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How To Use Same LinearLayout In Different Activities

I want to use same LinearLayout in different activities. Selected LinearLayout's id in picture is previewLinear. What I want to do is, use previewLinear in a different activity. I have A and B activities. Firstly I do some changes for previewLinear in activity A (adding border, slice it to pieces etc.) programmatically and I want to copy whole previewLinear to B activity.
pencerebol.xml
What I tried is;
A Activity: (container is static)
...
setContentView(R.layout.pencerebol);
...
container = (LinearLayout) findViewById(R.id.previewLinear);
container.setBackground(getResources().getDrawable(R.drawable.border));
B Activity:
...
setContentView(R.layout.pencerebol);
container = (LinearLayout) findViewById (R.id.previewLinear);
container = A.container; // I know that this line is completely wrong but this is what i want to do.
Thanks in advice.

You can use the <include> property in your XML files, you only create one layout and include it in your other activities/fragments, this is an example of that:
create a xml for your previewLinear layout, name it as:
layout_preview_linear.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/previewLinear"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
</LinearLayout>
and then in your activity A or B, you can include it as the following:
activity_a.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/activity_a_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<include
android:id="#+id/previewLayout"
layout="#layout/layout_preview_linear"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
You also can use that layout in your JAVA code as well, hope this will help you.

If I got it right you want to make LinearLayout from B activity look same as in A activity.
You can create method in A activity
static void createLinearLayout(LinearLayout layout){
layout.setBackground(getResources().getDrawable(R.drawable.border));
...
}
Then call it in B activity
A.createLinearLayout(container);

accessing objects of xml layout android

I have an activity (MainActivity.java) in which content view is like this
this.setContentView(R.layout.standalone_example);
my standalone_example.xml is like this
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<com.abc.view.PageCurlView
android:id="#+id/dcgpagecurlPageCurlView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:background="#drawable/page1" />
</RelativeLayout>
I am done some work in PageCurlView.java now I want to access objects and variables of PageCurlView.java in my MainActivity.java, I am searching for hours but couldnt find any answer, any suggestions thanks in advance.

You can get a reference to the inflated PageCurlView using findViewById() in your activity. In a method in your activity:
PageCurlView mPageCurlView = (PageCurlView) findViewById(R.id.dcgpagecurlPageCurlView1);
You can then call methods or access public variables on mPageCurlView. Please note that setContentView() must be called first in your activity before you can use findViewById().

Does LayoutInflater work with a layout xml file that uses includes?

Here's the rub: I have a layout that uses the include tag. The layout is simple ->
<LinearLayout>
<TextView ...>
<LinearLayout>
<include ...>
</LinearLayout>
</LinearLayout>
Now the included file is nothing more than:
<LinearLayout>
<TextView ... android:id="#+id/inner_text">
</LinearLayout>
Now, if I try to access the TextView inner_text in either the create or onStart call, it throws a NPE. I have tried using LayoutInflater to infate the included xml file and then access inner_text but to no avail - it always fails.
So, the question is : does LayoutInflater work with included xml files of the parent xml file? What I would like to do is grab the contents of the included xml file - and set the whole thing to be either visible or not visible based on preferences.
Nothing seems to allow me to grab the TextView object.
Now, when I include the xml as just a nested element in the parent file (not using the include tag) - then it accesses that LinearLayout just fine - but that defeats my purpose of trying to make the layout of the view dynamic - that is, I can change the contents of the child included layout at will - and not have to do any changes to the parent layout.
Any help, pointers, suggestions -> greatly appreciated.

As suggestion I think you can have in the main xml some Layout component left empty, them in runtime, inflate the main xml, then the included xml and add the content of the included in the space you left in the main.
But I think you example have to work, internally the Android uses the inflater to inflate resources. Can you edit and tell a bit more? Code examples can be helpfully.

well, very strange, when you inflate a view from any xml resource (if xml resources have or have not nested resources with include) the view must hold all the parsed xml. So, yes, LayoutInflater work with included xml files of the parent xml file.
i copied here the way i'm doing now...
my generic layout (a header with text, progress bar and image)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="10dip">
<ImageView
android:id="#+id/genericHeaderLogoPin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:src="#drawable/logo_pin"/>
<TextView
android:id="#+id/genericHeaderTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="#id/genericHeaderLogoPin"
android:textSize="18dip"
android:textStyle="bold"
android:textColor="#FF0C9994"/>
<ProgressBar
android:id="#+id/genericHeaderProgressBar"
android:layout_width="25dip"
android:layout_height="25dip"
android:layout_centerVertical="true"
android:layout_toLeftOf="#id/genericHeaderLogoPin"
style="#android:style/Widget.ProgressBar.Inverse"
android:visibility="gone"/>
</RelativeLayout>
my parent layout... include the generic layout and a ListView
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="#drawable/background_new_search_activity_1">
<include layout="#layout/generic_header_layout" android:id="#+id/listaBusquedasHeader"/>
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:cacheColorHint="#00000000"/>
</LinearLayout>
my onCreate method that inflate the parent layout mentioned above:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
requestWindowFeature(Window.FEATURE_NO_TITLE);
LayoutInflater inflater = LayoutInflater.from(this);
View view = inflater.inflate(R.layout.lista_busquedas_activity, null);
setContentView(view);
listView = (ListView) findViewById(android.R.id.list);
listView.setOnItemClickListener(listItemClickListener);
((TextView)findViewById(R.id.genericHeaderTitle)).setText(R.string.messagesActivityTitle);
}
and that´s all, i hope this helps you.

Thanx for the help - I discovered what my problem was - I was trying to inflate the included file - not the parent container - so that's why it never found the elements. I wish the documentation would have mentioned that - logically I would think the parent xml file would load - but the included files may need inflating - guess not.
Works now thanks to your code examples you submitted.
Thanx.

