I have a RecyclerView adapter that looks like this:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
private static Context context;
private List<Message> mDataset;
public RecyclerAdapter(Context context, List<Message> myDataset) {
this.context = context;
this.mDataset = myDataset;
}
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnCreateContextMenuListener, View.OnClickListener {
public TextView title;
public LinearLayout placeholder;
public ViewHolder(View view) {
super(view);
view.setOnCreateContextMenuListener(this);
title = (TextView) view.findViewById(R.id.title);
placeholder = (LinearLayout) view.findViewById(R.id.placeholder);
}
}
#Override
public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.message_layout, parent, false);
ViewHolder vh = new ViewHolder((LinearLayout) view);
return vh;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Message item = mDataset.get(position);
holder.title.setText(item.getTitle());
int numImages = item.getImages().size();
if (numImages > 0) {
View test = LayoutInflater.from(holder.placeholder.getContext()).inflate(R.layout.images, holder.placeholder, false);
ImageView image = (ImageView) test.findViewById(R.id.image);
Glide.with(context)
.load("http://www.website.com/test.png")
.fitCenter()
.into(image);
holder.placeholder.addView(test);
}
}
#Override
public int getItemCount() {
return mDataset.size();
}
}
However, some of the items in the RecyclerView are showing images when they shouldn't be. How can I stop this from happening?
I do the check if (numImages > 0) { in onBindViewHolder(), but that's still not stopping it from showing images for items that shouldn't have images.
You should set imageView.setImageDrawable (null)
In onBindViewHolder() before setting the image using glide.
Setting image drawable to null fix the issue.
Hope it helps!
The problem is in onBindViewHolder, here:
if (numImages > 0) {
View test = LayoutInflater.from(holder.placeholder.getContext()).inflate(R.layout.images, holder.placeholder, false);
ImageView image = (ImageView) test.findViewById(R.id.image);
Glide.with(context)
.load("http://www.website.com/test.png")
.fitCenter()
.into(image);
holder.placeholder.addView(test);
}
If numImages is equal to 0, you're simply allowing the previously started load into the view you're reusing to continue. When it finishes, it will still load the old image into your view. To prevent this, tell Glide to cancel the previous load by calling clear:
if (numImages > 0) {
View test = LayoutInflater.from(holder.placeholder.getContext()).inflate(R.layout.images, holder.placeholder, false);
ImageView image = (ImageView) test.findViewById(R.id.image);
Glide.with(context)
.load("http://www.website.com/test.png")
.fitCenter()
.into(image);
holder.placeholder.addView(test);
} else {
Glide.clear(image);
}
When you call into(), Glide handles canceling the old load for you. If you're not going to call into(), you must call clear() yourself.
Every call to onBindViewHolder must include either a load() call or a clear() call.
I also had issues with RecyclerView showing wrong images. This happens because RecyclerView is not inflating view for every new list item: instead list items are being recycled.
By recycling views we can ruffly understand cloning views. A cloned view might have an image set from the previous interaction.
This is especially fair if your are using Picasso, Glide, or some other lib for async loading. These libs hold reference to an ImageView, and set an image on that refference when image is loaded.
By the time the image gets loaded, the item view might have gotten cloned, and the image is going to be set to the wrong clone.
To make a long story short, I solved this problem by restricting RecyclerView from cloning my item views:
setIsRecyclable(false)in ViewHolder constructor.
Now RecyclerView is working a bit slower, but at least the images are set right.
Or else cansel loading image in onViewRecycled(ViewHolder holde)
The issue here is that, as you are working with views that are going to be recycled, you'll need to handle all the possible scenarios at the time your binding your view.
For example, if you're adding the ImageView to the LinearLayout on position 0 of the data source, then, if position 4 doesn't met the condition, its view will most likely have the ImageView added when binding position 0.
You can add the content of R.layout.images content inside your
R.layout.message_layout layout's R.id.placeholder and showing/hiding the placeholder depending on the case.
