Question

My problem is communication between custom GameView (extends SurfaceView) and TextView: I want to set TextView’s text from inside of the GameView.
In main activity i’m using this layout file, it should explain structure of my app:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<RelativeLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" 
    android:background="#00ff00"
    >
    <TextView
        android:id="@+id/scoreTV"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="score: 0" 
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="back"
        android:layout_alignParentRight="true" />                   
</RelativeLayout>
<org.gk.grApp.GameView
    android:id="@+id/gameplayScreen"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    />
</LinearLayout>

I can’t change TextView’s text in my GameView object, because it’s impossible to touch UI thread from another.
Handler doesn’t work too, because i can’t give a handler’s reference to GameView’s constructor, that is performed after loading this xml file (a read about default constructor for xml files eg here How can I use GLSurfaceView in a LinearLayout together with other Views, such as TextView or Button?).
Do you have any idea what I should do now? Maybe my deduction is wrong, so please, tell me about this.

EDIT: I changed my xml file, instead of GameView I have now:

<LinearLayout
    android:id="@+id/gameplayScreen"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    >
    </LinearLayout>

Also I added an argument (third) into constructor’s signature:

public GameView(Context context, AttributeSet as, Handler h) { ... } 

and changed my onCreate in GameplayActivity:

protected void onCreate(Bundle savedInstanceState) {        
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gameplay);

    LinearLayout ll = (LinearLayout)findViewById(R.id.gameplayScreen);
    GV = new GameView(this, null, scoreHandler);
    ll.addView(GV);         
}

It works, now I can set TextView’s text but after clicking on the back button another exception is thrown:
“Performing pause of activity that is not resumed: {org.gk.grApp/org.gk.grApp.MainMenuActivity}”. I just started searching information about this.

Answer 1

First make a reference to the TextView on the activity level:

TextView txv;

In onCreate assign this reference:

txv = (TextView) findViewById(R.id.MyTextView);

Then make a method in your Activity after onCreate like this:

public void setTextView(final String txt){
    MyActivity.this.runOnUiThread(new Runnable() {     
        public void run() {         
            txv.setText(txt);     
        } 
     });
}

Then you make a call from your custom view:

((MyActivity) getContext()).setTextView(str);