    layoutDoneTimerId = startTimer(15);
  }

  void
  TreeCanvas::reset(void) {
    QMutexLocker locker(&mutex);
    Space* rootSpace =
      root->getStatus() == FAILED ? nullptr :
                           root->getSpace(*na,curBest,c_d,a_d);
    if (curBest != nullptr) {
      delete curBest;
      curBest = new BestNode(nullptr);
    }
    if (root) {
      DisposeCursor dc(root,*na);
      PreorderNodeVisitor<DisposeCursor>(dc).run();
    }
    delete na;
    na = new Node::NodeAllocator(curBest != nullptr);
    int rootIdx = na->allocate(rootSpace);
    assert(rootIdx == 0); (void) rootIdx;
    root = (*na)[0];
    root->setMarked(true);
    currentNode = root;
    pathHead = root;
    scale = 1.0;
    stats = Statistics();
    for (int i=bookmarks.size(); i--;)
      emit removedBookmark(i);
    bookmarks.clear();
    root->layout(*na);

    emit statusChanged(currentNode, stats, true);
    update();
  }

  void
  TreeCanvas::bookmarkNode(void) {
    QMutexLocker locker(&mutex);
    if (!currentNode->isBookmarked()) {
      bool ok;
      QString text =
        QInputDialog::getText(this, "Add bookmark", "Name:",
                              QLineEdit::Normal,"",&ok);
      if (ok) {
        currentNode->setBookmarked(true);
        bookmarks.append(currentNode);
        if (text == "")
          text = QString("Node ")+QString().setNum(bookmarks.size());
        emit addedBookmark(text);
      }
    } else {
      currentNode->setBookmarked(false);
      int idx = bookmarks.indexOf(currentNode);
      bookmarks.remove(idx);
      emit removedBookmark(idx);
    }
    currentNode->dirtyUp(*na);
    update();
  }

  void
  TreeCanvas::setPath(void) {
    QMutexLocker locker(&mutex);
    if(currentNode == pathHead)
      return;

    pathHead->unPathUp(*na);
    pathHead = currentNode;

    currentNode->pathUp(*na);
    currentNode->dirtyUp(*na);
    update();
  }

  void
  TreeCanvas::inspectPath(void) {
    QMutexLocker locker(&mutex);
    setCurrentNode(root);
    if (currentNode->isOnPath()) {
      inspectCurrentNode();
      int nextAlt = currentNode->getPathAlternative(*na);
      while (nextAlt >= 0) {
        setCurrentNode(currentNode->getChild(*na,nextAlt));
        inspectCurrentNode();
        nextAlt = currentNode->getPathAlternative(*na);
      }
    }
    update();
  }

  void
  TreeCanvas::startCompareNodes(void) {
    QMutexLocker locker(&mutex);
    compareNodes = true;
    compareNodesBeforeFP = false;
    setCursor(QCursor(Qt::CrossCursor));
  }

  void
  TreeCanvas::startCompareNodesBeforeFP(void) {
    QMutexLocker locker(&mutex);
    compareNodes = true;
    compareNodesBeforeFP = true;
    setCursor(QCursor(Qt::CrossCursor));
  }

  void
  TreeCanvas::emitStatusChanged(void) {
    emit statusChanged(currentNode, stats, true);
  }

  void
  TreeCanvas::navUp(void) {
    QMutexLocker locker(&mutex);

