Android编程实现的简易路径导航条功能示例

/**
 * 显示路径的View，支持返回上一级，支持点击某个位置回到指定层级。
 */
public class PathTextView extends LinearLayout {
  private TextView mTextView;
  private HorizontalScrollView hsView;
  private OnItemClickListener mListener;
  //保存每一个路径的id和名称
  private LinkedList<PathItem> pathItemList;
  //可点击部门文本颜色
  private static final int TEXT_COLOR = Color.parseColor("#48a0c7");
  //分隔符
  private static final String DIV_STR = " - ";
  public PathTextView(Context context) {
    super(context);
  }
  public PathTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    View root = LayoutInflater.from(context).inflate(R.layout.simple_tv, this, true);
    hsView = (HorizontalScrollView) root.findViewById(R.id.path_hs);
    mTextView = (TextView) root.findViewById(R.id.path_tv);
    mTextView.setMovementMethod(LinkMovementMethod.getInstance());
    mTextView.setOnLongClickListener(new View.OnLongClickListener() {
      @Override
      public boolean onLongClick(View v) {
        return true;
      }
    });
    pathItemList = new LinkedList<>();
  }
  /**
   * 初始化根路径名称。
   */
  public void initRoot(String text) {
    mTextView.append(createSpannableString(-1, text));
    pathItemList.addLast(new PathItem(-1, text));
  }
  /**
   * 继续拼接一个路径。
   */
  public void append(long id, String text) {
    mTextView.append(DIV_STR);
    mTextView.append(createSpannableString(id, text));
    pathItemList.addLast(new PathItem(id, text));
    //HorizontalScrollView滑动到最右边
    hsView.postDelayed(new Runnable() {
      @Override
      public void run() {
        hsView.fullScroll(HorizontalScrollView.FOCUS_RIGHT);
      }
    }, 100);
  }
  /**
   * 返回父级路径，一般用户点击“返回”时调用。
   */
  public void backParent() {
    int lastItemLength = pathItemList.removeLast().text.length();
    CharSequence oldCs = mTextView.getText();
    mTextView.setText(oldCs.subSequence(0, oldCs.length() - lastItemLength - DIV_STR.length()));
  }
  private SpannableString createSpannableString(long id, String text) {
    SpannableString spStr = new SpannableString(text);
    ClickableSpan clickSpan = new MyClickableSpan(id);
    spStr.setSpan(clickSpan, 0, text.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
    spStr.setSpan(new ForegroundColorSpan(TEXT_COLOR), 0, text.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
    return spStr;
  }
  private class MyClickableSpan extends ClickableSpan {
    private long id;
    MyClickableSpan(long id) {
      super();
      this.id = id;
    }
    @Override
    public void onClick(View widget) {
      //更新当前路径
      int backCount = 0;
      while (pathItemList.getLast().id != id) {
        backParent();
        backCount++;
      }
      //回调
      if (mListener != null && backCount > 0) {
        mListener.onClick(id, backCount);
      }
    }
  }
  private class PathItem {
    private long id;
    private String text;
    private PathItem(long id, String text) {
      this.id = id;
      this.text = text;
    }
  }
  public interface OnItemClickListener {
    /**
     * @param currentId 返回后目录的id.
     * @param backCount 返回层级的数量.
     */
    void onClick(long currentId, int backCount);
  }
  /**
   * 设置点击某个中间路径时的回调。
   */
  public void setOnItemClickListener(OnItemClickListener listener) {
    this.mListener = listener;
  }
}

<?xml version="1.0" encoding="utf-8"?>
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/path_hs"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="@color/light_gray2"
  android:scrollbars="none">
  <TextView
    android:id="@+id/path_tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@color/light_gray2"
    android:paddingBottom="12dp"
    android:paddingLeft="8dp"
    android:paddingRight="8dp"
    android:paddingTop="12dp"
    android:textSize="15sp" />
</HorizontalScrollView>