fedilab-Android-App/app/src/main/java/app/fedilab/android/activities/SlideMediaActivity.java

/* Copyright 2017 Thomas Schneider
 *
 * This file is a part of Fedilab
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * Fedilab is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with Fedilab; if not,
 * see <http://www.gnu.org/licenses>. */
package app.fedilab.android.activities;



import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.widget.RelativeLayout;

import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentStatePagerAdapter;
import androidx.viewpager.widget.PagerAdapter;
import androidx.viewpager.widget.ViewPager;


import org.jetbrains.annotations.NotNull;

import java.util.ArrayList;

import app.fedilab.android.R;
import app.fedilab.android.client.Entities.Attachment;
import app.fedilab.android.fragments.MediaSliderFragment;
import app.fedilab.android.helper.Helper;



/**
 * Created by Thomas on 25/06/2017.
 * Media Activity
 */

public class SlideMediaActivity extends BaseActivity  {

    private ArrayList<Attachment> attachments;
    private int mediaPosition;
    private ViewPager mPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        SharedPreferences sharedpreferences = getSharedPreferences(Helper.APP_PREFS, MODE_PRIVATE);
        int theme = sharedpreferences.getInt(Helper.SET_THEME, Helper.THEME_DARK);
        if (theme == Helper.THEME_BLACK)
            setTheme(R.style.TransparentBlack);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_media_pager);
        supportPostponeEnterTransition();
        supportStartPostponedEnterTransition();
        CoordinatorLayout main_container_media = findViewById(R.id.main_container_media);
        if (theme == Helper.THEME_LIGHT) {
            main_container_media.setBackgroundResource(R.color.mastodonC2);
        } else if (theme == Helper.THEME_BLACK) {
            main_container_media.setBackgroundResource(R.color.black);
        } else if (theme == Helper.THEME_DARK) {
            main_container_media.setBackgroundResource(R.color.mastodonC1_);
        }
        attachments = getIntent().getParcelableArrayListExtra("mediaArray");
        if (getIntent().getExtras() != null)
            mediaPosition = getIntent().getExtras().getInt("position", 1);
        gestureDetector = new GestureDetector(new SwipeDetector());

        if (attachments == null || attachments.size() == 0)
            finish();
        mPager = findViewById(R.id.media_viewpager);

        PagerAdapter mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
        mPager.setAdapter(mPagerAdapter);

        mPager.setCurrentItem(mediaPosition-1);

    }

    private MediaSliderFragment mCurrentFragment;


    public MediaSliderFragment getCurrentFragment() {
        return mCurrentFragment;
    }

    /**
     * Media Pager
     */
    private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {

        ScreenSlidePagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @NotNull
        @Override
        public Fragment getItem(int position) {
            Bundle bundle = new Bundle();
            MediaSliderFragment mediaSliderFragment = new MediaSliderFragment();
            bundle.putInt("position", position);
            Log.v(Helper.TAG,"position: " + position);
            Log.v(Helper.TAG,"attachments.get(position): " + attachments.get(position));
            bundle.putParcelable("attachment", attachments.get(position));
            mediaSliderFragment.setArguments(bundle);
            return mediaSliderFragment;
        }

        @Override
        public void setPrimaryItem(@NotNull ViewGroup container, int position, @NotNull Object object) {
            if (getCurrentFragment() != object) {
                mCurrentFragment = ((MediaSliderFragment) object);
            }
            super.setPrimaryItem(container, position, object);
        }

        @Override
        public int getCount() {
            return attachments.size();
        }
    }

    private static final int SWIPE_MIN_DISTANCE = 120;
    private static final int SWIPE_MAX_OFF_PATH = 250;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;
    private GestureDetector gestureDetector;

    private class SwipeDetector extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {

            // Check movement along the Y-axis. If it exceeds SWIPE_MAX_OFF_PATH,
            // then dismiss the swipe.
            if (Math.abs(e1.getX() - e2.getX()) > SWIPE_MAX_OFF_PATH)
                return false;

            // Swipe from left to right.
            // The swipe needs to exceed a certain distance (SWIPE_MIN_DISTANCE)
            // and a certain velocity (SWIPE_THRESHOLD_VELOCITY).
            if (e2.getY() - e1.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                if( mCurrentFragment.canSwipe()) {
                    finish();
                    return true;
                }else{
                    return false;
                }
            }

            return false;
        }
    }


    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        // TouchEvent dispatcher.
        if (gestureDetector != null) {
            if (gestureDetector.onTouchEvent(ev))
                // If the gestureDetector handles the event, a swipe has been
                // executed and no more needs to be done.
                return true;
        }
        return super.dispatchTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
    }

}