Develop Reference

How to remove item from ArrayList<HashMap<String, String>> one by one in android

I am new to Android. I am Using "com.devsmart.android.ui.HorizontalListView" to show my items(playing cards). In the List I am getting 8 cards in the first attempt. What I want if I again call the method the there must be 7 cards so on means 1 cards must be remove from the list at each time till the list gets empty. But I am not able not do this removing of item from the list. I am posting my code here. Help will be appreciated.
MainActivity.java
ArrayList<HashMap<String, String>> aList9;
Button btn_aditional_card;
HorizontalListView list1;
int[] cards3 = new int[]{
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1,
R.drawable.card1
};
public class MainActivity extends AppCompatActivity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_aditional_card = (Button) findViewById(R.id.btn_aditional_card);
list1 = (HorizontalListView) findViewById(R.id.listview1);
btn_aditional_card.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
add8();
}
});
}
public void add8() {
final android.view.animation.Animation animScale = AnimationUtils.loadAnimation(this, R.anim.slide_right_in);
list1.startAnimation(animScale);
aList9 = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < 8; i++) {
HashMap<String, String> hm = new HashMap<String, String>();
hm.put("card", Integer.toString(cards3[i]));
aList9.add(hm);
}
String[] from = {"card"};
int[] to = {R.id.ImageView};
final SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), aList9, R.layout.activity_animation__adapter, from, to);
list1.setAdapter(adapter);
adapter.notifyDataSetChanged();
list1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
aList9.remove(aList9.size() - 1);
adapter.notifyDataSetChanged();
}
});
}
Here removing of item from the list must be done on list1.setOnItemClickListener but I don't have any idea how.

In your list1.setOnItemClickListener, do this:
if (aList9.size() > 0) {
aList9.remove(aList9.size() - 1);
adapter.notifyDataSetChanged();
}
When removing item from data list, you have to notify your adapter to update view.

You can remove the last item from the list like;
if (aList9.size() > 0) {
aList9.remove(aList9.size() - 1);
}
Another solution,
Take Length of your integer array and traverse the loop inside your add8 method according to this length and at the end of the method decrement the length by one, like;
int length = cards3.length;
Inside your add8 method;
for (int i = 0; i < length; i++) {
HashMap<String, String> hm = new HashMap<String, String>();
hm.put("card", Integer.toString(cards3[i]));
aList9.add(hm);
}
After for loop decrement the length like;
length--;
Hope you'll get the solution.

In your main activity the code should look like.I am using arraylist instead you can use hashmap.This code is only to show you way what you need to do. follow this code in your project you will get solution this is tested in my site and working fine you need to change somewhere according to your code.In button click i am only removing last item from arraylist and notifying that dataset changed.hope it will help you.
ArrayList<String> arrlist = new ArrayList<String>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
arrlist.add("B");
arrlist.add("C");
arrlist.add("D");
arrlist.add("E");
arrlist.add("F");
arrlist.add("G");
ListView lv = (ListView) findViewById(R.id.listview);
Button btnShowList = (Button) findViewById(R.id.btnShowList);
final ArrayAdapter adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, arrlist);
//Listview adapter
lv.setAdapter(adapter);
btnShowList.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (arrlist.size() > 0) {
arrlist.remove(arrlist.size() - 1);
adapter.notifyDataSetChanged();
}
}
});
}

Read the comments
class MainActivity extends AppCompatActivity {
//make your Adapter global
private SimpleAdapter adapter;
ArrayList<HashMap<String, String>> aList9;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
add8();
btn_aditional_card.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// on button click you can add a view to the listview if you want
// if you don't want this just comment out the following line
// i still don't understand what you want to do with this button
alist9.add(...);
// if you add stuff in the array list then notify the adapter
// it will update the view
adapter.notifyDataSetChanged();
}
});
}
public void add8() {
// initialize your ArrayList and listview
//populate them
for(int i = 0; i < 8; i++) {
// do your stuff.
// populate the list
}
// initialize your adapter as before
adapter = new SimpleAdapter(....);
listview.setadapter(adapter);
adapter.notifyDataSetChanged();
list1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// delete the items like this
// check if size is greater than 0 and then remove
aList9.remove(aList9.size() - 1);
adapter.notifyDataSetChanged();
}
});
}
}

