android实现滑动解锁

整体代码

public class LoadAwaySlideUnlockView extends View {
    public interface UnlockListener {
        void onLoadAwayUnlock();
    }
    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 Paint mBluePaint;//划过去之后蓝色背景的画笔
    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 LoadAwaySlideUnlockView(Context context) {
        this(context, null);
    }
    public LoadAwaySlideUnlockView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
    public LoadAwaySlideUnlockView(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }
    public void setText(String text){
        mText = text;
    }
    public LoadAwaySlideUnlockView(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;
        mTextSize = 30;//文字大小
        mTextLeft = 10;//文字距离左边
        mMoveX = 0;
        mGradientIndex = 0;
        mSliPaint = new Paint();
        mSliPaint.setColor(Color.parseColor("#4a4c5b"));
        mSliPaint.setAntiAlias(true);
        mBgPaint = new Paint();
        mBgPaint.setColor(Color.parseColor("#a6a6a6"));
        mBgPaint.setAntiAlias(true);
        mBluePaint = new Paint();
        mBluePaint.setColor(Color.parseColor("#009496"));
        mBluePaint.setAntiAlias(true);
        mPaint = new Paint();
        mPaint.setColor(Color.WHITE);
        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);
        //最大滑动距离
        mSlidableLength = (int) (specWidthSize -(mMoveX+mR*3+margin*3-mMoveX+margin));
        //有效距离
        mEffectiveLength = mSlidableLength-20;
        mSliderRect=new Rect((int)margin, (int)margin, 300, (int)(height - margin));
        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
        );
        mHandler.removeMessages(MSG_REDRAW);
        mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
    }
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //背景色
        RectF oval = new RectF(margin, margin, width - margin, height - margin);// 设置个新的长方形
        canvas.drawRect(oval,mBgPaint);
        //划过去背景色
        RectF ovalBlue= new RectF(margin,margin,mMoveX+margin,mR*2+margin*3);
        canvas.drawRect(ovalBlue,mBluePaint);
        //文字
        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);
        //滑块
        RectF oval2 = new RectF(mMoveX+margin,margin,mMoveX+mR*3+margin*3,mR*2+margin*3);// 设置个新的长方形
        canvas.drawRect(oval2,mSliPaint);//方形
        //三个小箭头
        Bitmap bitmap = BitmapFactory.decodeResource(this.getContext().getResources(), R.mipmap.arrow_right_small);
        canvas.drawBitmap(bitmap,mMoveX+(mMoveX+mR*3+margin*3-mMoveX)/2-15,mR-margin,mSliPaint);
        canvas.drawBitmap(bitmap,mMoveX+(mMoveX+mR*3+margin*3-mMoveX)/2,mR-margin,mSliPaint);
        canvas.drawBitmap(bitmap,mMoveX+(mMoveX+mR*3+margin*3-mMoveX)/2+15,mR-margin,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) {
//        Log.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");
                Log.e("SlideU","按下");
                break;
            case MotionEvent.ACTION_MOVE:
                Log.e("SlideU","移动");
                mLastX = event.getX();
                if (mLastX > mStartX) {
                    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:
                Log.e("SlideU","超出或抬起");
                mVelocityTracker.computeCurrentVelocity(1000, mMaxVelocity);
                float velocityX = mVelocityTracker.getXVelocity();
                Log.e("SlideU","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 =Integer.MAX_VALUE){
                        mGradientIndex = 0;
                    }
                    mHandler.sendEmptyMessageDelayed(MSG_REDRAW, DRAW_INTERVAL);
                    break;
            }
        }
    };
}

slideUnlock.setText("中间提示文字");
slideUnlock.setSlideListener(this);