Develop Reference

setVisibility(View.GONE) not removing space in listview item

I am making a question that could be like a duplicated question, but i have tried everything and nothing worked for me. I have created a listview witch every item has two views, one textview and one checkbox. Its like a multiselect listview. Every item has a level on its own: easy, normal, hard. When a level is chosen from a dropdown: All, Easy, Normal, Hard.. the list changes, just like a filter system.
But when i write listView.getChildAt(i).setVisibility(View.GONE); the content of the row is removed but the space occupied is not released.
Any help?
This is my code:
public class CreatePresentation extends Activity
{
DatabaseHelper db = new DatabaseHelper(this);
MyCustomAdapter dataAdapter = null;
List<Slider> list;
ListView listView;
String Text;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.create_presentation);
displayListView();
checkButtonClick();
}
private void displayListView()
{
list = new ArrayList<Slider>();
ArrayList<Slider> oldList = db.getAllSliders();
for (Slider anOldList : oldList) {
String s = anOldList.toString();
int in = anOldList.getId();
String lev = anOldList.getLevel();
Slider slider = new Slider(in, s, lev, false);
list.add(slider);
}
dataAdapter = new MyCustomAdapter(this, R.layout.list_check_box, list);
listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(dataAdapter);
}
private class MyCustomAdapter extends ArrayAdapter<Slider> {
private ArrayList<Slider> list;
public MyCustomAdapter(Context context, int textViewResourceId, List<Slider> list) {
super(context, textViewResourceId, list);
this.list = new ArrayList<Slider>();
this.list.addAll(list);
}
private class ViewHolder {
TextView text;
CheckBox checkbox;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
final Slider slider = list.get(position);
if (convertView == null) {
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.list_check_box, null);
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.sliderTitle);
holder.checkbox = (CheckBox) convertView.findViewById(R.id.checkBox);
convertView.setTag(holder);
Spinner dropdown = (Spinner)findViewById(R.id.spinner);
String[] items = new String[]{"Tutto", "Facile", "Medio", "Difficile"};
ArrayAdapter<String> adapter = new ArrayAdapter<String (CreatePresentation.this, android.R.layout.simple_spinner_item, items);
dropdown.setAdapter(adapter);
Text = dropdown.getSelectedItem().toString();
holder.checkbox.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
Slider slider = (Slider) cb.getTag();
slider.setSelected(cb.isChecked());
}
});
try {
if (list.get(position).getLevel().equals("Facile"))
convertView.setBackgroundColor(Color.parseColor("#477C3D"));
else if (list.get(position).getLevel().equals("Medio"))
convertView.setBackgroundColor(Color.parseColor("#936019"));
else if (list.get(position).getLevel().equals("Difficile"))
convertView.setBackgroundColor(Color.parseColor("#A02307"));
} catch (Throwable e) {
e.printStackTrace();
}
dropdown.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parentView, View selectedItemView, final int position, long id) {
Text = parentView.getItemAtPosition(position).toString();
try {
if (Text.equals("All")){
Runnable run = new Runnable(){
public void run(){
for (int i = 0; i < list.size(); i++) {
listView.getChildAt(i).setVisibility(View.VISIBLE);
}
}
};
runOnUiThread(run);
}
if (Text.equals("Easy")){
Runnable run = new Runnable(){
public void run(){
for (int i = 0; i < list.size(); i++) {
if (list.get(i).getLevel().equals("Easy")) {
listView.getChildAt(i).setVisibility(View.VISIBLE);
}
else {
listView.getChildAt(i).setVisibility(View.GONE);
}
}
}
};
runOnUiThread(run);
}
if (Text.equals("Normal")){
Runnable run = new Runnable(){
public void run(){
for (int i = 0; i < list.size(); i++) {
if (list.get(i).getLevel().equals("Normal"))
listView.getChildAt(i).setVisibility(View.VISIBLE);
else {
listView.getChildAt(i).setVisibility(View.GONE);
}
dataAdapter.notifyDataSetChanged();
}
}
};
runOnUiThread(run);
}
if (Text.equals("Hard")){
Runnable run = new Runnable(){
public void run(){
for (int i = 0; i < list.size(); i++) {
if (list.get(i).getLevel().equals("Hard"))
listView.getChildAt(i).setVisibility(View.VISIBLE);
else
listView.getChildAt(i).setVisibility(View.GONE);
}
}
};
runOnUiThread(run);
}
} catch (Throwable e) {
e.printStackTrace();
}
}
#Override
public void onNothingSelected(AdapterView<?> parentView) {
}
});
holder.checkbox.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
Slider slider = (Slider) cb.getTag();
slider.setSelected(cb.isChecked());
}
});
}
else
{
holder = (ViewHolder) convertView.getTag();
}
holder.text.setText(slider.getQuestion());
holder.checkbox.setChecked(slider.isSelected());
holder.checkbox.setTag(slider);
return convertView;
}
}

the best way to do this is to remove the item from the list and call dataAdapter.notifyDataSetChanged()

