com.flexible.viewholders.ContentViewHolder.java Source code

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Here is the source code for com.flexible.viewholders.ContentViewHolder.java

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/*
 * Copyright 2016 Davide Steduto
 *
 * 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.flexible.viewholders;

import android.support.v4.view.ViewCompat;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.FrameLayout;

import com.flexible.flexibleadapter.FlexibleAdapter;

/**
 * This Class separates the initialization of an eventual StickyHeader ViewHolder from a Normal
 * ViewHolder. It improves code readability of FlexibleViewHolder.
 * <p>Because itemView is declared final, we can't initialize it twice, this separation must be
 * done in the constructor.</p>
 *
 * @author Davide Steduto
 * @since 18/06/2016 Created
 */
abstract class ContentViewHolder extends RecyclerView.ViewHolder {

    private int mBackupPosition = RecyclerView.NO_POSITION;
    private View contentView;

    /**
     * @param view         The {@link View} being hosted in this ViewHolder
     * @param adapter      Adapter instance of type {@link FlexibleAdapter}
     * @param stickyHeader true if the ViewHolder is a header to be sticky
     * @since 5.0.0-b7
     */
    ContentViewHolder(View view, FlexibleAdapter adapter, boolean stickyHeader) {
        // Since itemView is declared "final", the split is done before the View is initialized
        super(stickyHeader ? new FrameLayout(view.getContext()) : view);

        if (stickyHeader) {
            itemView.setLayoutParams(
                    adapter.getRecyclerView().getLayoutManager().generateLayoutParams(view.getLayoutParams()));
            ((FrameLayout) itemView).addView(view); //Add View after setLayoutParams
            float elevation = ViewCompat.getElevation(view);
            if (elevation > 0) {
                ViewCompat.setBackground(itemView, view.getBackground());
                ViewCompat.setElevation(itemView, elevation);
            }
            contentView = view;
        }
    }

    /*-----------------------*/
    /* STICKY HEADER METHODS */
    /*-----------------------*/

    /**
     * In case this ViewHolder represents a Header Item, this method returns the contentView of the
     * FrameLayout, otherwise it returns the basic itemView.
     *
     * @return the real contentView
     * @since 5.0.0-b7
     */
    public final View getContentView() {
        return contentView != null ? contentView : itemView;
    }

    /**
     * Overcomes the situation of returning an unknown position (-1) of ViewHolders created out of
     * the LayoutManager (ex. StickyHeaders).
     * <p><b>NOTE:</b> Always call this method, instead of {@code getAdapterPosition()}, in case
     * of StickyHeaders use case.</p>
     *
     * @return the Adapter position result of {@link #getAdapterPosition()} OR the backup position
     * preset and known, if the previous result was {@link RecyclerView#NO_POSITION}.
     * @see #setBackupPosition(int)
     * @since 5.0.0-b6
     */
    public final int getFlexibleAdapterPosition() {
        int position = getAdapterPosition();
        if (position == RecyclerView.NO_POSITION) {
            position = mBackupPosition;
        }
        return position;
    }

    /**
     * Restore the Adapter position if the original Adapter position is unknown.
     * <p>Called by StickyHeaderHelper to support the clickListeners events.</p>
     *
     * @param backupPosition the known position of this ViewHolder
     * @since 5.0.0-b6
     */
    public final void setBackupPosition(int backupPosition) {
        mBackupPosition = backupPosition;
    }

}