Android自定义LocationMarker的实现详解

目录

• 自定义View LocationMarker
• 应用自定义View到AMapView中

今天讲一个比较简单的东西自定义绘制Marker 其实就是自定义view, 跟轨迹没太多关联，还有轨迹源码在文末分享出来，对您有帮助的话给个star呗。

如下面的gif中的轨迹中的LocationMarker

自定义View LocationMarker

主要包括绘制水滴状，绘制圆、绘制文字，绘制底部椭圆阴影，主要是绘制水滴状，这里用的贝塞尔三阶绘制，首先直接看代码：

public class LocationMarker extends View {
    private Path mPath;
    private Paint mFillCirclePaint;
    private Paint mTextPaint;
    private VPoint p2;
    private VPoint p4;
    private HPoint p1;
    private HPoint p3;
    private Context mContext;

    private float c;
    private float blackMagic = 0.551915024494f;
    private int wrapperColor;
    private int circleColor;

    private int radius = DisplayUtil.dip2px(20);
    private String mMilePost;
    private int textSize = 13;

    private boolean drawBottomShader;

    public LocationMarker(Context context, int radius, String milePost, int textSize) {
        this(context, null);
        this.mContext = context;
        this.radius = radius;
        this.mMilePost = milePost;
        this.textSize = textSize;
        init();
    }

    public LocationMarker(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        this.mContext = context;
        init();
    }

    public LocationMarker(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        this.mContext = context;
        init();
    }

    /**
     * 初始化操作
     */
    private void init() {
        mFillCirclePaint = new Paint();
        mFillCirclePaint.setColor(0xFFFFFFFF);
        mFillCirclePaint.setStyle(Paint.Style.FILL);
        mFillCirclePaint.setStrokeWidth(1);
        mFillCirclePaint.setAntiAlias(true);
        mPath = new Path();
        p2 = new VPoint();
        p4 = new VPoint();
        p1 = new HPoint();
        p3 = new HPoint();
        c = radius * blackMagic;
        initTextPain();
        wrapperColor = R.color.location_wrapper;
        circleColor = R.color.location_inner_circle;
    }

    public void setColors(int wrapperColorResource, int circleColorResource){
        this.wrapperColor = wrapperColorResource;
        this.circleColor = circleColorResource;
    }

    private void initTextPain() {
        mTextPaint = new Paint();
        mTextPaint.setColor(0xFFFFFFFF);
        mTextPaint.setStyle(Paint.Style.FILL);
        mTextPaint.setStrokeWidth(1);
        mTextPaint.setAntiAlias(true);
        mTextPaint.setTypeface(Typeface.DEFAULT_BOLD);
        mTextPaint.setTextSize(DisplayUtil.sp2px(mContext, textSize));
    }

    @Override
    protected void onDraw(Canvas canvas) {
        mPath.reset();
        canvas.translate(getWidth() / 2, getHeight() / 2);
        drawWaterDrop(canvas, radius);
    }

    private void drawWaterDrop(Canvas canvas, int radius) {
        canvas.save();
        Path path = getPath(radius);

      //内部圆的path
        Path circle = new Path();
        circle.addCircle(p3.x, p3.y + radius, radius - radius / 5, Path.Direction.CCW);

        //去锯齿
        canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG));
        drawBottomOval(canvas);
      //绘制外部的水滴状
        drawBezierPath(canvas, ColorUtil.getResourcesColor(mContext, wrapperColor), path);
      //绘制内部的圆
        drawBezierPath(canvas, ColorUtil.getResourcesColor(mContext, circleColor), circle);
        drawText(canvas, mMilePost);
        canvas.restore();
    }

  	//绘制底部的阴影，drawBottomShader控制是否显示阴影
    private void drawBottomOval(Canvas canvas){
        if (drawBottomShader){
            RectF rectF = new RectF();
            float width = DisplayUtil.dip2px(12);
            float height = DisplayUtil.dip2px(4);
            rectF.set(p1.x - width/2, p1.y - height/2, p1.x + width/2, p1.y + height/2);
            int color = mFillCirclePaint.getColor();
            mFillCirclePaint.setColor(ColorUtil.getResourcesColor(mContext, R.color.location_bottom_shader));
            canvas.drawOval(rectF, mFillCirclePaint);
            mFillCirclePaint.setColor(color);
        }
    }

  	//绘制Marker中心的文字
    private void drawText(Canvas canvas, String mileStr) {
        RectF rectF = new RectF();
        float width = mTextPaint.measureText(mileStr);

        float rectFLeft = p3.x - width / 2 ;
        float rectFRight = p3.x + width / 2 ;

        float rectHeight = TextUtil.getTxtHeight1(mTextPaint);
        float rectTop = p2.y + DisplayUtil.dip2px(2);//调整位置，看起来居中
        float rectBottom = p2.y + rectHeight;

        rectF.set(rectFLeft, rectTop, rectFRight, rectBottom);

        Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics();
        float top = fontMetrics.top;//为基线到字体上边框的距离,即上图中的top
        float bottom = fontMetrics.bottom;//为基线到字体下边框的距离,即上图中的bottom
        int baseLineY = (int) (rectF.centerY() + (top + bottom) / 2);//基线中间点的y轴计算公式
        canvas.drawText(mileStr, rectF.left, baseLineY, mTextPaint);
    }