As you want to remove your view but keep your item inside your List I suggest you to use a different method. When the user choose a value that will cause the item to be hide just set that value to your item and then call
dataAdapter.notifyDataSetChanged();
Doing this you have to modify the logic inside your getView(), I mean if you find an item that is eligible to get hide instead of return convertView inside the getView() method of your customAdapter just return an empty view, like this you item won't be shown but it will still be in your list;)

You can use a parent Layout for Yuor item to resolve the issue:
For example:
<LinearLayout ...>
<!-- Here Your item content starts -->
<LinearLayout android:id="#+id/content">
...
</LinearLayout>
<!-- Here Your content ends -->
</LinearLayout>
Java code:
listView.getChildAt(i).getChildAt(0).setVisibility(View.GONE);

just like a filter system. Why "like", why not make it actually filterable? There are two options. Easier one is overriding toString of your slider. Other one is creating custom filter, which wouldn't use object's toString method. However, I don't remember how exactly to do second one, only that it's possible.
Slider:
String toString(){
return this.type;
}
When spinner selection changes:
adapter.getFilter().filter(selectedDifficulty);
This will automatically display items you want to see.

You shouldnt change visibility of views generated by adapter - they change every time when you scroll listview. Instead you should change the behaviour of underlying adapter.

You can try this layout instead of the ListView since there's only 4 filters:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<include
android:id="#+id/filter_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
layout="#layout/<your_listview_adapter>"
android:visibility="visible" />
<include
android:id="#+id/filter_2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
layout="#layout/<your_listview_adapter>"
android:visibility="visible" />
<include
android:id="#+id/filter_3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
layout="#layout/<your_listview_adapter>"
android:visibility="visible" />
<include
android:id="#+id/filter_4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
layout="#layout/<your_listview_adapter>"
android:visibility="visible" />
</LinearLayout>
When you want to hide one of the filters you can just do something like:
findViewById(R.id.filter_4).setVisibility(View.GONE);
EDIT:
For instance, if you want to add information to a TextView inside the first include you just have to call the View like this:
View filter1 = findViewById(R.id.filter_1);
TextView tv1 = (TextView) filter1.findViewById(R.id.<the_id_of_the_textview);
tv1.setText("StackOverflow filter");

To prevent add another layout in outside of your layout. You just hide the item's all child views, not item itself.
For example:
if(i == 1){ // assume we need hide the first item.
//item itself
ViewGroup parent = ((ViewGroup) holder.convertView);
for (int j = 0; j < parent.getChildCount(); j++) {
parent.getChildAt(j).setVisibility(View.GONE);
}
}
And i have test this code, works fine for me.

findViewById returns null. BUT WHY?

I have an Adroid Activity and I want to introduce a custom list view. This is my onCreate() activity method.
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LoadListView();
ListView lvw = (ListView)findViewById(android.R.id.list);
lvw.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// selected item
String element = ((TextView) view).getText().toString();
// Launching new Activity on selecting single List Item
Intent i = new Intent(getApplicationContext(), AddEntryActivity.class);
// sending data to new activity
i.putExtra("entryToEdit", element);
long idToEdit = Long.parseLong(hEntries.get(position).toString());
i.putExtra("idToEdit", idToEdit);
startActivity(i);
}
});
DbAccess oDb = new DbAccess(this);
}
As you can see LoadListView() method is called to load listview items:
private void LoadListView()
{
oDb = new DbAccess(this);
oDb.open();
List<cAttivita> entries = oDb.getAttivita();
CustomListAdapter listAdapter = new CustomListAdapter(MainActivity.this, android.R.layout.simple_list_item_1 , entries);
ListView lvwAttivita = (ListView)findViewById(android.R.id.list);
lvwAttivita.setAdapter(listAdapter);
hEntries = new HashMap();
for(int i = 0; i < entries.size(); i++)
{
hEntries.put(i, entries.get(i).getId());
}
}
CustomListAdapter class:
public CustomListAdapter(Context context, int textViewResourceId , List<cAttivita> list )
{
super(context, textViewResourceId, list);
mContext = context;
id = textViewResourceId;
items = list ;
}
#Override
public View getView(int position, View v, ViewGroup parent)
{
View mView = v ;
if(mView == null){
LayoutInflater vi = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mView = vi.inflate(id, null);
}
TextView text = (TextView) mView.findViewById(R.id.textView);
if(items.get(position) != null )
{
text.setTextColor(Color.WHITE);
text.setText(items.get(position).toString());
text.setBackgroundColor(Color.RED);
int color = Color.argb( 200, 255, 64, 64 );
text.setBackgroundColor( color );
}
return mView;
}
This is activity_main.xml code:
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/textView"
android:textSize="20px"
android:paddingTop="10dip"
android:paddingBottom="10dip"/>
<ListView xmlns:android="schemas.android.com/apk/res/android";
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Attività"/>
The problem is in the line:
TextView text = (TextView) mView.findViewById(R.id.textView);
Why text returns null?

