com.ahamed.multiviewadapter.util.SimpleDividerDecoration.java Source code

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Here is the source code for com.ahamed.multiviewadapter.util.SimpleDividerDecoration.java

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/*
 * Copyright 2017 Riyaz Ahamed
 *
 * 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.
 */

package com.ahamed.multiviewadapter.util;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.LinearLayout;
import com.ahamed.multiviewadapter.annotation.PositionType;

/**
 * SimpleDividerDecoration is a {@link RecyclerView.ItemDecoration} that can be used as a divider
 * between items of a {@link LinearLayoutManager}. It supports both {@link #HORIZONTAL} and
 * {@link #VERTICAL} orientations.
 *
 * This code has been adapted from official support library's  {@link DividerItemDecoration}
 */
public class SimpleDividerDecoration implements ItemDecorator {

    public static final int HORIZONTAL = LinearLayout.HORIZONTAL;
    public static final int VERTICAL = LinearLayout.VERTICAL;

    private static final int[] ATTRS = new int[] { android.R.attr.listDivider };
    private final Rect mBounds = new Rect();
    private final Drawable mDivider;
    private int mOrientation;

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

    @Override
    public void getItemOffsets(Rect outRect, int position, @PositionType int positionType) {
        if (positionType == POSITION_LAST_ITEM) {
            return;
        }
        if (mOrientation == VERTICAL) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }

    @Override
    public void onDraw(Canvas canvas, RecyclerView parent, View child, int position,
            @PositionType int positionType) {
        if (parent.getLayoutManager() == null) {
            return;
        }
        if (positionType == POSITION_LAST_ITEM) {
            return;
        }
        if (mOrientation == VERTICAL) {
            drawVertical(canvas, parent, child);
        } else {
            drawHorizontal(canvas, parent, child);
        }
    }

    public void setOrientation(int orientation) {
        if (orientation != HORIZONTAL && orientation != VERTICAL) {
            throw new IllegalArgumentException("Invalid orientation. It should be either HORIZONTAL or VERTICAL");
        }
        mOrientation = orientation;
    }

    @SuppressLint("NewApi")
    private void drawVertical(Canvas canvas, RecyclerView parent, View child) {
        canvas.save();
        final int left;
        final int right;
        if (parent.getClipToPadding()) {
            left = parent.getPaddingLeft();
            right = parent.getWidth() - parent.getPaddingRight();
            canvas.clipRect(left, parent.getPaddingTop(), right, parent.getHeight() - parent.getPaddingBottom());
        } else {
            left = 0;
            right = parent.getWidth();
        }

        parent.getDecoratedBoundsWithMargins(child, mBounds);
        final int bottom = mBounds.bottom + Math.round(ViewCompat.getTranslationY(child));
        final int top = bottom - mDivider.getIntrinsicHeight();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
        canvas.restore();
    }

    @SuppressLint("NewApi")
    private void drawHorizontal(Canvas canvas, RecyclerView parent, View child) {
        canvas.save();
        final int top;
        final int bottom;
        if (parent.getClipToPadding()) {
            top = parent.getPaddingTop();
            bottom = parent.getHeight() - parent.getPaddingBottom();
            canvas.clipRect(parent.getPaddingLeft(), top, parent.getWidth() - parent.getPaddingRight(), bottom);
        } else {
            top = 0;
            bottom = parent.getHeight();
        }

        parent.getLayoutManager().getDecoratedBoundsWithMargins(child, mBounds);
        final int right = mBounds.right + Math.round(ViewCompat.getTranslationX(child));
        final int left = right - mDivider.getIntrinsicWidth();
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(canvas);
        canvas.restore();
    }
}