    /**
     * 画圆
     */
    private Path getPath(int radius) {
        CircleModel(radius);
        Path path = new Path();
        p1.setY(p1.y + radius * 0.2f * 1.05f); //设置 p1 底部左右两个点的y值
        p1.y += radius * 0.2f * 1.05f;//设置 p1 自己的y值
        path.moveTo(p1.x, p1.y);
        path.cubicTo(p1.right.x, p1.right.y, p2.bottom.x, p2.bottom.y, p2.x, p2.y);
        path.cubicTo(p2.top.x, p2.top.y, p3.right.x, p3.right.y, p3.x, p3.y);
        path.cubicTo(p3.left.x, p3.left.y, p4.top.x, p4.top.y, p4.x, p4.y);
        path.cubicTo(p4.bottom.x, p4.bottom.y, p1.left.x, p1.left.y, p1.x, p1.y);
        path.close();

        return path;
    }

    private void drawBezierPath(Canvas canvas, int color, Path path) {
        int colorOrigin = mFillCirclePaint.getColor();
        mFillCirclePaint.setColor(color);
        canvas.drawPath(path, mFillCirclePaint);
        mFillCirclePaint.setColor(colorOrigin);
    }

    private void CircleModel(int radius) {
        c = radius * blackMagic;
        p1.setY(radius);//右边
        p3.setY(-radius);// 左边
        p3.x = p1.x = 0;//圆心

        p3.left.x = -c;
        p3.right.x = c;
        p1.left.x = -c * 0.36f;
        p1.right.x = c * 0.36f;
        //p1.p3属于圆的上下两点
        p2.setX(radius); // 下边
        p4.setX(-radius);// 上边
        p2.y = p4.y = 0;//  圆心
        p2.top.y = p4.top.y = -c;
        p2.bottom.y = p4.bottom.y = c;
    }

    public void setDrawBottomShader(boolean drawBottomShader) {
        this.drawBottomShader = drawBottomShader;
    }
}

简单的讲一下，主要通过三阶贝塞尔曲线来绘制圆，在圆的基础上，对Bottom方向的P1(包含 p1本身以及left、right两个control点)拉升，类似行星跟卫星的潮汐引力在朝下拉升的方向形成水滴形的尖角。

这里left、top、right、bottom四个方向，每个方向共三个点，共同确定这个圆。

VPoint 代表垂直方向的 left、right，这里是 p2跟p4 分表包含三个点，三点成线跟圆的左边、右边相切。

public class VPoint {
    public float x;
    public float y;
    public PointF top = new PointF();
    public PointF bottom = new PointF();

    public void setX(float x) {
        this.x = x;
        top.x = x;
        bottom.x = x;
    }

    public void adjustY(float offset) {
        top.y -= offset;
        bottom.y += offset;
    }

    public void adjustAllX(float offset) {
        this.x += offset;
        top.x += offset;
        bottom.x += offset;
    }

    public void adjustAllY(float offset) {
        this.y += offset;
        top.y += offset;
        bottom.y += offset;
    }

    public void adjustAllXY(float x, float y) {
        adjustAllX(x);
        adjustAllY(y);
    }
}

同样， HPoint 代表水边方向圆的切线，p1跟p3代表Bottom、Top上的三个点。

public class HPoint {
    public float x;
    public float y;
    public PointF left = new PointF();
    public PointF right = new PointF();

    public void setY(float y) {
        this.y = y;
        left.y = y;
        right.y = y;
    }

    public void adjustAllX(float offset) {
        this.x += offset;
        left.x += offset;
        right.x += offset;
    }

    public void adjustAllY(float offset) {
        this.y += offset;
        left.y += offset;
        right.y += offset;
    }

    public void adjustAllXY(float x, float y) {
        adjustAllX(x);
        adjustAllY(y);
    }
}

其它的见代码注释。

应用自定义View到AMapView中

这里就直接参考高德的demo，需要注意一点的是，在加载自定义的LocationMarker时，我在LocationMarker的外层包了两层父View，试过了一层显示不出来

private void addMarker(LatLng position, String displayStr,int radius, int textSize, int wrapperColor, int circleColor, boolean showBottomShader){
		View view = View.inflate(RecordCorrectShowActivity.this, R.layout.custom_location_view, null);
		RelativeLayout locationContainer = view.findViewById(R.id.locationContainer);
		LocationMarker locationMarker = new LocationMarker(mMapView.getContext(),
				DisplayUtil.dip2px(radius), displayStr, textSize);
		locationMarker.setColors(wrapperColor, circleColor);
		locationMarker.setDrawBottomShader(showBottomShader);

		locationContainer.addView(locationMarker);
		BitmapDescriptor markerIcon = BitmapDescriptorFactory.fromView(view);

		MarkerOptions optionPosition = new MarkerOptions()
				.position(position)
				.icon(markerIcon);
		Marker marker = mAMap.addMarker(optionPosition);

		Animation markerAnimation = new ScaleAnimation(0, 1, 0, 1); //初始化生长效果动画
		markerAnimation.setDuration(1000);  //设置动画时间 单位毫秒
		marker.setAnimation(markerAnimation);

		marker.startAnimation();
	}

两层父view的

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <RelativeLayout
        android:id="@+id/locationContainer"
        android:layout_width="50dp"
        android:layout_height="55dp"/>

</LinearLayout>

下次讲优化轨迹路径，从采集时到最后的优化。

代码请前往 运动轨迹， 代码包含了很多图表Chart的代码没有分开，有空对这个库做个系列，因为MAAndroidChart没法满足需求做的库， 代码中需要自己去高德平台上注册Key。

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