So, your onBindViewHolder method would be something like:
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Message item = mDataset.get(position);
holder.title.setText(item.getTitle());
int numImages = item.getImages().size();
if (numImages > 0) {
holder.placeholder.setVisivility(View.VISIBLE);
ImageView image = (ImageView)holder.placeholder.findViewById(R.id.image);
Glide.with(context)
.load("http://www.website.com/test.png")
.fitCenter()
.into(image);
}else{
holder.placeholder.setVisibility(View.INVISIBLE);
}
}
Sometimes when using RecyclerView, a View may be re-used and retain the size from a previous position that will be changed for the current position. To handle those cases, you can create a new [ViewTarget and pass in true for waitForLayout]:
#Override
public void onBindViewHolder(VH holder, int position) {
Glide.with(fragment)
.load(urls.get(position))
.into(new DrawableImageViewTarget(holder.imageView,/*waitForLayout=*/ true));
https://bumptech.github.io/glide/doc/targets.html
I also had the same problem and ended with below solution and it working fine for me..
Have your hands on this solution might be work for you too (Put below code in your adapter class)-
If you are using Kotlin -
override fun getItemId(position: Int): Long {
return position.toLong()
}
override fun getItemViewType(position: Int): Int {
return position
}
If you are using JAVA -
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getItemViewType(int position) {
return position;
}
This works for me in onBindViewHolder!
if(!m.getPicture().isEmpty())
{
holder.setIsRecyclable(false);
Picasso.with(holder.profile_pic.getContext()).load(m.getPicture()).placeholder(R.mipmap.ic_launcher_round).into(holder.profile_pic);
Animation fadeOut = new AlphaAnimation(0, 1);
fadeOut.setInterpolator(new AccelerateInterpolator());
fadeOut.setDuration(1000);
holder.profile_pic.startAnimation(fadeOut);
}
else
{
holder.setIsRecyclable(true);
}
I was having same issue I solved by writing holder.setIsRecyclable(false).Worked for me.
#Override
public void onBindViewHolder(#NonNull RecylerViewHolder holder, int position) {
NewsFeed currentFeed = newsFeeds.get(position);
holder.textView.setText(currentFeed.getNewsTitle());
holder.sectionView.setText(currentFeed.getNewsSection());
if(currentFeed.getImageId() == "NOIMG") {
holder.setIsRecyclable(false);
Log.v("ImageLoad","Image not loaded");
} else {
Picasso.get().load(currentFeed.getImageId()).into(holder.imageView);
Log.v("ImageLoad","Image id "+ currentFeed.getImageId());
}
holder.dateView.setText(getModifiedDate(currentFeed.getDate()));
}
override fun getItemId(position: Int): Long {
return position.toLong()
}
override fun getItemViewType(position: Int): Int {
return position
}
This Works for Me
I Had the same issue and i fixed it like this:
GOAL : onViewAttachedToWindow
#Override
public void onViewAttachedToWindow(Holder holder) {
super.onViewAttachedToWindow(holder);
StructAllItems sfi = mArrayList.get(position);
if (!sfi.getPicHayatParking().isEmpty()) {
holder.viewFliperMelk.addSlider(new TextSliderView(mContext.getApplicationContext()).image(T.GET_MELK_IMAGE + '/' + sfi.getPicHayatParking() + ".jpg").setScaleType(BaseSliderView.ScaleType.CenterCrop));
}
if (!sfi.getPicSleepRoom().isEmpty()) {
holder.viewFliperMelk.addSlider(new TextSliderView(mContext.getApplicationContext()).image(T.GET_MELK_IMAGE + '/' + sfi.getPicSleepRoom() + ".jpg").setScaleType(BaseSliderView.ScaleType.CenterCrop));
}
if (!sfi.getPicSalonPazirayi().isEmpty()) {
holder.viewFliperMelk.addSlider(new TextSliderView(mContext.getApplicationContext()).image(T.GET_MELK_IMAGE + '/' + sfi.getPicSalonPazirayi() + ".jpg").setScaleType(BaseSliderView.ScaleType.CenterCrop));
}
if (!sfi.getPicNamayeStruct().isEmpty()) {
holder.viewFliperMelk.addSlider(new TextSliderView(mContext.getApplicationContext()).image(T.GET_MELK_IMAGE + '/' + sfi.getPicNamayeStruct() + ".jpg").setScaleType(BaseSliderView.ScaleType.CenterCrop));
}
}
I had a similar issue when getting pictures from the photo gallery and putting them in a recyclerview with GridLayoutManager(never had the issue with Glide). So in the adapter onBindViewHolder use a HashMap or SparseIntArray to put the current hashcode(this is the common thing that the recycled views have in common) and adapter position inside it. Then call your background task and then once it's done and before you set the image, check to see if the hashcode key - which will always have the current adapter position as the value - still has the same value (adapter position) as when you first called the background task.
