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alexfu/DividerItemDecoration.java

Last active July 21, 2025 07:30
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Revisions

  1. alexfu revised this gist Dec 28, 2014. No changes.
  2. alexfu created this gist Jul 7, 2014.
    93 changes: 93 additions & 0 deletions DividerItemDecoration.java
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    /*
    * Copyright (C) 2014 The Android Open Source Project
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
    * distributed under the License is distributed on an "AS IS" BASIS,
    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    * See the License for the specific language governing permissions and
    * limitations under the License.
    */
    public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{
    android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;

    private int mOrientation;

    public DividerItemDecoration(Context context, int orientation) {
    final TypedArray a = context.obtainStyledAttributes(ATTRS);
    mDivider = a.getDrawable(0);
    a.recycle();
    setOrientation(orientation);
    }

    public void setOrientation(int orientation) {
    if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
    throw new IllegalArgumentException("invalid orientation");
    }
    mOrientation = orientation;
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
    if (mOrientation == VERTICAL_LIST) {
    drawVertical(c, parent);
    } else {
    drawHorizontal(c, parent);
    }
    }

    public void drawVertical(Canvas c, RecyclerView parent) {
    final int left = parent.getPaddingLeft();
    final int right = parent.getWidth() - parent.getPaddingRight();

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
    final View child = parent.getChildAt(i);
    final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
    .getLayoutParams();
    final int top = child.getBottom() + params.bottomMargin;
    final int bottom = top + mDivider.getIntrinsicHeight();
    mDivider.setBounds(left, top, right, bottom);
    mDivider.draw(c);
    }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
    final int top = parent.getPaddingTop();
    final int bottom = parent.getHeight() - parent.getPaddingBottom();

    final int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
    final View child = parent.getChildAt(i);
    final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
    .getLayoutParams();
    final int left = child.getRight() + params.rightMargin;
    final int right = left + mDivider.getIntrinsicHeight();
    mDivider.setBounds(left, top, right, bottom);
    mDivider.draw(c);
    }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
    if (mOrientation == VERTICAL_LIST) {
    outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
    } else {
    outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
    }
    }
    }