/*

  KLayout Layout Viewer
  Copyright (C) 2006-2017 Matthias Koefferlein

  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 2 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, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

*/


#include "dbUserObject.h"
#include "dbClipboard.h"
#include "tlString.h"
#include "tlAssert.h"
#include "layPlugin.h"
#include "layRenderer.h"
#include "laySnap.h"
#include "layLayoutView.h"
#include "laybasicConfig.h"
#include "layConverters.h"
#include "layLayoutCanvas.h"
#include "layProperties.h"
#include "antService.h"
#include "antPropertiesPage.h"
#include "antConfig.h"

namespace ant
{

// -------------------------------------------------------------
//  Convert buttons to an angle constraint

static lay::angle_constraint_type 
ac_from_buttons (unsigned int buttons)
{
  if ((buttons & lay::ShiftButton) != 0) {
    if ((buttons & lay::ControlButton) != 0) {
      return lay::AC_Any;
    } else {
      return lay::AC_Ortho;
    }
  } else {
    if ((buttons & lay::ControlButton) != 0) {
      return lay::AC_Diagonal;
    } else {
      return lay::AC_Global;
    }
  }
}

// -------------------------------------------------------------
//  Functionality to draw a ruler object

static void
tick_spacings (double d, double min_d, int &minor_ticks, double &ticks)
{
  if (min_d > d) {

    minor_ticks = -1;
    ticks = -1;

  } else {

    const double log10 = log (10.0);

    //  as a safety measure, not too many ticks are created.
    min_d = std::max (min_d, 0.001 * d);

    double l1 = log (min_d) / log10;
    double l0 = floor (l1);
    l1 -= l0;

    if (l1 < 0.3) {
      minor_ticks = 5;
    } else if (l1 < 0.7) {
      minor_ticks = 2;
    } else {
      minor_ticks = 1;
    }

    ticks = exp (log10 * l0) * 10.0;

  }
}

/**
 *  @brief Draw a ruler with the given parameters
 *
 *  @param q1 The first point in pixel space
 *  @param q2 The second point in pixel space
 *  @param length_u The ruler length in micron
 *  @param min_spc_u The minimum tick spacing in micron
 *  @param label The label text to draw
 *  @param sel True to draw ruler in "selected" mode
 *  @param right True to draw the ruler with ticks to the right (as seem from p1 to p2 in transformed space)
 *  @param style The style with which to draw the ruler
 *  @param bitmap The bitmap to draw the ruler on
 */
void 
draw_ruler (const db::DPoint &q1, const db::DPoint &q2, double length_u, double min_spc_u, const std::string &label, bool sel, bool right, ant::Object::style_type style, lay::CanvasPlane *bitmap, lay::Renderer &renderer)
{
  double arrow_width = 8 / renderer.resolution ();
  double arrow_length = 12 / renderer.resolution ();
  double sel_width = 2 / renderer.resolution ();

  if (length_u < 1e-5 /*micron*/) {

    if (sel) {
      
      db::DBox b (q1 - db::DVector (sel_width * 0.5, sel_width * 0.5),
                  q2 + db::DVector (sel_width * 0.5, sel_width * 0.5));

      renderer.draw (b, bitmap, bitmap, 0, 0);
      
    } else {
      renderer.draw (db::DEdge (q1, q1), 0, bitmap, 0, 0);
    }

    renderer.draw (db::DBox (q1, q1), 
                     label,
                     db::DefaultFont, 
                     db::HAlignLeft, 
                     db::VAlignBottom,
                     db::DFTrans (db::DFTrans::r0), 0, 0, 0, bitmap);
                     
  } else {

    //  compute the tick distribution
    double tick_length = (style == ant::Object::STY_ruler ? 8 : 0) / renderer.resolution ();

    double ticks = -1.0;
    int minor_ticks = -1;
    
    if (tick_length > 0) {
      tick_spacings (length_u, min_spc_u, minor_ticks, ticks);
    }

    //  normal and unit vector
    
    double len = q1.double_distance (q2);
    if (style == ant::Object::STY_arrow_end && len < double (arrow_length) * 1.2) {
      arrow_length = len / 1.2;
      arrow_width = arrow_length * 2.0 / 3.0;
    } else if (style == ant::Object::STY_arrow_both && len < double (arrow_length) * 2.4) {
      arrow_length = len / 2.4;
      arrow_width = arrow_length * 2.0 / 3.0;
    }
    
    db::DVector qq (q2.y () - q1.y (), q1.x () - q2.x ());
    qq *= 1.0 / len;
    if (!right) {
      qq = -qq;
    }

    db::DVector qu = q2 - q1;
    qu *= 1.0 / len;
      
    //  produce polygon stuff
      
    if (sel) {
      
      db::DVector qw = qq * (double (sel_width) * 0.5);
      
      db::DVector dq1, dq2;
      if (style == ant::Object::STY_arrow_both || style == ant::Object::STY_arrow_start) {
        dq1 = qu * double (arrow_length - 1);
      }
      if (style == ant::Object::STY_arrow_both || style == ant::Object::STY_arrow_end) {
        dq2 = qu * double (-(arrow_length - 1));
      }

      db::DPolygon p;
      db::DPoint points[] = {
        db::DPoint (q1 + dq1 + qw),
        db::DPoint (q2 + dq2 + qw),
        db::DPoint (q2 + dq2 - qw),
        db::DPoint (q1 + dq1 - qw),
      };
      p.assign_hull (points, points + sizeof (points) / sizeof (points [0]));
      renderer.draw (p, bitmap, bitmap, 0, 0);
      
    }

    if (style == ant::Object::STY_arrow_end || style == ant::Object::STY_arrow_both) {
      db::DPolygon p;
      db::DPoint points[] = {
        db::DPoint (q2),
        db::DPoint (q2 + qq * double (arrow_width * 0.5) - qu * double (arrow_length)),
        db::DPoint (q2 - qq * double (arrow_width * 0.5) - qu * double (arrow_length)),
      };
      p.assign_hull (points, points + sizeof (points) / sizeof (points [0]));
      renderer.draw (p, bitmap, bitmap, 0, 0);
    } 
    
    if (style == ant::Object::STY_arrow_start || style == ant::Object::STY_arrow_both) {
      db::DPolygon p;
      db::DPoint points[] = {
        db::DPoint (q1),
        db::DPoint (q1 + qq * double (arrow_width * 0.5) + qu * double (arrow_length)),
        db::DPoint (q1 - qq * double (arrow_width * 0.5) + qu * double (arrow_length))
      };
      p.assign_hull (points, points + sizeof (points) / sizeof (points [0]));
      renderer.draw (p, bitmap, bitmap, 0, 0);
    }

