Working on Android Music Player Project, and ran into the issue where my app crashes on start up:-CodePudding

I am trying to add a player using Sliding Up Panel but the app crashes on startup. If you want to see my full code; https://github.com/Kailash8460/poptune.git

MainActivity.java

package com.example.poptunemusicplayerapplication;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;

import com.example.poptunemusicplayerapplication.fragments.MainFragment;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.sothree.slidinguppanel.SlidingUpPanelLayout;


public class MainActivity extends AppCompatActivity {

    private static final int KEY_PER = 123;
    private SlidingUpPanelLayout panelLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) !=
                PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this, new String[]
                    {Manifest.permission.READ_EXTERNAL_STORAGE}, KEY_PER);
            return;
        }
        else {
            UiInitialize();
        }

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

        switch (requestCode){
            case KEY_PER:
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    UiInitialize();
                }
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }

    }

    private void UiInitialize() {

        ImageLoader.getInstance().init(ImageLoaderConfiguration.createDefault(this));
        panelLayout = (SlidingUpPanelLayout) findViewById(R.id.sliding_layout);

        Fragment fragment = new MainFragment();
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.main_container, fragment);
        transaction.commit();

        /*List<Song> songList = new SongLoader().getAllSongs(this);

        for (Song song : songList){
            Log.i("DATA","Title:"   song.title);
        }*/

    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<com.sothree.slidinguppanel.SlidingUpPanelLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@ id/sliding_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="bottom"
    app:umanoPanelHeight="68dp"
    app:umanoShadowHeight="4dp"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@ id/main_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <FrameLayout
        android:id="@ id/control_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</com.sothree.slidinguppanel.SlidingUpPanelLayout>

MainFragment.java Here there is no issue on SongsFragment, ArtistFragment and AlbumFragment files, because I have run this application before adding the sliding up panel and that was successfully run but after adding this Sliding Up Panel application crashes on startup.

package com.example.poptunemusicplayerapplication.fragments;

import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.viewpager.widget.ViewPager;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.poptunemusicplayerapplication.R;
import com.google.android.material.tabs.TabLayout;

import java.util.ArrayList;
import java.util.List;

public class MainFragment extends Fragment {

    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;

    public MainFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        toolbar = (Toolbar) rootView.findViewById(R.id.toolbar);
        ((AppCompatActivity)getActivity()).setSupportActionBar(toolbar);
        tabLayout = (TabLayout) rootView.findViewById(R.id.tabs);
        viewPager = (ViewPager) rootView.findViewById(R.id.view_pager);

        setUpViewPager(viewPager);
        tabLayout.setupWithViewPager(viewPager);

        return rootView;
    }

    private void setUpViewPager(ViewPager viewPager) {
        FragmentAdapter adapter = new FragmentAdapter(getActivity().getSupportFragmentManager());
        adapter.AddFragments(new SongsFragment(), "Songs");
        adapter.AddFragments(new ArtistFragment(), "Artist");
        adapter.AddFragments(new AlbumFragment(), "Album");
        viewPager.setAdapter(adapter);
    }

    private class FragmentAdapter extends FragmentPagerAdapter {

        private List<Fragment> fragmentList = new ArrayList<>();
        private List<String> titleList = new ArrayList<>();

        public FragmentAdapter(@NonNull FragmentManager fm) {
            super(fm);
        }

        @NonNull
        @Override
        public Fragment getItem(int position) {
            return fragmentList.get(position);
        }

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

        public void AddFragments(Fragment fragment, String title) {
            fragmentList.add(fragment);
            titleList.add(title);
        }

        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {
            return titleList.get(position);
        }
    }

}

fragment_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@ id/fragmentmainlist"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragments.MainFragment">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@ id/appbar"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.Dark">

        <androidx.appcompat.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:id="@ id/toolbar"
            app:layout_scrollFlags="scroll|enterAlways"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/Theme.AppCompat.Light"/>

        <com.google.android.material.tabs.TabLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@ id/tabs"/>

    </com.google.android.material.appbar.AppBarLayout>

    <androidx.viewpager.widget.ViewPager
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@ id/view_pager"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

Errors

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.poptunemusicplayerapplication, PID: 28426
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.poptunemusicplayerapplication/com.example.poptunemusicplayerapplication.MainActivity}: android.view.InflateException: Binary XML file line #14: Binary XML file line #14: Error inflating class com.sothree.slidinguppanel.SlidingUpPanelLayout
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2988)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3073)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1734)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:7025)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:441)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
     Caused by: android.view.InflateException: Binary XML file line #14: Binary XML file line #14: Error inflating class com.sothree.slidinguppanel.SlidingUpPanelLayout
     Caused by: android.view.InflateException: Binary XML file line #14: Error inflating class com.sothree.slidinguppanel.SlidingUpPanelLayout
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.newInstance0(Native Method)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
        at android.view.LayoutInflater.createView(LayoutInflater.java:647)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:706)
        at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:195)
        at com.example.poptunemusicplayerapplication.MainActivity.onCreate(MainActivity.java:39)
        at android.app.Activity.performCreate(Activity.java:7258)
        at android.app.Activity.performCreate(Activity.java:7249)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1222)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2941)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3073)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1734)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:7025)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:441)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
     Caused by: java.lang.IllegalArgumentException: gravity must be set to either top or bottom
        at com.sothree.slidinguppanel.SlidingUpPanelLayout.setGravity(SlidingUpPanelLayout.java:366)
        at com.sothree.slidinguppanel.SlidingUpPanelLayout.<init>(SlidingUpPanelLayout.java:288)
        at com.sothree.slidinguppanel.SlidingUpPanelLayout.<init>(SlidingUpPanelLayout.java:270)
        at java.lang.reflect.Constructor.newInstance0(Native Method) 
        at java.lang.reflect.Constructor.newInstance(Constructor.java:334) 
        at android.view.LayoutInflater.createView(LayoutInflater.java:647) 
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:790) 
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730) 
        at android.view.LayoutInflater.inflate(LayoutInflater.java:492) 
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423) 
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374) 
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:706) 
        at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:195) 
        at com.example.poptunemusicplayerapplication.MainActivity.onCreate(MainActivity.java:39) 
        at android.app.Activity.performCreate(Activity.java:7258) 
        at android.app.Activity.performCreate(Activity.java:7249) 
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1222) 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2941) 
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3073) 
        at android.app.ActivityThread.-wrap11(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1734) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:164) 
        at android.app.ActivityThread.main(ActivityThread.java:7025) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:441) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)

getting error at MainActivity.java:39

Line 39 of MainActivity.java:-

setContentView(R.layout.activity_main);

CodePudding user response：

After looking at the layout in the demo app for SlidingUpPanelLayout, I see it is expecting the android:gravity attribute to be set, not android:layout_gravity.

Try this instead for your layout:

<?xml version="1.0" encoding="utf-8"?>
<com.sothree.slidinguppanel.SlidingUpPanelLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@ id/sliding_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="bottom"
    app:umanoPanelHeight="68dp"
    app:umanoShadowHeight="4dp"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@ id/main_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <FrameLayout
        android:id="@ id/control_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</com.sothree.slidinguppanel.SlidingUpPanelLayout>