Question

Android design pattern guide says widget’s content and layout can be dynamically adjusted to the size the user defined through resize operation here: Design guide for widgets

Example provided in the design guide:

But I do not see anything in the docs as to how to accomplish this. How do we change the layout as per resize operation? Any ideas regarding the approach will be appreciated.

Answer 1

Thanks to A–C , this is possible for Jellybean and above devices and is simple to implement.
Below is the sample code using onAppWidgetOptionsChanged method

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public void onAppWidgetOptionsChanged(Context context,
        AppWidgetManager appWidgetManager, int appWidgetId, Bundle newOptions) {

    Log.d(DEBUG_TAG, "Changed dimensions");

    // See the dimensions and
    Bundle options = appWidgetManager.getAppWidgetOptions(appWidgetId);

    // Get min width and height.
    int minWidth = options.getInt(AppWidgetManager.OPTION_APPWIDGET_MIN_WIDTH);
    int minHeight = options
            .getInt(AppWidgetManager.OPTION_APPWIDGET_MIN_HEIGHT);

            // Obtain appropriate widget and update it.
    appWidgetManager.updateAppWidget(appWidgetId,
            getRemoteViews(context, minWidth, minHeight));

    super.onAppWidgetOptionsChanged(context, appWidgetManager, appWidgetId,
            newOptions);
}

/**
 * Determine appropriate view based on width provided.
 * 
 * @param minWidth
 * @param minHeight
 * @return
 */
private RemoteViews getRemoteViews(Context context, int minWidth,
        int minHeight) {
    // First find out rows and columns based on width provided.
    int rows = getCellsForSize(minHeight);
    int columns = getCellsForSize(minWidth);

    if (columns == 4) {
        // Get 4 column widget remote view and return
    } else {
                    // Get appropriate remote view.
        return new RemoteViews(context.getPackageName(),
                R.layout.quick_add_widget_3_1);
    }
}

/**
 * Returns number of cells needed for given size of the widget.
 * 
 * @param size Widget size in dp.
 * @return Size in number of cells.
 */
 private static int getCellsForSize(int size) {
  int n = 2;
  while (70 * n - 30 < size) {
    ++n;
  }
  return n - 1;
 }