(Global variable)
private SparseIntArray hashMap = new SparseIntArray();
onBindViewHolder(ViewHolder holder, int position){
holder.imageView.setImageResource(R.drawable.grey_square);
hashMap.put(holder.hashCode(), position);
yourBackgroundTask(ViewHolder holder, int position);
}
yourBackGroundTask(ViewHolder holder, int holderPosition){
do some stuff in the background.....
*if you want to stop to image from downloading / or in my case
fetching the image from MediaStore then do -
if(hashMap.get(holder.hashCode())!=(holderPos)){
return null;
}
- in the background task, before the call to get the
image
onPostExecute{
if(hashMap.get(holder.hashCode())==(holderPosition)){
holder.imageView.setImageBitmap(result);
}
}
}
So i am just providing an extension to this answer since there is not much space to leave it as comment.
After trying out like mentioned in one of above solutions i found out that, the real issue can still be addressed even if you are using a static resource(is not being downloaded and is available locally)
So basically on onBindViewHolder event i just converted the resource to drawable and added it like below :
imageView.setImageDrawable(ContextCompat.getDrawable(context,R.drawable.album_art_unknown));
this way you wont have an empty space on the view while glide/async downloader is loading the actual image from network.
plus looking at that being reloaded every time i also added below code while calling the recycler adapter class;
recyclerView.setItemViewCacheSize(10);
recyclerView.setDrawingCacheEnabled(true);
so by using above way you wont need to set setIsRecyclable(false) which is degrading if you have larger datasets.
By doing this i you will have a flicker free loading of recyclerview of course except for the initial loads.
I would like to say that if you send the ImageView and any load-async command (for instance loading from S3), the recycler view does get confused.
I did set the bitmap null in the onViewRecycled and tested with attach and detach views etc. the issue never went away.
The issue is that if a holderView gets used for image-1, image-10 and stops at the scroll with image-19, what the user sees is image-1, then image-10 and then image-19.
One method that worked for me is to keep a hash_map that helps know what is the latest image that needs to be displayed on that ImageView.
Remember, the holder is recycled, so the hash for that view is persistent.
1- Create this map for storing what image should be displayed,
public static HashMap<Integer, String> VIEW_SYNCHER = new HashMap<Integer, String>();
2- In your Adapter, onBindViewHolder,
String thumbnailCacheKey = "img-url";
GLOBALS.VIEW_SYNCHER.put(holder.thumbnailImage.hashCode(), thumbnailCacheKey);
3- Then you have some async call to make the network call and load the image in the view right ?
In that code after loading the image from S3, you test to make sure what goes into the View,
// The ImageView in the network data loader, get its hash.
int viewCode = iim.imView[0].hashCode();
if (GLOBALS.VIEW_SYNCHER.containsKey(viewCode))
if (GLOBALS.VIEW_SYNCHER.get(viewCode).equals(bitmapKey))
iim.imView[0].setImageBitmap(GLOBALS.BITMAP_CACHE.get(bitmapKey).bitmapData);
So essentially, you make sure what is the last image key that should go into a view, then when you download the image you check to make sure that's the last image URL that goes in that view.
This solution worked for me.
I'm trying to change the background image of a certain button when clicked in a recyclerView. The button's background image is changing properly but also changing the background of the button found in the 8th..16th..etc row as well. (I am currently populating data in the recycler view using a for-loop for testing)
My code is
#Override
public void onBindViewHolder(final myFirstAdapter.ViewHolder holder, int position) {
firstlistitem listItem = listItems.get(position);
holder.itemView.setTag(position);
holder.btnBookMark.setTag(position);
holder.btnBookMark.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
holder.btnBookMark.setBackgroundResource(R.drawable.bookmarkred);
}
});
}
The background is changing because, its a RecyclerView and it recyclers the view and reuses it. Hence, when you click on 8th position and scroll to bottom, it is reusing the item at 8 position with custom background for other items. Because of this you are getting custom background for later items on scroll.