    //  produce edge and text stuff
    
    if (! sel) {
      renderer.draw (db::DEdge (q1, q2), 0, bitmap, 0, 0);
    }
    
    //  create three tick vectors in tv_text, tv_short and tv_long
    double tf = tick_length;
    db::DVector tv_text;
    if (style == ant::Object::STY_arrow_start || style == ant::Object::STY_arrow_both || style == ant::Object::STY_arrow_end) {
      tv_text = qq * (arrow_width * 0.5 + 2.0);
    } else {
      tv_text = qq * (tf + 2.0);
    }
    db::DVector tv_short = qq * tf * 0.5;
    db::DVector tv_long  = qq * tf;

    bool text_left;
    if (fabs (qq.x ()) > 1e-6) {
      text_left = qq.x () > 0.0;
    } else {
      text_left = q2.x () < q1.x ();
    }
    bool text_bottom;
    if (fabs (qq.y ()) > 1e-6) {
      text_bottom = qq.y () > 0.0;
    } else {
      text_bottom = q1.y () > q2.y ();
    }

    if (tick_length > 0) {
      renderer.draw (db::DEdge (q1, q1 + tv_long), 0, bitmap, 0, 0);
      renderer.draw (db::DEdge (q2, q2 + tv_long), 0, bitmap, 0, 0);
    }
    
    renderer.draw (db::DBox (q2 + tv_text, q2 + tv_text), 
                   label,
                   db::DefaultFont, 
                   (text_left ? db::HAlignLeft : db::HAlignRight), 
                   (text_bottom ? db::VAlignBottom : db::VAlignTop),
                   db::DFTrans (db::DFTrans::r0), 0, 0, 0, bitmap);
                     
    if (minor_ticks > 0 && ticks > 0.0) {

      db::DVector q = q2 - q1;

      int nmax = int (floor ((length_u / ticks) * double (minor_ticks) - 1e-6));
      for (int n = 1; n <= nmax; ++n) {

        double r = ticks * double (n) / double (minor_ticks) / length_u;

        db::DPoint qq = q1 + q * r;
        qq = db::DPoint (floor (qq.x () + 0.5), floor (qq.y () + 0.5));

        if (n % minor_ticks == 0) {
          renderer.draw (db::DEdge (qq, qq + tv_long), 0, bitmap, 0, 0);
        } else {
          renderer.draw (db::DEdge (qq, qq + tv_short), 0, bitmap, 0, 0);
        }

      }

    }

  }
}

void 
draw_ruler (const ant::Object &ruler, const db::DCplxTrans &trans, bool sel, lay::CanvasPlane *bitmap, lay::Renderer &renderer)
{
  //  round the starting point, shift both, and round the end point 
  std::pair <db::DPoint, db::DPoint> v = lay::snap (trans * ruler.p1 (), trans * ruler.p2 ());
  db::DPoint q1 = v.first;
  db::DPoint q2 = v.second;
  
  bool xy_swapped = ((trans.rot () % 2) != 0);
  double lu = ruler.p1 ().double_distance (ruler.p2 ());
  int min_tick_spc = int (0.5 + 20 / renderer.resolution ());  //  min tick spacing in canvas units
  double mu = double (min_tick_spc) / trans.ctrans (1.0);

  if (ruler.outline () == Object::OL_diag) {
    draw_ruler (q1, q2, lu, mu, ruler.text (), sel, q2.x () < q1.x (), ruler.style (), bitmap, renderer);
  }
  if ((!xy_swapped && (ruler.outline () == Object::OL_xy || ruler.outline () == Object::OL_diag_xy)) ||
      ( xy_swapped && (ruler.outline () == Object::OL_yx || ruler.outline () == Object::OL_diag_yx))) {
    bool r = (q2.x () > q1.x ()) ^ (q2.y () < q1.y ());
    if (ruler.outline () == Object::OL_diag_xy || ruler.outline () == Object::OL_diag_yx) {
      draw_ruler (q1, q2, lu, mu, ruler.text (), sel, !r, ruler.style (), bitmap, renderer);
    }
    draw_ruler (q1, db::DPoint (q2.x (), q1.y ()), lu, mu, ruler.text_x (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
    draw_ruler (db::DPoint (q2.x (), q1.y ()), q2, lu, mu, ruler.text_y (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
  }
  if ((!xy_swapped && (ruler.outline () == Object::OL_yx || ruler.outline () == Object::OL_diag_yx)) ||
      ( xy_swapped && (ruler.outline () == Object::OL_xy || ruler.outline () == Object::OL_diag_xy))) {
    bool r = (q2.x () > q1.x ()) ^ (q2.y () > q1.y ());
    if (ruler.outline () == Object::OL_diag_xy || ruler.outline () == Object::OL_diag_yx) {
      draw_ruler (q1, q2, lu, mu, ruler.text (), sel, !r, ruler.style (), bitmap, renderer);
    }
    draw_ruler (q1, db::DPoint (q1.x (), q2.y ()), lu, mu, ruler.text_y (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
    draw_ruler (db::DPoint (q1.x (), q2.y ()), q2, lu, mu, ruler.text_x (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
  }
  if (ruler.outline () == Object::OL_box) {
    bool r = (q2.x () > q1.x ()) ^ (q2.y () < q1.y ());
    draw_ruler (q1, db::DPoint (q2.x (), q1.y ()), lu, mu, ruler.text_x (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
    draw_ruler (db::DPoint (q2.x (), q1.y ()), q2, lu, mu, ruler.text_y (trans.fp_trans ()), sel, r, ruler.style (), bitmap, renderer);
    draw_ruler (q1, db::DPoint (q1.x (), q2.y ()), lu, mu, "", sel, !r, ruler.style (), bitmap, renderer);
    draw_ruler (db::DPoint (q1.x (), q2.y ()), q2, lu, mu, ruler.text (), sel, !r, ruler.style (), bitmap, renderer);
  }
}


// -------------------------------------------------------------

//  search range for select in pixels
static unsigned int search_range = 5;   // TODO: make variable?

