qgscomposerscalebar.cpp

一个非常好的GIS开源新版本

/***************************************************************************
                           qgscomposerscalebar.cpp
                             -------------------
    begin                : March 2005
    copyright            : (C) 2005 by Radim Blazek
    email                : [e-mail]
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#include "qgscomposerscalebar.h"
#include "qgscomposermap.h"
#include "qgsproject.h"

#include <QFontDialog>
#include <QPainter>
#include <QGraphicsScene>

#include <cmath>
#include <iostream>

//can we/should we remove the x and y parameters?
QgsComposerScalebar::QgsComposerScalebar ( QgsComposition *composition, int id, 
	                                            int x, int y )
    : QWidget(composition),
    QAbstractGraphicsShapeItem(0),
    mComposition(composition),
    mMap(0),
    mBrush(QColor(150,150,150))
{
  setupUi(this);

  std::cout << "QgsComposerScalebar::QgsComposerScalebar()" << std::endl;
  mId = id;
  mSelected = false;

  mMapCanvas = mComposition->mapCanvas();

  QAbstractGraphicsShapeItem::setPos(x, y);

  init();

  // Set map to the first available if any
  std::vector < QgsComposerMap * >maps = mComposition->maps();
  if (maps.size() > 0)
    {
      mMap = maps[0]->id();
    }
  // Set default according to the map
  QgsComposerMap *map = mComposition->map(mMap);
  if (map)
    {
      mMapUnitsPerUnit = 1.;
      mUnitLabel = "m";

      // make one segment cca 1/10 of map width and it will be 1xxx, 2xxx or 5xxx
      double mapwidth = 1. * map->QGraphicsRectItem::rect().width() / map->scale();

      mSegmentLength = mapwidth / 10;

      int powerOf10 = int (pow(10.0, int (log(mSegmentLength) / log(10.0)))); // from scalebar plugin

      int isize = (int) ceil(mSegmentLength / powerOf10);

      if (isize == 3)
        isize = 2;
      else if (isize == 4)
        isize = 5;
      else if (isize > 5 && isize < 8)
        isize = 5;
      else if (isize > 7)
        isize = 10;

      mSegmentLength = isize * powerOf10;

      // the scale bar will take cca 1/4 of the map width
      // But always have at least one segment.
      mNumSegments = std::max(1, (int) (mapwidth / 4 / mSegmentLength));

      int segsize = (int) (mSegmentLength * map->scale());

      int fontsize = segsize / 3;

      if(fontsize < 6)
      {
        fontsize = 6;
      }

      mFont.setPointSize(fontsize);
  } else
    {
      mFont.setPointSize(6);
      mMapUnitsPerUnit = 1.;
      mUnitLabel = "m";
      mSegmentLength = 1000.;
      mNumSegments = 5;
    }

  // Calc size
  recalculate();

  // Add to scene
  mComposition->canvas()->addItem(this);

  QAbstractGraphicsShapeItem::show();
  QAbstractGraphicsShapeItem::update();

  writeSettings();
}

QgsComposerScalebar::QgsComposerScalebar ( QgsComposition *composition, int id ) 
    : QAbstractGraphicsShapeItem(0),
    mComposition(composition),
    mMap(0),
    mBrush(QColor(150,150,150))
{
  std::cout << "QgsComposerScalebar::QgsComposerScalebar()" << std::endl;

  setupUi(this);

  mId = id;
  mSelected = false;

  mMapCanvas = mComposition->mapCanvas();

  init();

  readSettings();

  // Calc size
  recalculate();

  // Add to scene
  mComposition->canvas()->addItem(this);

  QAbstractGraphicsShapeItem::show();
  QAbstractGraphicsShapeItem::update();
}

void QgsComposerScalebar::init(void)
{
  mUnitLabel = "m";

  // Rectangle
  QAbstractGraphicsShapeItem::setZValue(50);
//    setActive(true);

  // Default value (map units?) for the scalebar border
  mPen.setWidthF(.5);

  // Plot style
  setPlotStyle(QgsComposition::Preview);

  connect(mComposition, SIGNAL(mapChanged(int)), this, SLOT(mapChanged(int)));
}

QgsComposerScalebar::~QgsComposerScalebar()
{
  std::cerr << "QgsComposerScalebar::~QgsComposerScalebar()" << std::endl;
  QGraphicsItem::hide();
}

