Hello Android UI Gurus, I have been struggling for a few days now with an annoying UI issue. I've whittled the project down to nothing but a small demonstration of the problem. I admit I'm pretty new to Android UI work, but at the same time I'm an experienced, qualified engineer and I just can't seem to figure this out. I was hoping to get some feedback from some of you out there who are more familiar with the internals and idiosyncrasies of the platform. Any help would be greatly appreciated!
The desired behavior: I have a list view. Each list view row consists of a text element, and a hidden image. When an item is selected from the list, I'd like to make the image visible, and, start an animation on it. Pretty standard stuff here, we're talking basically about a "loading" spinner. The problem: After selecting 2 or sometimes 3 items in the list, I see spinners become visible and start animating for rows which were never selected. The two things that lead me to believe this is a bug with the platform are: A) Putting in a break point I can clearly see that the underlying data source from the list does not have the "isSpinning" property set for the items that begin animating in a seemingly random manner. and B) The only code that makes the image visible and begins the animation for that row is inside of my custom data adapter. Before it can start the animation it changes the text field in that row as well. The text fields are not changed in the rows where my spinners seem to appear of their own accord. The code: As I said when I started this post I've removed everything from the project except the relevant UI code. Here is what I have. /res/layout main.xml=> <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/ android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello"/> <ListView android:id="@+id/android:list" android:layout_width="fill_parent" android:layout_height="fill_parent" android:cacheColorHint="#0000" android:background="@android:color/transparent" android:dividerHeight="1dip"/> </LinearLayout> list_view_row.xml=> <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/ android" android:layout_width="fill_parent" android:layout_height="?android:attr/listPreferredItemHeight" android:padding="6dip"> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:id="@+id/label" android:textSize="11sp" android:padding="2dip" android:gravity="center_vertical|center" android:layout_gravity="center_vertical|center" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#ffffff"/> <ImageView android:id="@+id/spinner" android:padding="2dip" android:src="@drawable/loading" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </LinearLayout> </LinearLayout> /res/anim rotate.xml=> <?xml version="1.0" encoding="UTF-8"?> <rotate xmlns:android="http://schemas.android.com/apk/res/android"; android:fromDegrees="0" android:toDegrees="360" android:pivotX="50%" android:pivotY="50%" android:repeatCount="infinite" android:interpolator="@android:anim/linear_interpolator" android:duration="1900" /> /res/drawable spinner.png /src MyContainer.java=> public class MyContainer { private String mText = ""; private Boolean mLoading = false; public void setText(String mText) { this.mText = mText; } public String getText() { return mText; } public void setIsLoading(Boolean mLoading) { this.mLoading = mLoading; } public Boolean isLoading() { return mLoading; } } CustomAdapter.java=> public class CustomAdapter extends ArrayAdapter<MyContainer> { private ArrayList<MyContainer> items; private Context c = null; public CustomAdapter(Context context, int textViewResourceId, ArrayList<MyContainer> items) { super(context, textViewResourceId, items); this.items = items; this.c = context; } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if (v == null) { LayoutInflater vi = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.list_view_row, null); } TextView label = (TextView) v.findViewById(R.id.label); ImageView spinner = (ImageView) v.findViewById(R.id.spinner); MyContainer item = (MyContainer) items.get(position); if (item.isLoading()) { label.setText("***"+item.getText()+"***"); spinner = (ImageView)v.findViewById(R.id.spinner); spinner.setVisibility(View.VISIBLE); Animation spinnerAnimation = AnimationUtils.loadAnimation(getContext(), R.anim.rotate); spinner.startAnimation(spinnerAnimation); } else { label.setText(item.getText()); spinner.setVisibility(View.INVISIBLE); } return v; } } Main.java=> public class Main extends ListActivity { private ArrayList<MyContainer> mItems = null; private CustomAdapter mAdapter; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mItems = new ArrayList<MyContainer>(); for (int i=0; i<10; i++) { MyContainer item = new MyContainer(); item.setIsLoading(false); item.setText("item number "+Integer.toString(i)); mItems.add(item); } mAdapter = new CustomAdapter(this, R.layout.list_view_row, mItems); setListAdapter(mAdapter); } /** * Listview on click handler. */ @Override public void onListItemClick(ListView parent, View v, int position, long id){ MyContainer item = (MyContainer)parent.getItemAtPosition(position); for (int i = 0; i<mItems.size(); i++) { MyContainer tmp = mItems.get(i); if (tmp.equals(item)) { tmp.setIsLoading(true); break; } } mAdapter.notifyDataSetChanged(); } } -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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