X-Git-Url: https://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=src%2Ftim%2Fprune%2Fload%2Fjson%2FJsonBlock.java;fp=src%2Ftim%2Fprune%2Fload%2Fjson%2FJsonBlock.java;h=83486c72ad90ced1bb29accb6471cd4af29ca400;hp=0000000000000000000000000000000000000000;hb=cd5dd0c207b676067e85e0885b90f05445b7e229;hpb=1db53356139320890a8d10e982865a1899e11b81

diff --git a/src/tim/prune/load/json/JsonBlock.java b/src/tim/prune/load/json/JsonBlock.java
new file mode 100644
index 0000000..83486c7
--- /dev/null
+++ b/src/tim/prune/load/json/JsonBlock.java
@@ -0,0 +1,227 @@
+package tim.prune.load.json;
+
+import java.util.ArrayList;
+
+/**
+ * Structure to hold the contents of a Json block during parsing.
+ * This will be held within the current [] or {} block
+ */
+public class JsonBlock
+{
+	private String _latitude = null;
+	private String _longitude = null;
+	private String _altitude = null;
+
+	private Expectation _nextField = Expectation.NONE;
+	private BlockType _type = BlockType.NONE;
+	private boolean _hasNonNumbers = false;
+	private ArrayList<String> _pointCoords = null;
+	private ArrayList<ArrayList<String>> _coordList = null;
+
+
+	private enum BlockType {
+		NONE, FIELDS, POINTCOORDS, ISPOINTLIST, HASPOINTLIST
+	}
+	private enum Expectation {
+		NONE, LATITUDE, LONGITUDE, ALTITUDE, COORDS
+	}
+
+	/** Internal method to remove quotes and NaNs from altitude strings */
+	private String modifyAltitudeString(String inAlt)
+	{
+		if (inAlt == null || inAlt.equals("") || inAlt.equals("\"\"")) {
+			return null;
+		}
+		String result = inAlt;
+		if (inAlt.length() > 2 && inAlt.startsWith("\"") && inAlt.endsWith("\""))
+		{
+			result = inAlt.substring(1, inAlt.length()-1);
+		}
+		if (result.equals("NaN")) {return null;}
+		return result;
+	}
+
+	/**
+	 * Receive a token to this block
+	 * @param inToken token from Json source
+	 */
+	public void addToken(String inToken)
+	{
+		if (inToken == null || inToken.isEmpty()) {return;}
+		if (!_hasNonNumbers && !looksLikeNumber(inToken)) {
+			_hasNonNumbers = true;
+		}
+		if (inToken.equals("\"latitude\"")) {
+			_nextField = Expectation.LATITUDE;
+		}
+		else if (inToken.equals("\"longitude\"")) {
+			_nextField = Expectation.LONGITUDE;
+		}
+		else if (inToken.equals("\"altitude\"")) {
+			_nextField = Expectation.ALTITUDE;
+		}
+		else if (inToken.equals("\"coordinates\"")) {
+			_nextField = Expectation.COORDS;
+		}
+		else
+		{
+			switch (_nextField)
+			{
+				case LATITUDE:
+					_latitude = inToken;
+					_type = BlockType.FIELDS;
+					break;
+				case LONGITUDE:
+					_longitude = inToken;
+					_type = BlockType.FIELDS;
+					break;
+				case ALTITUDE:
+					_altitude = modifyAltitudeString(inToken);
+					_type = BlockType.FIELDS;
+					break;
+				default:
+					if (!_hasNonNumbers && looksLikeNumber(inToken))
+					{
+						if (_pointCoords == null) {
+							_pointCoords = new ArrayList<String>();
+						}
+						_pointCoords.add(inToken);
+						_type = BlockType.POINTCOORDS;
+					}
+					break;
+			}
+			_nextField = Expectation.NONE;
+		}
+	}
+
+	/** @return true if String can be parsed as a double */
+	private static boolean looksLikeNumber(String inToken)
+	{
+		double value = Double.NaN;
+		try {
+			value = Double.parseDouble(inToken);
+		}
+		catch (NumberFormatException nfe) {}
+		return !Double.isNaN(value);
+	}
+
+	/** @return true if named fields are valid */
+	public boolean areFieldsValid() {
+		return _type == BlockType.FIELDS && _latitude != null && _longitude != null;