If you have many items which will have changed background do this.
class ViewHolder extends RecyclerView.ViewHolder{
boolean newBackground = false;
Button button
ViewHolder(View itemView){
...
button.setOnClickListner((v) - > newBackground = true);
}
}
Then you can check the value of newBackground and set the background in onBindViewHolder()
If you have only one item of which the background will change at a time then you can declare a field in the Adapter and check that to change the background.
class MyAdapter extends RecyclerView.Adapter<ViewHolder>{
int newBackgroundPos = -1;
#Override
public final void onBindViewHolder(ViewHolder holder, int position) {
holder.button.setOnClickListener((v) -> newBackGroundPos = position);
if(position == newBackgroundPos)
holder.itemView.setBackground(newBackground);
else
holder.itemView.setBackground(normalBackground);
}
}
I have a RecyclerView with each element representing an event. I want to let the user select events by clicking it. Once selected, the event(s) and a report button will be colored:
UI before performing a click: click here.
UI After performing a click: click here.
It's pretty simple and allegedly works; I set an OnClickListener for each ViewHolder which is responsible for coloring the item, and when fired it's triggering another event in the owning activity named onOccurrenceSelected, which is responsible for changing the button's state.
However, when scrolling through the RecyclerView's items, other irrelevant items are colored like their OnClickListener was triggered (though it wasn't), and when scrolling back the selected event is colored as not selected. While this is happening, the only event that's supposed to color the items is not triggered.
Any explanation for such behavior? Thanks!
EDIT: Here are some relevant code from the adapter:
private List<Occurrence> mDataSet;
private Activity activity;
public <OccurrencesActivity extends OnOccurrenceSelectedListener> OccurrencesAdapter(OccurrencesActivity occurrencesActivity, List<Occurrence> occurrences) {
this.activity = (android.app.Activity) occurrencesActivity;
mDataSet = occurrences;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
Occurrence instance = mDataSet.get(position);
...
setOnClickListener(holder, instance);
}
private void setOnClickListener(final ViewHolder holder, final Occurrence occurrence) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!occurrence.isSelected()) {
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
} else {
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}
occurrence.setSelected(!occurrence.isSelected());
((OnOccurrenceSelectedListener)activity).onOccurrenceSelected(mDataSet);
}
});
}
Recyclerview always resuse views while scrolling so you have to store selected positions into temporary arraylist and then keep condition check into onBindViewHolder that whether that particular position is already exists in arraylist or not? I updated your adaper. find the below changes with comment
private List<Occurrence> mDataSet;
private Activity activity;
//Added here temporary ArrayList
private ArrayList<String> mSelectedPosition = new ArrayList<String>;
public <OccurrencesActivity extends OnOccurrenceSelectedListener> OccurrencesAdapter(OccurrencesActivity occurrencesActivity, List<Occurrence> occurrences) {
this.activity = (android.app.Activity) occurrencesActivity;
mDataSet = occurrences;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
//Set ViewTag
holder.itemView.setTag(position);
//Check everyposition during view binding process
if(mSelectedPosition.contains(String.valueOf(position))){
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}else{
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}
Occurrence instance = mDataSet.get(position);
...
setOnClickListener(holder, instance);
}
private void setOnClickListener(final ViewHolder holder, final Occurrence occurrence) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Get Position
int position = (int) view.getTag();
//Remove SelectedPosition if Already there
if(mSelectedPosition.contains(position))
mSelectedPosition.remove(String.valueOf(position));
else
mSelectedPosition.add(String.valueOf(position));
notifyDataSetChanged();
//Not sure about this lines
occurrence.setSelected(!occurrence.isSelected());
((OnOccurrenceSelectedListener)activity).onOccurrenceSelected(mDataSet);
}
});
}
Its the default behaviour of recyclerview. it will recycle/reuse views which are not in use currently. If you want to save the state which is colored or not. Then save a parameter in your List<Object> per position. and as per position in onBindViewHolder method use that position to change the color.
