Android自定义RecyclerView实现不固定刻度的刻度尺

本文实例为大家分享了自定义RecyclerView实现不固定刻度的刻度尺的具体代码，供大家参考，具体内容如下

##不均匀刻度效果图

##等比例刻度效果图

实现功能目前

1、实现类似日期/分类等大小不固定的水平刻度尺效果
2、实现标准刻度尺效果
3、监听RecyclerView滑动时居中条目
4、去掉边缘阴影

定义RecyclerView

public class CenterRecyclerView extends RecyclerView {

//设置RecyclerView的速度
  private static final int MAXIMUM_FLING_VELOCITY = 3000;
//画中轴线
  private Paint mCenterLinePaint;
  private Context context;
  private CenterLayoutManager mLayoutManager;
  private Paint mTextPaint;
  private String text = "";
  private String textUnit = "";
  private Paint mTextUnitPaint;
  private int mWidth;
  private int mHeight;
  private int mLineStartY;
  private int mLineEndY;
  private int mTextStartY;

  public CenterRecyclerView(@NonNull Context context) {
    this(context, null);
  }

  public CenterRecyclerView(@NonNull Context context, @Nullable AttributeSet attrs) {
    this(context, attrs, -1);
  }

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

  private void init(Context context, AttributeSet attrs) {
    this.context = context;
    initPaint();
  }

  public void setTypeface(Typeface typeface) {
    mTextPaint.setTypeface(typeface);
    mTextUnitPaint.setTypeface(typeface);
  }

  private void initPaint() {
    mCenterLinePaint = new Paint();
    mCenterLinePaint.setAntiAlias(true);
    mCenterLinePaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
    mCenterLinePaint.setTextAlign(Paint.Align.CENTER);
    mCenterLinePaint.setColor(0xff6e9fff);

    mTextUnitPaint = new Paint();
    mTextUnitPaint.setStyle(Paint.Style.FILL);
    mTextUnitPaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
    mTextUnitPaint.setTextSize(ScreenUtil.dip2px(context, 15));
    mTextUnitPaint.setColor(Color.parseColor("#DD5F00"));

    mTextPaint = new Paint();
    mTextPaint.setStyle(Paint.Style.FILL);
    mTextPaint.setStrokeWidth(ScreenUtil.dip2px(context, 4));
    mTextPaint.setTextSize(ScreenUtil.dip2px(context, 60));
    mTextPaint.setColor(Color.parseColor("#DD5F00"));
    mTextPaint.setTextAlign(Paint.Align.CENTER);
  }

  @Override
  public void addOnScrollListener(@NonNull OnScrollListener listener) {
    super.addOnScrollListener(listener);
    postInvalidate();
  }

  @Override
  protected void onMeasure(int widthSpec, int heightSpec) {
    super.onMeasure(widthSpec, heightSpec);

  }

//获取相关参数
  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    super.onLayout(changed, l, t, r, b);
    mWidth = getWidth();
    mHeight = getHeight();
    int lineHeight = ScreenUtil.dip2px(context, 58);
    mLineStartY = mHeight / 2 - lineHeight / 2;
    mLineEndY = mHeight / 2 + lineHeight / 2;
    mTextStartY = mHeight / 2 - ScreenUtil.dip2px(context, 55);
  }

  @Override
  public void draw(Canvas c) {
    super.draw(c);
    Log.d("szjjyh", "draw: " + getWidth());
    drawCenterLine(c);
    drawText(c);
  }

//画线
  private void drawCenterLine(Canvas canvas) {
    canvas.drawLine(mWidth / 2, mLineStartY, mWidth / 2, mLineEndY, mCenterLinePaint);
  }

//画字/画单位
  private void drawText(Canvas c) {
    c.drawText(text, mWidth / 2, mTextStartY, mTextPaint);
    if (textUnit != null && textUnit.length() != 0) {
      float textWidth = mTextPaint.measureText(text);
      c.drawText(textUnit, (mWidth + textWidth) / 2, mTextStartY, mTextUnitPaint);
    }
  }

  public String getText() {
    return text;
  }

  public void setText(String text) {
    if (text == null) {
      return;
    }
    this.text = text;
  }

  public String getTextUnit() {
    return textUnit;
  }

  public void setTextUnit(String textUnit) {
    if (textUnit == null) {
      return;
    }
    this.textUnit = textUnit;
  }

  @Override
  public void setAdapter(@Nullable Adapter adapter) {
    super.setAdapter(adapter);
  }

  @Override
  public void setLayoutManager(@Nullable LayoutManager layout) {
    super.setLayoutManager(layout);
    mLayoutManager = (CenterLayoutManager) layout;
  }

