Develop Reference

How to set position of view while using addView

I'm adding multiple Views by code into Layout. I need each new View to be above previous one(top of the parent layout).
EDIT: To be more accurate I'll describe what the app module should does. User start with clean screen and one button at the bottom of the screen. The button adds a View at the top of the screen. Next clicks should add next views above previous ones to make the newest View be on the top of a container. The app saves state and on restart user see views in the same order.

Call the following method from Button's onClick Event.
private final int LAYOUT_TOP_INDEX = 0;
private void addViewOnTop(View view){
if(layout != null && view !=null)
layout.addView(view, LAYOUT_TOP_INDEX);
}
where 'layout' is your Layout (e.g., LinearLayout) to which the View is to be added.

Would really need more information from you to give a more accurate answer, but if you're saying what i think you are then you can just add these views to a LinearLayout with orientation set to vertical.
And assuming you're iterating through a list to dynamically add views, instead of incrementing from 0, increment down from the size of the list.
for(int i = size; i >= 0; i--){
linearLayout.add(new TextView(Context));
}

View positions inside ViewGroups are defined by the LayoutParams
How does this happen? Views pass their LayoutParams to their parent ViewGroups
//100% programatic approach with simple LayoutParams
LinearLayout myLinearLayout = new LinearLayout(this);
//if the **parent** of the new linear layout is a FrameLayout
FrameLayout.LayoutParams layoutParams =
new FrameLayout.LayoutParams(
FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT);
//or if you have the XML file you don't have to worry about this
//myLinearLayout = (LinearLayout)findViewById(R.id.my_simple_linear_layout);
//you could have a LinkedList<TextView>
LinkedList<TextView> textViewList = new LinkedList<>();
//assuming the order is the correct order to be displayed
Iterator<TextView> descendingIterator = textViewList.descendingIterator();
while(descendingIterator.hasNext())
{
//just add each TextView programatically to the ViewGroup
TextView tView = descendingIterator.next();
myLinearLayout.addView(tView);
}
Just like we defined LayoutParams for the LinearLayout we could also define LayoutParams for the TextView
IMPORTANT: when setting LayoutParams you need to be sure they fit the VIEWGROUP, that is the parent of the View being added
private TextView textViewFactory(String myText) {
TextView tView = new TextView(getBaseContext());
//controling the position relatively to the PARENT
//because you are adding the textview to a LINEAR LAYOUT
LinearLayout.LayoutParams paramsExample =
new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT, 1.0f);
tView.setLayoutParams(paramsExample);
//configuring the insides of the textview
//you can also do all kinds of stuff programatically
tView.setGravity(Gravity.CENTER_HORIZONTAL);
tView.setPadding(10, 10, 10, 10);
tView.setTypeface(Typeface.DEFAULT_BOLD);// (null, Typeface.BOLD_ITALIC);
tView.setTypeface(Typeface.SANS_SERIF);
tView.setTypeface(null, Typeface.ITALIC);
tView.setTypeface(Typeface.defaultFromStyle(R.style.AppTheme));
tView.setId(R.id.aux_info);
tView.setText(myText);
//.........all kinds of stuff really
return tView;
}

If you mean adding a view programmatically so that the new one is added above the previous one, instead of below it, then I suggest this:
Maintain an ArrayList with the items you want to turn into views
Put them into a ListView
When you want to add a new view that must appear at the top of the list, insert it as the first element of your ArrayList and recreate the ListView from it.

Confusion with findViewById()

I am trying to programmatically add LinearLayouts inside an existing RelativeLayout. Each LinearLayout will contain some buttons and I want to be able to toggle the visibility of each set of buttons by setting the visibility of the container LinearLayout.
// We iterate over a list and call the following to create the new
// layout assigning an index from a int counter
LinearLayout LL = new LinearLayout(MainActivity.this);
LL.setOrientation(LinearLayout.VERTICAL);
LL.setId(nextId);
LinearLayout.LayoutParams LLParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
LL.setWeightSum(6f);
LL.setLayoutParams(LLParams);
LinearLayout mll=((LinearLayout) findViewById(R.id.menuLayout));
mll.addView(LL);
My problem comes when I try to retrieve these layouts later, for instance to be able to toggle their visibility on/off. I thought I would be able to use
LinearLayout ll = (LinearLayout) findViewById(layoutIndex);
But findViewById() gives me an error when I try to supply an int, it wants a resource ID. Is there an easy way I can convert the ints that I have assigned as the Ids for these layouts to R.id.XXX ids?
Thanks,
Andy

findViewById(id) looks up elements that were included as part of the XML defining a layout.
You will probably have better luck with getChildAt(index), which returns the View at the passed index.