// -------------------------------------------------------------

View::View (ant::Service *rulers, const ant::Object *ruler, bool selected)
  : lay::ViewObject (rulers->widget ()), 
    mp_rulers (rulers), m_selected (selected), mp_ruler (ruler)
{
  //  .. nothing else ..
}

View::~View ()
{
  //  .. nothing else ..
}

void 
View::transform_by (const db::DCplxTrans &t)
{
  if (m_trans != t) {
    m_trans = t;
    redraw ();
  }
}

void 
View::ruler (const ant::Object *r)
{
  mp_ruler = r;
  redraw ();
}

void 
View::render (const lay::Viewport &vp, lay::ViewObjectCanvas &canvas) 
{ 
  if (! mp_ruler) {
    return;
  }

  int basic_width = int(0.5 + 1.0 / canvas.resolution ());

  QColor c (mp_rulers->color ());
  if (! c.isValid ()) {
    c = QColor (canvas.foreground_color ().rgb ());
  }

  //  obtain bitmap to render on
  lay::CanvasPlane *plane;
  if (mp_rulers->with_halo ()) {
    std::vector <lay::ViewOp> ops;
    ops.reserve (2);
    //  we use 2 and 3 for the bitmap index. Since selection markers are using 0 and 1, rulers
    //  that are dragged appear in front of them.
    ops.push_back (lay::ViewOp (canvas.background_color ().rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, 3 * basic_width, 2));
    ops.push_back (lay::ViewOp (c.rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, basic_width, 3));
    plane = canvas.plane (ops);
  } else {
    plane = canvas.plane (lay::ViewOp (c.rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, basic_width));
  }

  draw_ruler (*mp_ruler, vp.trans () * m_trans, m_selected, plane, canvas.renderer ());
}

// -------------------------------------------------------------
//  ant::Service implementation

Service::Service (db::Manager *manager, lay::LayoutView *view)
  : lay::ViewService (view->view_object_widget ()), 
    lay::Editable (view),
    lay::Plugin (view),
    lay::Drawing (1/*number of planes*/, view->drawings ()),
    db::Object (manager),
    m_halo (true),
    m_snap_mode (lay::AC_Any),
    m_grid (0.001),
    m_grid_snap (false), m_obj_snap (false), m_snap_range (1),
    m_max_number_of_rulers (-1 /*unlimited*/),
    mp_view (view),
    mp_active_ruler (0),
    mp_transient_ruler (0),
    m_drawing (false), m_current (),
    m_move_mode (MoveNone),
    m_current_template (0)
{ 
  mp_view->annotations_changed_event.add (this, &Service::annotations_changed);
}

Service::~Service ()
{
  for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
    delete *r;
  }
  m_rulers.clear ();
  clear_transient_selection ();
}

bool 
Service::configure (const std::string &name, const std::string &value)
{
  bool taken = true;

  if (name == cfg_ruler_color) {

    QColor color;
    lay::ColorConverter ().from_string (value, color);

    //  make the color available for the dynamic view objects too.
    if (lay::test_and_set (m_color, color)) {
      widget ()->touch ();
    }

  } else if (name == cfg_ruler_halo) {

    bool halo;
    tl::from_string (value, halo);

    //  make the color available for the dynamic view objects too.
    if (lay::test_and_set (m_halo, halo)) {
      widget ()->touch ();
    }

  } else if (name == cfg_ruler_grid_micron) {

    double g = 0;
    tl::from_string (value, g);
    m_grid = g;
    taken = false; // to let others use the grid too.

  } else if (name == cfg_max_number_of_rulers) {

    int n = -1;
    tl::from_string (value, n);
    if (n != m_max_number_of_rulers) {
      m_max_number_of_rulers = n;
      reduce_rulers (n);
    }

  } else if (name == cfg_ruler_snap_range) {

    int n = 0;
    tl::from_string (value, n);
    m_snap_range = n;

  } else if (name == cfg_ruler_obj_snap) {
    tl::from_string (value, m_obj_snap);
  } else if (name == cfg_ruler_grid_snap) {
    tl::from_string (value, m_grid_snap);
  } else if (name == cfg_ruler_snap_mode) {

    lay::angle_constraint_type sm = lay::AC_Any;
    ACConverter ().from_string (value, sm);
    m_snap_mode = sm;

  } else if (name == cfg_ruler_templates) {
    m_ruler_templates = ant::Template::from_string (value); 
  } else if (name == cfg_current_ruler_template) {
    
    int n = 0;
    tl::from_string (value, n);
    m_current_template = n;

  } else {
    taken = false;
  }

  return taken;

}

const ant::Template &
Service::current_template () const
{
  if (m_current_template >= m_ruler_templates.size ()) {
    static ant::Template s_def_template;
    return s_def_template;
  } else {
    return m_ruler_templates [m_current_template];
  }
}

void 
Service::config_finalize ()
{
}

void
Service::annotations_changed ()
{
  //  NOTE: right now, we don't differentiate: every annotation change may be a change in an image too.
  //  We just forward this event as a potential image changed event
  annotations_changed_event ();
}

std::vector <lay::ViewOp>
Service::get_view_ops (lay::RedrawThreadCanvas &canvas, QColor background, QColor foreground, QColor /*active*/) const
{
  int basic_width = int(0.5 + 1.0 / canvas.resolution ());

  //  the changing of the view ops is done here since it may depend on the 
  //  background color which might be changed by another configure call later.
  std::vector <lay::ViewOp> view_ops;
  if (m_halo) {
    view_ops.push_back (lay::ViewOp (background.rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, 3 * basic_width, 0));
  }
  if (m_color.isValid ()) {
    view_ops.push_back (lay::ViewOp (m_color.rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, basic_width, 0));
  } else {
    view_ops.push_back (lay::ViewOp (foreground.rgb (), lay::ViewOp::Copy, 0, 0, 0, lay::ViewOp::Rect, basic_width, 0));
  }

  return view_ops;
}

void 
Service::clear_highlights ()
{
  for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
    (*r)->visible (false);
  }
}

void 
Service::restore_highlights ()
{
  for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
    (*r)->visible (true);
  }
}

void 
Service::highlight (unsigned int n)
{
  for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
    (*r)->visible (n-- == 0);
  }
}

void 
Service::clear_rulers ()
{
  drag_cancel ();
  reduce_rulers (0);
}

void 
Service::drag_cancel () 
{
  if (m_drawing) {

    widget ()->ungrab_mouse (this);

    if (mp_active_ruler) {
      delete mp_active_ruler;
      mp_active_ruler = 0;
    }

    m_drawing = false;

  }
}

int
Service::insert_ruler (const ant::Object &ruler, bool limit_number)
{
  //  determine the last id
  int idmax = -1;
  for (lay::AnnotationShapes::iterator r = mp_view->annotation_shapes ().begin (); r != mp_view->annotation_shapes ().end (); ++r) {
    const ant::Object *robj = dynamic_cast <const ant::Object *> (r->ptr ());
    if (robj) {
      if (robj->id () > idmax) {
        idmax = robj->id ();
      }
    }
  }

  //  create the ruler from the template
  ant::Object *new_ruler = new ant::Object (ruler);
  new_ruler->id (idmax + 1);
  mp_view->annotation_shapes ().insert (db::DUserObject (new_ruler));

  //  delete surplus rulers
  if (limit_number) {
    reduce_rulers (m_max_number_of_rulers);
  }

  return new_ruler->id ();
}

/**
 *  @brief Helper function to determine which move mode to choose given a certain search box and ant::Object
 */
static bool
dragging_what (const ant::Object *robj, const db::DBox &search_dbox, ant::Service::MoveMode &mode, db::DPoint &p1)
{
  db::DPoint p12, p21;
  bool has_p12 = false, has_p21 = false;
  
  if (robj->outline () == ant::Object::OL_xy || robj->outline () == ant::Object::OL_diag_xy || robj->outline () == ant::Object::OL_box) {
    p12 = db::DPoint (robj->p2 ().x (), robj->p1 ().y ());
    has_p12 = true;
  }
  if (robj->outline () == ant::Object::OL_yx || robj->outline () == ant::Object::OL_diag_yx || robj->outline () == ant::Object::OL_box) {
    p21 = db::DPoint (robj->p1 ().x (), robj->p2 ().y ());
    has_p21 = true;
  }
 
