Develop Reference

Set gravity of view children from loop of constraintlayout

when I access children which are dynamically created as TextView with a loop of a ConstraintLayout, they are returned as View, which don't have setGravity.
Does anyone know a way to set the gravity of these views (gravity for the TextView/child, not the layout)?
for (int i = 0;i < constraintLayout.getChildCount();i++) {
final View child = constraintLayout.getChildAt(i);
Object tag = child.getTag(R.id.tagId);
if(tag != null) {
//child.setGravity(Gravity.START); // Doesn't work...
} else {} }
I didn't see any option for setting Gravity through
ConstraintLayout.LayoutParams or ConstraintSet either.
Also, I tried final TextView child = (TextView) constraintLayout.getChildAt(i);: However, this resulted in a fatal exception: java.lang.ClassCastException: android.widget.ImageView cannot be cast to android.widget.TextView. Note: The children are textviews, not imageviews...

Cast the view to TextView first, then call setGravity.
final View child = constraintLayout.getChildAt(i);
Object tag = child.getTag(R.id.tagId);
if (tag != null) {
if (child instanceof TextView) {
TextView tv = (TextView) child;
tv.setGravity(Gravity.START);
}
} else {}

NullPointer while using dynamic view in android

I have created a dynamic view which repeats for a specific times. The view has 2 textViews and 2 radio buttons with default values. I want to change the Text values from program but getting nullpointer exception, Here is my code:
LayoutInflater inflater = (LayoutInflater)context.getSystemService
(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout scrollViewLinearlayout = (LinearLayout)findViewById(R.id.parent); // The layout inside scroll view
//int count=50;
for(int i = 0; i < Studentlist.length; i++){
String data = Studentlist[i];
String RollNum = data.split("--")[0];
String Name = data.split("--")[1];
LinearLayout layout2 = new LinearLayout(context);
layout2.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
View item = inflater.inflate(R.layout.item_layout, null, false);
layout2.addView(item);
layout2.setId(i);
TextView trollnum = (TextView)findViewById(R.id.RollNum);
trollnum.setText(RollNum);
TextView tname = (TextView)findViewById(R.id.Name);
tname.setText(Name);
scrollViewLinearlayout.addView(layout2);
Log.d("Id is: ", trollnum.getText().toString());
I am getting nullpointer at 'trollnum.setText(RollNum);'
How do i change the text in the View?

You are trying to find the view in the activity's layout where it doesn't exist instead of finding it in the layout you just inflated.
Replace
TextView trollnum = (TextView)findViewById(R.id.RollNum);
TextView tname = (TextView)findViewById(R.id.Name);
With
TextView trollnum = (TextView) item.findViewById(R.id.RollNum);
TextView tname = (TextView) item.findViewById(R.id.Name);

how to display output in textview using android?

i am newbie in android and i m not getting how to produce this output:
Discipline name:1
{ complete for loop code execute from 0 to 9
}
then it will come outside and will update textview text:ie
Discipline name:2
and will enter inside For Loop
{
complete for loop code execute from 0 to 9
}
here is the java code:
public class SummaryDetailActivity extends Activity
{ TableLayout summaryDetailDisciplineTableLayout;
LayoutInflater mInflater;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.summarydetail_view);
mInflater = getLayoutInflater();
summaryDetailDisciplineTableLayout = (TableLayout)findViewById(R.id.summaryDetail_disciplinetable);
//PLEASE SEE THESE LINE OF CODE:
for(int i=0;i<2;i++)
{
TextView disciplineTextView = (TextView)findViewById(R.id.summaryDetail_disciplinetext);
disciplineTextView.setText("discipline name: "+i);
for(int j=0;j<10;j++)
{TableRow disciplineRow = (TableRow) mInflater.inflate(R.layout.summarydetailrow_view,null);
TextView disciplineDeviceLabel = (TextView) disciplineRow.findViewById(R.id.summaryDetail_info1);
TextView disciplineQuantityLabel = (TextView)disciplineRow.findViewById(R.id.summaryDetail_hypen);
TextView disciplineLocationLabel = (TextView) disciplineRow.findViewById(R.id.summaryDetail_info2);
disciplineDeviceLabel.setText("device no." + j);
disciplineQuantityLabel.setText("quantity No." + j);
disciplineLocationLabel.setText("Location No." + j);
disciplineRow.setId(j);
summaryDetailDisciplineTableLayout.addView(disciplineRow);
}
}
}
}
this code is producing this output:

Why your code is not working the way you want. Is because this
TextView disciplineTextView = (TextView)findViewById(R.id.summaryDetail_disciplinetext);
is initiate as static view that can't be clone in your loop. That's why the value
of the discipline name is 1 not 0. The loop only update the value not clone the view.
You should do this
TextView disciplineTextView = new Textview(this);
disciplineTextView.setLayoutParams(new TableLayout.LayoutParams(TableLayout.LayoutParams.WRAP_CONTENT, TableLayout.LayoutParams.WRAP_CONTENT));
disciplineTextView.setText("discipline name: "+i);
summaryDetailDisciplineTableLayout.addView(disciplineTextView);
for(int j=0;j<10;j++) {
-your code-
}
You should change the xml structure for better UI.
Hope this helps.

Here's how I would've done it.
Inside my XML code, I would create a LinearLayout and within that, a TableLayout.
After fetching the id of my TableLayout, I would dynamically create TableRows and TextViews. You can set their layouts using TableRow.LayoutParams or LayoutParams. You can simply set the text after that and just add them onto the TableRow that you add to TableLayout.
Hope this suggestion helps !

I think that in onCreate() you should use inflater first and then set the view that you have just inflated.
Try this:
View view = getLayoutInflater().inflate(R.layout.summarydetail_view, null);
setContentView(view);

Android: set xml layout to table row?

I have table, which is described in main xml layout. I need to know, if there is any chance to set layout to each table row, so I don't need to recreate each time? Where layout is simple, I can do that by code, but at this time layout is pretty complicated.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ebank_saskaitos);
this.setFirstBlock();
}
private void setFirstBlock() {
TableLayout ll = (TableLayout) findViewById(R.id.first_block);
ll.addView(this.tableChild());
}
private TableRow tableChild() {
TableRow tr = new TableRow(this);
//row implementation
return tr;
}

use LayoutInflater like this way:
private View tableChild() {
TableRow tr = new TableRow(this);
View v = LayoutInflater.from(mContext).inflate(R.layout.layout_for_my_table_row, tr, false);
//want to get childs of row for example TextView, get it like this:
TextView tv = (TextView)v.findViewById(R.id.my_row_text_view);
tv.setText("This is another awesome way for dynamic custom layouts.");
return v;//have to return View child, so return made 'v'
}

How to display Images in Android on Runtime & make radio buttons as radio groups in List

