Writing custom LinearLayout for android.

Question

I have a custom layout that draws a transparent rounded rectangle beneath its children. The problem is when I try to add it to my xml file, it doesn't show up. Also, when I try to add parameters to it (i.e. android:layout_width) the popup shows that none of them are available. The same thing happens to any child views I add. Can anyone help?

public class RoundRectLayout extends LinearLayout 
{ 
 private RectF shape;
 public RoundRectLayout(Context context)
 {
  super(context);
  LayoutInflater layoutInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  layoutInflater.inflate(R.layout.settings, this);
  shape = new RectF();
 }

 public RoundRectLayout(Context context, AttributeSet attrs)
 {
  super(context, attrs);
  LayoutInflater layoutInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
  layoutInflater.inflate(R.layout.settings, this);
  shape = new RectF();
 }

 @Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh)
 {
  shape = new RectF(0, 0, w - 5, h - 5);
  super.onSizeChanged(w, h, oldw, oldh);
 }

 @Override
 protected void dispatchDraw(Canvas canvas)
 {
  Paint temp = new Paint();
  temp.setAlpha(125);
  canvas.drawRoundRect(shape, 10f, 10f, temp);
  super.dispatchDraw(canvas);
 }
}

Answer 1

If you just want a rounded rectangle background for your LinearLayout, you can define a drawable shape in an xml file in "res/drawable/":

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"&gt; 
    <solid android:color="#50000000"/>    
    <stroke android:width="3dp"
            android:color="#ffffffff"/>
    <padding android:left="5dp"
             android:top="5dp"
             android:right="5dp"
             android:bottom="5dp"/> 
    <corners android:bottomRightRadius="7dp"
             android:bottomLeftRadius="7dp" 
             android:topLeftRadius="7dp"
             android:topRightRadius="7dp"/> 
</shape>

Then you set the layout's background to the name of your drawable xml file. If you named it round_border.xml, set the background to:

<LinearLayout
   android:background="@drawable/round_border"
   ...

The transparency is set in the following...

<solid android:color="#50000000"/>    

First 2 digits denotes transparency, last 6 digits is the colour.

Answer 2

I think it is the plugin which fails but you can specify android:layout_*, it will be took into account. Anyway if you just want to draw a round rect layout, follow Marco's instructions