/**
* Draws grid similarly to the "world" version, but with some changes: - Center the grid on the
* screen - label the grid lines in CRS units - outline the grid
*
* @param context
* @param showLabels is true, the bottom and right edges of the map are covered with white strips,
* and labels for the grid lines are placed in the white strips.
*/
private void drawGrid(MapGraphicContext context, boolean showLabels) {
GridStyle style = getStyle(context.getLayer());
double[] gridSize = style.getGridSize();
try {
MathTransform mt = CRS.findMathTransform(DefaultGeographicCRS.WGS84, context.getCRS(), true);
if (!mt.isIdentity()) {
double x = gridSize[0] / 2.0;
double y = gridSize[1] / 2.0;
double[] toTransform = new double[] {-x, -y, x, y};
double[] dest = new double[4];
mt.transform(toTransform, 0, dest, 0, 2);
gridSize = new double[] {Math.abs(dest[2] - dest[0]), Math.abs(dest[3] - dest[1])};
}
} catch (Exception e) {
MapGraphicPlugin.log("", e); // $NON-NLS-1$
}
Envelope bounds = context.getViewportModel().getBounds();
Coordinate centerCoord = bounds.centre();
gridSize = style.getGridSize();
Coordinate topLeftCenterCoord =
new Coordinate(centerCoord.x - gridSize[0] / 2, centerCoord.y + gridSize[1] / 2);
Coordinate topLeftMostCoord = new Coordinate(topLeftCenterCoord);
while (topLeftMostCoord.x - gridSize[0] > bounds.getMinX()) {
topLeftMostCoord.x -= gridSize[0];
}
while (topLeftMostCoord.y + gridSize[1] < bounds.getMaxY()) {
topLeftMostCoord.y += gridSize[1];
}
Coordinate coord = topLeftMostCoord;
ViewportGraphics graphics = context.getGraphics();
int mapPixelWidth = context.getMapDisplay().getWidth();
int mapPixelHeight = context.getMapDisplay().getHeight();
// cover the right side and bottom of map with thin strips
final int RIGHT_STRIP_WIDTH = (int) (mapPixelWidth * 0.05);
final int BOTTOM_STRIP_HEIGHT = (int) (mapPixelHeight * 0.03);
final int GRID_LINE_EXTENSION = (int) (RIGHT_STRIP_WIDTH * 0.1);
graphics.setColor(Color.white);
graphics.fillRect(mapPixelWidth - RIGHT_STRIP_WIDTH, 0, RIGHT_STRIP_WIDTH, mapPixelHeight);
graphics.fillRect(0, mapPixelHeight - BOTTOM_STRIP_HEIGHT, mapPixelWidth, BOTTOM_STRIP_HEIGHT);
// draw grid lines
graphics.setColor(style.getColor());
Point pixel = null;
while (true) {
pixel = context.worldToPixel(coord);
coord.x += gridSize[0];
coord.y -= gridSize[1];
Point next = context.worldToPixel(coord);
if (next.x - pixel.x < 2 || next.y - pixel.y < 2) {
context.getLayer().setStatus(ILayer.WARNING);
context.getLayer().setStatusMessage(Messages.GridMapGraphic_grids_too_close);
break;
}
if ((pixel.x >= mapPixelWidth && pixel.y >= mapPixelHeight)) break;
// draw vertical lines and labels
if (pixel.x < mapPixelWidth)
graphics.drawLine(
pixel.x, 0, pixel.x, mapPixelHeight - BOTTOM_STRIP_HEIGHT + GRID_LINE_EXTENSION);
if (showLabels) {
graphics.drawString(
(int) (coord.y) + "",
pixel.x,
mapPixelHeight - BOTTOM_STRIP_HEIGHT + GRID_LINE_EXTENSION,
ViewportGraphics.ALIGN_MIDDLE,
ViewportGraphics.ALIGN_TOP);
}
// draw horizontal lines and labels
if (pixel.y < mapPixelHeight)
graphics.drawLine(
0, pixel.y, mapPixelWidth - RIGHT_STRIP_WIDTH + GRID_LINE_EXTENSION, pixel.y);
if (showLabels) {
graphics.drawString(
(int) (coord.x) + "",
mapPixelWidth - RIGHT_STRIP_WIDTH + GRID_LINE_EXTENSION,
pixel.y,
ViewportGraphics.ALIGN_LEFT,
ViewportGraphics.ALIGN_MIDDLE);
}
pixel = next;
}
// outline the map
graphics.drawRect(
0, 0, mapPixelWidth - RIGHT_STRIP_WIDTH, mapPixelHeight - BOTTOM_STRIP_HEIGHT);
}
