Android 自定义滑动解锁View

package com.inks.jisaimedicalforch8.view;

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.Interpolator;

import com.inks.inkslibrary.utils.L;
import com.inks.jisaimedicalforch8.UI.R;

/**
 * Created by inks on 2018/6/29 0029.
 */

public class SlideUnlockView extends View {
    public interface UnlockListener {
        void onUnlock();
    }

    private UnlockListener mUnlockListener;


    public void setUnlockListener(UnlockListener unlockListener) {
        mUnlockListener = unlockListener;
    }

    private static final int MSG_REDRAW = 1;
    private static final int DRAW_INTERVAL = 50;
    private static final int STEP_LENGTH = 10;//速度

    private Paint mPaint;//文字的画笔
    private Paint mSliPaint;//滑块画笔
    private Paint mBgPaint;//背景画笔

    private VelocityTracker mVelocityTracker;//滑动速度
    private int mMaxVelocity;
    private LinearGradient mGradient;//渐变色
    private LinearGradient bgGradient;//背景渐变色

    private LinearGradient sliGradient;//滑块渐变色
//    LinearGradient有两个构造函数;
//
//    public LinearGradient(float x0, float y0, float x1, float y1, int[] colors, float[] positions,Shader.TileMode tile)
//
//    参数:
//
//    float x0: 渐变起始点x坐标
//
//    float y0:渐变起始点y坐标
//
//    float x1:渐变结束点x坐标
//
//    float y1:渐变结束点y坐标
//
//    int[] colors:颜色 的int 数组
//
//    float[] positions: 相对位置的颜色数组,可为null,  若为null,可为null,颜色沿渐变线均匀分布
//
//    Shader.TileMode tile: 渲染器平铺模式
//
//
//
//    public LinearGradient(float x0, float y0, float x1, float y1, int color0, int color1,Shader.TileMode tile)
//
//    float x0: 渐变起始点x坐标
//
//    float y0:渐变起始点y坐标
//
//    float x1:渐变结束点x坐标
//
//    float y1:渐变结束点y坐标
//
//    int color0: 起始渐变色
//    int color1: 结束渐变色
//
//    Shader.TileMode tile: 渲染器平铺模式

    private int[] mGradientColors;
    private int[] bgGradientColors;
    private int mGradientIndex;
    private Interpolator mInterpolator;
    private float mDensity;
    private Matrix mMatrix;
    private ValueAnimator mValueAnimator;


    private int width;
    private int height;

    private String mText;//文字
    private int mTextSize;//文字大小
    private int mTextLeft;//文字距离左边
    private int mR;//滑块的半径
    private float margin;


    private Rect mSliderRect;
    private int mSlidableLength;    // SlidableLength = BackgroundWidth - LeftMagins - RightMagins - SliderWidth
    private int mEffectiveLength;   // Suggested length is 20pixels shorter than SlidableLength
    private float mEffectiveVelocity = 1000;//滑块自动回滚的速度

    private float mStartX;
    private float mStartY;
    private float mLastX;
    private float mMoveX;

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

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

    public SlideUnlockView(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public SlideUnlockView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        mDensity = getResources().getDisplayMetrics().density;
        ViewConfiguration configuration = ViewConfiguration.get(context);
        mMaxVelocity = configuration.getScaledMaximumFlingVelocity();
        mInterpolator = new AccelerateDecelerateInterpolator();

        setClickable(true);
        setFocusable(true);
        setFocusableInTouchMode(true);

        mSlidableLength = 200;
        mText = ">> 滑动进入主页";
        mTextSize = 36;//文字大小
        mTextLeft = 50;//文字距离左边
        mMoveX = 0;
        mGradientIndex = 0;
        mSliPaint = new Paint();
        mSliPaint.setAntiAlias(true);

        mBgPaint = new Paint();
        mBgPaint.setAntiAlias(true);