    VisualNode* p = currentNode->getParent(*na);

    setCurrentNode(p);

    if (p != nullptr) {
      centerCurrentNode();
    }
  }

  void
  TreeCanvas::navDown(void) {
    QMutexLocker locker(&mutex);
    if (!currentNode->isHidden()) {
      switch (currentNode->getStatus()) {
      case STOP:
      case UNSTOP:
      case BRANCH:
          {
            int alt = std::max(0, currentNode->getPathAlternative(*na));
            VisualNode* n = currentNode->getChild(*na,alt);
            setCurrentNode(n);
            centerCurrentNode();
            break;
          }
      case SOLVED:
      case FAILED:
      case UNDETERMINED:
        break;
      }
    }
  }

  void
  TreeCanvas::navLeft(void) {
    QMutexLocker locker(&mutex);
    VisualNode* p = currentNode->getParent(*na);
    if (p != nullptr) {
      int alt = currentNode->getAlternative(*na);
      if (alt > 0) {
        VisualNode* n = p->getChild(*na,alt-1);
        setCurrentNode(n);
        centerCurrentNode();
      }
    }
  }

  void
  TreeCanvas::navRight(void) {
    QMutexLocker locker(&mutex);
    VisualNode* p = currentNode->getParent(*na);
    if (p != nullptr) {
      unsigned int alt = currentNode->getAlternative(*na);
      if (alt + 1 < p->getNumberOfChildren()) {
        VisualNode* n = p->getChild(*na,alt+1);
        setCurrentNode(n);
        centerCurrentNode();
      }
    }
  }

  void
  TreeCanvas::navRoot(void) {
    QMutexLocker locker(&mutex);
    setCurrentNode(root);
    centerCurrentNode();
  }

  void
  TreeCanvas::navNextSol(bool back) {
    QMutexLocker locker(&mutex);
    NextSolCursor nsc(currentNode,back,*na);
    PreorderNodeVisitor<NextSolCursor> nsv(nsc);
    nsv.run();
    VisualNode* n = nsv.getCursor().node();
    if (n != root) {
      setCurrentNode(n);
      centerCurrentNode();
    }
  }

  void
  TreeCanvas::navPrevSol(void) {
    navNextSol(true);
  }

  void
  TreeCanvas::exportNodePDF(VisualNode* n) {
#if QT_VERSION >= 0x040400
    QString filename = QFileDialog::getSaveFileName(this, tr("Export tree as pdf"), "", tr("PDF (*.pdf)"));
    if (filename != "") {
      QPrinter printer(QPrinter::ScreenResolution);
      QMutexLocker locker(&mutex);

      BoundingBox bb = n->getBoundingBox();
      printer.setFullPage(true);
      printer.setPaperSize(QSizeF(bb.right-bb.left+Layout::extent,
                                  n->getShape()->depth() * Layout::dist_y +
                                  Layout::extent), QPrinter::Point);
      printer.setOutputFileName(filename);
      QPainter painter(&printer);

      painter.setRenderHint(QPainter::Antialiasing);

      QRect pageRect = printer.pageRect();
      double newXScale =
        static_cast<double>(pageRect.width()) / (bb.right - bb.left +
                                                 Layout::extent);
      double newYScale =
        static_cast<double>(pageRect.height()) /
                            (n->getShape()->depth() * Layout::dist_y +
                             Layout::extent);
      double printScale = std::min(newXScale, newYScale);
      painter.scale(printScale,printScale);

      int printxtrans = -bb.left+(Layout::extent / 2);

      painter.translate(printxtrans, Layout::dist_y / 2);
      QRect clip(0,0,0,0);
      DrawingCursor dc(n, *na, curBest, painter, clip, showCopies);
      currentNode->setMarked(false);
      PreorderNodeVisitor<DrawingCursor>(dc).run();
      currentNode->setMarked(true);
    }
#else
    (void) n;
#endif
  }

  void
  TreeCanvas::exportWholeTreePDF(void) {
#if QT_VERSION >= 0x040400
    exportNodePDF(root);
#endif
  }

  void
  TreeCanvas::exportPDF(void) {
#if QT_VERSION >= 0x040400
    exportNodePDF(currentNode);
#endif
  }

  void
  TreeCanvas::print(void) {
    QPrinter printer;
    if (QPrintDialog(&printer, this).exec() == QDialog::Accepted) {
      QMutexLocker locker(&mutex);

