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@yrom
Last active September 2, 2018 16:57
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SpacesItemDecoration for RecyclerView.
import android.graphics.Rect;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int space;
private int spanCount;
private int lastItemInFirstLane = -1;
public SpacesItemDecoration(int space) {
this(space, 1);
}
/**
* @param space
* @param spanCount spans count of one lane
*/
public SpacesItemDecoration(int space, int spanCount) {
this.space = space;
this.spanCount = spanCount;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) view.getLayoutParams();
final int position = params.getViewPosition();
final int spanSize;
final int index;
if (params instanceof GridLayoutManager.LayoutParams) {
GridLayoutManager.LayoutParams gridParams = (GridLayoutManager.LayoutParams) params;
spanSize = gridParams.getSpanSize();
index = gridParams.getSpanIndex();
}else{
spanSize = 1;
index = position % spanCount;
}
// invalid value
if (spanSize < 1 || index < 0) return;
if (spanSize == spanCount) { // full span
outRect.left = space;
outRect.right = space;
} else {
if (index == 0) { // left one
outRect.left = space;
}
// spanCount >= 1
if (index == spanCount - 1) { // right one
outRect.right = space;
}
if (outRect.left == 0) {
outRect.left = space / 2;
}
if (outRect.right == 0) {
outRect.right = space / 2;
}
}
// set top to all in first lane
if (position < spanCount && spanSize <= spanCount) {
if (lastItemInFirstLane < 0) { // lay out at first time
lastItemInFirstLane = position + spanSize == spanCount ? position : lastItemInFirstLane;
outRect.top = space;
} else if (position <= lastItemInFirstLane) { // scroll to first lane again
outRect.top = space;
}
}
outRect.bottom = space;
}
}
@MuhammadShaker
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It doesn't work correctly when using StaggeredGridLayoutManager

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