ondraw method is not working

Question

i am working on application in which my ondraw method is not working properly ...... in my applicationi am using framelayout ... so i am used three class... 1)acticvity 2) image choosing 3) drawing

my image selection is working fine but my drawing class is not working fine ..it is not displaying any thing .... my drawing class is as follow ...

public class Draw extends View {
    String info = "";
    float x = 0;    
    float y = 0;    
    int color = Color.GREEN;    
    public Draw(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
    }
    public Draw(Context context, AttributeSet attrs) {
          super(context, attrs);

    }

    @Override protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        Paint paint = new Paint();
        paint.setStyle(Paint.Style.FILL_AND_STROKE);
        paint.setColor(color);
        paint.setStrokeWidth(15);
        paint.setTextSize(30);

        canvas.drawLine(x-10, y, x+10, y, paint);
        canvas.drawLine(x, y-10, x, y+10, paint);
        canvas.drawText(info, x, y, paint);

    }

    public void updateInfo(String t_info, float t_x, float t_y){
        info = t_info;
        x = t_x;
        y = t_y;

        invalidate();
    }

    public void clearInfo(){
        info = "";
        x = 0;
        y = 0;
        invalidate();
    }
}

I am calling this from my mainactivity class.but i first call it from image selecting class as follow

public class FirstImage extends ImageView implements OnTouchListener {


    MotionEvent event;
    int a;
    Bitmap image;
    String huma ="human";
    String info = "human";
     float x = 0; //init value 
     float y = 0; //init value
     Animation animationFadeIn;


    public FirstImage(Context context) { 
        super(context); 




    } 
    public FirstImage(Context context, AttributeSet attrs) { 
        super(context, attrs);
        } 


    public void changeImage(int id){

                    this.setImageResource(id);
                a=id;
                    final Animation animationFadeout=AnimationUtils.loadAnimation(getContext(), R.anim.zoomin);
                    this.startAnimation(animationFadeout);
                    this.setOnTouchListener(this);

    }
    @Override
    public boolean onTouch(View arg0, MotionEvent me) {

        switch(me.getAction()){
        case MotionEvent.ACTION_DOWN:
            x=me.getX();
            y= me.getY();
            pageinfo(x,y);
            break;
        case MotionEvent.ACTION_MOVE:
            x=me.getX();
            y= me.getY();
            pageinfo(x,y);
            break;
        case MotionEvent.ACTION_UP:
            x=me.getX();
            y= me.getY();
            pageinfo(x,y);
            break;
        case MotionEvent.ACTION_OUTSIDE:
            x=me.getX();
            y= me.getY();
            pageinfo(x,y);
            break;
        default: return true;
        }
        return false;
    }
    public void pageinfo(float x, float y) {
        // TODO Auto-generated method stub
        ((AshActivity)getContext()).updateMsg(info, x,y);
    }
    } 

it is called from the main activitry class

 public class AshActivity extends Activity  {
ImageView i;
    Draw j;
    TextView t,k;
    ImageButton back;
    ImageButton next;
    OnClickListener l2 = null;
       OnClickListener l = null;
    int count=0;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         i = (FirstImage)findViewById(R.id.image);


         j=(Draw)findViewById(R.id.info);
         t=(TextView)findViewById(R.id.textView);
         k=(TextView)findViewById(R.id.textView1);
         back=(ImageButton)findViewById(R.id.button1);
         next=(ImageButton)findViewById(R.id.button2);
         if (count==0){
             ((FirstImage) i).changeImage(R.drawable.human);

         }
         //addListenerOnButton();
    }


    public void updateMsg(String info, float x, float y) {
        // TODO Auto-generated method stub
        j.updateInfo(info, x, y);
    }



}

my layout xml file is as folow

<?xml version="1.0" encoding="utf-8"?>

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:name="http://schemas.android.com/apk/res/com.example.nam" 
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >


  <!--  Screen Design for VIDEOS -->
<TableLayout 
    android:id="@+id/tablelayout"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:stretchColumns="1">

     <TableRow
          android:id="@+id/tableRow1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" >

          <TextView
               android:id="@+id/textView"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:padding="15dip"
              android:text="pic on click which will tell where is the dna located in human body or cell "
              android:textSize="18dip" />
      </TableRow>


      <TableRow
          android:id="@+id/tableRow2"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" >
    <FrameLayout
        android:layout_width="wrap_content"
          android:layout_height="wrap_content" >
         <com.example.nam.FirstImage
             android:id="@+id/image"
             android:layout_height="wrap_content" 
             android:layout_width="fill_parent" />
          <com.example.nam.Draw
             android:id="@+id/info"
             android:layout_height="wrap_content" 
             android:layout_width="fill_parent" />

      </FrameLayout>   
      </TableRow>

      <TableRow
          android:id="@+id/tableRow3"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" >

          <LinearLayout
              android:id="@+id/linearLayout1"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content" >

              <ImageButton
                  android:id="@+id/button1"
                  android:layout_width="100dp"
                  android:layout_height="wrap_content"
                  android:src="@drawable/monotone_arrow_next_left"/>
              <ImageButton
                  android:id="@+id/button2"
                  android:layout_width="100dp"
                  android:layout_height="wrap_content"
                 android:src="@drawable/monotone_arrow_next_lrightcopy"/>

          </LinearLayout>

      </TableRow>
       <TableRow
          android:id="@+id/tableRow4"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" >
          <TextView
              android:id="@+id/textView1"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:padding="15dip"
              android:text="please don't mind  "
              android:textSize="18dip" />
          </TableRow>

  </TableLayout>
  </ScrollView>

what is the problem i am not getting that ....

Answer 1

The problem is that your Draw instance's layout_height is 0.

This is due to the LayoutParams you've registered to it (wrap_content); If you change the FrameLayout's attributes, the desired text will be displayed:

<FrameLayout android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <ro.rekaszeru.sample.FirstImage android:id="@+id/image"
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" />
    <ro.rekaszeru.sample.Draw android:id="@+id/info"
        android:layout_width="fill_parent" 
        android:layout_height="fill_parent" />
</FrameLayout>

Please also note, that the text size of 30 is very large...