Android - How to convert DP to PX - density independent to absolute pixels

Question

I have a situation wherein I need to add layouts at runtime as follows:

1. A Button layout is already defined in XML:

2. When the user clicks the Button, an EditText and another Button are dynamically added to the existing layout:

It works correctly on Gingerbread (Android 2.3.5):

And doesn't work on Kitkat (Android 4.4.2):

Does someone know a workaround for this problem ? Here's the code I've used:

public class MainActivity extends Activity {

private boolean comment = true;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);     

    Button button = (Button)findViewById(R.id.commentbutton);
    button.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View v){
            if(comment == true){
                comment = false;
                LinearLayout l = (LinearLayout)findViewById(R.id.comment_layout);
                l.setOrientation(LinearLayout.VERTICAL);

                final EditText e = new EditText(v.getContext());
                e.setId(R.id.commentbox);
                LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(250,100);
                lp.setMargins(0, 20, 0, 0);
                e.setLayoutParams(lp);
                e.setSingleLine(true);
                e.setImeOptions(EditorInfo.IME_ACTION_DONE);
                l.addView(e);

                final Button b = new Button(v.getContext());
                b.setId(R.id.submitbutton);
                lp = new LinearLayout.LayoutParams(150,33);
                lp.setMargins(0, 20, 0, 0);
                b.setLayoutParams(lp);
                b.setText("Submit");
                b.setTextColor(Color.BLACK);
                b.setTypeface(null, Typeface.BOLD);
                b.setBackgroundColor(Color.parseColor("#CCCCCC"));
                b.setFocusable(true);
                b.setFocusableInTouchMode(true);
                l.addView(b);

                e.setOnEditorActionListener(new OnEditorActionListener() {
                    public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                        if (actionId == EditorInfo.IME_ACTION_DONE) {
                            b.performClick();
                            return true;
                        }
                        return false;
                    }
                });

                LinearLayout ll = new LinearLayout(v.getContext());
                ll.setId(R.id.productbottomlayout);
                lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,25);
                ll.setLayoutParams(lp);
                ll.setFocusable(true);
                ll.setFocusableInTouchMode(true);
                l.addView(ll);
                ll.requestFocus();

                b.setOnClickListener(new OnClickListener(){
                    @Override
                    public void onClick(View v){
                        LinearLayout l = (LinearLayout) findViewById(R.id.comment_layout);
                        EditText e = (EditText) findViewById(R.id.commentbox);
                        l.removeView(e);
                        Button b = (Button) findViewById(R.id.submitbutton);
                        l.removeView(b);
                        LinearLayout ll = (LinearLayout) findViewById(R.id.productbottomlayout);
                        l.removeView(ll);
                        MainActivity.this.comment = true;
                    }
                });
            }
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

}

Here's the XML Layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<LinearLayout 
            android:id="@+id/comment_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:layout_marginBottom="25dp"
            android:layout_gravity="center"
            android:gravity="center">

            <Button 
                android:id="@+id/commentbutton"
                android:layout_width="150dp"
                android:layout_height="30dp"
                android:text="Add Comment"
                android:textColor="#000000"
                android:textStyle="bold"
                android:background="#CCCCCC"
                android:onClick="showCommentBox"/>

        </LinearLayout>

</RelativeLayout>

Also, when we add layouts programmatically like this, we need to set an ID manually for each layout element.

I've done that. Here they are:

<resources>
    <item  type = "id" name = "commentbox"></item>
    <item  type = "id" name = "submitbutton"></item>
    <item type="id" name="productbottomlayout"></item>
</resources>

Answer 1

// Try this way,hope this will help you to solve your problem...

Define this method in your class
public int convertSizeToDeviceDependent(int value) {
     DisplayMetrics dm = new DisplayMetrics();
     getWindowManager().getDefaultDisplay().getMetrics(dm);
     return ((dm.densityDpi * value) / 160);
}

Try to replace this line:
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(250,100);

With this:
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(convertSizeToDeviceDependent(250),convertSizeToDeviceDependent(100));

Try to replace this line:
lp = new LinearLayout.LayoutParams(150,33);

With this:
lp = new LinearLayout.LayoutParams(convertSizeToDeviceDependent(150),convertSizeToDeviceDependent(33));

Try to replace this line:
lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,25);

With this:
lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,convertSizeToDeviceDependent(25));

Answer 2

Add this method and use it to convert all pixels to dpi:

    public static int dpi(int i) {
            Resources r = getResources();
     int value = (int) TypedValue.applyDimension(
            TypedValue.COMPLEX_UNIT_DIP, i,
            r.getDisplayMetrics());
    return value;
}

source: https://stackoverflow.com/a/6327095/1977021

Answer 3

The problem is that you are setting the dimension in a pixel measurement unit. Use DP, or LayoutParams.WRAP_CONTENT to make your app scalable and responsive.

So, that's how I'll set my layoutParams:

lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);