Yes! Find all LinearLayout in a container without using ID.
LinearLayout mll= (LinearLayout) findViewById(R.id.menuLayout);//container
for(int i=0; i<mll.getChildCount(); ++i) {
View nextChild = mll.getChildAt(i);
if (nextChild instanceof LinearLayout ) {
//TODO add your code here nextChild is a LL that you wanna find
}
}

Placing Multiple Buttons to a Relative Layout without a Grid in Android

I want to add multiple buttons to a layout programmatically.
However, count of buttons is different every time and I just want them to placed next to each other with a wrap content width. After a line is filled, it should go to next line and continue that way.
What is the cleanest way to achieve that?
Thanks.

LinearLayout verticalLayout = new LinearLayout(context);
verticalLayout.setOrientation(LinearLayout.VERTICAL);
while(isActive) {
LinearLayout horziontalLayout = new LinearLayout(context);
horziontalLayout.setOrientation(LinearLayout.HORIZONTAL);
add buttons here..
//Example Button button = new Button(context);
//horziontalLayout.addView(button);
verticalLayout.addView(horziontalLayout);
isActive = false // when youe done filling up buttons..
}

easiest way should be having a vertical LinearLayout in wich you add multiple horizontal LinearLayout
//vertical one
LinearLayout vlinear = new LinearLayout(this);
vlinear.setOrientation(LinearLayout.VERTICAL);
LayoutParams vlinearParams = new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);
vlinear.setLayoutParams(vlinearParams);
parentgroup.addView(vlinear);
//horizontal lines
for (int i=0;i<numlines){
LinearLayout hlinear = new LinearLayout(this);
hlinear.setOrientation(LinearLayout.HORIZONTAL);
LayoutParams vlinearParams = new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);
hlinear.setLayoutParams(hlinearParams);
vlinear.addView(hlinear);
///add the loop for adding cells
for...
hlinear.addView(cell);
}

Need help for displaying message text with images as a list

I need to start an application that contains a list of text with images. I need to display these text messages in a list with images. I am displaying these messages with images by using linear layouts as shown below.
for(int i=0;i<messages.size();i++)
{
FrameLayout f1= new FrameLayout(this);
LinearLayout l1 = new LinearLayout(this);
LinearLayout l2 = new LinearLayout(this);
im =new ImageView(this);
TextView tv =new TextView(this);
tv.setText(messages.get(i).getmessage());
im.setImageResource(R.drawable.person);
l1.addView(tv);
l2.addView(im);
f1.addView(l1);
f1.addView(l2);
((LinearLayout)findViewById(R.id.LinearlayoutMessage)).addView(f1);
}
After some time I need to refresh only images in the image view. I am trying to do this by setting id's to each image view's but I get only last image view id.
I know there is listview, but is it suitable for my requirement? I don't know how can I do my task. Can anyone please help me?

My suggestion would be to use Adapter for showing image and respective text. It will help you get selected/focused item.
Please share result.