  //  HINT: this was implemented returning a std::pair<MoveMode, db::DPoint>, but 
  //  I was not able to get it to work in gcc 4.1.2 in -O3 mode ...
  
  if (search_dbox.contains (robj->p1 ())) {
    p1 = robj->p2 ();
    mode = ant::Service::MoveP1;
    return true;
  }
  if (search_dbox.contains (robj->p2 ())) {
    p1 = robj->p1 ();
    mode = ant::Service::MoveP2;
    return true;
  }
  if (has_p12 && search_dbox.contains (p12)) {
    p1 = p12;
    mode = ant::Service::MoveP12;
    return true;
  }
  if (has_p21 && search_dbox.contains (p21)) {
    p1 = p21;
    mode = ant::Service::MoveP21;
    return true;
  }
  if (has_p12 && search_dbox.touches (db::DBox (p12, robj->p2 ()))) {
    p1 = db::DPoint (p12.x (), search_dbox.center ().y ());
    mode = ant::Service::MoveP2X;
    return true;
  }
  if (has_p21 && search_dbox.touches (db::DBox (p21, robj->p1 ()))) {
    p1 = db::DPoint (p21.x (), search_dbox.center ().y ());
    mode = ant::Service::MoveP1X;
    return true;
  }
  if (has_p12 && search_dbox.touches (db::DBox (p12, robj->p1 ()))) {
    p1 = db::DPoint (search_dbox.center ().x (), p12.y ());
    mode = ant::Service::MoveP1Y;
    return true;
  }
  if (has_p21 && search_dbox.touches (db::DBox (p21, robj->p2 ()))) {
    p1 = db::DPoint (search_dbox.center ().x (), p21.y ());
    mode = ant::Service::MoveP2Y;
    return true;
  }
  if ((robj->outline () == ant::Object::OL_diag || robj->outline () == ant::Object::OL_diag_xy || robj->outline () == ant::Object::OL_diag_yx)
    && db::DEdge (robj->p1 (), robj->p2 ()).distance_abs (search_dbox.center ()) <= search_dbox.width () * 0.5) {
    p1 = search_dbox.center ();
    mode = ant::Service::MoveRuler;
    return true;
  }
  
  return false;
}

bool 
Service::begin_move (lay::Editable::MoveMode mode, const db::DPoint &p, lay::angle_constraint_type /*ac*/)
{
  //  cancel any pending move or drag operations, reset mp_active_ruler
  widget ()->drag_cancel (); // KLUDGE: every service does this to the same service manager

  //  choose move mode
  if (mode == lay::Editable::Selected) {

    m_move_mode = MoveSelected;
    m_p1 = p;
    m_trans = db::DTrans (db::DPoint () - m_p1);

    for (std::vector <ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
      (*r)->thaw ();
    }
    return false;

  } else if (mode == lay::Editable::Partial) {
  
    m_move_mode = MoveNone;

    //  compute search box
    double l = double (search_range) / widget ()->mouse_event_trans ().mag ();
    db::DBox search_dbox = db::DBox (p, p).enlarged (db::DVector (l, l));

    //  test, wether we are moving a handle of one selected object
    for (std::map<obj_iterator, unsigned int>::const_iterator r = m_selected.begin (); r != m_selected.end (); ++r) {

      obj_iterator ri = r->first;
      const ant::Object *robj = dynamic_cast <const ant::Object *> ((*ri).ptr ());
      if (robj) {
        
        if (dragging_what (robj, search_dbox, m_move_mode, m_p1) && m_move_mode != MoveRuler) {
          
          //  found anything: make the moved ruler the selection
          clear_selection ();
          m_selected.insert (std::make_pair (ri, 0));
          m_current = *robj;
          m_original = m_current; 
          m_rulers.push_back (new ant::View (this, &m_current, true));
          m_rulers.back ()->thaw ();
          return true;
          
        }

      }
      
    }

    //  nothing was found
    return false;

  } else if (mode == lay::Editable::Any) {
  
    m_move_mode = MoveNone;

    //  compute search box
    double l = double (search_range) / widget ()->mouse_event_trans ().mag ();
    db::DBox search_dbox = db::DBox (p, p).enlarged (db::DVector (l, l));

    //  box-selection

    lay::AnnotationShapes::touching_iterator r = mp_view->annotation_shapes ().begin_touching (search_dbox);

    while (m_move_mode == MoveNone && ! r.at_end ()) {
      
      const ant::Object *robj = dynamic_cast <const ant::Object *> ((*r).ptr ());
      if (robj) {
        
        if (dragging_what (robj, search_dbox, m_move_mode, m_p1)) {
          
          //  found anything: make the moved ruler the selection
          clear_selection ();
          m_selected.insert (std::make_pair (mp_view->annotation_shapes ().iterator_from_pointer (&*r), 0));
          m_current = *robj;
          m_original = m_current; 
          m_rulers.push_back (new ant::View (this, &m_current, true));
          m_rulers.back ()->thaw ();
          return true;
          
        }

      }
      
      ++r;
      
    }

    //  nothing was found
    return false;

  } else {
    return false;
  }
}

void
Service::move_transform (const db::DPoint &p, db::DFTrans tr, lay::angle_constraint_type /*ac*/)
{
  if (m_rulers.empty () || m_selected.empty ()) {
    return;
  }

  if (m_move_mode == MoveRuler) {

    db::DVector dp = p - db::DPoint ();

    m_original.transform (db::DTrans (m_p1 - db::DPoint ()) * db::DTrans (tr) * db::DTrans (db::DPoint () - m_p1));
    m_current.transform (db::DTrans (dp) * db::DTrans (tr) * db::DTrans (-dp));

    //  display current rulers' parameters
    show_message ();

    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveSelected) {

    m_trans *= db::DTrans (m_p1 - db::DPoint ()) * db::DTrans (tr) * db::DTrans (db::DPoint () - m_p1);

    for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
      (*r)->transform_by (db::DCplxTrans (m_trans));
    }