        mPaint = new Paint();
        mPaint.setTextSize(mTextSize);
        //该方法即为设置基线上那个点究竟是left,center,还是right
        mPaint.setTextAlign(Paint.Align.LEFT);
      //  mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int specWidthSize = MeasureSpec.getSize(widthMeasureSpec);//宽
        int specHeightSize = MeasureSpec.getSize(heightMeasureSpec);//高

        mMatrix = new Matrix();

        width = specWidthSize;
        height = specHeightSize;
        mTextLeft = (int) (height * 1.5);
        margin = height / 20;
        mR = (int) (((height-margin*2) / 2)-margin);

        mSlidableLength = (int) (specWidthSize -mR*2-margin*4);
        mEffectiveLength = mSlidableLength-20;

        mSliderRect = new Rect((int) margin,(int) margin, (int) (mR*2+ margin*2),
                (int) (mR*2+ margin*2));

        mGradientColors = new int[]{Color.argb(255, 120, 120, 120),
                Color.argb(255, 120, 120, 120), Color.argb(255, 255, 255, 255)};



        mGradient = new LinearGradient(0, 0, width/2, 0, mGradientColors,
                new float[]{0, 0.7f, 1}, Shader.TileMode.MIRROR);



        bgGradient = new LinearGradient(
                0, 0, 0, (float) ((height)/2.0),
                Color.argb(80, 0X77, 0X77, 0X77), Color.argb(200, 0X11, 0X11, 0X11),
                Shader.TileMode.CLAMP
        );

        sliGradient = new LinearGradient(
                0, 0, 0, (float) ((height)/2.0),
                Color.argb(80, 0Xbb, 0Xbb, 0Xbb), Color.argb(200, 0X77, 0X77, 0X77),
                Shader.TileMode.CLAMP
        );

//        bgGradientColors = new int[]{Color.argb(80, 0X77, 0X77, 0X77),
//                Color.argb(200, 0X11, 0X11, 0X11), Color.argb(80, 0X77, 0X77, 0X77)};
//        bgGradient = new LinearGradient(margin, 0, margin, height-margin, bgGradientColors,
//                new float[]{0, 0.5f, 1}, Shader.TileMode.MIRROR);
        mBgPaint.setShader(bgGradient);

        mSliPaint.setShader(sliGradient);
        mHandler.removeMessages(MSG_REDRAW);
        mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
    }


    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        RectF oval = new RectF(margin, margin, width - margin, height - margin);// 设置个新的长方形
        canvas.drawRoundRect(oval, (float) ((height - margin*2)/2.0),  (float) ((height - margin*2)/2.0), mBgPaint);//第二个参数是x半径，第三个参数是y半径

        mPaint.setShader(mGradient);
        Paint.FontMetrics fontMetrics = mPaint.getFontMetrics();
        float top = fontMetrics.top;//为基线到字体上边框的距离
        float bottom = fontMetrics.bottom;//为基线到字体下边框的距离
        int baseLineY = (int) (height / 2 - top / 2 - bottom / 2);//基线中间点的y轴计算公式
        canvas.drawText(mText, mTextLeft, baseLineY, mPaint);

        canvas.drawCircle(mR + mMoveX+margin*2, height/2, mR, mSliPaint);


    }

    public void reset() {
        if (mValueAnimator != null) {
            mValueAnimator.cancel();
        }
        mMoveX = 0;
        mPaint.setAlpha(255);

        mHandler.removeMessages(MSG_REDRAW);
        mHandler.sendEmptyMessageDelayed(MSG_REDRAW,200);
    }




    @Override
    public boolean onTouchEvent(MotionEvent event) {

        L.e(event.getAction()+"");
        // 点击是否在滑块上
        if (event.getAction() != MotionEvent.ACTION_DOWN
                && !mSliderRect.contains((int) mStartX, (int) mStartY)) {
            if (event.getAction() == MotionEvent.ACTION_UP
                    || event.getAction() == MotionEvent.ACTION_CANCEL) {
                mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
            }
            return super.onTouchEvent(event);
        }
        acquireVelocityTrackerAndAddMovement(event);

