Develop Reference

How to unregister and register BroadcastReceiver from another class? [duplicate]

Thank you in advance and dont be very hard with me, it is my first question.
I was trying to add a new item to my recyclerView through the adapter by declaring a method in my adapter called addItem(String newItem)
Then I tried to call this method when the floating button is clikced and the problem is that the method does not even appear when i hit cntrl+space and if i write it down it gets on red.
I have already tried to rebuild the project and nothing changes.
¿Any ideas about how to solve it?
MainActivity class
package com.example.sakur.recyclerviewapp;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
private FloatingActionButton mFloatingActionButton;
private List<String> recyclerItems = Collections.emptyList();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
recyclerItems = new ArrayList<>();
recyclerItems.add("First item");
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new MyAdapter(recyclerItems);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.floating_action_button);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String itemNuevo = "New Card";
mAdapter.addItem(itemNuevo);
Snackbar.make(view, "Item added successfully", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
and the MyAdapter class
package com.example.sakur.recyclerviewapp;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.Collections;
import java.util.List;
/**
* Created by Sakur on 19/12/2015.
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<String> mDataset= Collections.emptyList();
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<String> myDataset) {
mDataset = myDataset;
}
public void addItem(String newItem){
mDataset.add(newItem);
notifyDataSetChanged();
}
// Create new views (invoked by the layout manager)
#Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_card, parent, false);
// set the view's size, margins, paddings and layout parameters
//...
ViewHolder vh = new ViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mTextView.setText(mDataset.get(position));
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mDataset.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView mTextView;
public ImageView mImageView;
public ViewHolder(View v) {
super(v);
mTextView = (TextView) v.findViewById(R.id.text_card);
}
}
}

addItem(String) is not a method of RecyclerView.Adapter, but of your MyAdapter subclass. Obviously, RecyclerView.Adapter has no knowledge of the existence neither of your MyAdapter nor of your addItem(String).
you can either change
private RecyclerView.Adapter mAdapter;
into
private MyAdapter mAdapter;
or cast mAdapter. E.g.
if (mAdater instanceof MyAdapter) {
((MyAdapter) mAdapter).addItem(...);
}

How to display image located in drawable folder in full screen in viewpager app?

I have developed an app that is suppose to show the image to user using viewpager. But my problem is that my images are not showing in full screen . can any one please suggest the codes for how to make this work ?. Following are my codes..
Mainactivity.java
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ShareActionProvider;
public class MainActivity extends Activity {
MediaPlayer oursong;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
oursong = MediaPlayer.create(MainActivity.this, R.raw.a);
oursong.start ();
ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
ImageAdapter adapter = new ImageAdapter(this);
viewPager.setAdapter(adapter);
}
private ShareActionProvider mShareActionProvider;
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate menu resource file.
getMenuInflater().inflate(R.menu.activity_main, menu);
// Locate MenuItem with ShareActionProvider
MenuItem item = menu.findItem(R.id.menu_item_share);
// Fetch and store ShareActionProvider
mShareActionProvider = (ShareActionProvider) item.getActionProvider();
// Return true to display menu
return true;
}
// Call to update the share intent
private void setShareIntent(Intent shareIntent) {
if (mShareActionProvider != null) {
mShareActionProvider.setShareIntent(shareIntent);
}
}
#Override
protected void onPause(){
super.onPause();
oursong.release();
}
}
imageadapter.java
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
public class ImageAdapter extends PagerAdapter {
Context context;
private int[] GalImages = new int[] {
R.drawable.one,
R.drawable.two,
R.drawable.three
};
ImageAdapter(Context context){
this.context=context;
}
#Override
public int getCount() {
return GalImages.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView imageView = new ImageView(context);
int padding = context.getResources().getDimensionPixelSize(R.dimen.padding_medium);
imageView.setPadding(padding, padding, padding, padding);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
imageView.setImageResource(GalImages[position]);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
}

If you really want it to be fullscreen (be careful to the resolution of your assets), you should use a different scale type for your ImageView:
imageView.setScaleType(fullscreen ? ImageView.ScaleType.CENTER_CROP : ImageView.ScaleType.CENTER_INSIDE);
This will crop your image, keeping the initial ratio.
Source

add colors to paint-app in android?