I did something similar.. I just did a list of TextViews (two TextView per row), and i needed to update one TextView in the list.. What i did was a vertical LinearLayout, and add Horizontal LinearLayouts that contained my TextViews.. Then i had a List of strings to look for the index of the one i needed to modify, and then search it with LinearLayout.getChildAt(int) and update the value...
CODE:
I have a list of strings and a counter that says how many times come this string...
private ArrayList<String> strList;
private ArrayList<Integer> counterList;
When the String is new:
strList.add(new_string);
TextView str = new TextView(getApplicationContext());
str.setText(sTemp);
str.setLayoutParams(strsTextView.getLayoutParams());
TextView strcounter = new TextView(getApplicationContext());
strcounter.setLayoutParams(counterTextView.getLayoutParams());
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT,1);
LinearLayout ll = new LinearLayout(this);
ll.setLayoutParams(new LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT));
ll.setOrientation(LinearLayout.HORIZONTAL);
ll.addView(str, layoutParams);
layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT,3);
counterList.add(1);
strcounter.setText("1");
ll.addView(strcounter, layoutParams);
mLinearLayout.addView(ll,new LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT));
I check if the String is not new (is already in the strList)if(strList.indexOf(sTemp)!=0) and then do as follows:
Integer intaux =counterList.get(index);
intaux++;
counterList.set(index, intaux);
LinearLayout aux = (LinearLayout)mLinearLayout.getChildAt(index);
TextView aux2 = (TextView)aux.getChildAt(1);
aux2.setText(Integer.toString(intaux));
I hope i didn't miss anything and that this works for you.. If you don't understand anything tell me an i try to explain/correct it.
PS: I suppose that the Adapter solution of #abhijeet is a more elegant version of my implementation, but i haven't done it.

How to align a dynamically create UserInterface using RelativeLayout in Android

I want to create a relative Layout dynamically through code with 2 Textviews one below the other.How to implement android:layout_below property through code in Android.
can anyone help me in sorting out this issue.
Thanks in Advance,

final TextView upperTxt = (...)
upperTxt.setId(12345);
final TextView lowerTxt = (...);
final RelativeLayout.LayoutParams params = RelativeLayout.LayoutParams(this, null);
params.addRule(RelativeLayout.BELOW, 12345);
lowerTxt.setLayoutParams(params);

Here is my solution for my special Problem.
In case the username wouldn't be found in the db i had to create a RelativeLayout that looks like the xml-generated one.
// text view appears on top of the edit text
enterNameRequest = new TextView(mainActivity.getApplicationContext());
// fill the view with a string from strings.xml
enterNameRequest.setText(mainActivity.getResources().getString(R.string.enterNameRequest));
// edit text appears below text view and above button
enterName = new EditText(mainActivity.getApplicationContext());
enterName.setId(667);
// button appears at the bottom of the relative layout
saveUserName = new Button(mainActivity.getApplicationContext());
saveUserName.setText(mainActivity.getResources().getString(R.string.useUserName));
saveUserName.setId(666);
// generate the relative layout
RelativeLayout layout = new RelativeLayout(mainActivity.getApplicationContext());
layout.setId(668);
// set a background graphic by its id
layout.setBackgroundDrawable(mainActivity.getApplicationContext().getResources().getDrawable(R.drawable.background_head_neutral));
// runtime told me that i MUST use width and height parameters!
LayoutParams params2 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params2.addRule(RelativeLayout.ABOVE, 666);
enterName.setLayoutParams(params2);
LayoutParams params3 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params3.addRule(RelativeLayout.ABOVE, 667);
enterNameRequest.setLayoutParams(params3);
LayoutParams params4 = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
params4.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 668);
saveUserName.setLayoutParams(params4);
// add views
layout.addView(enterNameRequest);
layout.addView(enterName);
layout.addView(saveUserName);
/* todo: set button action */
mainActivity.setContentView(layout);
What i found out additionally:
It is not so good to manipulate the layout manually from within java!
You should better use a new Activity and set a new layout in it.
This way, the application-code is readable a lot better!
I even tried to set several layouts (not manually, but wit setContentView) in one activity, and it turned out that i didn't know where what was accessing what else... Also, i had a great problem in adding onClickListeners... so you better use -- android:onClick="myButtonMethod" -- in your button tag in the xml and have a method in your according activity, which uses the layout, like this:
public void myButtonMethod(View v){
// do stuff
}
This improves performance because you are not using additional Listeners - but you use the already available Listener that is bound to your activity in every case.

u can try this
LinearLayout.LayoutParams leftMarginParams = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);``
leftMarginParams.leftMargin = 50;
Button btn1 = new Button(this);
btn1.setText("Button1");
linLayout.addView(btn1, leftMarginParams)