+	}
+
+	/** @return true if list of 2 or 3 doubles for a single point is valid */
+	public boolean areSingleCoordsValid()
+	{
+		return !_hasNonNumbers && _pointCoords != null
+			&& _pointCoords.size() >= 2 && _pointCoords.size() <= 3;
+	}
+
+	/**
+	 * @param inNewSegment new segment flag
+	 * @return created point
+	 */
+	public JsonPoint createSinglePoint(boolean inNewSegment)
+	{
+		return new JsonPoint(_latitude, _longitude, _altitude, inNewSegment);
+	}
+
+	/**
+	 * Child block has finished processing a single set of point coordinates
+	 * @param inChild child block
+	 */
+	public void addSingleCoordsFrom(JsonBlock inChild)
+	{
+		if (_type == BlockType.NONE && _nextField == Expectation.COORDS
+			&& inChild._type == BlockType.POINTCOORDS)
+		{
+			// Named coordinates field
+			_type = BlockType.FIELDS;
+			_longitude = inChild.getSinglePointCoords(0);
+			_latitude = inChild.getSinglePointCoords(1);
+			_altitude = inChild.getSinglePointCoords(2);
+		}
+		else if ((_type == BlockType.NONE || _type == BlockType.ISPOINTLIST)
+			&& !_hasNonNumbers && _nextField == Expectation.NONE
+			&& inChild._type == BlockType.POINTCOORDS)
+		{
+			// add coordinates to list
+			_type = BlockType.ISPOINTLIST;
+			if (_coordList == null) {
+				_coordList = new ArrayList<ArrayList<String>>();
+			}
+			_coordList.add(inChild._pointCoords);
+		}
+	}
+
+	/** @return point coordinate for given index, or null if not present */
+	private String getSinglePointCoords(int inIndex)
+	{
+		if (_pointCoords == null || inIndex < 0 || inIndex >= _pointCoords.size()) {
+			return null;
+		}
+		return _pointCoords.get(inIndex);
+	}
+
+	/** @return true if list of point coords is valid */
+	public boolean isCoordListValid()
+	{
+		return !_hasNonNumbers && _type == BlockType.ISPOINTLIST
+			&& _coordList != null;
+	}
+
+	/** @return true if this block has a valid list of point coords */
+	public boolean hasValidCoordList()
+	{
+		return _type == BlockType.HASPOINTLIST && _coordList != null;
+	}
+
+	/**
+	 * Child block has finished processing a list of point coordinates
+	 * @param inChild child block
+	 */
+	public void addCoordListFrom(JsonBlock inChild)
+	{
+		if (_type == BlockType.NONE && _nextField == Expectation.COORDS
+			&& inChild._type == BlockType.ISPOINTLIST)
+		{
+			_coordList = inChild._coordList;
+			_type = BlockType.HASPOINTLIST;
+		}
+		else if ((_type == BlockType.NONE || _type == BlockType.ISPOINTLIST)
+			&& !_hasNonNumbers && inChild._type == BlockType.ISPOINTLIST)
+		{
+			if (_coordList == null) {
+				_coordList = new ArrayList<ArrayList<String>>();
+			}
+			_coordList.addAll(inChild._coordList);
+			_type = BlockType.ISPOINTLIST;
+		}
+	}
+
+	/**
+	 * @return number of points in the list, if this block has a list
+	 */
+	public int getNumPoints()
+	{
+		if (hasValidCoordList()) {
+			return _coordList.size();
+		}
+		return 0;
+	}
+
+	/**
+	 * @param inIndex point index within list
+	 * @return created point for specified index
+	 */
+	public JsonPoint createPointFromList(int inIndex)
+	{
+		if (inIndex < 0 || inIndex >= getNumPoints()) {return null;}
+		ArrayList<String> pointCoords = _coordList.get(inIndex);
+		if (pointCoords.size() < 2 || pointCoords.size() > 3) {return null;}
+		final String longitude = pointCoords.get(0);
+		final String latitude = pointCoords.get(1);
+		final String altitude = ((pointCoords.size() == 3) ? pointCoords.get(3) : null);
+		return new JsonPoint(latitude, longitude, altitude, inIndex == 0);
+	}
+}