Try by Setting Tag to your item in onBindViewHolder of Adapter
holder.yourItem.setTag(position);
And then Inside the onClickListener,Just save that position in shared Pref. if it's selected, whenever you set adapter then before setting values just check that is it selected or not based on shared Pref. and perform action for same.
public void onClick(View view) {
if (!occurrence.isSelected()) {
//save position in share pref.
}
}
Please have a look at related Question. I got to know some hint from comments and now putting it in a new way.
I am using a RecyclerView with StaggeredGridView adapter to display the data. How do I get to know that how many items needed to be loaded for current devices to fit the whole screen?
process
Determine the screen size
Determine how many items needed to be loaded to fit full screen
Fetch data from Server with number of items
Display them
When user scroll down device fetch same amount of items and so on.
Question
I am not able to understand How to get done with first two points.
Code for Adapter
public class StaggeredGridAdapter extends RecyclerView.Adapter<StaggeredGridAdapter.StaggeredGridView> {
private Context context;
private String INTENT_VALUE = "warehouse";
private List<Warehouse> warehouses = new ArrayList<Warehouse>();
private AppDelegate app;
int size;
public StaggeredGridAdapter(Context context) {
this.context = context;
app = (AppDelegate) context;
}
public void addItems(List<Warehouse> response) {
size = response.size();
warehouses = response;
}
#Override
public StaggeredGridView onCreateViewHolder(ViewGroup parent, int viewType) {
View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.grid_item, parent, false);
StaggeredGridView staggeredGridView = new StaggeredGridView(layoutView);
return staggeredGridView;
}
#Override
public void onBindViewHolder(StaggeredGridView holder, int position) {
holder.textView.setText(warehouses.get(position).getFace());
}
#Override
public int getItemCount() {
return size;
}
class StaggeredGridView extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView textView;
public StaggeredGridView(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.img_name);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
Intent intent = new Intent(context, WareHouseDetailActivity.class);
intent.putExtra(INTENT_VALUE, warehouses.get(getAdapterPosition()));
v.getContext().startActivity(intent);
}
}
}
code for filling data into adapter
mRecyclerView = (RecyclerView) mActivity.findViewById(R.id.staggering_grid);
mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL));
mAdapter = new StaggeredGridAdapter(mContext);
mAdapter.addItems(response);
mRecyclerView.setAdapter(mAdapter);
As to find the Height and Width, you can use the DisplayMetrics.
final DisplayMetrics displayMetrics = this.getApplicationContext().getResources().getDisplayMetrics();
This displayMetrics will give Height, Width and Density. Use the height of the single View (or row) and the total height to calculate the number of items.
Why do you want the Exact number of items, if it's a server call you are making, you could just make a rough estimate on the number of items based on the device size. Also, I think it's better to keep the number of items sent by server a constant and not dependent on the device height. If you received more than the number of items you can fit in the screen, well, the user can scroll to see them anyways.
Rather than trying to work out how much you'll need to load, you could set it up to automatically load more when you're close to the end of the list.
Consider this method:
#Override
public void onBindViewHolder(StaggeredGridView holder, int position) {
holder.textView.setText(warehouses.get(position).getFace());
}
This is called when the item is ready to be displayed on the screen. By doing something like if(position > getItemCount() - 5{ // load more } then you could be automatically loading more as and when they're required.
So I had my listview working perfectly then I decided to add a context menu. As soon as I did that whenever I normal clicked an item in my listview, the entire list gets inverted on the first click. Subsequent clicks do nothing to the order, but when the first item is de-selected again the list returns to normal. When I take out the context menu logic that I added, the list view problem does not go away.
I've attached a debugger and the elements in my list adapter are never reordered, and the ListView itself is never set to reverse with .setStackFromBottom()
Here is my onClick listener registered to handle the click events of the list view items:
public void onClick(View v) {
ViewHolder holder = (ViewHolder) v.getTag();
CheckBox b = holder.box;
Boolean check = b.isChecked();
b.setChecked(!check);
if (!check) {
mChecked.add(holder.fu);
if (mChecked.size() == 1) {
buttonLayout.setVisibility(View.VISIBLE);
}
} else {
mChecked.remove(holder.fu);
if (mChecked.size() == 0) {
buttonLayout.setVisibility(View.GONE);
}
}
}
The viewholder class just holds references to objects I use in the listview for optimizations. I cannot figure out why this is causing my list to invert when displayed, I've tried moving the listener to a different view in the layout, I've tried re-writing the listener, nothing seems to work! Any advice would be appreciated.
