TransitionDrawable doesn't account for padding?

问题

I tried the accepted solution posted here, but it appears to ignore padding. When the second view (in this case a button) displays, it's much smaller than the original which has padding. Is there a workaround for that? Thanks

回答1:

Yes, TransitionDrawable extends from LayerDrawable which ignores the padding. This is the getPadding() method in the base Android code, which gets rid of anything you specified:

    @Override
    public boolean getPadding(Rect padding) {
        // Arbitrarily get the padding from the first image.
        // Technically we should maybe do something more intelligent,
        // like take the max padding of all the images.
        padding.left = 0;
        padding.top = 0;
        padding.right = 0;
        padding.bottom = 0;
        final ChildDrawable[] array = mLayerState.mChildren;
        final int N = mLayerState.mNum;
        for (int i=0; i<N; i++) {
            reapplyPadding(i, array[i]);
            padding.left += mPaddingL[i];
            padding.top += mPaddingT[i];
            padding.right += mPaddingR[i];
            padding.bottom += mPaddingB[i];
        }
        return true;
    }

See base Android code here.

To deal with it, I had to first save the padding values before setting the faulty drawable background on my view:

    int bottom = theView.getPaddingBottom();
    int top = theView.getPaddingTop();
    int right = theView.getPaddingRight();
    int left = theView.getPaddingLeft();
    theView.setBackgroundResource(R.drawable.faulty_drawable);
    theView.setPadding(left, top, right, bottom);

来源：https://stackoverflow.com/questions/6104677/transitiondrawable-doesnt-account-for-padding