android字体渐变仿音乐歌词

 
package com.example.colorText;

import android.animation.ObjectAnimator;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

public class MainActivity extends Activity {

 @Override

 protected void onCreate(Bundle savedInstanceState) {

  super.onCreate(savedInstanceState);

  setContentView(R.layout.activity_main);

  final View view=findViewById(R.id.id_changeTextColorView);

  findViewById(R.id.btn).setOnClickListener(new OnClickListener() {

   

   @SuppressLint("NewApi")

   @Override

   public void onClick(View v) {

    //对象要有set get方法

    ObjectAnimator.ofFloat(view, "progress", 0,1).setDuration(3000).start();

        

    

   }

  });

  

 }

 

}

 

package com.example.colorText;

import android.content.Context;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Rect;

import android.graphics.Paint.FontMetrics;

import android.graphics.Paint.Style;

import android.util.AttributeSet;

import android.util.Log;

import android.util.TypedValue;

import android.view.View;

import android.view.View.MeasureSpec;

import android.widget.TextView;

public class myView extends View {

 private static final String TAG = "myView";

 private float progress = 0;

 private String text = "橘子群岛";

 private int mWidth;

 private int mHeight;

 private Rect mbounds;

 private int textWidth;

 private int textHeight;

 private int startX;

 private int startY;

 private Paint paint;

 private Paint oriPain;

 private boolean isStart = true;

 public myView(Context context) {

  this(context, null);

 }

 public myView(Context context, AttributeSet attrs) {

  this(context, attrs, 0);

 }

 public myView(Context context, AttributeSet attrs, int defStyle) {

  super(context, attrs, defStyle);

  paint = new Paint(Paint.ANTI_ALIAS_FLAG);

  oriPain = new Paint(Paint.ANTI_ALIAS_FLAG);

  oriPain.setColor(0xffff0000);

  oriPain.setDither(true);

  paint.setTextSize(sp2px(30));

  oriPain.setTextSize(sp2px(30));

  paint.setStyle(Style.FILL);

  // oriPain.setStyle(Style.STROKE);//空心字

  oriPain.setStyle(Style.FILL);

  paint.setColor(0xff0000ff);

  mbounds = new Rect();

  TypedArray ta = context.obtainStyledAttributes(attrs,

    R.styleable.ColorTrackView);

  

  progress = ta.getFloat(R.styleable.ColorTrackView_progress, 0);

        ta.recycle();

  

 }

 @Override

 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  measureText();

  int width = getWidthMeasure(widthMeasureSpec);

  int height = getHeightMeasure(heightMeasureSpec);

  setMeasuredDimension(width, height);

  startX = getMeasuredWidth() / 2 - textWidth / 2;

  startY = getMeasuredHeight() / 2 + textHeight / 2;

  super.onMeasure(widthMeasureSpec, heightMeasureSpec);

 }

 private void measureText() {

  textWidth = (int) oriPain.measureText(text);

  FontMetrics fm = oriPain.getFontMetrics();

  textHeight = (int) (fm.descent + fm.ascent);

        oriPain.getTextBounds(text, 0, text.length(), mbounds);

 }

 private int getHeightMeasure(int heights) {

  int mode = MeasureSpec.getMode(heights);

  int val = MeasureSpec.getSize(heights);

  int result = 0;

  switch (mode) {

  case MeasureSpec.EXACTLY:

   result = val;

   break;

  case MeasureSpec.AT_MOST:

   // break;//不要break 就可以 把上面的 result = textWidth; 注掉；

  case MeasureSpec.UNSPECIFIED:

   result = textHeight + getPaddingTop() + getPaddingBottom();

   break;

  }

  // EXACTLY的值 是精确的 最大也是屏幕大小 AT_MOST warp_content 动态大小 不会超过屏幕

  result = mode == MeasureSpec.AT_MOST ? Math.min(result, val) : result;

  return result;

 }

 private int getWidthMeasure(int widths) {

  int mode = MeasureSpec.getMode(widths);

  int width = MeasureSpec.getSize(widths);

  int result = 0;

  if (mode == MeasureSpec.EXACTLY) {

   // 精确值

   result = width;

  } else if (mode == MeasureSpec.UNSPECIFIED) {

  

   result = textWidth;

  }

  if (mode == MeasureSpec.AT_MOST) {

   result = textWidth + getPaddingLeft() + getPaddingRight();

  }

  // EXACTLY的值 是精确的 最大也是屏幕大小 AT_MOST warp_content 动态大小 不会超过屏幕

  result = mode == MeasureSpec.AT_MOST ? Math.min(result, width) : result;

  // 如果这个模式 就会取到 result = textWidth;不会取到超过 math_content

  return result;

 }

 @Override

 protected void onDraw(Canvas canvas) {

  super.onDraw(canvas);

  int l = (int) (startX + progress * mbounds.width());

  canvas.drawColor(0xaa11ff11);

  canvasDrawLeft(canvas, l);

 }

 private void canvasDrawOriginal(Canvas canvas) {

  //textHeight是负值，getMeasuredHeight() / 2字体的底部在控件中间，要加上字体的一半

 canvas.drawText(text,startX ,getMeasuredHeight() / 2-(textHeight) / 2, oriPain);

  // 高度一半 减去字体descent()+ ascent()=字体高度 的一半 让字体一半在上面 一半在下面

 }

 private void canvasDrawLeft(Canvas canvas, int l) {

  canvas.save();

  canvasDrawOriginal(canvas);

  canvas.clipRect(startX, 0, l, getMeasuredHeight());

  canvas.drawText(

    text,

    startX,

    getMeasuredHeight() / 2

      - ((oriPain.descent() + oriPain.ascent()) / 2), paint);

  canvas.restore();

 }

 public float getProgress() {

  return progress;

 }

 public void setProgress(float progress) {

  this.progress = progress;

  invalidate();// 必须 构造 get set 方法不然 接收不到 外面穿进来的值

 }

 private int sp2px(float dpVal) {

  return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,

    dpVal, getResources().getDisplayMetrics());

 }

}