使用方法:
LineItemizedOverlay overlay = new LineItemizedOverlay();
overlay.addOverlay(/*起點的OverlayItem*/);
overlay.addOverlay(/*終點的OverlayItem*/);
overlay.addLinePoint(/*要畫的軌跡的GeoPoint的List*/);
mapView.getOverlays().add(overlay);
/**
*
*/
package com.xtyon.tuola.truck.map;
import java.util.ArrayList;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.MapView;
import com.google.android.maps.OverlayItem;
import com.google.android.maps.Projection;
/**
* 地圖上的線型圖層:包括一個起點,一個終點,以及之間的曲線
* @author superwang
*/
public class LineItemizedOverlay extends ItemizedOverlay<OverlayItem> {
private static final int LAYER_FLAGS = Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG
| Canvas.HAS_ALPHA_LAYER_SAVE_FLAG | Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG;
/**
* 用于保存起點/終點數據
*/
private final ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
/**
* 用于保存構成曲線的點的數據
*/
private final ArrayList<GeoPoint> linePoints = new ArrayList<GeoPoint>();
/**
* @param defaultMarker
*/
public LineItemizedOverlay() {
super(null);
// TODO Auto-generated constructor stub
}
/* (non-Javadoc)
* @see com.google.android.maps.ItemizedOverlay#createItem(int)
*/
@Override
protected OverlayItem createItem(int i) {
return mOverlays.get(i);
}
/* (non-Javadoc)
* @see com.google.android.maps.ItemizedOverlay#size()
*/
@Override
public int size() {
// TODO Auto-generated method stub
return mOverlays.size();
}
/**
* 調價起點/終點
* description:
* @param overlay
*/
public void addOverlay(OverlayItem overlay) {
mOverlays.add(overlay);
populate();
}
/**
* 添加曲線中的點
* description:
* @param point
*/
public void addLinePoint(GeoPoint point) {
linePoints.add(point);
}
public ArrayList<GeoPoint> getLinePoints() {
return linePoints;
}
/**
* 畫起點/終點/軌跡
*/
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
if (!shadow) {
//System.out.println("!!!!!!!!!!!!!!");
canvas.save(LAYER_FLAGS);
//canvas.save();
Projection projection = mapView.getProjection();
int size = mOverlays.size();
Point point = new Point();
Paint paint = new Paint();
paint.setAntiAlias(true);
OverlayItem overLayItem;
//畫起點/終點
for (int i = 0; i < size; i++) {
overLayItem = mOverlays.get(i);
Drawable marker = overLayItem.getMarker(0);
//marker.getBounds()
/* 象素點取得轉換 */
projection.toPixels(overLayItem.getPoint(), point);
if (marker != null) {
boundCenterBottom(marker);
}
/* 圓圈 */
//Paint paintCircle = new Paint();
//paintCircle.setColor(Color.RED);
paint.setColor(Color.RED);
canvas.drawCircle(point.x, point.y, 5, paint);
/* 文字設置 */
/* 標題 */
String title = overLayItem.getTitle();
/* 簡介 */
// String snippet = overLayItem.getSnippet();
//
// StringBuffer txt = new StringBuffer();
// if (title != null && !"".equals(title))
// txt.append(title);
//
// if (snippet != null && !"".equals(snippet)) {
// if (txt.length() > 0) {
// txt.append(":");
// }
// txt.append(snippet);
// }
//Paint paintText = new Paint();
if (title != null && title.length() > 0) {
paint.setColor(Color.BLACK);
paint.setTextSize(15);
canvas.drawText(title, point.x, point.y, paint);
}
}
//畫線
boolean prevInBound = false;//前一個點是否在可視區域
Point prev = null;
int mapWidth = mapView.getWidth();
int mapHeight = mapView.getHeight();
//Paint paintLine = new Paint();
paint.setColor(Color.RED);
//paint.setPathEffect(new CornerPathEffect(10));
paint.setStrokeWidth(2);
int count = linePoints.size();
//Path path = new Path();
//path.setFillType(Path.FillType.INVERSE_WINDING);
for (int i = 0; i < count; i++) {
GeoPoint geoPoint = linePoints.get(i);
//projection.toPixels(geoPoint, point); //這一行似乎有問題
point = projection.toPixels(geoPoint, null);
if (prev != null) {
if (point.x >= 0 && point.x <= mapWidth && point.y >= 0 && point.y <= mapHeight) {
if ((Math.abs(prev.x - point.x) > 2 || Math.abs(prev.y - point.y) > 2)) {
//這里判斷點是否重合，重合的不畫線，可能會導致畫線不在路上
canvas.drawLine(prev.x, prev.y, point.x, point.y, paint);
//path.lineTo(point.x, point.y);
prev = point;
prevInBound = true;
}
} else {
//在可視區與之外
if (prevInBound) {//前一個點在可視區域內，也需要劃線
//path.lineTo(point.x, point.y);
canvas.drawLine(prev.x, prev.y, point.x, point.y, paint);
}
prev = point;
prevInBound = false;
}
} else {
//path.moveTo(point.x, point.y);
prev = point;
}
}
//canvas.drawPath(path, paint);
canvas.restore();
//DebugUtils.showMemory();
}
super.draw(canvas, mapView, shadow);
}
}