  }

}

void 
Service::move (const db::DPoint &p, lay::angle_constraint_type ac)
{
  if (m_rulers.empty () || m_selected.empty ()) {
    return;
  }

  if (m_move_mode == MoveP1) {
    
    m_current.p1 (snap2 (m_p1, p, &m_current, ac).second);
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP2) {
    
    m_current.p2 (snap2 (m_p1, p, &m_current, ac).second);
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP12) {
    
    db::DPoint p12 = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p1 (db::DPoint (m_current.p1 ().x(), p12.y ()));
    m_current.p2 (db::DPoint (p12.x (), m_current.p2 ().y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP21) {
    
    db::DPoint p21 = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p1 (db::DPoint (p21.x (), m_current.p1 ().y ()));
    m_current.p2 (db::DPoint (m_current.p2 ().x(), p21.y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP1X) {
    
    db::DPoint pc = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p1 (db::DPoint (pc.x (), m_current.p1 ().y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP2X) {
    
    db::DPoint pc = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p2 (db::DPoint (pc.x (), m_current.p2 ().y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP1Y) {
    
    db::DPoint pc = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p1 (db::DPoint (m_current.p1 ().x (), pc.y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveP2Y) {
    
    db::DPoint pc = snap2 (m_p1, p, &m_current, ac).second;
    m_current.p2 (db::DPoint (m_current.p2 ().x (), pc.y ()));
    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveRuler) {

    //  try two ways of snapping
    db::DVector dp = p - m_p1;

    db::DPoint p1 = m_original.p1 () + dp;
    db::DPoint p2 = m_original.p2 () + dp;

    std::pair<bool, db::DPoint> r1 = snap1 (p1, m_obj_snap && m_original.snap ());
    db::DPoint q1 = r1.second;
    std::pair<bool, db::DPoint> r2 = snap1 (p2, m_obj_snap && m_original.snap ());
    db::DPoint q2 = r2.second;

    if ((!r2.first && r1.first) || ((r1.first || (!r1.first && !r2.first)) && q1.distance (p1) < q2.distance (p2))) {
      q2 = q1 + (m_original.p2 () - m_original.p1 ());
    } else {
      q1 = q2 + (m_original.p1 () - m_original.p2 ());
    }

    m_current.p1 (q1);
    m_current.p2 (q2);

    m_rulers [0]->redraw ();

  } else if (m_move_mode == MoveSelected) {

    db::DVector dp = p - m_trans (m_p1);
    //  round the drag distance to grid if required: this is the least we can do in this case
    if (m_grid_snap) {
      dp = db::DVector (lay::snap (dp.x (), m_grid), lay::snap (dp.y (), m_grid));
    } 

    m_trans = db::DTrans (dp) * m_trans;

    for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
      (*r)->transform_by (db::DCplxTrans (m_trans));
    }

  }

  if (m_move_mode != MoveSelected) {
    show_message ();
  }

}

void 
Service::show_message ()
{
  //  display current rulers' parameters
  std::string pos = std::string ("lx: ") + tl::micron_to_string (m_current.p2 ().x () - m_current.p1 ().x ()) 
                      + "  ly: " + tl::micron_to_string (m_current.p2 ().y () - m_current.p1 ().y ()) 
                      + "  l: " + tl::micron_to_string (m_current.p2 ().distance (m_current.p1 ()));
  view ()->message (pos);
}

void 
Service::end_move (const db::DPoint &, lay::angle_constraint_type)
{
  if (! m_rulers.empty () && ! m_selected.empty ()) {

    if (m_move_mode == MoveSelected) {

      //  replace the rulers that were moved:
      for (std::map<obj_iterator, unsigned int>::const_iterator s = m_selected.begin (); s != m_selected.end (); ++s) {

        const ant::Object *robj = dynamic_cast<const ant::Object *> (s->first->ptr ());
        if (robj) {

          //  compute moved object and replace
          ant::Object *rnew = new ant::Object (*robj);
          rnew->transform (m_trans);
          mp_view->annotation_shapes ().replace (s->first, db::DUserObject (rnew));
          annotation_changed_event (rnew->id ());

        }

      }

      //  and make selection "visible"
      selection_to_view ();

    } else if (m_move_mode != MoveNone) {

      //  replace the ruler that was moved
      mp_view->annotation_shapes ().replace (m_selected.begin ()->first, db::DUserObject (new ant::Object (m_current)));
      annotation_changed_event (m_current.id ());

      //  clear the selection (that was artifically created before)
      clear_selection ();

    }

  }

  //  termine the operation
  m_move_mode = MoveNone;

}

void
Service::selection_to_view ()
{
  annotation_selection_changed_event ();

  //  the selection objects need to be recreated since we destroyed the old rulers
  for (std::vector<ant::View *>::iterator r = m_rulers.begin (); r != m_rulers.end (); ++r) {
    delete *r;
  }
  m_rulers.clear ();
  m_rulers.reserve (m_selected.size ());
  for (std::map<obj_iterator, unsigned int>::iterator r = m_selected.begin (); r != m_selected.end (); ++r) {
    r->second = (unsigned int) m_rulers.size ();
    const ant::Object *robj = dynamic_cast<const ant::Object *> (r->first->ptr ());
    m_rulers.push_back (new ant::View (this, robj, true /*selected*/));
  }
}

db::DBox 
Service::selection_bbox ()
{
  db::DBox box;
  for (std::map<obj_iterator, unsigned int>::iterator r = m_selected.begin (); r != m_selected.end (); ++r) {
    const ant::Object *robj = dynamic_cast<const ant::Object *> (r->first->ptr ());
    if (robj) {
      box += robj->box ();
    }
  }
  return box;
}

void 
Service::transform (const db::DCplxTrans &trans)
{
  //  replace the rulers that were transformed:
  for (std::map<obj_iterator, unsigned int>::const_iterator s = m_selected.begin (); s != m_selected.end (); ++s) {

    const ant::Object *robj = dynamic_cast<const ant::Object *> (s->first->ptr ());
    if (robj) {

      //  compute transformed object and replace
      ant::Object *rnew = new ant::Object (*robj);
      rnew->transform (trans);
      mp_view->annotation_shapes ().replace (s->first, db::DUserObject (rnew));
      annotation_changed_event (rnew->id ());

    }

  }

  selection_to_view ();
}

void 
Service::edit_cancel () 
{
  //  Cancel any move operation
  if (m_move_mode != MoveNone) {

    m_move_mode = MoveNone;
    selection_to_view ();

  }
}

bool 
Service::mouse_press_event (const db::DPoint &p, unsigned int buttons, bool prio) 
{
  return mouse_click_event (p, buttons, prio);
}

bool 
Service::mouse_click_event (const db::DPoint &p, unsigned int buttons, bool prio) 
{
  if (prio && (buttons & lay::LeftButton) != 0) {

    if (! m_drawing) {

      //  cancel any edit operations so far
      m_move_mode = MoveNone;

      //  reset selection
      clear_selection ();
         
      //  set the maximum number of rulers minus 1 to account for the new ruler
      //  and clear surplus rulers
      reduce_rulers (m_max_number_of_rulers - 1);

      m_p1 = snap1 (p, m_obj_snap && current_template ().snap ()).second;

