Develop Reference

App crashes on orientation change in android

My application crashes when I flip orientation. If the commented out line in onCreate runs I can't flip orientation at all. without it I can flip but can't change my background image but when it flips back it still crashes.
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
private DrawerLayout mDrawerLayout;
private ListView mListView;
private ImageView bgimage;
int[] drwables = {R.drawable.cindy, R.drawable.fred, R.drawable.kate, R.drawable.keith, R.drawable.matt, R.drawable.rickey};
private ActionBarDrawerToggle toggle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState != null){
Toast.makeText(this, "made it", Toast.LENGTH_SHORT).show();
int n = savedInstanceState.getInt("imageId");
Toast.makeText(this, ""+n, Toast.LENGTH_SHORT).show();
bgimage = (ImageView) findViewById(R.id.imgOne);
int[] drwables = {R.drawable.cindy, R.drawable.fred, R.drawable.kate, R.drawable.keith, R.drawable.matt, R.drawable.rickey};
Toast.makeText(this, ""+drwables.length, Toast.LENGTH_SHORT).show();
//This code here
//bgimage.setImageResource(drwables[n]);
}
else{
bgimage = (ImageView) findViewById(R.id.imgOne);
}
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mListView = (ListView) findViewById(R.id.left_drawer);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
String[] names = getResources().getStringArray(R.array.bandImages);
ArrayAdapter<String> itemsAdapter = new ArrayAdapter<String>(this, R.layout.nav_list_row, R.id.textView, names);
mListView.setAdapter(itemsAdapter);
mListView.setOnItemClickListener(this);
toggle = new ActionBarDrawerToggle(this, mDrawerLayout, (Toolbar) findViewById(R.id.toolbar), R.string.open, R.string.closed) {
public void onDrawerClosed(View view) {
super.onDrawerClosed(view);
getSupportActionBar().setTitle(getTitle());
invalidateOptionsMenu();
}
public void onDrawerOpened(View view) {
super.onDrawerOpened(view);
getSupportActionBar().setTitle(getTitle());
invalidateOptionsMenu();
}
};
mDrawerLayout.addDrawerListener(toggle);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
toggle.syncState();
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState){
int n = Integer.parseInt(bgimage.getTag().toString());
savedInstanceState.putInt("imageId", n);
super.onSaveInstanceState(savedInstanceState);
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mListView);
menu.findItem(R.id.action_about).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
#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 void onItemClick(AdapterView<?> parent, View view, int position, long id) {
bgimage = (ImageView) findViewById(R.id.imgOne);
bgimage.setImageResource(drwables[position]);
bgimage.setTag(position);
}
#Override
public boolean onOptionsItemSelected(MenuItem item){
int id = item.getItemId();
if(R.id.action_about == id){
Toast.makeText(this, "Lab 2 Spring 2016, Zack G Johnson", Toast.LENGTH_SHORT).show();
return true;
}
else{
return super.onOptionsItemSelected(item);
}
}
}

Try to place setContentView method before finding and using layout elements.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//put it here
setContentView(R.layout.activity_main);
if(savedInstanceState != null){
Toast.makeText(this, "made it", Toast.LENGTH_SHORT).show();
int n = savedInstanceState.getInt("imageId");
Toast.makeText(this, ""+n, Toast.LENGTH_SHORT).show();
bgimage = (ImageView) findViewById(R.id.imgOne);
int[] drwables = {R.drawable.cindy, R.drawable.fred, R.drawable.kate, R.drawable.keith, R.drawable.matt, R.drawable.rickey};
Toast.makeText(this, ""+drwables.length, Toast.LENGTH_SHORT).show();
//This code here
//bgimage.setImageResource(drwables[n]);
}
else{
bgimage = (ImageView) findViewById(R.id.imgOne);
}
...

