I'm having a problem while implementing a "mark as favorite" function in my listview. I have an ImageButton placed on the right side of every listview item and "on click" I want to change the image of the button. It should look like this:
That's pretty easy to implement and works perfectly fine. The problem now is when I scroll the list, the selected image buttons (stars) won't stay the same.
To keep the selection of a listview item isn't that hard, but to keep the changed image in the list is an issue for me. The former can be implemented in this way: https://stackoverflow.com/a/9281155/2054118
So I tried something similar. In the getView() method I init my imagebutton and its OnClickListener to save the actual position in a LinkedList. All positions of the selected ImageButtons should be in the list:
MyAdapter.java:
private LinkedList<Integer> selectedIndeces;
...
private static class ViewHolder {
...
public ImageButton favoriteButton;
}
public void changeSelectedPositions(int pos) {
int index = this.selectedIndeces.indexOf(pos);
if (index != -1) {
// image button in this row was selected
this.selectedIndeces.remove(index);
} else {
// mark position of the image button as selected
this.selectedIndeces.add(pos);
}
notifyDataSetChanged();
}
...
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View rowView = convertView;
// reuse views
if (rowView == null) {
rowView = this.mInflater.inflate(R.layout.talk_list_child, null);
// configure view holder
ViewHolder viewHolder = new ViewHolder();
...
ImageButton ib = (ImageButton) rowView.findViewById(R.id.ib_favorite);
ib.setFocusable(false);
ib.setFocusableInTouchMode(false);
ib.setOnClickListener(new OnClickListener() {
public void onClick(View button) {
// Set the button's appearance
button.setSelected(!button.isSelected());
changeSelectedPositions(position);
}
});
viewHolder.favoriteButton = ib;
}
// fill data
ViewHolder holder = (ViewHolder) rowView.getTag();
...
if (selectedIndeces.contains(position)) {
holder.favoriteButton.setImageResource(R.drawable.fav_selected);
} else {
holder.favoriteButton.setImageResource(R.drawable.fav_unselected);
}
}
But the problem is that the position I get in getView() isn't always the same and depends on where the list is scrolled to?
So to shorten my question: How can I keep the selection/image of my ImageButtons in the ListView even when I scroll?
You saved your position while preparing viewHolder
. Then after scrolling, view is recycled and the same viewHolder
with previously stored position is used. You can just set listener every time you get getView()
call.
Move
ib.setOnClickListener(new OnClickListener() {
public void onClick(View button) {
// Set the button's appearance
button.setSelected(!button.isSelected());
changeSelectedPositions(position);
}
});
Just before
if (selectedIndeces.contains(position)) {
Keep an array list to save the position which is clicked in your adapter
iconClickedPostion = new ArrayList();
Whenever you handle your click for the image button in the list, add the position of the listview in the arraylist.
iconClickedPostion.add(position);
In getView(), check the condition if it is already clicked then set the desired image.
if(iconClickedPostion.contains(position)){ completedIcon.setImageResource(R.drawable.ic_done); } else { completedIcon.setImageResource(iconId[position]); }
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