i have a little problem with eclipse/android.
i am trying to mak my own paint-app in android. my problem is i can only paint with one color(black) , now i want to add 3 more colors(red,green,blue).
im still a newbie to android developing, and i dont know how i can add that option.
anyone has any suggestions?
here is my code so far
-SingleTouchEventView
package nl.hr.teken0;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class SingleTouchActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SingleTouchEventView(this, null));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.main_fragment, container,
false);
return rootView;
}
}
}
SingleTouchActivity
package nl.hr.teken0;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class SingleTouchActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SingleTouchEventView(this, null));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.main_fragment, container,
false);
return rootView;
}
}
}

You can use a color picker. An example: https://code.google.com/p/android-color-picker/
Just import it like other libraries so that the source is in the "src" folder and then add the layout to the preferences file.
Preferences xml file:
<yuku.ambilwarna.widget.AmbilWarnaPreference
android:key="your_preference_key"
android:defaultValue="0xff6699cc"
android:title="Pick a color" />

Simple android app with one button: "unfortunately -app- has stopped"

I'm completely new to Android.
I want just a button that does a task but the sample code on the internet does not work.
Even though eclipse does not give any errors i can't run this app on my device. Here's the code:
package com.example.myfirstapp;
import com.example.myfirstapp.R;
import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
#SuppressLint("ValidFragment")
public class MainActivity extends ActionBarActivity {
static Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment implements View.OnClickListener {
public PlaceholderFragment() {
}
public void onClick(View v){
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.sicioldrart.com"));
startActivity(browserIntent);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
btn=(Button) getView().findViewById(R.id.bottone);
btn.setOnClickListener(this);
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}
Thanks for the help

You need to have an inflated view before you can look for yout button.
move this:
btn=(Button) getView().findViewById(R.id.bottone);
btn.setOnClickListener(this);
below
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
and change getView() with rootView

btn=(Button) getView().findViewById(R.id.bottone);
btn.setOnClickListener(this);
these two lines will come after
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
and replace getView() with rootView
btn=(Button) rootView.findViewById(R.id.bottone);
btn.setOnClickListener(this);

Android prompting to save image or set wallpaper from gridview

I would like the user to get the option once the chosen image is clicked to set the image as their wallpaper or to save it to their SD card.
This is my first time doing this so I need some guidance. I have looked at other questions similar to this one but everyone uses different methods to the one I have done to set up displaying the images.
Thanks in advance, here's the code:
AdapterView for Displayimagesin:
package com.question;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
public class AdapterViewADV extends BaseAdapter {
private Context mContext;
public Integer[] mThumbIds = {
R.drawable.Image1,
R.drawable.Image2,
R.drawable.Image3,
R.drawable.Image4,
R.drawable.Image5,
R.drawable.Image6
};
public AdapterViewADV(Context c){
mContext = c;
}
#Override
public int getCount() {
return mThumbIds.length;
}
#Override
public Object getItem(int position) {
return mThumbIds[position];
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView = null;
if(convertView == null){
imageView = new ImageView(mContext);imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setLayoutParams(new GridView.LayoutParams(NO_SELECTION, NO_SELECTION));
convertView = imageView;
}else{
imageView = (ImageView)convertView;
}
imageView.setImageResource(mThumbIds[position]);
return convertView;
}
}
Class displaying images in:
package com.question;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.Toast;
public class Displayimagesin extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_battlefield4);
GridView gridView = (GridView) findViewById(R.id.grid_view);
// Instance of ImageAdapter Class
gridView.setAdapter(new AdapterViewADV(this));
gridView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(Displayimagesin.this, "Wallpaper set",
Toast.LENGTH_SHORT).show();
}
});
}
}

set wallpaper by calling WallpaperManager .
get a reference to your image to Bitmap.
something like this
WallpaperManager wm=WallpaperManager.getInstance(this);
wm.setBitmap(bitmap);
and in manifest file add permission
android.permission.SET_WALLPAPER
hope it helps.

Try to use WallpaperManager to set wallpaper
WallpaperManager myWallpaperManager=WallpaperManager.getInstance(getApplicationContext());
myWallpaperManager.setResource(mThumbIds[curruntPosition]);