#define FONT_WORKAROUND_SCALE 10
QRectF QgsComposerScalebar::render(QPainter * p)
{
#ifdef QGISDEBUG
  std::cout << "QgsComposerScalebar::render() "<< std::endl;
#endif

  // Painter can be 0, create dummy to avoid many if below
  QPainter *painter;
  QPixmap *pixmap=NULL;
  if (p)
  {
      painter = p;
  }else
  {
    pixmap = new QPixmap(1, 1);
    painter = new QPainter(pixmap);
  }
#ifdef QGISDEBUG
  std::cout << "mComposition->scale() = " << mComposition->scale() << std::endl;
#endif

  QgsComposerMap *map = mComposition->map(mMap); //Get the topmost map from the composition

  double segwidth;
  if(map)
  {
    segwidth = (mSegmentLength * map->scale());  //width of one segment
  }
  else //if there is no map, make up a segment width
  {
    segwidth = mSegmentLength/100;
  }
  double width = (segwidth * mNumSegments); //width of whole scalebar
  double barLx = -width / 2; //x offset to the left

  double barHeight = (25.4 * mComposition->scale() * mFont.pointSize() / 72);

  double tickSize = barHeight * 1.5; //ticks go from the base of the bar to 1/2 the bar's height above it

  // Draw background rectangle
  painter->setPen(QPen(QColor(255, 255, 255), 0));
  painter->setBrush(QBrush(QColor(255, 255, 255), Qt::SolidPattern));
  painter->drawRect(QRectF(barLx, -barHeight, width, barHeight));

  // set the painter to have grey background and black border
  painter->setPen(QPen(QColor(0, 0, 0), mPen.widthF()));
  painter->setBrush(QBrush(QColor(127, 127, 127)));//default to solid brush

  // fill every other segment with grey
  for (int i = 0; i < mNumSegments; i += 2)
  {
    painter->drawRect(QRectF(barLx + ((double)i * segwidth), -barHeight, segwidth, barHeight));
  }

  // draw a box around the all of the segments
  painter->setBrush(Qt::NoBrush);
  painter->drawRect(QRectF(barLx, -barHeight, width, barHeight));

  // set up the pen to draw the tick marks
  painter->setPen(QPen(QColor(0, 0, 0), mPen.widthF()));

  // draw the tick marks
  for (int i = 0; i <= mNumSegments; i++)
  {
    painter->drawLine(QLineF(barLx + ((double)i * segwidth), 0, barLx + (i * segwidth), -tickSize));
  }


  // labels

  // Font size in canvas units
  float size = 25.4 * mComposition->scale() * mFont.pointSizeFloat() / 72;


  // Create QFontMetrics so we can correctly place the text
  QFont font(mFont);
  font.setPointSizeFloat(size);
  QFontMetrics metrics(font);

  font.setPointSizeFloat(size * FONT_WORKAROUND_SCALE); //hack to work around Qt font bug

  if (plotStyle() == QgsComposition::Postscript)
  {
    font.setPointSizeF(metrics.ascent() * 72.0 / mComposition->resolution() * FONT_WORKAROUND_SCALE);
  }

  painter->setFont(font);

  // Not sure about Style Strategy, QFont::PreferMatch?
  font.setStyleStrategy((QFont::StyleStrategy) (QFont::PreferOutline | QFont::PreferAntialias));

  double offset = .5 * tickSize; //vertical offset above the top of the tick marks
  double textRightOverhang=0;//amount the label text hangs over the right edge of the scalebar - used for the bounding box

  for (int i = 0; i <= mNumSegments; i++)
  {
    int lab = (int) ((double)i * mSegmentLength / mMapUnitsPerUnit);

    QString txt = QString::number(lab);
    double shift = (double)metrics.width(txt) / 2;

    if (i == mNumSegments) //on the last label, append the appropriate unit symbol
    {
      txt.append(" " + mUnitLabel);
      textRightOverhang = (double)metrics.width(txt) - shift;
    }

    double x = barLx + (i * segwidth) - shift; //figure out the bottom left corner and draw the text
    double y = -tickSize - offset - metrics.descent();

    painter->save();
    painter->scale(1./FONT_WORKAROUND_SCALE, 1./FONT_WORKAROUND_SCALE);
    painter->drawText(QPointF(x * FONT_WORKAROUND_SCALE, y * FONT_WORKAROUND_SCALE), txt);
    painter->restore();

  }//end of label drawing

  double totalHeight = tickSize + offset + metrics.height();