Change the following line of code inside your getView() of your CustomAdapter.
TextView text = (TextView) mView.findViewById(android.R.id.text1);
as you are taking android.R.layout.simple_list_item_1 as layout it should be android.R.id.text1 which is declared internally in Android library.
Change my line of code inside getView() and it works for you.

Showing graphical instead of strings in an imagelist with title

At the moment I am getting items out of my database and add them to a string called result which I return and set to my TextView:
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.level);
loadDataBase();
int level = Integer.parseInt(getIntent().getExtras().getString("level"));
questions = new ArrayList<Question>();
questions = myDbHelper.getQuestionsLevel(level);
tvQuestion = (TextView) findViewById(R.id.tvQuestion);
i = 0;
String data = getAllItems();
tvQuestion.setText(data);
}
private String getAllItems() {
result = "";
for (i = 0; i<9; i++){
result = result + questions.get(i).getQuestion() + "\n";
}
return result;
// TODO Auto-generated method stub
}
The thing is, all these items also have a title(string) and graphical thumb (string) in the database. I would like to show them as illustrated in the picture below, each with an onclicklistener on it, instead of a boring list of items below eachother. Each item has a picture and title.
Since my beginning programming skills, I am wondering how to do this best, and if you know any good tutorials on it which explain it well?
Thanks!

if i understood your question you need to create a customize an adapter.
Create a new simple class like this which holds an string and a picture
Class ObjectHolder {
int Image;
String Title;
}
and create a getter and setter for this two
then create custom ArrayAdapter
Class CustomArrayAdapter extends ArrayAdapter<ObjectHolder> {
public CustomArrayAdapter(Context C, ObjectHolder[] Arr) {
super(C, R.layout.caa_xml, Arr);
}
#Override
public View getView(int position, View v, ViewGroup parent)
{
View mView = v ;
if(mView == null){
LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
mView = vi.inflate(R.layout.cpa_xml, null);
}
TextView text = (TextView) mView.findViewById(R.id.tv_caarow);
ImageView image = (ImageView) mView.findViewById(R.id.iv_caarow);
if(mView != null )
{ text.setText(getItem(position).getText());
image.setImageResource(getItem(position).getImage());
return mView;
}
}
and create caa_xml.xml in res\layout\
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/iv_caarow"
android:src="#drawable/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/tv_caarow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingBottom="15dip"
android:layout_BottomOf="#+id/iv_caarow" />
</RelativeLayout>
and use it like this.
GridView GV= (GridView) findViewById(R.Id.gv); // reference to xml or create in java
ObjectHolder[] OHA;
// assign your array, any ways!
mAdapter CustomArrayAdapter= CustomArrayAdapter(this, OHA);
GridView.setAdapter(mAdapter);

How do I populate spinner with global string array variable?