How to get a view from a resource?

I have a UI, I build it dynamically. I should want to put some component in a xml resource file. So I do :
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+android:id/titreItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</TextView>
... in a file res/layout/titreitem.xml as I see anywhere. But I don't understand how get it to put inside my UI. So, inside activity.onCreate, I want to do something like :
RelativeLayout myBigOne = new RelativeLayout(this);
TextView thingFromXML = [what here ? ];
myBigOne.addView(thingFromXML);
setContentView(myBigOne);

Use a LayoutInflater....The Entire Layout can be inflated, without dynamically creating it....
LayoutInflater li = LayoutInflater.from(context);
View theview = li.inflate(R.layout.whatever, null);

Approach seems to be little incorrect. You should put RelativeLayout to the xml as your TextView made, and inflate the whole xml. Afterwards, you will be free to add views to your layout. So, do this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:id="#+androi:id/relLayout>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+android:id/titreItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</TextView>
</RelativeLayout>
In your activity:
setContentView(R.layout.titreitem);
RelativeLayout layout = (RelativeLayout)findViewByid(R.id.relLayout);
layout.addView(...);

How to specify id when uses include in layout xml file

In my layout xml file, I have included other layout xml file (each
with a different android id).
<include layout="#layout/view_contact_name" android:id="+id/test1"/>
<include layout="#layout/view_contact_name" android:id="+id/test2"/>
But when I run it in the emulator, and start Hierarchy Viewer, each of
the layout still shows 'NO_ID', and in my code, I have
findViewById(R.id.test1) and findViewById(R.id.test2) both returns null.
Can anyone please help me with my problem ?

Specify the ID in the <include>
<include layout="#layout/test" android:id="#+id/test1" />
Then use two findViewById to access fields in the layout
View test1View = findViewById(R.id.test1);
TextView test1TextView = (TextView) test1View.findViewById(R.id.text);
Using that approach, you can access any field in any include you have.

I found out, that if you are using <merge> tag in your include layout, then the ID of include transfers to the merge tag which is not real view.
So either remove merge, or replace it with some layout.
Tor Norbye wrote:
The <include> tag is not a real view, so findByView will not find it. The #id attribute (and any other attributes you've set on the include tag) gets applied on the root tag of the included layout instead. So your activity.getView(R.id.included1) should in fact be the <TextView> itself.

Romain Guy indicates that you can override the ID of an included layout by putting an android:id attribute inside the <include> tag.
<include android:id="#+id/cell1" layout="#layout/workspace_screen" />

I think the top answer misses the most important point and might mislead people into thinking the <include/> tag creates a View that holds the include contents.
The key point is that include's id is passed to the root view of the include's layout file.
Meaning that this:
// activity_main.xml
<include layout="#layout/somelayout" android:id="#+id/someid"/>
// somelayout.xml
<?xml version="1.0" encoding="utf-8"?>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
Becomes this:
// activity_main.xml
<ImageView
android:id="#+id/someid"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

yes is like this, but careful when the layout inserted in include field is a custom one and you want to access that root layout. That layout in this case #layout/test test, is actually returned in first line.
test test1View = (test)findViewById(R.id.test1);

you must set id each include tag
included child element set a
new id. if you look how to generate new id, look at this entry:
https://stackoverflow.com/a/15442898/1136117

Problem is we try to use id which is not declared in current layout file.
Instead of declaring again, id can be simply referred using #+id/. If you refactor original id name through Android Studio it does refactor in included layout as well.
<include layout="#layout/toolbar"/>
<TextView
android:id="#+id/txt_description"
android:layout_width="match_parent"
android:layout_height="wrap_content"
**android:layout_below="#+id/toolbar"**
android:layout_marginTop="16dp"
android:paddingLeft="8dp"
android:paddingRight="8dp"/>

In a case of using <RecyclerView> find the id of <include> by using an instance of inflated view or else it will return null.
public class ViewHolder extends RecyclerView.ViewHolder {
private mTextView;
public ViewHolder(View view) {
super(view);
View include_1 = view.findViewById(R.id.include_1);
mTextView = (TextView) include_1.findViewById(R.id.text_id);
}
}

If you have set id to either root tag of included layout then you can use that id
or you can set id to included layout.
But you can not set id to both it may throw exception.
<include layout="#layout/view_contact_name" android:id="+id/test1"/>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
....
</LinearLayout>
Or
<include layout="#layout/view_contact_name"/>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:id="#+id/llBottomMainView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
....
</LinearLayout>

When talking about include you either have an id on the root view inside the included layout file or on the include line itself and not on both. For example:
<include layout="#layout/layout1" android:id="#+id/layout1"/>
Layout 1 file
<RelativeLayout
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/layout2">
</RelativeLayout>
The above example is wrong because technically you have two id's declared for the same layout. So what you have to do is pick which element will have the id.

To specify the id when you are including a xml file is like setting it to any xml element
Example:
*list_layout.xml*
`<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvNames"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>`
*activity_main.xml*
`<RelativeLayout
tools:context=".MainActivity">
<include
layout="#layout/list_layout"
android:id="#+id/myList" />
</RelativeLayout>`
Now if you want to get that to use in .kt file, just use normally findViewById
Exemplo
*MainActivity.kt*
`val myList: RecycleView = findViewById(R.id.myList)`

Wow, I can't believe this question doesn't have the right answer yet. It's simple tags suck. You can only change things that start with android:layout_ which android:id doesn't match. So the answer is you can't. Sorry. What you can do instead is create a class that will be a ViewGroup which will inflate the included views inside, then add that as a tag in your layout, but that's about it.