flightgear/src/GUI/CanvasWidget.cxx

/*
 * CanvasWidget.cxx
 *
 *  Created on: 03.07.2012
 *      Author: tom
 */

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include "CanvasWidget.hxx"

#include <Canvas/canvas_mgr.hxx>
#include <Main/fg_os.hxx>      // fgGetKeyModifiers()
#include <Scripting/NasalSys.hxx>

#include <simgear/canvas/Canvas.hxx>

//------------------------------------------------------------------------------
CanvasWidget::CanvasWidget( int x, int y,
                            int width, int height,
                            SGPropertyNode* props,
                            const std::string& module ):
  puObject(x, y, width, height),
  _canvas_mgr( dynamic_cast<CanvasMgr*>(globals->get_subsystem("Canvas")) ),
  _tex_id(0),
  _no_tex_cnt(0)
{
  if( !_canvas_mgr )
  {
    SG_LOG(SG_GENERAL, SG_ALERT, "CanvasWidget: failed to get canvas manager!");
    return;
  }

  _canvas = _canvas_mgr->createCanvas
  (
    props->getStringValue("name", "gui-anonymous")
  );

  int view[2] = {
    // Get canvas viewport size. If not specified use the widget dimensions
    props->getIntValue("view[0]", width),
    props->getIntValue("view[1]", height)
  };

  SGPropertyNode* cprops = _canvas->getProps();
  cprops->setIntValue("size[0]", view[0] * 2); // use higher resolution
  cprops->setIntValue("size[1]", view[1] * 2); // for antialias
  cprops->setIntValue("view[0]", view[0]);
  cprops->setIntValue("view[1]", view[1]);
  cprops->setBoolValue("render-always", true);
  cprops->setStringValue( "name",
                           props->getStringValue("name", "gui-anonymous") );
  SGPropertyNode* input = cprops->getChild("input", 0, true);
  _mouse_x = input->getChild("mouse-x", 0, true);
  _mouse_y = input->getChild("mouse-y", 0, true);
  _mouse_down = input->getChild("mouse-down", 0, true);
  _mouse_drag = input->getChild("mouse-drag", 0, true);

  SGPropertyNode *nasal = props->getNode("nasal");
  if( !nasal )
    return;

  FGNasalSys *nas = dynamic_cast<FGNasalSys*>(globals->get_subsystem("nasal"));
  if( !nas )
    SG_LOG( SG_GENERAL,
            SG_ALERT,
            "CanvasWidget: Failed to get nasal subsystem!" );

  const std::string file = std::string("__canvas:")
                         + cprops->getStringValue("name");

  SGPropertyNode *load = nasal->getNode("load");
  if( load )
  {
    const char *s = load->getStringValue();
    nas->handleCommand(module.c_str(), file.c_str(), s, cprops);
  }
}

//------------------------------------------------------------------------------
CanvasWidget::~CanvasWidget()
{
  if( _canvas )
    // TODO check if really not in use anymore
    _canvas->getProps()
           ->getParent()
           ->removeChild( _canvas->getProps()->getName(),
                          _canvas->getProps()->getIndex(),
                          false );
}

//------------------------------------------------------------------------------
void CanvasWidget::doHit(int button, int updown, int x, int y)
{
  puObject::doHit(button, updown, x, y);

  // CTRL allows resizing and SHIFT allows moving the window
  if( fgGetKeyModifiers() & (KEYMOD_CTRL | KEYMOD_SHIFT) )
    return;

  _mouse_x->setIntValue(x - abox.min[0]);
  _mouse_y->setIntValue(abox.max[1] - y);

  if( updown == PU_DRAG )
    _mouse_drag->setIntValue(button);
  else if( updown == PU_DOWN )
    _mouse_down->setIntValue(button);

  if( button != active_mouse_button )
    return;

  if (updown == PU_UP)
    puDeactivateWidget();
  else if (updown == PU_DOWN)
    puSetActiveWidget(this, x, y);
}

//------------------------------------------------------------------------------
int CanvasWidget::checkKey(int key, int updown)
{
  return puObject::checkKey(key, updown);
}

//------------------------------------------------------------------------------
void CanvasWidget::setSize(int w, int h)
{
  puObject::setSize(w, h);

  _canvas->getProps()->setIntValue("view[0]", w);
  _canvas->getProps()->setIntValue("view[1]", h);
}

//------------------------------------------------------------------------------
void CanvasWidget::draw(int dx, int dy)
{
  if( !_tex_id )
  {
    _tex_id = _canvas_mgr->getCanvasTexId( _canvas->getProps()->getIndex() );

    // Normally we should be able to get the texture after one frame. I don't
    // know if there are circumstances where it can take longer, so we don't
    // log a warning message until we have tried a few times.
    if( !_tex_id )
    {
      if( ++_no_tex_cnt == 5 )
        SG_LOG(SG_GENERAL, SG_WARN, "CanvasWidget: failed to get texture!");
      return;
    }
    else
    {
      if( _no_tex_cnt >= 5 )
        SG_LOG
        (
          SG_GENERAL,
          SG_INFO,
          "CanvasWidget: got texture after " << _no_tex_cnt << " tries."
        );
      _no_tex_cnt = 0;
    }
  }

  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, _tex_id);
  glBegin( GL_QUADS );
    glColor3f(1,1,1);
    glTexCoord2f(0,0); glVertex2f(dx + abox.min[0], dy + abox.min[1]);
    glTexCoord2f(1,0); glVertex2f(dx + abox.max[0], dy + abox.min[1]);
    glTexCoord2f(1,1); glVertex2f(dx + abox.max[0], dy + abox.max[1]);
    glTexCoord2f(0,1); glVertex2f(dx + abox.min[0], dy + abox.max[1]);
  glEnd();
  glDisable(GL_TEXTURE_2D);
}