android How to send listview item to another activity

I am trying to send row item from list view to another activity but maybe I do something wrong.
I made one app for food.
And I want when the user click to "First Activity" the list item from this listview to be send to "Second Activity" and when the user click to "Add to cart" the listview item go to Cart.class
But when I click to "Add to cart" the Activity is send me tо Cart.class but there have nothing.
In cart.xml I have listvew.
Sorry for my bad english
Thanks in advance.
First Activity.
public class UnderCal extends Activity {
String classes[] = {"Grilled chicken","Asiago","Spicy"};
int[] meal = new int[]{
R.drawable.grilledchicken,
R.drawable.asiago,
R.drawable.spicy
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.under_menu);
final List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();
for(int i=0;i<3;i++){
HashMap<String, String> hm = new HashMap<String,String>();
hm.put("food", Integer.toString(meal[i]));
hm.put("txt", "" + classes[i]);
aList.add(hm);
}
// Keys used in Hashmap
String[] from = {"food","arrow","txt"};
// Ids of views in listview_layout
int[] to = { R.id.food,R.id.arrow,R.id.txt};
// Instantiating an adapter to store each items
// R.layout.listview_layout defines the layout of each item
SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), aList, R.layout.list_layout, from, to);
// Getting a reference to listview of main.xml layout file
final ListView listView = ( ListView ) findViewById(R.id.mylist);
// Setting the adapter to the listView
listView.setAdapter(adapter);
listView.setDivider(new ColorDrawable(0xffffffff));
listView.setDividerHeight(1);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View v, int position, long id)
{
if (position == 0)
{
Intent intent = new Intent(UnderCal.this,GrilledChicken.class);
// intent.putExtra("get", aList.get(position));
String result = (String) listView.getItemAtPosition(position).toString();
intent.putExtra("get",result);
startActivity(intent);
overridePendingTransition(R.anim.animation3, R.anim.animation4);
}
}
});
}
Second Activity.
public class GrilledChicken extends Activity {
Button butadd;
//HashMap<String, String> hm;
String list;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.grilled_chicken);
//hash
// hm =(HashMap<String, String>)getIntent().getSerializableExtra("get");
Bundle extras = getIntent().getExtras();
list = extras.getString("get");
butadd=(Button) findViewById(R.id.butadd);
butadd.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(GrilledChicken.this,Cart.class);
// intent.putExtra("hm",hm);
intent.putExtra("list",list);
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(intent);
}
});
Cart.class
public class Cart extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Remove title bar
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.cart);
Bundle extras = getIntent().getExtras();
String pos = extras.getInt("list");
}
}

For get item from your listview you have to write following code.
String item = food.get(position).toString();
Write this on your Itemclick method

Put the following code in your Cart.class
Bundle extras = getIntent().getExtras();
String list_data = extras.getString("list");
Now list_data contains the data.
There is another way through which you can do the task also.
Create a separate Global Class
Global.class
public class Globalclass {
public static String list_data;
}
And then in your FirstActivity replace the following
intent.putExtra("get",result);
with
Globalclass.list_data=result;
Now you can access the list_dataanywhere like the following
String data=Globalclass.list_data;

Try this once I hope this will help you.
First of all do this in YourFirstActivity
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent = new Intent(getActivity(), YourSecondActivity.class);
YourModel yourModel = (YourModel) parent.getItemAtPosition(position);
intent.putExtra("yourModel", yourModel);
startActivity(intent);
}
});
At another Activity do this.
YourModel yourModel= (YourModel) getIntent().getSerializableExtra("yourModel");
From yourModel object you will get all the data of your ListView selected item of YourFirstActivity to YourSecondActivity.

Multiple Send ListView Item:-
ArrayList<String>checked11 = new ArrayList<String>();
SparseBooleanArray checked = listView1.getCheckedItemPositions();
final ArrayList<String> selectedItems = new ArrayList<String>();
for (int i = 0; i < checked.size(); i++) {
int position = checked.keyAt(i);
if (checked.get(i))
selectedItems.add(checked11.get(position));
}
String[] outputStrArr = new String[selectedItems.size()];
for (int i = 0; i < selectedItems.size(); i++) {
outputStrArr[i] = selectedItems.get(i);
}
use Bunddle :
Bundle bundle = new Bundle();
Intent intent = new Intent(getApplicationContext(),
OtherActivity.class);
bundle.putStringArray("selectedItems", outputStrArr);
intent.putExtra("screen2", "sub");
intent.putExtras(bundle);
intent.putExtra(EXTRA_RESPONSE, selected);
startActivity(intent);

sqlite Viewlist error

i trying tu put some elements from database to a List view,
my problem is that when i starrt my activity, I get this:
**com.example.restaurant.Restaurant#2be2d1d0
com.example.restaurant.Restaurant#2be3d3a8**
instead of database objects.
public class Liste extends Activity{
private ListView listview;
private Button boutonAjouter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.liste_restaurant);
listview = (ListView)findViewById(R.id.listView1);
Restaurant mcdo = new Restaurant("mcdo","brossard","take-out","fastfood","450-555-5555");
Restaurant burger = new Restaurant("burger","longueuil","take-out","fastfood","450-999-9999");
RestaurantBDD restaurantBDD = new RestaurantBDD(this);
restaurantBDD.openForWrite();
restaurantBDD.insertRestaurant(mcdo);
restaurantBDD.insertRestaurant(burger);
ArrayList <Restaurant> restaurantlist = restaurantBDD.getAllRestaurants();
restaurantBDD.close();
ArrayAdapter <Restaurant> adapter = new ArrayAdapter<Restaurant>(this, android.R.layout.simple_list_item_1, restaurantlist);
listview.setAdapter(adapter);
boutonAjouter = (Button) findViewById(R.id.btn_nouveau);
boutonAjouter.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Liste.this, Formulaire.class);
startActivity(intent);
}
});
}
}

