1 /**
 2      * <p>Adds a child view. If no layout parameters are already set on the child, the
 3      * default parameters for this ViewGroup are set on the child.</p>
 4      * 
 5      * <p><strong>Note:</strong> do not invoke this method from
 6      * {@link #draw(android.graphics.Canvas)}, {@link #onDraw(android.graphics.Canvas)},
 7      * {@link #dispatchDraw(android.graphics.Canvas)} or any related method.</p>
 8      *
 9      * @param child the child view to add
10      *
11      * @see #generateDefaultLayoutParams()
12      */
13     public void addView(View child) {
14         addView(child, -1);
15     }
16 
17 public void addView(View child, int index) {
18         if (child == null) {
19             throw new IllegalArgumentException("Cannot add a null child view to a ViewGroup");
20         }
21         LayoutParams params = child.getLayoutParams();
22         if (params == null) {
23             params = generateDefaultLayoutParams();
24             if (params == null) {
25                 throw new IllegalArgumentException("generateDefaultLayoutParams() cannot return null");
26             }
27         }
28         addView(child, index, params);
29     }
30 
31 protected LayoutParams generateDefaultLayoutParams() {
32         return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
33     }