垂直进度条VerticalSeekBar

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。
垂直进度条VerticalSeekBar_第1张图片
左边是官方例子中的,右边是改进过的。
请自行测试~~
测试源码

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