Edit: here is the code for the view holder
/** Class to provide a holder for ListViews. Used for optimization */
private class ViewHolder {
TextView date;
TextView gallons;
TextView cost;
TextView cpg;
TextView mpg;
CheckBox box;
FillUp fu;
}
as well as the adapter:
public class FillUpAdapter extends BaseAdapter {
ArrayList<FillUp> mElements;
ArrayList<FillUp> mChecked;
Context mContext;
public FillUpAdapter(Context c, ArrayList<FillUp> data) {
mContext = c;
mElements = data;
mChecked = new ArrayList<FillUp>();
}
public void clearChecked() {
mChecked.clear();
}
public ArrayList<FillUp> getChecked() {
return mChecked;
}
public boolean remove(FillUp f) {
mChecked.remove(f);
return mElements.remove(f);
}
#Override
public int getCount() {
return mElements.size();
}
#Override
public Object getItem(int arg0) {
return mElements.get(arg0);
}
#Override
public long getItemId(int arg0) {
return mElements.get(arg0).getId();
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout layout;
ViewHolder holder;
if (convertView != null) {
layout = (LinearLayout) convertView;
holder = (ViewHolder) layout.getTag();
} else {
layout = (LinearLayout) LayoutInflater.from(mContext).inflate(
R.layout.fillup_list_item, parent, false);
holder = new ViewHolder();
holder.cost = (TextView) layout
.findViewById(R.id.fillUpListTotalValue);
holder.cpg = (TextView) layout
.findViewById(R.id.fillUpListCostPerGal);
holder.gallons = (TextView) layout
.findViewById(R.id.fillUpListGalValue);
holder.mpg = (TextView) layout
.findViewById(R.id.fillUpMPGText);
holder.date = (TextView) layout
.findViewById(R.id.fillUpListDate);
holder.box = (CheckBox) layout
.findViewById(R.id.fillUpListCheckBox);
holder.fu = (FillUp) getItem(position);
layout.setTag(holder);
}
holder.date.setText(holder.fu.getDate());
holder.gallons.setText(holder.fu.getGallonsText());
holder.cpg.setText(holder.fu.getCostText());
holder.cost.setText(holder.fu.getTotalText());
holder.mpg.setText(String.format("%03.1f MPG",holder.fu.getMPG()));
if (convertView != null) {
holder.box.setChecked(mChecked.contains(holder.fu));
}
layout.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
ViewHolder holder = (ViewHolder) v.getTag();
CheckBox b = holder.box;
Boolean check = b.isChecked();
b.setChecked(!check);
if (!check) {
mChecked.add(holder.fu);
if (mChecked.size() == 1) {
buttonLayout.setVisibility(View.VISIBLE);
}
} else {
mChecked.remove(holder.fu);
if (mChecked.size() == 0) {
buttonLayout.setVisibility(View.GONE);
}
}
}
});
return layout;
}
}
UPDATE:
Ok, so I've narrowed it down to the visibility change on the buttonLayout view, which is a linear layout of buttons on the bottom of the Activity's layout, underneath the ListView. Whenever I change that view's visibility to View.VISIBLE (which happens when the first item is checked) the list's order is reversed. The order is restored when the view's visibility is set to View.GONE
I have no idea what would cause that though :(
After narrowing the scope a bit more, I discovered the problem was not the changing of the visibility of my button bar, but actually the passing around of FillUp objects in holder.fu of my ViewHolder class. By changing that to instead reference the adapter's getItem(position) method, everything seemed to work out. Quite an odd bug, since the adapter itself was not having the order of the elements changed, but passing around a reference to the object made it very unhappy.
If your listview background color changes when you click on it, I think it is about your theme. Just play with the cache color parameters of your listview, here is an example:
<ListView
android:layout_width="fill_parent"
android:id="#android:id/list"
android:scrollingCache="true"
android:persistentDrawingCache="all"
android:cacheColorHint="#0000"
android:layout_height="wrap_content"
android:fastScrollEnabled="true"
android:stackFromBottom="true"
android:smoothScrollbar="true"
android:paddingTop="115dip">
</ListView>