  @Override
  public boolean fling(int velocityX, int velocityY) {
    velocityX = solveVelocity(velocityX);
    velocityY = solveVelocity(velocityY);
    return super.fling(velocityX, velocityY);
  }

  private int solveVelocity(int velocity) {
    if (velocity > 0) {
      return Math.min(velocity, MAXIMUM_FLING_VELOCITY);
    } else {
      return Math.max(velocity, -MAXIMUM_FLING_VELOCITY);
    }
  }

//  @Override
//  protected float getLeftFadingEdgeStrength() {
//    return 0;
//  }
}

定义LinearLayoutManager

public class CenterLayoutManager extends LinearLayoutManager {
  public CenterLayoutManager(Context context) {
    super(context);
  }

  public CenterLayoutManager(Context context, int orientation, boolean reverseLayout) {
    super(context, orientation, reverseLayout);
  }

  public CenterLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    super(context, attrs, defStyleAttr, defStyleRes);
  }
//计算偏移量自己适配
 @Override
  public void scrollToPosition(int position) {
    scrollToPositionWithOffset(position,-15);
  }

  @Override
  public void scrollToPositionWithOffset(int position, int offset) {
    super.scrollToPositionWithOffset(position, offset);
  }
  @Override
  public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
    RecyclerView.SmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
    smoothScroller.setTargetPosition(position);
    startSmoothScroll(smoothScroller);
  }

  public void smoothScrollToPosition(RecyclerView recyclerView, int position) {
    RecyclerView.SmoothScroller smoothScroller = new CenterSmoothScroller(recyclerView.getContext());
    smoothScroller.setTargetPosition(position);
    startSmoothScroll(smoothScroller);
  }


  private static class CenterSmoothScroller extends LinearSmoothScroller {

    CenterSmoothScroller(Context context) {
      super(context);
    }

//滑动到中间位置
    @Override
    public int calculateDtToFit(int viewStart, int viewEnd, int boxStart, int boxEnd, int snapPreference) {
      return (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2);
    }
//滚动速度设置
    @Override
    protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
      return 4;
    }

    @Override
    protected int getVerticalSnapPreference() {
      return super.getVerticalSnapPreference();
    }
  }
  
}

滑动事件监听

public class CenterScrollListener extends RecyclerView.OnScrollListener {

  private CenterLayoutManager mLayoutManager;
  RecyclerView recyclerView;
  private int mPosition;
  private double intScrollState;
  private int mFirstItemPosition1;
  private int mLastItemPosition1;
  private boolean is_Stop;
  private String TAG = "CenterScrollListener";
  private double is_playSound;

  public CenterScrollListener(OnItemCenterScrollistner onItemCenterScrollistner) {
    this.onItemCenterScrollistner = onItemCenterScrollistner;
  }

  public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
    init(recyclerView);
    intScrollState = newState;
    is_Stop = false;

    if (intScrollState == RecyclerView.SCROLL_STATE_IDLE) {
      Log.e(TAG, "onScrollStateChanged: 11111:"+mPosition);
      CeterScroll(0, mPosition);
    }
  }

  public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
    init(recyclerView);
    int x = Math.abs(dx);
    if (!is_Stop && x <= 1) {
      is_Stop = true;
      if (dx >= 0) {
        mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;
        View childAt = mLayoutManager.findViewByPosition(mPosition);
        if (childAt.getLeft() < ScreenUtil.getScreenWidth(recyclerView.getContext()) / 2) {
          mPosition = mPosition + 1;
        }
        Log.e(TAG, "111111: w:" + childAt.getWidth() + " :l:" +
            childAt.getLeft() + " :r:" + childAt.getRight());
      } else {
        mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;
        View childAt = mLayoutManager.findViewByPosition(mPosition);
        if (childAt.getLeft() > ScreenUtil.getScreenWidth(recyclerView.getContext()) / 2) {
          mPosition = mPosition - 1;
        }
      }
    }
    CeterScroll(x, mPosition);
  }