Updated code snipped as asked:
int MovieNum=children.size();
String[] MovieName=new String[MovieNum];
String[] MovieCover=new String[MovieNum];
RadioGroup rg = new RadioGroup (this);
rg = (RadioGroup) findViewById(R.id.radioGroup1);
RadioButton rb[]= new RadioButton[children.size()];
//LinearLayout layout = (LinearLayout) findViewById(R.id.layout);
//LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
//layout.addView(rg, p);
for (int i = 0; i < children.size(); i++)
{
Element movieAtt = (Element)doc.getRootElement().getChild("movies").getChildren("movie").get(i);
MovieName[i]=movieAtt.getAttributeValue( "Title" );
MovieCover[i]=movieAtt.getAttributeValue( "cover" );
ShowTime[i]=movieAtt.getAttributeValue( "showtime" );
TweetText+=" I will see "+movieAtt.getAttributeValue("Title");
System.out.println(TweetText);
//ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.rowlayout, R.id.label, MovieName);
//setListAdapter(adapter);
//String item = (String) getListAdapter().getItem(position);
rb[i] = new RadioButton(this);
rb[i].setText(movieAtt.getAttributeValue("Title"));
rg.addView(rb[i]);
//Calling this func to get Images
//LoadImageFromWebOperations(movieAtt.getAttributeValue( "cover" ));
}
}
}
catch (MalformedURLException e1)
{
e1.printStackTrace();
System.out.println("ErrorThrowedIs: "+e1);
Toast.makeText(getBaseContext(), e1.toString(),5);
}
}
public static Drawable LoadImageFromWebOperations(String url)
{
try
{
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
return d;
}
catch (Exception e)
{
return null;
}
}
//Updated code ends here
I have to display 3 things in my list View. One is going to be a Radio button corresponding to every row. I can not use Radio group as i am not aware of the list length which is dynamically generated. So i can not set it as Radio group.
I wish to know how can i do the same.
Also what i am doing is, i want to get an image along in the same list for every row which is created from the path i get at runtime.
So during my program, i would get these values :
for (int i = 0; i < mvLen; i++)
{
Element movieAtt = (Element)doc.getRootElement().getChild("movies").getChildren("movie").get(i);
MovieName[i]=movieAtt.getAttributeValue( "Title" );
MovieCover[i]=movieAtt.getAttributeValue( "cover" );
ShowTime[i]=movieAtt.getAttributeValue( "showtime" );
Now clearly this is an string array of Movie
Names in MovieName and array of strings of URL for the cover of that movie. I wish to display all those images in front of the Movie Names. My list adapter and corrosponding XML file are listed as below. Can anyone suggest changes/hints for the same . I have been reading http://www.vogella.de/articles/AndroidListView/article.html as well. But could not figure out much to meet my requirements.

So. Create RadioGroup in your class RadioGroup radioGroup = new RadioGroup(this); and simply add radiobuttons to it when you filling content radioGroup.addView(radioButton);
Summary:
RadioGroup radioGroup = new RadioGroup(this);
//Cycle begin
RadioButton rButton = (RadioButton)findViewById(R.id.my_radiobutton);
// OR
RadioButton radioButton = new RadioButton(this);
radioButton .setText(R.string.radio_group_snack);
radioButton .setId(R.id.snack);
radioGroup.addView(rButton);
radioGroup.addView(radioButton);
//Cycle end
Example of custom adapter and getview method(it's 100% work code):
public class MyCustomAdapter extends ArrayAdapter<String> {
public MyCustomAdapter(Context context, int textViewResourceId,
String[] objects) {
super(context, textViewResourceId, objects);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
String[] users = getUsers(); //it returns list of users in String array
LayoutInflater inflater=getLayoutInflater();
View row=inflater.inflate(R.layout.main, parent, false);
TextView label=(TextView)row.findViewById(R.id.label); //TextView decalred in my layout xml file
label.setText(users[position]);
ImageView icon=(ImageView)row.findViewById(R.id.icon); //ImageView decalred in my layout xml file
byte[] bb = getAvatar(users[position]); //some method where I get image for user. It not interesting for us so I cut it from here...
if(bb != null && bb.length != 0){
icon.setImageBitmap(BitmapFactory.decodeByteArray(bb, 0, bb.length)); //SET IMAGE FOR ROW
icon.setVisibility(View.VISIBLE); //SET VISIBILITY OF IMAGE
}
//RIGHT HERE YOU CAN MANIPULATE WITH YOUR RADIOBUTTONS. FOR EXAMPLE:
RadioButton rButton = (RadioButton)findViewById(R.id.my_radio_button);
radioGroup.addView(rButton); //WHERE radioGroup IS RADIOGROUP YOU INITIALIZED BEFORE;
return row;
}
}
}
And this is my onCreate method:
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
db.open();
String[] users = db.getUsersList();
ListView listView = getListView();
this.setListAdapter(new MyCustomAdapter(this, R.layout.main, users));
db.close();
}

For each row in the list get the radioButton and add it to the RadioGroup.
You might have to create all the radioButton's upfront and store them in a list.Set them in the ContentView depending on the position