      BoundingBox bb = root->getBoundingBox();
      QRect pageRect = printer.pageRect();
      double newXScale =
        static_cast<double>(pageRect.width()) / (bb.right - bb.left +
                                                 Layout::extent);
      double newYScale =
        static_cast<double>(pageRect.height()) /
                            (root->getShape()->depth() * Layout::dist_y +
                             2*Layout::extent);
      double printScale = std::min(newXScale, newYScale)*100;
      if (printScale<1.0)
        printScale = 1.0;
      if (printScale > 400.0)
        printScale = 400.0;
      printScale = printScale / 100.0;

      QPainter painter(&printer);
      painter.setRenderHint(QPainter::Antialiasing);
      painter.scale(printScale,printScale);
      painter.translate(xtrans, 0);
      QRect clip(0,0,0,0);
      DrawingCursor dc(root, *na, curBest, painter, clip, showCopies);
      PreorderNodeVisitor<DrawingCursor>(dc).run();
    }
  }

  VisualNode*
  TreeCanvas::eventNode(QEvent* event) {
    int x = 0;
    int y = 0;
    switch (event->type()) {
    case QEvent::ToolTip:
        {
          QHelpEvent* he = static_cast<QHelpEvent*>(event);
          x = he->x();
          y = he->y();
          break;
        }
    case QEvent::MouseButtonDblClick:
    case QEvent::MouseButtonPress:
    case QEvent::MouseButtonRelease:
    case QEvent::MouseMove:
        {
          QMouseEvent* me = static_cast<QMouseEvent*>(event);
          x = me->x();
          y = me->y();
          break;
        }
    case QEvent::ContextMenu:
        {
          QContextMenuEvent* ce = static_cast<QContextMenuEvent*>(event);
          x = ce->x();
          y = ce->y();
          break;
        }
    default:
      return nullptr;
    }
    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());
    int xoff = sa->horizontalScrollBar()->value()/scale;
    int yoff = sa->verticalScrollBar()->value()/scale;

    BoundingBox bb = root->getBoundingBox();
    int w =
      static_cast<int>((bb.right-bb.left+Layout::extent)*scale);
    if (w < sa->viewport()->width())
      xoff -= (sa->viewport()->width()-w)/2;

    VisualNode* n;
    n = root->findNode(*na,
                       static_cast<int>(x/scale-xtrans+xoff),
                       static_cast<int>((y-30)/scale+yoff));
    return n;
  }

  bool
  TreeCanvas::event(QEvent* event) {
    if (mutex.tryLock()) {
      if (event->type() == QEvent::ToolTip) {
        VisualNode* n = eventNode(event);
        if (n != nullptr) {
          QHelpEvent* he = static_cast<QHelpEvent*>(event);
          QToolTip::showText(he->globalPos(),
                             QString(n->toolTip(*na,curBest,
                                                c_d,a_d).c_str()));
        } else {
          QToolTip::hideText();
        }
      }
      mutex.unlock();
    }
    return QWidget::event(event);
  }

  void
  TreeCanvas::resizeToOuter(void) {
    if (autoZoom)
      zoomToFit();
  }

  void
  TreeCanvas::paintEvent(QPaintEvent* event) {
    QMutexLocker locker(&layoutMutex);
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());
    int xoff = sa->horizontalScrollBar()->value()/scale;
    int yoff = sa->verticalScrollBar()->value()/scale;

    BoundingBox bb = root->getBoundingBox();
    int w =
      static_cast<int>((bb.right-bb.left+Layout::extent)*scale);
    if (w < sa->viewport()->width())
      xoff -= (sa->viewport()->width()-w)/2;

    QRect origClip = event->rect();
    painter.translate(0, 30);
    painter.scale(scale,scale);
    painter.translate(xtrans-xoff, -yoff);
    QRect clip(static_cast<int>(origClip.x()/scale-xtrans+xoff),
               static_cast<int>(origClip.y()/scale+yoff),
               static_cast<int>(origClip.width()/scale),
               static_cast<int>(origClip.height()/scale));
    DrawingCursor dc(root, *na, curBest, painter, clip, showCopies);
    PreorderNodeVisitor<DrawingCursor>(dc).run();