      //  create and start dragging the ruler
      
      m_current = ant::Object (m_p1, m_p1, 0, current_template ());
      show_message ();
      
      if (mp_active_ruler) {
        delete mp_active_ruler;
      }
      mp_active_ruler = new ant::View (this, &m_current, false /*not selected*/);
      mp_active_ruler->thaw ();
      m_drawing = true;

      widget ()->grab_mouse (this, false);

    } else {

      //  create the ruler object

      //  begin the transaction
      tl_assert (! manager ()->transacting ());
      manager ()->transaction (tl::to_string (QObject::tr ("Create ruler"))); 

      show_message ();

      insert_ruler (ant::Object (m_current.p1 (), m_current.p2 (), 0, current_template ()), true);

      //  stop dragging
      drag_cancel ();

      //  end the transaction
      manager ()->commit ();
      
    }

    return true;

  }

  return false;
}

bool 
Service::mouse_move_event (const db::DPoint &p, unsigned int buttons, bool prio) 
{
  if (m_drawing && prio) {

    set_cursor (lay::Cursor::cross);

    m_current.p2 (snap2 (m_p1, p, mp_active_ruler->ruler (), ac_from_buttons (buttons)).second);
    mp_active_ruler->redraw ();
    show_message ();

  }

  return false;
}

void 
Service::deactivated ()
{
  drag_cancel ();
}

std::pair<bool, db::DPoint> 
Service::snap1 (const db::DPoint &p, bool obj_snap, const std::vector <db::DEdge> &cutlines)
{
  db::DVector g;
  if (m_grid_snap) {
    g = db::DVector (m_grid, m_grid);
  }

  double snap_range = widget ()->mouse_event_trans ().inverted ().ctrans (m_snap_range);
  return lay::obj_snap (obj_snap ? mp_view : 0, p, g, snap_range, cutlines);
}


std::pair <bool, db::DPoint>
Service::snap2 (const db::DPoint &p1, const db::DPoint &p2, const ant::Object *obj, lay::angle_constraint_type ac)
{
  db::DVector g;
  if (m_grid_snap) {
    g = db::DVector (m_grid, m_grid);
  }

  double snap_range = widget ()->mouse_event_trans ().inverted ().ctrans (m_snap_range);
  lay::angle_constraint_type snap_mode = ac == lay::AC_Global ? (obj->angle_constraint () == lay::AC_Global ? m_snap_mode : obj->angle_constraint ()) : ac;

  return lay::obj_snap (m_obj_snap && obj->snap () ? mp_view : 0, p1, p2, g, snap_mode, snap_range);
}


struct RulerIdComp 
{
  bool operator() (const lay::AnnotationShapes::iterator &a, const lay::AnnotationShapes::iterator &b) const
  {
    return dynamic_cast<const ant::Object &>(*a->ptr ()).id () < dynamic_cast<const ant::Object &>(*b->ptr ()).id ();
  }
};

void
Service::reduce_rulers (int num)
{
  lay::AnnotationShapes::iterator rfrom = mp_view->annotation_shapes ().begin (); 
  lay::AnnotationShapes::iterator rto = mp_view->annotation_shapes ().end ();

  size_t n = std::distance (rfrom, rto);
  if (num >= 0 && int (n) > num) {

    //  clear selection
    clear_selection ();

    //  extract all rulers and other objects

    std::vector <lay::AnnotationShapes::iterator> positions;
    positions.reserve (n);

    for (lay::AnnotationShapes::iterator r = rfrom; r != rto; ++r) {
      const ant::Object *robj = dynamic_cast <const ant::Object *> (r->ptr ());
      if (robj) {
        positions.push_back (r);
      }
    }

    //  sort so we find the ones that are too old, remove them and sort the 
    //  remaining positions
    tl::sort (positions.begin (), positions.end (), RulerIdComp ());  // HINT: must be tl::sort, not std::sort because gcc 3.2.3 has some strange namespace resolution problems ..
    positions.erase (positions.begin () + (positions.size () - num), positions.end ());
    tl::sort (positions.begin (), positions.end ());  // HINT: must be tl::sort, not std::sort because gcc 3.2.3 has some strange namespace resolution problems ..

    //  now we can erase these positions
    mp_view->annotation_shapes ().erase_positions (positions.begin (), positions.end ());

  }

}

void 
Service::cut ()
{
  if (selection_size () > 0) {

    //  copy & delete the selected rulers
    copy_selected ();
    del_selected ();

  }
}

void 
Service::copy ()
{
  //  copy the selected rulers
  copy_selected ();
}

void
Service::copy_selected ()
{
  //  extract all selected rulers and paste in "micron" space
  for (std::map<obj_iterator, unsigned int>::iterator r = m_selected.begin (); r != m_selected.end (); ++r) {
    r->second = (unsigned int) m_rulers.size ();
    const ant::Object *robj = dynamic_cast<const ant::Object *> (r->first->ptr ());
    if (robj) {
      db::Clipboard::instance () += new db::ClipboardValue<ant::Object> (*robj);
    }
  }
}

void 
Service::paste ()
{
  if (db::Clipboard::instance ().begin () != db::Clipboard::instance ().end ()) {

    //  determine the last id
    int idmax = -1;
    for (lay::AnnotationShapes::iterator r = mp_view->annotation_shapes ().begin (); r != mp_view->annotation_shapes ().end (); ++r) {
      const ant::Object *robj = dynamic_cast <const ant::Object *> (r->ptr ());
      if (robj && robj->id () > idmax) {
        idmax = robj->id ();
      }
    }

    for (db::Clipboard::iterator c = db::Clipboard::instance ().begin (); c != db::Clipboard::instance ().end (); ++c) {
      const db::ClipboardValue<ant::Object> *value = dynamic_cast<const db::ClipboardValue<ant::Object> *> (*c);
      if (value) {
        ant::Object *ruler = new ant::Object (value->get ());
        ruler->id (++idmax);
        mp_view->annotation_shapes ().insert (db::DUserObject (ruler));
      }
    }

  }

}

void 
Service::del ()
{
  if (selection_size () > 0) {

    //  delete the selected rulers
    del_selected ();

  }
}

void
Service::del_selected ()
{
  //  positions will hold a set of iterators that are to be erased
  std::vector <lay::AnnotationShapes::iterator> positions;
  positions.reserve (m_selected.size ());
  for (std::map<obj_iterator, unsigned int>::iterator r = m_selected.begin (); r != m_selected.end (); ++r) {
    positions.push_back (r->first);
  }

  //  clear selection
  clear_selection ();