I am trying to populate a a spinner but I am getting an error with my String array saying "Array constants can only be used in initializers". My code works fine when i employ the string array as a local variable, but as a global variable it doesn't. I really need to be able to use my string array as a global variable. Thank you in advance. Here is my code:
deleteselection = (Spinner)view.findViewById(R.id.deletespinner);
ArrayAdapter<String> adapterdeletetype;
//createdenominationsarray = getResources().getStringArray(R.array.createdenominations); //<--works
//String [] createdenominationsarray = {"Select Portfolio", "Two", "Three"}; //<--works
createdenominationsarray = {"Select Portfolio", "Two", "Three"};// <--doesn'twork
adapterdeletetype = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item,createdenominationsarray){
#Override
public View getDropDownView(int position, View convertView, ViewGroup parent)
{
View v = null;
// If this is the initial dummy entry, make it hidden
if (position == 0) {
TextView tv = new TextView(getContext());
tv.setHeight(0);
tv.setVisibility(View.GONE);
v = tv;
}
else {
// Pass convertView as null to prevent reuse of special case views
v = super.getDropDownView(position, null, parent);
}
// Hide scroll bar because it appears sometimes unnecessarily, this does not prevent scrolling
parent.setVerticalScrollBarEnabled(false);
return v;
}
};
adapterdeletetype.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
denominationselection.setAdapter(adapterdeletetype);

I did the same thing for one of my project and it works for me. Below is the code snippet for your reference..
ArrayList<String> languages = new ArrayList<String>();
languages.add("English");
languages.add("German");
languages.add("French");
ArrayAdapter<String> langAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,languages);
ListView lv =(ListView)findViewById(R.id.listmain);
lv.setAdapter(langAdapter);
lv.setOnItemClickListener(new listclklisten(MainActivity.this));
public class listclklisten implements OnItemClickListener{
private Context parent;
public listclklisten(Context p){
parent=p;
}
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
// TO DO your code here
}
}

inside string.xml Write:
<string-array name="spinner_array_environtment">
<item>Test</item>
<item>Production</item>
</string-array>
Inside your MainActivity.java :
public class MainActivity extends Activity {
Spinner spinner_environment;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spinner_environment = (Spinner) findViewById(R.id.spinnerview);
adapter =ArrayAdapter.createFromResource(this, R.array.spinner_array_environtment,R.layout.spinner_phone);
adapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spinner_environment.setAdapter(adapter);
}
Inside spinner_phone.xml :
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/spinnerTarget"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="13dp"
android:textColor="#4C4646" />
try this out. Hope it will help you.

Android custom listview

Hi i've got a custom listview with a text view and a button in each row.
Im having trouble trying to use the buttons . Each button will fire a different intent. This is the xml file for the list view rows.
<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout
android:id="#+id/widget28"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android"
>
<Button
android:id="#+id/widget29"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Remind me"
android:layout_alignParentRight="true"
/>
<TextView android:id="#+id/text12"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#ff99ccff"
android:text="Text view" />
</RelativeLayout>
Then i have another xml file which simply contains the list view in a linear layout.
This is my custom array class.
public class customArray extends ArrayAdapter<String> {
int resource;
public customArray(Context cont, int _resource, List<String> items) {
super (cont, _resource,items);
resource = _resource;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
RelativeLayout rl;
String prod = getItem(position);
if (convertView == null) {
rl = new RelativeLayout(getContext());
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
vi.inflate(resource, rl, true);
} else {
rl = (RelativeLayout)convertView;
}
TextView t1 = (TextView)rl.findViewById(R.id.text12);
t1.setText(prod);
Button b1 = (Button)rl.findViewById(R.id.widget29);
return rl;
}
}
Then the final class which gets the data from a database and uses the custom adapter to display the information. Does anyone know how i would call each button?
`public class SatMain extends Activity {
/** Called when the activity is first created.
* #param cont */
#Override
public void onCreate(Bundle savedInstanceState)
{
List<String> results = new ArrayList<String>();
super.onCreate(savedInstanceState);
setContentView(R.layout.satmain);
dbAdapter db = new dbAdapter(this);
// button.setOnClickListener(m);
//---get all titles---
db.open();
db.InsertData();
Cursor c = db.getSat1();
if (c.moveToFirst())
{
do {
String pub = c.getString(c.getColumnIndex(db.KEY_Artist));
String pub1 = c.getString(c.getColumnIndex(db.KEY_Time));
results.add(pub + pub1 );
} while (c.moveToNext());
}
db.close();
ListView listProducts;
customArray ca = new customArray(this, R.layout.button, results);
listProducts = (ListView)findViewById(R.id.list1);
listProducts.setAdapter(ca);
ca.notifyDataSetChanged();
}
}`

In the "getView" method of your adapter, you should set an onClick listener for the button. You can do an anonymous class so that you can refer to the contents of the row in the button. I.e, add the following where you get b1 in your example.
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//create activity based on prod
}
});