    // int nodesLayouted = 1;
    // clock_t t0 = clock();
    // while (v.next()) { nodesLayouted++; }
    // double t = (static_cast<double>(clock()-t0) / CLOCKS_PER_SEC) * 1000.0;
    // double nps = static_cast<double>(nodesLayouted) /
    //   (static_cast<double>(clock()-t0) / CLOCKS_PER_SEC);
    // std::cout << "Drawing done. " << nodesLayouted << " nodes in "
    //   << t << " ms. " << nps << " nodes/s." << std::endl;

  }

  void
  TreeCanvas::mouseDoubleClickEvent(QMouseEvent* event) {
    if (mutex.tryLock()) {
      if(event->button() == Qt::LeftButton) {
        VisualNode* n = eventNode(event);
        if(n == currentNode) {
          inspectCurrentNode();
          event->accept();
          mutex.unlock();
          return;
        }
      }
      mutex.unlock();
    }
    event->ignore();
  }

  void
  TreeCanvas::contextMenuEvent(QContextMenuEvent* event) {
    if (mutex.tryLock()) {
      VisualNode* n = eventNode(event);
      if (n != nullptr) {
        setCurrentNode(n);
        emit contextMenu(event);
        event->accept();
        mutex.unlock();
        return;
      }
      mutex.unlock();
    }
    event->ignore();
  }

  void
  TreeCanvas::resizeEvent(QResizeEvent* e) {
    QAbstractScrollArea* sa =
      static_cast<QAbstractScrollArea*>(parentWidget()->parentWidget());

    int w = sa->horizontalScrollBar()->maximum()+e->oldSize().width();
    int h = sa->verticalScrollBar()->maximum()+e->oldSize().height();

    sa->horizontalScrollBar()->setRange(0,w-e->size().width());
    sa->verticalScrollBar()->setRange(0,h-e->size().height());
    sa->horizontalScrollBar()->setPageStep(e->size().width());
    sa->verticalScrollBar()->setPageStep(e->size().height());
  }

  void
  TreeCanvas::wheelEvent(QWheelEvent* event) {
    if (event->modifiers() & Qt::ShiftModifier) {
      event->accept();
      if (event->orientation() == Qt::Vertical && !autoZoom)
        scaleTree(scale*100+ceil(static_cast<double>(event->delta())/4.0),
                  event->x(), event->y());
    } else {
      event->ignore();
    }
  }

  bool
  TreeCanvas::finish(void) {
    if (finishedFlag)
      return true;
    stopSearchFlag = true;
    finishedFlag = true;
    for (int i=0; i<doubleClickInspectors.size(); i++)
      doubleClickInspectors[i].first->finalize();
    for (int i=0; i<solutionInspectors.size(); i++)
      solutionInspectors[i].first->finalize();
    for (int i=0; i<moveInspectors.size(); i++)
      moveInspectors[i].first->finalize();
    for (int i=0; i<comparators.size(); i++)
      comparators[i].first->finalize();
    return !searcher.isRunning();
  }

  void
  TreeCanvas::setCurrentNode(VisualNode* n, bool finished, bool update) {
    if (finished)
      mutex.lock();
    if (update && n != nullptr && n != currentNode &&
        n->getStatus() != UNDETERMINED && !n->isHidden()) {
      Space* curSpace = nullptr;
      for (int i=0; i<moveInspectors.size(); i++) {
        if (moveInspectors[i].second) {
          if (curSpace == nullptr)
            curSpace = n->getSpace(*na,curBest,c_d,a_d);
          try {
            moveInspectors[i].first->inspect(*curSpace);
          } catch (Exception& e) {
            qFatal("Exception in move inspector %d: %s.\n Stopping.",
                   i, e.what());
          }
        }
      }
    }
    if (n != nullptr) {
      currentNode->setMarked(false);
      currentNode = n;
      currentNode->setMarked(true);
      emit statusChanged(currentNode,stats,finished);
      if (update) {
        compareNodes = false;
        setCursor(QCursor(Qt::ArrowCursor));
        QWidget::update();
      }
    }
    if (finished)
      mutex.unlock();
  }