  //  erase all and insert the ones that we want to keep 
  tl::sort (positions.begin (), positions.end ());  // HINT: must be tl::sort, not std::sort because gcc 3.2.3 has some strange namespace resolution problems ..
  mp_view->annotation_shapes ().erase_positions (positions.begin (), positions.end ());
}

size_t 
Service::selection_size ()
{
  return m_selected.size ();
}

bool 
Service::select (obj_iterator obj, lay::Editable::SelectionMode mode)
{
  if (mode == lay::Editable::Replace || mode == lay::Editable::Add) {
    //  select
    if (m_selected.find (obj) == m_selected.end ()) {
      m_selected.insert (std::make_pair (obj, 0));
      return true;
    }
  } else if (mode == lay::Editable::Reset) {
    //  unselect
    if (m_selected.find (obj) != m_selected.end ()) {
      m_selected.erase (obj);
      return true;
    }
  } else {
    //  invert selection
    if (m_selected.find (obj) != m_selected.end ()) {
      m_selected.erase (obj);
    } else {
      m_selected.insert (std::make_pair (obj, 0));
    }
    return true;
  }
  return false;
}

void
Service::clear_selection ()
{
  select (db::DBox (), lay::Editable::Reset);
}

static bool 
is_selected (const ant::Object &ruler, const db::DPoint &pos, double enl, double &distance) 
{
  db::DBox b (ruler.p1 (), ruler.p2 ());

  //  enlarge this box by some pixels
  b.enlarge (db::DVector (enl, enl));

  if (! b.contains (pos)) {
    return false;
  }
  
  db::DEdge edges[4];
  unsigned int nedges = 0;
  
  if (ruler.outline () == ant::Object::OL_diag || 
      ruler.outline () == ant::Object::OL_diag_xy ||
      ruler.outline () == ant::Object::OL_diag_yx) {
    edges [nedges++] = db::DEdge (ruler.p1 (), ruler.p2 ());
  }
  if (ruler.outline () == ant::Object::OL_xy ||
      ruler.outline () == ant::Object::OL_diag_xy ||     
      ruler.outline () == ant::Object::OL_box) {
    edges [nedges++] = db::DEdge (ruler.p1 (), db::DPoint (ruler.p2 ().x (), ruler.p1 ().y ()));
    edges [nedges++] = db::DEdge (db::DPoint (ruler.p2 ().x (), ruler.p1 ().y ()), ruler.p2 ());
  }
  if (ruler.outline () == ant::Object::OL_yx ||
      ruler.outline () == ant::Object::OL_diag_yx ||     
      ruler.outline () == ant::Object::OL_box) {
    edges [nedges++] = db::DEdge (ruler.p1 (), db::DPoint (ruler.p1 ().x (), ruler.p2 ().y ()));
    edges [nedges++] = db::DEdge (db::DPoint (ruler.p1 ().x (), ruler.p2 ().y ()), ruler.p2 ());
  }
    
  for (unsigned int i = 0; i < nedges; ++i) {
    double d = edges [i].distance_abs (pos);
    if (d <= enl) {
      distance = d;
      return true;
    } 
  }  

  return false;
}

static bool 
is_selected (const ant::Object &ruler, const db::DBox &box, double /*enl*/)
{
  return (box.contains (ruler.p1 ()) && box.contains (ruler.p2 ()));
}

double
Service::click_proximity (const db::DPoint &pos, lay::Editable::SelectionMode mode)
{
  //  compute search box
  double l = double (search_range) / widget ()->mouse_event_trans ().mag ();
  db::DBox search_dbox = db::DBox (pos, pos).enlarged (db::DVector (l, l));

  //  for single-point selections either exclude the current selection or the
  //  accumulated previous selection from the search.
  const std::map<obj_iterator, unsigned int> *exclude = 0;
  if (mode == lay::Editable::Replace) {
    exclude = &m_previous_selection;
  } else if (mode == lay::Editable::Add) {
    exclude = &m_selected;
  } else if (mode == lay::Editable::Reset) {
    //  TODO: the finder should favor the current selection in this case.
  }

  //  point selection: look for the "closest" ruler
  double dmin = std::numeric_limits <double>::max ();
  bool any_found = false;

  lay::AnnotationShapes::touching_iterator r = mp_view->annotation_shapes ().begin_touching (search_dbox);
  while (! r.at_end ()) {
    const ant::Object *robj = dynamic_cast<const ant::Object *> ((*r).ptr ());
    if (robj && (! exclude || exclude->find (mp_view->annotation_shapes ().iterator_from_pointer (&*r)) == exclude->end ())) {
      double d;
      if (is_selected (*robj, pos, l, d)) {
        if (! any_found || d < dmin) {
          dmin = d;
        }
        any_found = true;
      }
    }
    ++r;
  }

  //  return the proximity value
  if (any_found) {
    return dmin;
  } else {
    return lay::Editable::click_proximity (pos, mode); 
  } 
}

bool
Service::transient_select (const db::DPoint &pos)
{
  clear_transient_selection ();

  //  if in move mode (which also receives transient_select requests) the move will take the selection,
  //  hence don't do a transient selection if there is one.
  if (view ()->has_selection () && view ()->is_move_mode ()) {
    return false;
  }

  bool any_selected = false;

  //  compute search box
  double l = double (search_range) / widget ()->mouse_event_trans ().mag ();
  db::DBox search_dbox = db::DBox (pos, pos).enlarged (db::DVector (l, l));

  //  point selection: look for the "closest" ruler
  double dmin = std::numeric_limits <double>::max ();

  lay::AnnotationShapes::touching_iterator r = mp_view->annotation_shapes ().begin_touching (search_dbox);
  lay::AnnotationShapes::touching_iterator rmin (r);
  while (! r.at_end ()) {
    const ant::Object *robj = dynamic_cast<const ant::Object *> ((*r).ptr ());
    if (robj && m_previous_selection.find (mp_view->annotation_shapes ().iterator_from_pointer (&*r)) == m_previous_selection.end ()) {
      double d;
      if (is_selected (*robj, pos, l, d)) {
        if (! any_selected || d < dmin) {
          rmin = r;
          dmin = d;
        }
        any_selected = true;
      }
    }
    ++r;
  }

  //  create the transient marker for the object found 
  if (any_selected) {
    const ant::Object *robj = dynamic_cast<const ant::Object *> ((*rmin).ptr ());
    //  HINT: there is no special style for "transient selection on rulers"
    mp_transient_ruler = new ant::View (this, robj, true /*selected*/);
  }

  if (any_selected && editables ()->selection_size () == 0) {
    display_status (true);
  }

  return any_selected;
}

void
Service::clear_transient_selection ()
{
  if (mp_transient_ruler) {
    delete mp_transient_ruler;
    mp_transient_ruler = 0;
  }
}

void
Service::clear_previous_selection ()
{
  m_previous_selection.clear ();
}

bool
Service::select (const db::DBox &box, lay::Editable::SelectionMode mode)
{
  bool needs_update = false;
  bool any_selected = false;

  //  clear before unless "add" is selected
  if (mode == lay::Editable::Replace) {
    if (! m_selected.empty ()) {
      m_selected.clear ();
      needs_update = true;
    }
  }