Moving the Drawer Toggle From Left To Right in Action Bar

In my Activity I have a drawer list that pops from the right but I'm not able to move the drawer toggle from the left to the right side. Please if somebody can help me solve this issue.I just want to move the toggle to the right of the action bar.
package com.parse.starter;
import com.parse.ParseUser;
public class UserDrawer extends AppCompatActivity {
//Declaring Variables
private ListView DrawerList;
private ArrayAdapter<String> Adapter;
private ActionBarDrawerToggle DrawerToggle;
private DrawerLayout DrawerLayout;
private String ActivityTitle;
final ParseUser currentUser = ParseUser.getCurrentUser();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_drawer);
DrawerList = (ListView) findViewById(R.id.navList);
DrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
ActivityTitle = getTitle().toString();
addDrawerItems();
setupDrawer();
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
Button Sample = (Button) findViewById(R.id.button);
}
//Method To Add Items To The List View
private void addDrawerItems() {
String[] DArray = {"Job List", "Notifications", "Messages", "Log Out"};
Adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, DArray);
DrawerList.setAdapter(Adapter);
DrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (position == 0) {
Intent i0 = new Intent(UserDrawer.this, Set_Info.class);
startActivity(i0);
} else if (position == 1) {
//Intent i1 = new Intent(Drawer1.this, AddPatient.class);
//startActivity(i1);
} else if (position == 2) {
//Intent i2 = new Intent(Drawer1.this, Notifications.class);
//startActivity(i2);
} else if (position == 3) {
//Intent i3 = new Intent(Drawer1.this, Message_Log.class);
//startActivity(i3);
} else if (position == 4) {
Intent i4 = new Intent(UserDrawer.this, MainActivity.class);
startActivity(i4);
Toast.makeText(getApplicationContext(), "You are Logged Out", Toast.LENGTH_LONG).show();
finish();
}
}
});
}
private void setupDrawer() {
DrawerToggle = new ActionBarDrawerToggle(this, DrawerLayout,
R.string.drawer_open, R.string.drawer_close) {
/** Called when a drawer has settled in a completely open state. */
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
getSupportActionBar().setTitle("Menu");
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
/** Called when a drawer has settled in a completely closed state. */
public void onDrawerClosed(View view) {
super.onDrawerClosed(view);
getSupportActionBar().setTitle(ActivityTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
DrawerToggle.setDrawerIndicatorEnabled(true);
DrawerLayout.setDrawerListener(DrawerToggle);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if(item != null && item.getItemId()==android.R.id.home){
if(DrawerLayout.isDrawerOpen(Gravity.RIGHT)){
//Notice the Gravity.Right
DrawerLayout.closeDrawer(Gravity.RIGHT);
}else{
DrawerLayout.openDrawer(Gravity.RIGHT);
}
}
return false;
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
DrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
DrawerToggle.onConfigurationChanged(newConfig);
}
#SuppressWarnings("ResourceType")
public void SampleClick(View view) {
try {
Intent i = new Intent(UserDrawer.this,Set_Info.class);
startActivity(i);
} catch (Exception e) {
}
}
}

Motion event has invalid pointer count 0 >> On opening/ closing/ selecting in Navigation Drawer

I get this error if I do anything with my navigation drawer.
Motion event has invalid pointer count 0; value must be between 1 and 16.
This error doesn't crash my activity. But just floods my log. Below is the activity. The adapter is custom adapter having image and text in a row.
public class FirstActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
private DrawerLayout drawerLayout;
private ActionBarDrawerToggle actionBarDrawerToggle;
private ListView navList;
private NavAdapter navAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first);
drawerLayout = (DrawerLayout)findViewById(R.id.drawerLayout);
navList = (ListView)findViewById(R.id.navigation_list);
navAdapter = new NavAdapter(this);
navList.setAdapter(navAdapter);
navList.setOnItemClickListener(this);
actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.opendrawer, R.string.closedrawer);
drawerLayout.setDrawerListener(actionBarDrawerToggle);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if(actionBarDrawerToggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
actionBarDrawerToggle.onConfigurationChanged(newConfig);
}
#Override
public void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
actionBarDrawerToggle.syncState();
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
navList.setItemChecked(position, true);
String menuItem = (((TextView)view.findViewById(R.id.drawerTV)).getText().toString());
getSupportActionBar().setTitle(menuItem);
}
}