  void
  TreeCanvas::mousePressEvent(QMouseEvent* event) {
    if (mutex.tryLock()) {
      if (event->button() == Qt::LeftButton) {
        VisualNode* n = eventNode(event);
        if (compareNodes) {
          if (n != nullptr && n->getStatus() != UNDETERMINED &&
              currentNode != nullptr &&
              currentNode->getStatus() != UNDETERMINED) {
            Space* curSpace = nullptr;
            Space* compareSpace = nullptr;
            for (int i=0; i<comparators.size(); i++) {
              if (comparators[i].second) {
                if (curSpace == nullptr) {
                  curSpace = currentNode->getSpace(*na,curBest,c_d,a_d);

                  if (!compareNodesBeforeFP || n->isRoot()) {
                    compareSpace = n->getSpace(*na,curBest,c_d,a_d);
                  } else {
                    VisualNode* p = n->getParent(*na);
                    compareSpace = p->getSpace(*na,curBest,c_d,a_d);
                    switch (compareSpace->status()) {
                    case SS_SOLVED:
                    case SS_FAILED:
                      break;
                    case SS_BRANCH:
                      compareSpace->commit(*p->getChoice(),
                                           n->getAlternative(*na));
                      break;
                    default:
                      GECODE_NEVER;
                    }
                  }
                }
                try {
                  comparators[i].first->compare(*curSpace,*compareSpace);
                } catch (Exception& e) {
                  qFatal("Exception in comparator %d: %s.\n Stopping.",
                    i, e.what());
                }
              }
            }
          }
        } else {
          setCurrentNode(n);
        }
        compareNodes = false;
        setCursor(QCursor(Qt::ArrowCursor));
        if (n != nullptr) {
          event->accept();
          mutex.unlock();
          return;
        }
      }
      mutex.unlock();
    }
    event->ignore();
  }

  void
  TreeCanvas::setRecompDistances(int c_d0, int a_d0) {
    c_d = c_d0; a_d = a_d0;
  }

  void
  TreeCanvas::setAutoHideFailed(bool b) {
    autoHideFailed = b;
  }

  void
  TreeCanvas::setAutoZoom(bool b) {
    autoZoom = b;
    if (autoZoom) {
      zoomToFit();
    }
    emit autoZoomChanged(b);
    scaleBar->setEnabled(!b);
  }

  void
  TreeCanvas::setShowCopies(bool b) {
    showCopies = b;
  }
  bool
  TreeCanvas::getShowCopies(void) {
    return showCopies;
  }

  bool
  TreeCanvas::getAutoHideFailed(void) {
    return autoHideFailed;
  }

  bool
  TreeCanvas::getAutoZoom(void) {
    return autoZoom;
  }

  void
  TreeCanvas::setRefresh(int i) {
    refresh = i;
  }

  void
  TreeCanvas::setRefreshPause(int i) {
    refreshPause = i;
    if (refreshPause > 0)
      refresh = 1;
  }

  bool
  TreeCanvas::getSmoothScrollAndZoom(void) {
    return smoothScrollAndZoom;
  }

  void
  TreeCanvas::setSmoothScrollAndZoom(bool b) {
    smoothScrollAndZoom = b;
  }

  bool
  TreeCanvas::getMoveDuringSearch(void) {
    return moveDuringSearch;
  }

  void
  TreeCanvas::setMoveDuringSearch(bool b) {
    moveDuringSearch = b;
  }

}}

// STATISTICS: gist-any