//事件监听
  private void init(@NonNull RecyclerView recyclerView) {
    this.recyclerView = recyclerView;
    if (mLayoutManager == null) {
      mLayoutManager = (CenterLayoutManager) recyclerView.getLayoutManager();
    }
    int firstItemPosition = mLayoutManager.findFirstVisibleItemPosition();
    int lastItemPosition = mLayoutManager.findLastVisibleItemPosition();
    mFirstItemPosition1 = mLayoutManager.findFirstCompletelyVisibleItemPosition();
    mLastItemPosition1 = mLayoutManager.findLastCompletelyVisibleItemPosition();
    mPosition = (mFirstItemPosition1 + mLastItemPosition1) / 2;

    if (is_playSound != mPosition) {
      is_playSound = mPosition;
      int count = mLayoutManager.getItemCount();
//          soundpool.play(soundmap.get(1), 1, 1, 0, 0, 1);
      if (onItemCenterScrollistner != null) {
//中间条目事件监听
        onItemCenterScrollistner.onItemCenterScrollistner(mLastItemPosition1, mPosition,count);
      }
    }

//目前由于要实现灰色条目当条目间距为10dp,屏幕宽度360时不能继续滑动
    if (mPosition <= 18) {
      CeterScroll(0, 18);
    }
  }

//速度变小时自动滚动到中间位置
  private void CeterScroll(int dx, int position) {
    if ((intScrollState == RecyclerView.SCROLL_STATE_SETTLING || intScrollState
        == RecyclerView.SCROLL_STATE_IDLE) && Math.abs(dx) <= 1) {
      mLayoutManager.smoothScrollToPosition(recyclerView, position);
    }
  }

  OnItemCenterScrollistner onItemCenterScrollistner;

  public void setOnItemCenterScrollistner(OnItemCenterScrollistner onItemCenterScrollistner) {
    this.onItemCenterScrollistner = onItemCenterScrollistner;
  }

  public interface OnItemCenterScrollistner {
    void onItemCenterScrollistner(int lastItemPosition1, int position, int count);
  }

adpater实现

public class DateAdapter extends BaseRecyclerAdapter {

  private static final int layoutId = R.layout.view_item_date;

  public DateAdapter(Context context, List datas) {
    super(context, datas, layoutId);
  }

  @Override
  protected void bindData(BaseViewHolder holder, CalendarDateBean data, int position) {
    if (data.getDay() == 1) {
//R.id.tv_1为线需要居中否则和中轴线不会完全对称  R.id.tv_2为大刻度文字
      holder.getView(R.id.tv_1).setScaleX(2F);
      holder.setText(R.id.tv_2, data.getMonth() + "月");
      holder.getView(R.id.tv_2).setVisibility(View.VISIBLE);
      holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#ffffff"));
    } else if (data.getDay() ==-1){
      holder.getView(R.id.tv_1).setScaleX(1F);
      holder.getView(R.id.tv_2).setVisibility(View.GONE);
      holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#222222"));
    }else {
      holder.getView(R.id.tv_1).setScaleX(1F);
      holder.getView(R.id.tv_2).setVisibility(View.GONE);
      holder.getView(R.id.tv_1).setBackgroundColor(Color.parseColor("#ffffff"));
    }
  }
  
}

activity 加载view展示

private void initRecyclerView() {
//此处试配时注意item10dp 宽度360 计算发放 360/10/2得到记得适配
    for (int i = 0; i < 18; i++) {
      TimeBean timeBean = new TimeBean();
      mList.add(timeBean);
    }
    for (int i = 0; i < 1440; i++) {
      int minute = i % 60;
      int hour = i / 60;
      if (CalendarUtil.getHourTime()==hour&&CalendarUtil.getMinuteTime()==minute){
        mPostion = i;
      }
      TimeBean timeBean = new TimeBean();
      timeBean.setHour(hour);
      timeBean.setMinute(minute);
      timeBean.setTimeDate(CalendarUtil.getHourToMinute(hour,minute));
      mList.add(timeBean);
    }
    for (int i = 0; i < 18; i++) {
      TimeBean timeBean = new TimeBean();
//      timeBean.setMinute(-1);
      mList.add(timeBean);
    }

    rv_data = findViewById(R.id.rv_data);
    mAdapter = new TimeAdapter(this, mList);
    rv_data.setAdapter(mAdapter);
//设置字体
    rv_data.setTypeface(Typeface.createFromAsset(getAssets(), "fonts/dincond_boldalternate.ttf"));
    CenterLayoutManager layoutManager = new CenterLayoutManager(this);
    layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
    rv_data.setLayoutManager(layoutManager);

    rv_data.scrollToPosition(mPostion);
    rv_data.addOnScrollListener(new CenterScrollListener((lastItemPosition, position,count) -> {
//更新文本和单位
      rv_data.setText(mList.get(position).getTimeDate());
      if (mList.get(position).getHour()>12){
        rv_data.setTextUnit("PM");
      }else {
        rv_data.setTextUnit("AM");
      }
    }));

  }

实现了基本代码全部写了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。