Set database object to be deleted in android

I've setup a database in android for my app however I'm stuck trying to delete a object within the database.
I'd like the button within BasicButtonsCard to delete the item that has been clicked on.
For example cardX holds data ABCD while cardY hold EFGH and on clicking the delete button on cardX, it deletes the card and its data.
Help is appreciated.
Code for input field:
public class note extends DialogFragment {
EditText memoryText, memoryTitle;
public interface NewPersonDialogListener{
void onFinishAddPersonDialog(String text, String title);
}
public note(){}
public Dialog onCreateDialog(Bundle savedInstanceState){
LayoutInflater i = getActivity().getLayoutInflater();
View rootview = i.inflate(R.layout.activity_note, null);
memoryText = (EditText)rootview.findViewById(R.id.memoryText);
memoryTitle = (EditText)rootview.findViewById(R.id.memoryTitle);
AlertDialog.Builder b = new AlertDialog.Builder(getActivity());
b.setTitle("Add New Memory");
b.setPositiveButton("Save", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
String text = memoryText.getText().toString();
String title = memoryTitle.getText().toString();
NewPersonDialogListener activity = (NewPersonDialogListener)getActivity();
activity.onFinishAddPersonDialog(text, title);
}
});
b.setNegativeButton("Cancel", null);
b.setView(rootview);
return b.create();
}
}
Code that handles MainActivity in the app:
public class MainActivity extends AppCompatActivity implements note.NewPersonDialogListener{
ImageButton runCommand;
DrawerLayout mDrawerLayout;
ListView mDrawerList;
ActionBarDrawerToggle mDrawerToggle;
String[] mDrawerListItems;
MaterialListView mListView;
MemoryDataSource dataSource;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
mDrawerLayout = (DrawerLayout)findViewById(R.id.drawer);
mDrawerList = (ListView)findViewById(android.R.id.list);
dataSource = new MemoryDataSource(this);
mListView = (MaterialListView) findViewById(R.id.material_listview);
generateList();
mListView.addOnItemTouchListener(new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(CardItemView cardItemView, int i) {
}
#Override
public void onItemLongClick(CardItemView cardItemView, int i) {
}
});
mDrawerListItems = getResources().getStringArray(R.array.drawer_list);
mDrawerList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mDrawerListItems));
mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch (position) {
case 0:
Intent intent = new Intent(MainActivity.this, MainActivity.class);
startActivity(intent);
break;
case 1:
intent = new Intent(MainActivity.this, bands.class);
startActivity(intent);
break;
case 2:
intent = new Intent(MainActivity.this, memory_vault.class);
startActivity(intent);
break;
}
mDrawerLayout.closeDrawer(mDrawerList);
}
});
runCommand = (ImageButton)findViewById(R.id.runCommand);
runCommand.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
/*
Intent i = new Intent(MainActivity.this, note.class);
startActivity(i);
*/
note noteFragment = new note();
noteFragment.show(getFragmentManager(), "tag");
}
});
mDrawerToggle = new ActionBarDrawerToggle(this,
mDrawerLayout,
toolbar,
R.string.drawer_open,
R.string.drawer_close){
public void onDrawerClosed(View v){
super.onDrawerClosed(v);
invalidateOptionsMenu();
syncState();
}
public void onDrawerOpened(View v){
super.onDrawerOpened(v);
invalidateOptionsMenu();
syncState();
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
mDrawerToggle.syncState();
}
public void generateList(){
dataSource.open();
List<memoryModel> list = dataSource.findMemory();
for (memoryModel model : list){
BasicButtonsCard card = new BasicButtonsCard(this);
card.setTitle(model.getmemoryTitle());
card.setDescription(model.getmemoryText());
card.setBackgroundColorRes(R.color.background_material_dark);
card.setDescriptionColorRes(R.color.abc_secondary_text_material_dark);
card.setTitleColorRes(R.color.abc_secondary_text_material_dark);
card.setLeftButtonText("LEFT");
card.setRightButtonText("RIGHT");
card.setDismissible(true);
card.setOnRightButtonPressedListener(new OnButtonPressListener() {
#Override
public void onButtonPressedListener(View view, Card card) {
Intent intent = new Intent(MainActivity.this, bands.class);
startActivity(intent);
}
});
card.setOnLeftButtonPressedListener(new OnButtonPressListener() {
#Override
public void onButtonPressedListener(View view, Card card) {
}
});
mListView.add(card);
}
}
#Override
public void onResume(){
super.onResume();
}
#Override
protected void onPostCreate(Bundle savedInstanceState){
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
#Override
public void onConfigurationChanged(Configuration newConfig){
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
#Override
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()){
case android.R.id.home: {
if (mDrawerLayout.isDrawerOpen(mDrawerList)){
mDrawerLayout.closeDrawer(mDrawerList);
} else {
mDrawerLayout.openDrawer(mDrawerList);
}
return true;
}
default: return super.onOptionsItemSelected(item);
}
}
#Override
public void onFinishAddPersonDialog(String text, String title) {
dataSource.open();
memoryModel model = new memoryModel();
model.setmemoryText(title);
model.setmemoryTitle(text);
dataSource.create(model);
dataSource.close();
generateList();
}
}

