Android垂直进度条 Android实现垂直进度条VerticalSeekBar

时间:2021-03-31 秦汉春秋人气:2

水平的进度条见多了，总会想见个垂直的进度条开开眼。今天咱就试试。
要说原理也简单，就是把宽高倒置，其他的理论上都不需要动，发现问题再补补也就行了。

官方提供

官方是提供了垂直进度条的例子源码的，位置在android-sdk-windows\sources\android-23\com\android\example\rscamera\VerticalSeekBar.java，当然首先你SDK中要有Android 6.0。

VerticalSeekBar.java

/**
 * Class to create a vertical slider
 */
public class VerticalSeekBar extends SeekBar {

 public VerticalSeekBar(Context context) {
  super(context);
 }

 public VerticalSeekBar(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle);
 }

 public VerticalSeekBar(Context context, AttributeSet attrs) {
  super(context, attrs);
 }

 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  super.onSizeChanged(h, w, oldh, oldw);
 }

 @Override
 protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(heightMeasureSpec, widthMeasureSpec);
  setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
 }

 protected void onDraw(Canvas c) {
  c.rotate(-90);
  c.translate(-getHeight(), 0);

  super.onDraw(c);
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  if (!isEnabled()) {
   return false;
  }

  switch (event.getAction()) {
   case MotionEvent.ACTION_DOWN:
   case MotionEvent.ACTION_MOVE:
   case MotionEvent.ACTION_UP:
    setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));
    onSizeChanged(getWidth(), getHeight(), 0, 0);
    break;

   case MotionEvent.ACTION_CANCEL:
    break;
  }
  return true;
 }
}

继承SeekBar是最简单快捷的，不用重写太多方法，只需要把

onMeasure
onSizeChanged
onDraw

三个方法作一些改动；但也有一些问题，比如只能响应onPregress方法，为了让他能响应onStartTrackingTouch和onStopTrackingTouch方法，只好再加一些代码，于是有了改进版。

稍作改进

VerticalSeekBar2.java

public class VerticalSeekBar2 extends SeekBar {
 private Drawable mThumb;
 private OnSeekBarChangeListener mOnSeekBarChangeListener;

 public VerticalSeekBar2(Context context) {
  super(context);
 }

 public VerticalSeekBar2(Context context, AttributeSet attrs) {
  super(context, attrs);
 }

 public VerticalSeekBar2(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle);
 }

 public void setOnSeekBarChangeListener(OnSeekBarChangeListener l) {
  mOnSeekBarChangeListener = l;
 }

 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  super.onSizeChanged(h, w, oldh, oldw);
 }

 @Override
 protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(heightMeasureSpec, widthMeasureSpec);
  setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
 }

 protected void onDraw(Canvas c) {
  c.rotate(-90);
  c.translate(-getHeight(), 0);

  super.onDraw(c);
 }

 void onProgressRefresh(float scale, boolean fromUser) {
  Drawable thumb = mThumb;
  if (thumb != null) {
   setThumbPos(getHeight(), thumb, scale, Integer.MIN_VALUE);
   invalidate();
  }
  if (mOnSeekBarChangeListener != null) {
   mOnSeekBarChangeListener.onProgressChanged(this, getProgress(), fromUser);
  }
 }

 private void setThumbPos(int w, Drawable thumb, float scale, int gap) {
  int available = w - getPaddingLeft() - getPaddingRight();

  int thumbWidth = thumb.getIntrinsicWidth();
  int thumbHeight = thumb.getIntrinsicHeight();

  int thumbPos = (int) (scale * available + 0.5f);

  // int topBound = getWidth() / 2 - thumbHeight / 2 - getPaddingTop();
  // int bottomBound = getWidth() / 2 + thumbHeight / 2 - getPaddingTop();
  int topBound, bottomBound;
  if (gap == Integer.MIN_VALUE) {
   Rect oldBounds = thumb.getBounds();
   topBound = oldBounds.top;
   bottomBound = oldBounds.bottom;
  } else {
   topBound = gap;
   bottomBound = gap + thumbHeight;
  }
  thumb.setBounds(thumbPos, topBound, thumbPos + thumbWidth, bottomBound);
 }

 public void setThumb(Drawable thumb) {
  mThumb = thumb;
  super.setThumb(thumb);
 }

 void onStartTrackingTouch() {
  if (mOnSeekBarChangeListener != null) {
   mOnSeekBarChangeListener.onStartTrackingTouch(this);
  }
 }

 void onStopTrackingTouch() {
  if (mOnSeekBarChangeListener != null) {
   mOnSeekBarChangeListener.onStopTrackingTouch(this);
  }
 }

 private void attemptClaimDrag() {
  if (getParent() != null) {
   getParent().requestDisallowInterceptTouchEvent(true);
  }
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  if (!isEnabled()) {
   return false;
  }

  switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:
   setPressed(true);
   onStartTrackingTouch();
   break;

  case MotionEvent.ACTION_MOVE:
   attemptClaimDrag();
   setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));
   break;
  case MotionEvent.ACTION_UP:
   onStopTrackingTouch();
   setPressed(false);
   break;

  case MotionEvent.ACTION_CANCEL:
   onStopTrackingTouch();
   setPressed(false);
   break;
  }
  return true;
 }

为了响应另外两个不知道怎么就被onPregress抛弃的方法，添了这么多代码真是罪过，不过都是从SeekBar的父类AbsSeekBar中仿写过来的，逻辑稍作改动就能用。

对比测试

上图。

左边是官方例子中的，右边是改进过的。

测试源码：垂直进度条VerticalSeekBar

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