recyclerview水平指示器从右到左

Question

嗨，请帮我在指示器水平recyclerview中使用此代码创建滑块，但rtl不支持如何在此代码中进行rtl并从左开始？

请参阅所附图片：

public class LinePagerIndicatorDecoration extends RecyclerView.ItemDecoration {
private int colorActive = 0xFFFFFFFF;
private int colorInactive = 0x66FFFFFF;
private static final float DP = Resources.getSystem().getDisplayMetrics().density;

/**
 * Height of the space the indicator takes up at the bottom of the view.
 */
private final int mIndicatorHeight = (int) (DP * 16);
/**
 * Indicator stroke width.
 */
private final float mIndicatorStrokeWidth = DP * 2;
/**
 * Indicator width.
 */
private final float mIndicatorItemLength = DP * 16;
/**
 * Padding between indicators.
 */
private final float mIndicatorItemPadding = DP * 4;

/**
 * Some more natural animation interpolation
 */
private final Interpolator mInterpolator = new AccelerateDecelerateInterpolator();
private final Paint mPaint = new Paint();

public LinePagerIndicatorDecoration() {
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(mIndicatorStrokeWidth);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setAntiAlias(true);
}

@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
    super.onDrawOver(c, parent, state);
    int itemCount = parent.getAdapter().getItemCount();
    // center horizontally, calculate width and subtract half from center
    float totalLength = mIndicatorItemLength * itemCount;
    float paddingBetweenItems = Math.max(0, itemCount - 1) * mIndicatorItemPadding;
    float indicatorTotalWidth = totalLength + paddingBetweenItems;
    float indicatorStartX = (parent.getWidth() - indicatorTotalWidth) / 2F;
    // center vertically in the allotted space
    float indicatorPosY = parent.getHeight() - mIndicatorHeight / 2F;
    drawInactiveIndicators(c, indicatorStartX, indicatorPosY, itemCount);
    // find active page (which should be highlighted)
    LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
    int activePosition = layoutManager.findFirstVisibleItemPosition();
    if (activePosition == RecyclerView.NO_POSITION) {
        return;
    }
    // find offset of active page (if the user is scrolling)
    final View activeChild = layoutManager.findViewByPosition(activePosition);
    int left = activeChild.getLeft();
    int width = activeChild.getWidth();

    // on swipe the active item will be positioned from [-width, 0]
    // interpolate offset for smooth animation
    float progress = mInterpolator.getInterpolation(left * -1 / (float) width);
    drawHighlights(c, indicatorStartX, indicatorPosY, activePosition, progress, itemCount);
}

private void drawInactiveIndicators(Canvas c, float indicatorStartX, float indicatorPosY, int itemCount) {
    mPaint.setColor(colorInactive);
    // width of item indicator including padding
    final float itemWidth = mIndicatorItemLength + mIndicatorItemPadding;
    float start = indicatorStartX;
    for (int i = 0; i < itemCount; i++) {
        // draw the line for every item
        c.drawLine(start, indicatorPosY, start + mIndicatorItemLength, indicatorPosY, mPaint);
        start += itemWidth;
    }
}

private void drawHighlights(Canvas c, float indicatorStartX, float indicatorPosY, int highlightPosition, float progress, int itemCount) {
    mPaint.setColor(colorActive);
    // width of item indicator including padding
    final float itemWidth = mIndicatorItemLength + mIndicatorItemPadding;
    if (progress == 0F) {
        // no swipe, draw a normal indicator
        float highlightStart = indicatorStartX + itemWidth * highlightPosition;
        c.drawLine(highlightStart, indicatorPosY,
                highlightStart + mIndicatorItemLength, indicatorPosY, mPaint);
    } else {
        float highlightStart = indicatorStartX + itemWidth * highlightPosition;
        // calculate partial highlight
        float partialLength = mIndicatorItemLength * progress;
        // draw the cut off highlight
        c.drawLine(highlightStart + partialLength, indicatorPosY, highlightStart + mIndicatorItemLength, indicatorPosY, mPaint);
        // draw the highlight overlapping to the next item as well
        if (highlightPosition < itemCount - 1) {
            highlightStart += itemWidth;
            c.drawLine(highlightStart, indicatorPosY, highlightStart + partialLength, indicatorPosY, mPaint);
        }
    }
}

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
    super.getItemOffsets(outRect, view, parent, state);
    outRect.bottom = mIndicatorHeight;
}}

Answer 1

您可以根据目标Android版本使用以下一项或多项。这些将反转视图中布局的方向。

• android:layoutDirection="rtl"在RecyclerView

• LinearLayoutManager.setReverseLayout(true)

• LinearLayoutManager.setStackFromEnd(true)