I will assume that you already have a RecyclerView with a button on each row since you didn't mention that as a problem. You should have a view holder class, and in the constructor of that class you can set up your listeners.
class Holder extends RecyclerView.ViewHolder{
public Holder(View itemView){
super(itemView);
View button = itemView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int rowNumber = getPosition();
// call delete method here
}
});
}
public void bind(int index){
// ...
}
}

Solved the issue of deleting data from the database. Since it was contained in a cardview layout with a button all I needed to do was add a onclick listener which would do the following
dataSource.deleteMemory(model.getmemoryTitle());
dataSource.deleteMemory(model.getmemoryText());
mListView.remove(card);

android-navigation drawer not open on activity change

it's weird , I spend last 5 hours on it , nothing worked. the problem is this ,When I go from activity a to activity b , and press back button and come back to activity a, the navigation drawer not open.
this is the code :
public abstract class DrawerActivity extends ActionBarActivity {
static LinearLayout fullLayout;
static FrameLayout actContent;
static DrawerLayout mDrawerLayout;
static ListView mDrawerList;
static ActionBarDrawerToggle mDrawerToggle;
static LinearLayout mDrawer;
List<HashMap<String, String>> mList;
SimpleAdapter mAdapter;
final private String COUNTRY = "country";
final private String FLAG = "flag";
final private String COUNT = "count";
#Override
public void setContentView(final int layoutResID) {
fullLayout= (LinearLayout) getLayoutInflater().inflate(R.layout.act_layout, null); // Your base layout here
actContent= (FrameLayout) fullLayout.findViewById(R.id.act_content);
getLayoutInflater().inflate(layoutResID, actContent, true); // Setting the content of layout your provided to the act_content frame
super.setContentView(fullLayout);
makelist();
}
mTitle = (String) getTitle();
// Getting a reference to the drawer listview
mDrawerList = (ListView) findViewById(R.id.drawer_list);
// Getting a reference to the sidebar drawer ( Title + ListView )
mDrawer = (LinearLayout) findViewById(R.id.drawer);
// Each row in the list stores country name, count and flag
mList = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < mCountries.length; i++) {
HashMap<String, String> hm = new HashMap<String, String>();
hm.put(COUNTRY, mCountries[i]);
hm.put(FLAG, Integer.toString(mFlags[i]));
mList.add(hm);
}
String[] from = { FLAG, COUNTRY };
int[] to = { R.id.flag, R.id.country };
mAdapter = new SimpleAdapter(this, mList, R.layout.drawer_layout, from,to);
// Getting reference to DrawerLayout
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,R.drawable.ic_navigation_drawer, R.string.drawer_open,R.string.drawer_close) {
/** Called when drawer is closed */
public void onDrawerClosed(View view) {
highlightSelectedCountry();
supportInvalidateOptionsMenu();
}
/** Called when a drawer is opened */
public void onDrawerOpened(View drawerView) {
supportInvalidateOptionsMenu();
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item != null && item.getItemId() == android.R.id.home) {
if (mDrawerLayout.isDrawerOpen(Gravity.RIGHT)) {
mDrawerLayout.closeDrawer(Gravity.RIGHT);
Log.v("this","close");
} else {
mDrawerLayout.openDrawer(Gravity.RIGHT);
}
}
return false;
}
};
// Setting event listener for the drawer
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrawerList.setAdapter(mAdapter);
}
public static boolean open() {
if (mDrawerLayout.isDrawerOpen(mDrawer)) {
mDrawerLayout.closeDrawer(Gravity.RIGHT);
return true;
} else {
mDrawerLayout.openDrawer(Gravity.RIGHT);
return true;
}
}
this is MainActivity class:
public class MainActivity extends DrawerActivity implements OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//suppose this is the imageview on the actionbar
ImageView img=(ImageView)dialogg.findViewById(R.id.img);
dateup.img(new OnClickListener() {
#Override
public void onClick(View v) {
DrawerActivity.open();
}
});
}
one thing I want to notice , the mainActivity extends DrawerActivity class.
Could you help me to solve this ?
thanks you

This
trys to use the method open() from the Abstract class and you use "mDrawerLayout" and this must be null at this moment i think
public void onClick(View v) {
DrawerActivity.open();
}
maybe you use
public void onClick(View v) {
this.open();
}
Then you will use the open-Method of your current Activity
And you have to implement the onClickListener in the Activity
An error msg would be nice to get more information about the error