Android自定義LocationMarker的實現詳解

2023-02-12 06:01:21

自定義View LocationMarker

主要包括繪製水滴狀，繪製圓、繪製文字，繪製底部橢圓陰影，主要是繪製水滴狀，這裡用的貝塞爾三階繪製，首先直接看程式碼：

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);

      //內部圓的path
        Path circle = new Path();
        circle.addCircle(p3.x, p3.y + radius, radius - radius / 5, Path.Direction.CCW);

        //去鋸齒
        canvas.setDrawFilter(new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG));
        drawBottomOval(canvas);
      //繪製外部的水滴狀
        drawBezierPath(canvas, ColorUtil.getResourcesColor(mContext, wrapperColor), path);
      //繪製內部的圓
        drawBezierPath(canvas, ColorUtil.getResourcesColor(mContext, circleColor), circle);
        drawText(canvas, mMilePost);
        canvas.restore();
    }

  	//繪製底部的陰影，drawBottomShader控制是否顯示陰影
    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);
        }
    }

  	//繪製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);//調整位置，看起來居中
        float rectBottom = p2.y + rectHeight;

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

        Paint.FontMetrics fontMetrics = mTextPaint.getFontMetrics();
        float top = fontMetrics.top;//為基線到字型上邊框的距離,即上圖中的top
        float bottom = fontMetrics.bottom;//為基線到字型下邊框的距離,即上圖中的bottom
        int baseLineY = (int) (rectF.centerY() + (top + bottom) / 2);//基線中間點的y軸計算公式
        canvas.drawText(mileStr, rectF.left, baseLineY, mTextPaint);
    }

    /**
     * 畫圓
     */
    private Path getPath(int radius) {
        CircleModel(radius);
        Path path = new Path();
        p1.setY(p1.y + radius * 0.2f * 1.05f); //設定 p1 底部左右兩個點的y值
        p1.y += radius * 0.2f * 1.05f;//設定 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);//右邊
        p3.setY(-radius);// 左邊
        p3.x = p1.x = 0;//圓心

        p3.left.x = -c;
        p3.right.x = c;
        p1.left.x = -c * 0.36f;
        p1.right.x = c * 0.36f;
        //p1.p3屬於圓的上下兩點
        p2.setX(radius); // 下邊
        p4.setX(-radius);// 上邊
        p2.y = p4.y = 0;//  圓心
        p2.top.y = p4.top.y = -c;
        p2.bottom.y = p4.bottom.y = c;
    }


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

簡單的講一下，主要通過三階貝塞爾曲線來繪製圓，在圓的基礎上，對Bottom方向的P1(包含 p1本身以及left、right兩個control點)拉昇，類似行星跟衛星的潮汐引力在朝下拉昇的方向形成水滴形的尖角。

這裡left、top、right、bottom四個方向，每個方向共三個點，共同確定這個圓。

VPoint 代表垂直方向的 left、right，這裡是 p2跟p4 分表包含三個點，三點成線跟圓的左邊、右邊相切。

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);
    }
}

同樣， HPoint 代表水邊方向圓的切線，p1跟p3代表Bottom、Top上的三個點。

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);
    }
}

其它的見程式碼註釋。

應用自定義View到AMapView中

這裡就直接參考高德的demo，需要注意一點的是，在載入自定義的LocationMarker時，我在LocationMarker的外層包了兩層父View，試過了一層顯示不出來

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); //初始化生長效果動畫
		markerAnimation.setDuration(1000);  //設定動畫時間 單位毫秒
		marker.setAnimation(markerAnimation);

		marker.startAnimation();
	}

兩層父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>

下次講優化軌跡路徑，從採集時到最後的優化。

程式碼請前往運動軌跡，程式碼包含了很多圖表Chart的程式碼沒有分開，有空對這個庫做個系列，因為MAAndroidChart沒法滿足需求做的庫，程式碼中需要自己去高德平臺上註冊Key。

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Android自定義LocationMarker的實現詳解

目錄

自定義View LocationMarker

應用自定義View到AMapView中

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