Loading a TextView from xml into a TextSwitcher

Question

I've been trying to setup a TextSwitcher with the TextView loading in from an xml file. I have this basic TextSwitcher example that uses an empty TextView working ok:

.java

public class TextSwitcherTest extends Activity 
{
    private TextSwitcher textSwitcher;

    private ViewFactory viewFactory = new ViewFactory() 
    {
        public View makeView() 
        {
            TextView textView = new TextView(TextSwitcherTest.this);

            return textView;
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        textSwitcher = (TextSwitcher) findViewById(R.id.textSwitcher);

        textSwitcher.setFactory(viewFactory);

        Animation in = AnimationUtils.loadAnimation(this,android.R.anim.fade_in);
        Animation out = AnimationUtils.loadAnimation(this,android.R.anim.fade_out);

        textSwitcher.setInAnimation(in);
        textSwitcher.setOutAnimation(out);

        textSwitcher.setText("test ok");
    }    
}

-

main.xml

<?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" >

    <TextSwitcher 
        android:id="@+id/textSwitcher"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

---

But when I change the code to try and load a TextView from an xml file, it spits out a pile of errors. Here's the amended code:

.java

public class TextSwitcherTest extends Activity 
{
    private TextSwitcher textSwitcher;

    private ViewFactory viewFactory = new ViewFactory() 
    {
        public View makeView() 
        {
            LayoutInflater inflater = LayoutInflater.from(TextSwitcherTest.this);

            TextView textView = (TextView) inflater.inflate(R.id.textView,null);

            return textView;
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        textSwitcher = (TextSwitcher) findViewById(R.id.textSwitcher);

        textSwitcher.setFactory(viewFactory);

        Animation in = AnimationUtils.loadAnimation(this,android.R.anim.fade_in);
        Animation out = AnimationUtils.loadAnimation(this,android.R.anim.fade_out);

        textSwitcher.setInAnimation(in);
        textSwitcher.setOutAnimation(out);

        textSwitcher.setText("test ok");
    }    
}

-

textview.xml

<?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/textView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

</LinearLayout>

Can anyone offer a suggestion where I'm going wrong? The code compiles ok but I'm sure it's with the LayoutInflater being misused in some way?

---

error messages (it didn't display the '11 more'):

07-22 03:51:24.096: W/dalvikvm(580): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
07-22 03:51:24.137: E/AndroidRuntime(580): FATAL EXCEPTION: main
07-22 03:51:24.137: E/AndroidRuntime(580): java.lang.RuntimeException: Unable to start activity ComponentInfo{test09.TextSwitcher01/test09.TextSwitcher01.TextSwitcherTest}: android.content.res.Resources$NotFoundException: Resource ID #0x7f050001 type #0x12 is not valid
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.os.Looper.loop(Looper.java:137)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread.main(ActivityThread.java:4424)
07-22 03:51:24.137: E/AndroidRuntime(580):  at java.lang.reflect.Method.invokeNative(Native Method)
07-22 03:51:24.137: E/AndroidRuntime(580):  at java.lang.reflect.Method.invoke(Method.java:511)
07-22 03:51:24.137: E/AndroidRuntime(580):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-22 03:51:24.137: E/AndroidRuntime(580):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-22 03:51:24.137: E/AndroidRuntime(580):  at dalvik.system.NativeStart.main(Native Method)
07-22 03:51:24.137: E/AndroidRuntime(580): Caused by: android.content.res.Resources$NotFoundException: Resource ID #0x7f050001 type #0x12 is not valid
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.content.res.Resources.loadXmlResourceParser(Resources.java:2110)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.content.res.Resources.getLayout(Resources.java:857)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
07-22 03:51:24.137: E/AndroidRuntime(580):  at test09.TextSwitcher01.TextSwitcherTest$1.makeView(TextSwitcherTest.java:23)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.widget.ViewSwitcher.obtainView(ViewSwitcher.java:80)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.widget.ViewSwitcher.setFactory(ViewSwitcher.java:99)
07-22 03:51:24.137: E/AndroidRuntime(580):  at test09.TextSwitcher01.TextSwitcherTest.onCreate(TextSwitcherTest.java:38)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.Activity.performCreate(Activity.java:4465)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
07-22 03:51:24.137: E/AndroidRuntime(580):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
07-22 03:51:24.137: E/AndroidRuntime(580):  ... 11 more

Answer 1

There are several things wrong with your code:

First, the LayoutInflater.inflate() method expects the id of a layout file in the form of R.layout.layout_name and not in the form of R.id.some_id:

TextView textView = (TextView) inflater.inflate(R.layout.textView, null);

Second, the code you use will throw a ClassCastException because the root of the inflated layout is a LinearLayout and not a TextView as you try to cast it. Your code should be:

LinearLayout ll = (Linearlayout) inflater.inflate(R.layout.textView, null);

But even the line above will not work because, as its name suggest, a TextSwitcher will take only children of type TextView, nothing can come between the TextSwitcher and the two TextView children. The correct code to use will be in the end:

Layout for textview.xml:

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/textView"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello" />

And the viewFactory field will be:

private ViewFactory viewFactory = new ViewFactory() {
        public View makeView()  {
            LayoutInflater inflater = LayoutInflater.from(TextSwitcherTest.this);
            TextView textView = (TextView) inflater.inflate(R.layout.textView, null);
            return textView;
        }
};

Answer 2

Pretty simple using mostly XML.

In your XML add a TextSwitcher root view and two TextViews within it:

<TextSwitcher
    android:id="@+id/textswitcher_id"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:inAnimation="@android:anim/fade_in"
    android:outAnimation="@android:anim/fade_out">

    <TextView
        android:id="@+id/tv_onboarding_next"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Text1" />

    <TextView
        android:id="@+id/tv_onboarding_letsgo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Text2" />

</TextSwitcher>

Then in code, wherever you want the animation action to occur:

Using Kotlin:

textswitcher_id.setText(getString("Text2"))

// and somewhere else, switch it back:

textswitcher_id.setText(getString("Text1"))

Or in Java:

findViewById(R.id.textswitcher_id).setText(getString("Text2"));

// and somewhere else, switch it back:

findViewById(R.id.textswitcher_id).setText(getString("Text1"));

Note:

• Within the XML you can also use two includes rather TextView twice, see: https://stackoverflow.com/a/42724239/1852191

• The reason we have the default text in the XML even though we set it programmatically later is because on the first view it will be blank, until it's set