  //  for single-point selections either exclude the current selection or the
  //  accumulated previous selection from the search.
  const std::map<obj_iterator, unsigned int> *exclude = 0;
  if (mode == lay::Editable::Replace) {
    exclude = &m_previous_selection;
  } else if (mode == lay::Editable::Add) {
    exclude = &m_selected;
  } else if (mode == lay::Editable::Reset) {
    //  TODO: the finder should favor the current selection in this case.
  }

  if (box.empty ()) {

    //  unconditional selection
    if (mode == lay::Editable::Reset) {
      if (! m_selected.empty ()) {
        m_selected.clear ();
        needs_update = true;
      }
    } else {

      lay::AnnotationShapes::iterator rfrom = mp_view->annotation_shapes ().begin (); 
      lay::AnnotationShapes::iterator rto = mp_view->annotation_shapes ().end ();

      //  extract all rulers
      for (lay::AnnotationShapes::iterator r = rfrom; r != rto; ++r) {
        const ant::Object *robj = dynamic_cast<const ant::Object *> ((*r).ptr ());
        if (robj) {
          any_selected = true;
          if (select (r, mode)) {
            needs_update = true;
          }
        }
      }
    }

  } else {

    //  compute search box
    double l = double (search_range) / widget ()->mouse_event_trans ().mag ();
    db::DBox search_dbox = box.enlarged (db::DVector (l, l));

    if (! box.is_point ()) {

      //  box-selection
      lay::AnnotationShapes::touching_iterator r = mp_view->annotation_shapes ().begin_touching (search_dbox);
      while (! r.at_end ()) {
        const ant::Object *robj = dynamic_cast<const ant::Object *> ((*r).ptr ());
        if (robj && (! exclude || exclude->find (mp_view->annotation_shapes ().iterator_from_pointer (&*r)) == exclude->end ())) {
          if (is_selected (*robj, box, l)) {
            any_selected = true;
            if (select (mp_view->annotation_shapes ().iterator_from_pointer (&*r), mode)) {
              needs_update = true;
            }
          }
        }
        ++r;
      }

    } else {

      //  point selection: look for the "closest" ruler
      double dmin = std::numeric_limits <double>::max ();

      lay::AnnotationShapes::touching_iterator r = mp_view->annotation_shapes ().begin_touching (search_dbox);
      lay::AnnotationShapes::touching_iterator rmin (r);
      while (! r.at_end ()) {
        const ant::Object *robj = dynamic_cast<const ant::Object *> ((*r).ptr ());
        if (robj && (! exclude || exclude->find (mp_view->annotation_shapes ().iterator_from_pointer (&*r)) == exclude->end ())) {
          double d;
          if (is_selected (*robj, box.p1 (), l, d)) {
            if (! any_selected || d < dmin) {
              rmin = r;
              dmin = d;
            }
            any_selected = true;
          }
        }
        ++r;
      }

      //  select the one that was found
      if (any_selected) {
        select (mp_view->annotation_shapes ().iterator_from_pointer (&*rmin), mode);
        m_previous_selection.insert (std::make_pair (mp_view->annotation_shapes ().iterator_from_pointer (&*rmin), mode));
        needs_update = true;
      }

    }

  }

  //  if required, update the list of ruler objects to display the selection
  if (needs_update) {
    selection_to_view ();
  }

  if (any_selected) {
    display_status (false);
  }

  //  return true if at least one element was selected
  return any_selected;
}

void 
Service::display_status (bool transient)
{
  View *selected_view = transient ? mp_transient_ruler : (m_rulers.size () == 1 ? m_rulers [0] : 0);
  if (! selected_view) {
    view ()->message (std::string ());
  } else {

    const ant::Object *ruler = selected_view->ruler ();

    std::string msg;
    if (! transient) {
      msg = tl::to_string (QObject::tr ("selected: "));
    }
    msg += tl::sprintf (tl::to_string (QObject::tr ("annotation(d=%s x=%s y=%s)")), ruler->text (), ruler->text_x (), ruler->text_y ());
    view ()->message (msg);

  }
}

lay::PropertiesPage *
Service::properties_page (QWidget *parent)
{
  return new PropertiesPage (this, parent);
}

void 
Service::get_selection (std::vector <obj_iterator> &sel) const
{
  sel.clear ();
  sel.reserve (m_selected.size ());

  //  positions will hold a set of iterators that are to be erased
  for (std::map<obj_iterator, unsigned int>::const_iterator r = m_selected.begin (); r != m_selected.end (); ++r) {
    sel.push_back (r->first);
  }
}

void
Service::delete_ruler (obj_iterator pos)
{
  //  delete the object
  m_selected.erase (pos);
  mp_view->annotation_shapes ().erase (pos);

  //  and make selection "visible"
  selection_to_view ();
}

void
Service::change_ruler (obj_iterator pos, const ant::Object &to)
{
  //  replace the object, keep the ID:
  ant::Object *new_ruler = new ant::Object (to);
  const ant::Object *current_ruler = dynamic_cast <const ant::Object *> (pos->ptr ());
  tl_assert (current_ruler != 0);
  new_ruler->id (current_ruler->id ());
  mp_view->annotation_shapes ().replace (pos, db::DUserObject (new_ruler));

  annotation_changed_event (new_ruler->id ());

  //  and make selection "visible"
  selection_to_view ();
}

void 
Service::paint_on_planes (const db::DCplxTrans &trans,
                          const std::vector <lay::CanvasPlane *> &planes,
                          lay::Renderer &renderer)
{
  if (planes.empty ()) {
    return;
  }

  db::DBox vp = db::DBox (trans.inverted () * db::DBox (db::DPoint (0.0, 0.0), db::DPoint (renderer.width (), renderer.height ())));

  lay::AnnotationShapes::touching_iterator user_object = mp_view->annotation_shapes ().begin_touching (vp);
  while (! user_object.at_end ()) {
    const ant::Object *ruler = dynamic_cast <const ant::Object *> ((*user_object).ptr ());
    if (ruler) {
      draw_ruler (*ruler, trans, false /*not selected*/, planes.front (), renderer);
    }
    ++user_object;
  }
}

AnnotationIterator
Service::begin_annotations () const
{
  return AnnotationIterator (mp_view->annotation_shapes ().begin (), mp_view->annotation_shapes ().end ());
}

void 
Service::menu_activated (const std::string &symbol)
{
  if (symbol == "ant::clear_all_rulers_internal") {
    clear_rulers ();
  } else if (symbol == "ant::clear_all_rulers") {
    manager ()->transaction (tl::to_string (QObject::tr ("Clear all rulers"))); 
    clear_rulers ();
    manager ()->commit ();
  } else {
    lay::Plugin::menu_activated (symbol);
  }
}

// -------------------------------------------------------------

} // namespace ant