1 package tim.prune.gui.map;
4 import java.awt.Dimension;
5 import java.awt.Graphics;
6 import javax.swing.JPanel;
8 import tim.prune.I18nManager;
9 import tim.prune.config.ColourScheme;
10 import tim.prune.config.Config;
13 * Class to show a scale bar on the main map of Prune
15 public class ScaleBar extends JPanel
18 private int _zoomLevel = -1;
20 private int _yTile = -1;
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;
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};
53 setPreferredSize(new Dimension(100, 20));
57 * Paint method to override display
58 * @param inG graphics object
60 public void paint(Graphics inG)
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]);
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)
81 // Abort if scale is now less than 1 unit (shouldn't ever be)
82 if (scale < 1) {return;}
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);
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);
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);
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);
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);
118 catch (ArrayIndexOutOfBoundsException ai) {}
123 * Update the scale level
124 * @param inZoom new zoom level
126 public void updateScale(int inZoom, int inYtile)