tim/prune/gui/map/ScaleBar.java

   1 package tim.prune.gui.map;
   2
   3 import java.awt.Color;
   4 import java.awt.Dimension;
   5 import java.awt.Graphics;
   6 import javax.swing.JPanel;
   7
   8 import tim.prune.I18nManager;
   9 import tim.prune.config.ColourScheme;
  10 import tim.prune.config.Config;
  11
  12 /**
  13  * Class to show a scale bar on the main map of Prune
  14  */
  15 public class ScaleBar extends JPanel
  16 {
  17         /** zoom level */
  18         private int _zoomLevel = -1;
  19         /** y tile number */
  20         private int _yTile = -1;
  21
  22         // Dimensions
  23         /** Offset from left side in pixels */
  24         private static final int LEFT_OFFSET = 20;
  25         /** Offset from top in pixels */
  26         private static final int Y_OFFSET = 10;
  27         /** Tick height in pixels */
  28         private static final int TICK_HEIGHT = 5;
  29         /** Margin between bar and end text in pixels */
  30         private static final int MARGIN_WIDTH = 8;
  31
  32         /** metric scales for each zoom level */
  33         private static final int[] _metricScales = {10000, 5000, 2000, 2000, 1000, 500, 200, 100,
  34                 50, 20, 10, 5, 2, 2, 1, -2, -5, -10, -20, -50, -100, -200};
  35         /** pixel counts for each zoom level (metric) */
  36         private static final int[] _metricPixels = {64, 64, 51, 102, 102, 102, 81, 81,
  37                 81, 65, 65, 65, 52, 105, 105, 105, 83, 83, 83, 67, 67, 67};
  38         /** imperial scales for each zoom level (num miles) */
  39         private static final int[] _mileScales = {10000, 10000, 5000, 2000, 2000, 1000, 500, 200,
  40                 100, 50, 20, 10, 5, 2, 1, -2, -2, -5, -10, -20, -50, -100};
  41         /** pixel counts for each zoom level (miles) */
  42         private static final int[] _milePixels = {79, 79, 79, 64, 127, 127, 127, 102,
  43                 102, 102, 81, 81, 81, 65, 65, 65, 130, 104, 104, 104, 104, 83, 83};
  44
  45
  46         /**
  47          * Constructor
  48          */
  49         public ScaleBar()
  50         {
  51                 super();
  52                 setOpaque(false);
  53                 setPreferredSize(new Dimension(100, 20));
  54         }
  55
  56         /**
  57          * Paint method to override display
  58          * @param inG graphics object
  59          */
  60         public void paint(Graphics inG)
  61         {
  62                 super.paint(inG);
  63                 if (_zoomLevel > -1)
  64                 {
  65                         try {
  66                                 boolean useMetric = Config.getConfigBoolean(Config.KEY_METRIC_UNITS);
  67                                 int rightSide = LEFT_OFFSET + (useMetric?_metricPixels[_zoomLevel]:_milePixels[_zoomLevel]);
  68                                 int scale = (useMetric?_metricScales[_zoomLevel]:_mileScales[_zoomLevel]);
  69
  70                                 // work out cos(latitude) from y tile and zoom, and apply to scale
  71                                 final double n = Math.pow(2, _zoomLevel);
  72                                 final double angle = Math.PI * (1 - 2.0*_yTile/n);
  73                                 final double lat = Math.atan(Math.sinh(angle));
  74                                 final double cosLat = Math.cos(lat);
  75                                 rightSide = (int) (rightSide / cosLat);
  76                                 // Adjust if scale is too large
  77                                 while (rightSide > 300)
  78                                 {
  79                                         rightSide /= 2;
  80                                         scale /= 2;
  81                                         // Abort if scale is now less than 1 unit (shouldn't ever be)
  82                                         if (scale < 1) {return;}
  83                                 }
  84
  85                                 // Determine colours to use
  86                                 Color barColour = Config.getColourScheme().getColour(ColourScheme.IDX_TEXT);
  87                                 Color blankColour = new Color(255-barColour.getRed(), 255-barColour.getGreen(), 255-barColour.getBlue());
  88                                 // Should this blank colour be set to saturation zero?
  89                                 // Draw blank bars behind
  90                                 inG.setColor(blankColour);
  91                                 inG.drawLine(LEFT_OFFSET, Y_OFFSET-1, rightSide+2, Y_OFFSET-1);
  92                                 inG.drawLine(LEFT_OFFSET, Y_OFFSET+2, rightSide+2, Y_OFFSET+2);
  93                                 inG.drawLine(LEFT_OFFSET-1, Y_OFFSET+2, LEFT_OFFSET-1, Y_OFFSET-TICK_HEIGHT);
  94                                 inG.drawLine(LEFT_OFFSET+2, Y_OFFSET+2, LEFT_OFFSET+2, Y_OFFSET-TICK_HEIGHT);
  95                                 inG.drawLine(rightSide-1, Y_OFFSET+2, rightSide-1, Y_OFFSET-TICK_HEIGHT);
  96                                 inG.drawLine(rightSide+2, Y_OFFSET+2, rightSide+2, Y_OFFSET-TICK_HEIGHT);
  97                                 // horizontal
  98                                 inG.setColor(barColour);
  99                                 inG.drawLine(LEFT_OFFSET, Y_OFFSET, rightSide, Y_OFFSET);
 100                                 inG.drawLine(LEFT_OFFSET, Y_OFFSET+1, rightSide, Y_OFFSET+1);
 101                                 // 0 tick
 102                                 inG.drawLine(LEFT_OFFSET, Y_OFFSET, LEFT_OFFSET, Y_OFFSET-TICK_HEIGHT);
 103                                 inG.drawLine(LEFT_OFFSET+1, Y_OFFSET, LEFT_OFFSET+1, Y_OFFSET-TICK_HEIGHT);
 104                                 // end tick
 105                                 inG.drawLine(rightSide, Y_OFFSET+1, rightSide, Y_OFFSET-TICK_HEIGHT);
 106                                 inG.drawLine(rightSide+1, Y_OFFSET+1, rightSide+1, Y_OFFSET-TICK_HEIGHT);
 107                                 // text
 108                                 String text = (scale>0?(""+scale):("1/"+(-scale))) + " "
 109                                         + I18nManager.getText(useMetric?"units.kilometres.short":"units.miles.short");
 110                                 inG.setColor(blankColour);
 111                                 inG.drawString(text, rightSide+MARGIN_WIDTH-1, Y_OFFSET);
 112                                 inG.drawString(text, rightSide+MARGIN_WIDTH+1, Y_OFFSET);
 113                                 inG.drawString(text, rightSide+MARGIN_WIDTH, Y_OFFSET-1);
 114                                 inG.drawString(text, rightSide+MARGIN_WIDTH, Y_OFFSET+1);
 115                                 inG.setColor(barColour);
 116                                 inG.drawString(text, rightSide+MARGIN_WIDTH, Y_OFFSET);
 117                         }
 118                         catch (ArrayIndexOutOfBoundsException ai) {}
 119                 }
 120         }
 121
 122         /**
 123          * Update the scale level
 124          * @param inZoom new zoom level
 125          */
 126         public void updateScale(int inZoom, int inYtile)
 127         {
 128                 _zoomLevel = inZoom;
 129                 _yTile = inYtile;
 130         }
 131 }