If you want to show a list with the names of the restaurants, supposing that your Restaurant class contains a string attribute "name", you should first create an array containing the names of the restaurants and then use an ArrayAdapter <String>:
String[] values = new String[restaurantlist.size()];
for(int i=0;i<restaurantlist.size();i++) {
values[i] = restaurantlist.get(i).getName();
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, values);
listview.setAdapter(adapter);

ListActivity Performance Issues

I have serious problems with my ListActivity. When I open it and start scrolling, the app freezes for some seconds and after that it can be scrolled smoothly. I don't get an "application not responding" error. I made a *.hprof heap dump and put it into MAT. Here you can see my leaks:
Seems like something is fishy. Maybe I'm not using the cursor in the right way.
Here you can take a look at my code:
public class ListViewActivity extends ListActivity implements OnClickListener {
// Resources
static String like;
// Cursor
private SimpleCursorAdapter adapter;
private Cursor cursor;
String[] showColumns;
int[] showViews;
// Database
private DBAccess dbAccess;
#Override
public void onCreate(Bundle savedInstanceState) {
// Remove title bar
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_listview);
ListViewActivity.like = "";
Intent intent = getIntent(); // gets the previously created intent
ListViewActivity.like = intent.getStringExtra("like");
new DatabaseTask().execute(null, null, null);
}
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
Cursor item = (Cursor) getListAdapter().getItem(position);
Intent intent = new Intent(ListViewActivity.this, ListClickActivity.class);
intent.putExtra("id", item.getString(0));
startActivity(intent);
}
private class DatabaseTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
Log.v("doInBackground", "started!");
dbAccess = new DBAccess(ListViewActivity.this, 1, "FishingMatey.db");
dbAccess.initDownloadedDatabase();
cursor = dbAccess
.createBewirtschafterListViewCursor(ListViewActivity.like);
showColumns = new String[] { "gewName", "reviergrenzen" };
showViews = new int[] { R.id.datensatz_gewName,
R.id.datensatz_reviergrenzen };
Log.v("doInBackground", "finished!");
return null;
}
protected void onPostExecute(Void params) {
adapter = new SimpleCursorAdapter(ListViewActivity.this,
R.layout.datensatz, cursor, showColumns, showViews);
setListAdapter(adapter);
dbAccess.closeDatabase();
Log.v("onPostExecute", "finished!");
}
}
}
EDIT1:
The issue doesn't come from the database because I have the same leak with the following code:
public class ListViewActivity extends ListActivity {
// Activity
public static Activity forFinish;
// Resources
static String like;
// Cursor
private SimpleAdapter adapter;
String[] showColumns;
int[] showViews;
#Override
public void onCreate(Bundle savedInstanceState) {
// Remove title bar
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_listview);
forFinish = this;
ListViewActivity.like = "";
Intent intent = getIntent(); // gets the previously created intent
ListViewActivity.like = intent.getStringExtra("like");
// create the grid item mapping
showColumns = new String[] { "gewName", "reviergrenzen" };
showViews = new int[] { R.id.datensatz_gewName,
R.id.datensatz_reviergrenzen };
// prepare the list of all records
List<HashMap<String, String>> fillMaps = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < 20; i++) {
HashMap<String, String> map = new HashMap<String, String>();
map.put("gewName", "See" + i);
map.put("reviergrenzen", "Revier" + i);
fillMaps.add(map);
}
// fill in the grid_item layout
SimpleAdapter adapter = new SimpleAdapter(this, fillMaps,
R.layout.datensatz, showColumns, showViews);
setListAdapter(adapter);
}
}
Would be awesome if someone can find the memory leak.
Greetings Mike!

If you are using images in your list items then move the image loading to a background task. You could have a look at smoothie, an asynchronous loading list that can be used with Android-BitmapCache for better performance.

Setting color of a textview dynamically

I am using a custom list view through the following code
public class details extends ListActivity {
/** Called when the activity is first created. */
Bundle extras;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.custom_list_view);
extras=getIntent().getExtras();
SimpleAdapter adapter = new SimpleAdapter(
this,
list,
R.layout.custom_row_view,
new String[] {"name","use"},
new int[] {R.id.text1,R.id.text2}
);
populateList();
setListAdapter(adapter);
}
static final ArrayList<HashMap<String,String>> list =
new ArrayList<HashMap<String,String>>();
private void populateList()
{
HashMap<String,String> temp1 = new HashMap<String,String>();
temp1.put("name","NAME");
temp1.put("use",extras.getString("name"));
list.add(temp1);
HashMap<String,String> temp2 = new HashMap<String,String>();
temp2.put("name","CHANGE IN PRICE");
temp2.put("use",extras.getString("change"));
TextView txt=(TextView)findViewById(R.id.text2);
double k=Double.parseDouble(extras.getString("change"));
if(k<0)
{
txt.setTextColor(Color.RED);
}
else
{
txt.setTextColor(Color.RED);
}
list.add(temp2);
}
}
I would like to set the color of the textview to green if change in price is grater than 0 else i want it to be red in color .The following code throws a null pointer exception at the setTextColor(). How exactly do i dothis