I followed this tutorial (http://www.vogella.com/tutorials/AndroidListView/article.html#expandablelistview)
for an expandable list view, in which I enter different shop names, categorized by the part of town they are located:
But there is obviously no need to have the same group several times (which is the case for Neukölln for example).
Here is what I tried to do:
SparseArray<Groups> groups = new SparseArray<Groups>();
DatabaseHandler db = new DatabaseHandler(this) ;
List<Shop> shops = db.getAllShops();
Groups group = null ;
String str = "null" ;
int i = 0 ;
for (Shop shop : shops){
// if current shop's district differs from district of the shop of the last iteration
if ( shop.getDistrict() != str ) {
// making sure that empty group is not appended into groups in the first iteration
if (group != null) {
groups.append(i, group);
i++;
}
// saving the district of the current shop
str = shop.getDistrict();
// creating a new group named after the current district
group = new Groups(str);
}
// adding shop name to the current district
group.subitems.add(shop.getName()) ;
}
// after last iteration the last group needs to be appended to the groups
groups.append(i, group);
I hope you can understand the basic idea of my code. I sure it has to work out, because I went through it on paper and in theory it works. My first idea was that those if-statements are responsible, but I have no clue how to repair this.