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mStartX = event.getX();
                mStartY = event.getY();
                mLastX = mStartX;
                mHandler.removeMessages(MSG_REDRAW);
                L.e("按下");
                break;

            case MotionEvent.ACTION_MOVE:
                L.e("移动");
                mLastX = event.getX();
                if (mLastX > mStartX) {
                    int alpha = (int) (255 - (mLastX - mStartX) * 3 / mDensity);
                    if (alpha > 1) {
                        mPaint.setAlpha(alpha);
                    } else {
                        mPaint.setAlpha(0);
                    }

                    if (mLastX - mStartX > mSlidableLength) {
                        mLastX = mStartX + mSlidableLength;
                        mMoveX = mSlidableLength;
                    } else {
                        mMoveX = (int) (mLastX - mStartX);
                    }
                } else {
                    mLastX = mStartX;
                    mMoveX = 0;
                }
                invalidate();
                break;

            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                L.e("抬起或超出");
                mVelocityTracker.computeCurrentVelocity(1000, mMaxVelocity);
                float velocityX = mVelocityTracker.getXVelocity();
                L.e("速度"+velocityX);
                if (mLastX - mStartX > mEffectiveLength || velocityX/2 > mEffectiveVelocity) {
                    startAnimator(mLastX - mStartX,  mSlidableLength, velocityX, true);
                } else {
                    startAnimator(mLastX - mStartX,  0, velocityX, false);
                    mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
                }
                releaseVelocityTracker();
                break;
        }
        return super.onTouchEvent(event);
    }

    private void startAnimator(float start, float end, float velocity, boolean isRightMoving) {
        if (velocity < mEffectiveVelocity) {
            velocity = mEffectiveVelocity;
        }
        int duration = (int) (Math.abs(end - start) * 1000 / velocity);
        mValueAnimator = ValueAnimator.ofFloat(start, end);
        mValueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                mMoveX = (Float) animation.getAnimatedValue();
                int alpha = (int) (255 - (mMoveX) * 3 / mDensity);
                if (alpha > 1) {
                    mPaint.setAlpha(alpha);
                } else {
                    mPaint.setAlpha(0);
                }
                invalidate();
            }
        });
        mValueAnimator.setDuration(duration);
        mValueAnimator.setInterpolator(mInterpolator);
        if (isRightMoving) {
            mValueAnimator.addListener(new Animator.AnimatorListener() {
                @Override
                public void onAnimationStart(Animator animation) {
                }

                @Override
                public void onAnimationEnd(Animator animation) {
                    L.e("解锁");
                   // reset();
                    if (mUnlockListener != null) {
                        mUnlockListener.onUnlock();
                    }
                }

                @Override
                public void onAnimationCancel(Animator animation) {
                }

                @Override
                public void onAnimationRepeat(Animator animation) {
                }
            });
        }
        mValueAnimator.start();
    }

    private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
        if (mVelocityTracker == null) {
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(ev);
    }

    private void releaseVelocityTracker() {
        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
    }





    private Handler mHandler = new Handler() {

        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case MSG_REDRAW:
                    if(mMatrix==null){
                        mMatrix = new Matrix();

                    }
                    mMatrix.setTranslate(mGradientIndex, 0);

                    if(mGradient==null){
                        L.e("mGradient空");
                        mGradientColors = new int[]{Color.argb(255, 120, 120, 120),
                                Color.argb(255, 120, 120, 120), Color.argb(255, 255, 255, 255)};

                        mGradient = new LinearGradient(0, 0, width/2, 0, mGradientColors,
                                new float[]{0, 0.7f, 1}, Shader.TileMode.MIRROR);
                    }

                    mGradient.setLocalMatrix(mMatrix);
                    invalidate();
                    mGradientIndex += STEP_LENGTH ;
                    if(mGradientIndex>=Integer.MAX_VALUE){
                        mGradientIndex = 0;
                    }
                    mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
                    break;
            }
        }
    };
}

<com.inks.jisaimedicalforch8.view.SlideUnlockView
    android:id="@+id/SlideUnlockView"
    android:layout_width="550dp"
    android:layout_height="100dp"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="750dp"

    />