Android中实现圆形进度条的方法

package com.fun.progressbarwithnumber;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.ProgressBar;

public class HorizontalProgressBarWithNumber extends ProgressBar {

  private static final int DEFAULT_TEXT_SIZE = 10;
  private static final int DEFAULT_TEXT_COLOR = 0XFFFC00D1;
  private static final int DEFAULT_COLOR_UNREACHED_COLOR = 0xFFd3d6da;
  private static final int DEFAULT_HEIGHT_REACHED_PROGRESS_BAR = 2;
  private static final int DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR = 2;
  private static final int DEFAULT_CIRCLE_COLOR = 0XFF3F51B5;

  protected Paint mPaint = new Paint();
  // 字体颜色
  protected int mTextColor = DEFAULT_TEXT_COLOR;
  // 字体大小
  protected int mTextSize = sp2px(DEFAULT_TEXT_SIZE);
  // 覆盖进度高度
  protected int mReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_REACHED_PROGRESS_BAR);
  // 覆盖进度颜色
  protected int mReachedBarColor = DEFAULT_TEXT_COLOR;
  // 未覆盖进度高度
  protected int mUnReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR);
  // 未覆盖进度颜色
  protected int mUnReachedBarColor = DEFAULT_COLOR_UNREACHED_COLOR;
  // 圆的颜色
  protected int mCircleColor = DEFAULT_CIRCLE_COLOR;

  protected int mRealWidth;

  protected boolean mIfDrawText = true;
  protected boolean mIfDrawCircle = true;

  protected static final int VISIBLE = 0;

  public HorizontalProgressBarWithNumber(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
  }

  public HorizontalProgressBarWithNumber(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    obtainStyledAttributes(attrs);
    mPaint.setTextSize(mTextSize);
    mPaint.setColor(mTextColor);
    mPaint.setAntiAlias(true);
  }

  private void obtainStyledAttributes(AttributeSet attrs) {
    // 获取自定义属性
    final TypedArray attributes = getContext().obtainStyledAttributes(attrs, R.styleable.HorizontalProgressBarWithNumber);
    mTextColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_text_color, DEFAULT_TEXT_COLOR);
    mTextSize = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_text_size, mTextSize);
    mCircleColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_circle_color, DEFAULT_CIRCLE_COLOR);
    mReachedBarColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_reached_color, mTextColor);
    mUnReachedBarColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_unreached_color, DEFAULT_COLOR_UNREACHED_COLOR);
    mReachedProgressBarHeight = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_reached_bar_height, mReachedProgressBarHeight);
    mUnReachedProgressBarHeight = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_unreached_bar_height, mUnReachedProgressBarHeight);
    int textVisible = attributes.getInt(R.styleable.HorizontalProgressBarWithNumber_progress_text_visibility, VISIBLE);
    if (textVisible != VISIBLE) {
      mIfDrawText = false;
    }
    attributes.recycle();
    int left = (int) (mReachedProgressBarHeight * 0.8), right = (int) (mReachedProgressBarHeight * 0.8);
    int top = (int) (mReachedProgressBarHeight * 0.3 + dp2px(1)), bottom = (int) (mReachedProgressBarHeight * 0.3 + dp2px(1));
    setPadding(left, top, right, bottom);
  }

  @Override
  protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int width = MeasureSpec.getSize(widthMeasureSpec);
    int height = measureHeight(heightMeasureSpec);
    setMeasuredDimension(width, height);
    mRealWidth = getMeasuredWidth() - getPaddingRight() - getPaddingLeft();
  }

  private int measureHeight(int measureSpec) {
    int result;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);
    if (specMode == MeasureSpec.EXACTLY) {
      result = specSize;
    } else {
      float textHeight = (mPaint.descent() - mPaint.ascent());
      result = (int) (getPaddingTop() + getPaddingBottom() + Math.max(
          Math.max(mReachedProgressBarHeight, mUnReachedProgressBarHeight), Math.abs(textHeight)));
      if (specMode == MeasureSpec.AT_MOST) {
        result = Math.min(result, specSize);
      }
    }
    return result;
  }


  @Override
  protected synchronized void onDraw(Canvas canvas) {
    canvas.save();
    canvas.translate(getPaddingLeft(), getHeight() / 2);

    boolean noNeedBg = false;
    float radio = getProgress() * 1.0f / getMax();
    float progressPosX = (int) (mRealWidth * radio);
    String text = getProgress() + "%";

    float textWidth = mPaint.measureText(text);
    float textHeight = (mPaint.descent() + mPaint.ascent()) / 2;

    float radius = (mReachedProgressBarHeight + getPaddingBottom() + getPaddingTop()) / 2;

    // 覆盖的进度
    float endX = progressPosX;
    if (endX > -1) {
      mPaint.setColor(mReachedBarColor);
      RectF rectF = new RectF(0, 0 - getPaddingTop() - getPaddingBottom(),
          endX, mReachedProgressBarHeight - getPaddingBottom());
      canvas.drawRoundRect(rectF, 25, 25, mPaint);
    }

    // 未覆盖的进度
    if (!noNeedBg) {
      float start = progressPosX;
      mPaint.setColor(mUnReachedBarColor);
      RectF rectF = new RectF(start, 0 - getPaddingTop() - getPaddingBottom(),
          mRealWidth + getPaddingRight() - radius, mReachedProgressBarHeight - getPaddingBottom());
      canvas.drawRoundRect(rectF, 25, 25, mPaint);
    }

    // 圆
    if (mIfDrawCircle) {
      mPaint.setColor(mCircleColor);
      canvas.drawCircle(progressPosX, 0, radius, mPaint);
    }

    // 文本
    if (mIfDrawText) {
      mPaint.setColor(mTextColor);
      canvas.drawText(text, progressPosX - textWidth / 2, -textHeight, mPaint);
    }

    canvas.restore();

  }

  /**
   * dp 2 px
   */
  protected int dp2px(int dpVal) {
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpVal, getResources().getDisplayMetrics());
  }

  /**
   * sp 2 px
   */
  protected int sp2px(int spVal) {
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, spVal, getResources().getDisplayMetrics());
  }

}