好久沒有自定義View了，複習複習~

package com.test.views;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

import com.test.R;

/**
 * 圓角矩形文本框
 */
public class RoundedRectangleTextView extends View {
    private Paint mPaintText;
    private Paint mPaintBg;
    //豎直方向的值
    private float strokeWidth = 10; //框的粗細
    private float textDividerStrokeW = 20;   //文字和框的水平的間隔
    private float textHeight = 20;   //文字高度

    //水平方向的值
    private float textDividerStrokeH = 20;   //文字和框水平的間隔
    private float textWidth = 40;   //文字寬度

    private boolean isSelected = false; //是否選中
    private String mText = "";

    public RoundedRectangleTextView(Context context) {
        this(context, null);
    }

    public RoundedRectangleTextView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public RoundedRectangleTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mPaintText = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaintBg = new Paint(Paint.ANTI_ALIAS_FLAG);
    }

    public void setText(String text) {
        if (TextUtils.isEmpty(text)) {
            mText = "";
        } else {
            mText = text;
        }
        invalidate();
    }

    public void setSelected(boolean isSelected) {
        this.isSelected = isSelected;
        invalidate();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //這裏要先把文字寬高算出來再去度量整個寬高
        mPaintText.setTextSize(60);
        mPaintText.setFakeBoldText(true);
        Rect rect = new Rect();
        mPaintText.getTextBounds(mText, 0, mText.length(), rect);
        textHeight = rect.height();
        textWidth = rect.width();

        int width = MeasureSpec.getSize(widthMeasureSpec);
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        int heightMode = MeasureSpec.getMode(heightMeasureSpec);

        int wrapWidth = (int) (textWidth + 2 * textDividerStrokeW + 2 * strokeWidth);
        int wrapHeight = (int) (textHeight + 2 * textDividerStrokeH + 2 * strokeWidth);

        if (widthMode == MeasureSpec.AT_MOST && heightMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(wrapWidth, wrapHeight);
        } else if (widthMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(wrapWidth, height);
        } else if (heightMode == MeasureSpec.AT_MOST) {
            setMeasuredDimension(width, wrapHeight);
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        int width = getWidth();
        int height = getHeight();

        if (isSelected) {
            //畫背景
            drawRec(canvas, mPaintBg, width, height);
        }
        //畫中間的文字
        drawText(canvas, mPaintText, width, height);
    }

    private void drawRec(Canvas canvas, Paint mPaint, int width, int height) {
        mPaint.setColor(getResources().getColor(R.color.colorAccent));
        mPaint.setStyle(Paint.Style.STROKE);//空心矩形框
        mPaint.setStrokeWidth(10);
        RectF rectF = new RectF(0 + strokeWidth / 2, 0 + strokeWidth / 2, width - strokeWidth / 2, height - strokeWidth / 2);
        canvas.drawRoundRect(rectF, 60, 60, mPaint);
    }

    private void drawText(Canvas canvas, Paint paintCenter, int width, int height) {
        Rect rect1 = new Rect();
        paintCenter.getTextBounds(mText, 0, mText.length(), rect1);
        int x = width / 2 - rect1.centerX();
        int y = height / 2 - rect1.centerY();
        canvas.drawText(mText, x, y, paintCenter);
    }
}