Develop Reference

Android : put listfragment inside xml layout

ListFragment by defaults shows a progressbar while the data get loaded. I plan on putting the listfragment in xml file and have it show progressbar till I get the data from the server.
The reason I m trying to put listfragment inside xml is because in my layout I have a linearlayout above the place where I plan to put listfragment.
Here is my xml file.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<LinearLayout
android:id="#+id/filterHolder"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:background="#color/white"
>
<ToggleButton
android:id="#+id/filterToggleButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#color/white"
android:textColor="#color/black"
android:textOff="#string/filterToggleButtonText"
android:textOn="#string/filterToggleButtonText"
android:drawableLeft="#drawable/filter_small"
/>
</LinearLayout>
<fragment
andorid:name="in.coupondunia.androidapp.testListFragment"
android:id="#+id/couponsByCategoryFragment"
android:layout_below="#id/filterHolder"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</RelativeLayout>

Have you tried using http://developer.android.com/reference/android/app/ListFragment.html#setListShown(boolean) with parameter true? From the docs it might work.

Custom elements and package name

When creating a custom element with attributes in Android I need to put the namespace of the application in the layout.
For example:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:whatever="http://schemas.android.com/apk/res/org.example.mypackage"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<org.example.mypackage.MyCustomView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
whatever:my_custom_attribute="Hello, world!" />
</LinearLayout>
Does this also requires that the structure of my project in Eclipse be the same as the name of the Android package as definied in the Manifest - as per the example?
Would this work too:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:whatever="http://schemas.android.com/apk/res/org.mycompany.myproduct"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<org.example.mypackage.MyCustomView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
whatever:my_custom_attribute="Hello, world!" />
</LinearLayout>

Its the package name of your application that should be reflected. So its correct to use it as you are doing.
For example:
In xmlns:whatever="http://schemas.android.com/apk/res/org.mycompany.myproduct the last part org.mycompany.myproduct should be the same as your package name. And you may change xmlns:whatever to anything like xmlns:theblitz but then make sure you do use theblitz as a prefix for your attributes in the xml.
For more info, read this

Accessing Android views on nested layouts

I have trouble accessing Views from a layout that is included in another layout.
Please take a look at this picture:
http://dl.dropbox.com/u/3473245/layout_includes.png
How do I access the 4 text views programmatically?
Its probably something really simple that I'm missing.
Thank you very much!

You can do as follows:
main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<include android:id="#+id/item_base_lang" layout="#layout/dictionary_list_item" />
<include android:id="#+id/item_learn_lang" layout="#layout/dictionary_list_item" />
</LinearLayout>
dictionary_list_item.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/dictionary_list_item_text_header"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<TextView
android:id="#+id/dictionary_list_item_text_content"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
To set the text programmatically:
((TextView)findViewById(R.id.item_base_lang).findViewById(R.id.dictionary_list_item_text_header)).setText("item_base_lang_header");
((TextView)findViewById(R.id.item_base_lang).findViewById(R.id.dictionary_list_item_text_content)).setText("item_base_lang_content");
((TextView)findViewById(R.id.item_learn_lang).findViewById(R.id.dictionary_list_item_text_header)).setText("item_learn_lang_header");
((TextView)findViewById(R.id.item_learn_lang).findViewById(R.id.dictionary_list_item_text_content)).setText("item_learn_lang_content");
This Android wiki page shows how to use reusable UI components with XML layouts, but it doesn't show how to access nested reusable components from code.
Although it is fairly straightforward, it might be not so clear for those who are pretty new to Android Views.

The following two lines should help you get the languageHeader of both includes. You can do the same for languageText
findViewByid(R.id.activityBaseLangView).findViewById(R.id.languageHeader)
findViewByid(R.id.activityLearnLangView).findViewById(R.id.languageHeader)

Title bar in Android

My class extends a ListActivity, I would like to have a title bar just as "Sound settings" in the following image;
What would be the proper way to create such title.
Thank you for your time.

Creating custom layout can solve this problem.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
android:orientation="vertical"
<TextView android:id="#+id/textViewCategoriesTitle"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/categoriesTitle"
android:background="#123"
android:layout_gravity="center_horizontal"
android:textSize="30sp" />
<ListView android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="#+id/listViewCategories"
android:layout_gravity="center_vertical|center_horizontal" />
</LinearLayout>
Hope this can help.

You could add a header view to the list view :
getListView().addHeaderView(myTitleView);
I'm not sure how you can be sure to get the exact same look, though. I would try with just a basic layout containing a TextView and see how that works out.

import xml into another xml

I have lots of control repeated in my xml (a Button for instance). Is there any possibility to write the Button once in a xml and then import it in all the layout I need it?

You can use
<include layout="#layout/commonlayout" android:id="#+id/id" />
commonlayout.xml should be defined in res/layout where you can add the repeated parts.

As Labeeb P rightly said, it works.
Just want to add that you can also override parameters too:
<include
layout="#layout/commonlayout"
android:id="#+id/id"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginLeft="2sp"
android:layout_marginRight="2sp"
/>

In addition to those great answers, you can also avoid code duplication by using the <merge> tag, like so:
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/add"/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/delete"/>
</merge>
The <merge> part gets stripped when you include it into other xml. This might help including more than a single Button at a time. See the official documentation.

You can use the default include XML tag to include an external layout:
<include layout="#layout/somelayout" />
This layout should have an outside ViewGroup that encapsulates the content or a merge tag to avoid having to use an unnecessary layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/hello_world" />
</LinearLayout>
<!-- OR -->
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<TextView android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/hello_world" />
</merge>
Also, if you need a better way to include pieces of layout that acts like a container (a custom ViewGroup), you can use this custom ViewGroup. Note that this does not import an XML into another XML file, it inflates the content from the external layout and replaces into the view. It's similar to ViewStub, a "ViewGroupStub" like.
This lib acts as if the ViewStub could be used as following (note that this example does not work! ViewStub isn't a ViewGroup subclass!):
<ViewStub layout="#layout/somecontainerlayout"
inflate_inside="#+id/somecontainerid">
<TextView android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="#string/hello_world" />
</ViewStub>