didi/DoKit · error · RuntimeException

failed to get size

Error message

failed to get size

What it means

Same fail-fast guard as the horizontal variant, but in VerticalDividerItemDecoration.getDividerSize: it needs a divider WIDTH for outRect.set(0, 0, size, 0) and throws RuntimeException when no mPaintProvider, mSizeProvider, or mDrawableProvider is set. Note the vertical variant has no mSpaceProvider branch, so a space provider alone will NOT satisfy it. Thrown during RecyclerView layout as soon as getItemOffsets runs.

Source

Thrown at Android/dokit/src/main/java/com/didichuxing/doraemonkit/kit/toolpanel/decoration/VerticalDividerItemDecoration.java:209

    @Override
    protected void setItemOffsets(Rect outRect, int position, RecyclerView parent) {
        if (mPositionInsideItem) {
            outRect.set(0, 0, 0, 0);
            return;
        }
        outRect.set(0, 0, getDividerSize(position, parent), 0);
    }

    private int getDividerSize(int position, RecyclerView parent) {
        if (mPaintProvider != null) {
            return (int) mPaintProvider.dividerPaint(position, parent).getStrokeWidth();
        } else if (mSizeProvider != null) {
            return mSizeProvider.dividerSize(position, parent);
        } else if (mDrawableProvider != null) {
            Drawable drawable = mDrawableProvider.drawableProvider(position, parent);
            return drawable.getIntrinsicWidth();
        }
        throw new RuntimeException("failed to get size");
    }

    /**
     * Interface for controlling divider margin
     */
    public interface MarginProvider {

        /**
         * Returns top margin of divider.
         *
         * @param position Divider position (or group index for GridLayoutManager)
         * @param parent   RecyclerView
         * @return top margin
         */
        int dividerTopMargin(int position, RecyclerView parent);

        /**
         * Returns bottom margin of divider.

View on GitHub (pinned to 626827cddb)

Solutions

1. Set a size provider before build(): .sizeProvider((position, parent) -> dividerWidthPx)
2. Or use the common one-liner .drawable(drawableRes) / .drawableProvider(...) so getIntrinsicWidth() is used
3. Do not rely on spaceProvider here — the vertical decoration has no space branch; use size or drawable/paint provider
4. Remove the decoration entirely if no divider is wanted

Example fix

// before
recyclerView.addItemDecoration(new VerticalDividerItemDecoration.Builder(this).build());

// after
recyclerView.addItemDecoration(
    new VerticalDividerItemDecoration.Builder(this)
        .sizeProvider((position, parent) -> Math.round(1 * getResources().getDisplayMetrics().density))
        .build());

// Always configure a size source for the vertical divider.
VerticalDividerItemDecoration deco = new VerticalDividerItemDecoration.Builder(context)
    .sizeProvider((position, parent) -> Math.round(1 * context.getResources().getDisplayMetrics().density))
    .build();
recyclerView.addItemDecoration(deco);

try {
  recyclerView.addItemDecoration(deco);
} catch (RuntimeException e) {
  if (e.getMessage() != null && e.getMessage().contains("failed to get size")) {
    Log.w(TAG, "Vertical divider lacks size/drawable provider; skipping", e);
  } else throw e;
}

When it happens

Trigger: new VerticalDividerItemDecoration.Builder(context).build() with zero provider setters; or setting only a marginProvider (which controls insets, not size); or porting code from the horizontal decoration that relied on spaceProvider.

Common situations: Copy-pasting divider setup between list layouts where the vertical one lost its size/drawable provider; assuming marginProvider determines thickness.

Related errors

• failed to get size
• Use setColor method of Paint class to specify line color. Do
• Use setStrokeWidth method of Paint class to specify line siz
• maxStoredHeapDumps must be at least 1
• Cannot set the LeakDirectoryProvider after it has already be

AI-assisted analysis of didi/DoKit@626827cddb (2026-08-14). Data as JSON: /api/errors/6b336bfd4c6f6516. Report an issue: GitHub.