Hide items in a listview - android

I have tried to hide items in a custom list adapter. I can hide the visibility of the text but I cannot hide the whole list item. It still shows the dividers etc. I have tried:
tv.setVisibility(View.INVISIBLE);
tv.setVisibility(View.GONE);
convertView.setVisibility(View.INVISIBLE);
convertView.setVisibility(View.GONE);
When I use the convertView i get a null pointer exception.

You can set ContentView with No Element.
In getView() of Your Custom Adapter.
if(condition)
{
convertView=layoutInflater.inflate(R.layout.row_null,null);
return convertView;
}
else
{
convertView=layoutInflater.inflate(R.layout.row_content,null);
return convertView;
}
your XML row_null.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</LinearLayout>

You have 3 ways to do this:
Remove the items from your list inside or outside the adapter.
Inside the adapter you can do it in the Constructor.
private List<String> list;
public MyAdapter(Context context, List<String> list) {
list.remove(0);
list.remove(1);
list.remove(<whateverPositionYouLike>);
this.list = list;
}
You need to figure out how many items you want to hide and need to build a similar logic.
#Override
public int getCount() {
// In this adapter, we are supposed to hide the first item of the list view
// Returning 0 if no of items are already 0
if(list.size() <=1)
return 0;
// if number of items are more than one, returning one item less
return list.size() - 1;
}
#Override
public Object getItem(int position) {
// skipping the position
return list.get(position + 1);
}
`
#Override
public View getView(final int position, View v, ViewGroup arg2) {
// this is important, as we are supposed to skip the first item of listview
final int localPosition = position +1;
ViewHolderItem holder;
if (v == null) {
holder = new ViewHolderItem();
v = inflater.inflate(R.layout.list_row, null);
v.setTag(holder);
} else {
holder = (ViewHolderItem) v.getTag();
}
return v;
}
`
Answer provided by #hims_3009

You cannot in the way you are trying to, you'll need to use a custom Adapter and implement in there the logic for showing/not showing a line.

If you want to hide a row in a listview, you need to delete data in that position. For example if you use array adapter and want to hide the row on 5. position. You have to delete line from your array and the call notifyDatasetChanged() method.
(You can delete data from array by using tempArray)
or use this way
private List<String> items = new ArrayList<String>();
// make list a new array, clearing out all old values in it.
for(i=0; i<10; i++)
{
if((i != 5) && (i != 6)){
// if k = 5 or 6, dont add those items to the list
items.add(something[i]); /// whatever your list items are.
}
}
ArrayAdapter<String> itemList = new
ArrayAdapter<String>(this,R.layout.itemlistlayout);
setListAdapter(itemlist);

If you want to hide an entire item you need to build some logic into your getView() method to make it skip over various parts of your data.
lets say you have an ArrayAdapter and I want to hide the data that is at index 2. Your getView() method could look something like this.
#Override
public View getView(int pos, View convertView, ViewGroup, parent){
View mView = convertView;
//TODO: Check if convertView was null, and inflate
// or instantiate if needed.
//Now we are going to set the data
mTxt = mView.findViewById(R.id.mTxt);
if(pos >= 2){
//If position is 2 or above, we ignore it and take the next item.
mTxt.setText(this.getItem(pos + 1).toString());
}else{
//If position is below 2 then we take the current item.
mTxt.setText(this.getItem(pos).toString());
}
return mView;
}
Note that this example is generalized, it is not meant to be able to be dropped directly into your project. I had to make assumptions about some things which I don't know the truth on. You can use the same concept as I've shown here though and modify it to your situation to be able to "hide" rows in your ListView.

If you already have a custom list adapter you can just call notifyDataSetChanged() on the adapter and the adapter itself has of course to implement the logic to filter out the views for the rows you want to hide. These are the methods that come to my mind that need to reflect that logic:
#Override
public Object getItem(int position) {
return mItems.get(position);
}
#Override
public int getCount() {
return mItems.size();
}
#Override
public View getView(final int position, final View convertView, final ViewGroup parent) {
// here goes your logic to hide a row
Additionally you might have to change getItemId() as well.

I think I have a much easier / safer solution: you just have to "embed" your item in a Layout, and change the visibility of this parent layout.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- Embed ListView Item into a "parent" Layout -->
<LinearLayout
android:id="#+id/parentLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- This is the normal content of your ListView Item -->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="World" />
</LinearLayout>
</LinearLayout>
Then in your code just do:
public View getView(int position, View view, ViewGroup parent) {
if (view == null) {
LayoutInflater li = mActivity.getLayoutInflater();
view = li.inflate(R.layout.my_listview_item, null);
}
LinearLayout parentLayout = (LinearLayout) view.findViewById(R.id.parentLayout);
if (shouldDisplayItem(position)) {
parentLayout.setVisibility(View.VISIBLE);
} else {
parentLayout.setVisibility(View.GONE);
}
return view;
}
This way you always use/reuse the same item, and just hide/show it.

Related

Correct way to implement onMeasure() and onLayout() in custom AdapterView

I know that I should measure children in onMeasure() and layout them in onLayout(). The question is in what of these methods should I add/recycle views so I could measure all children together with an eye on how they are mutually positioned (i.e. grid, list or whatever)?
My first approach was to add/recycle views in onLayout() but from that point I can't measure my children because they aren't added to AdapterView yet and getChildCount() returns 0 in onMeasure(). And I can't measure AdapterView itself without children being already layouted because it really depends upon their mutual positions, right?
I'm really confused with android layouting process in AdapterView when childrens are added/removed dynamically.
I can't post a comment because I'm a new user, but can you describe WHAT you're trying to do, as opposed to HOW you're trying to do it? Frequently, you will find that this is an issue of design as opposed to coding. Especially if you're coming from a different platform (example, iOS). From experience, I found that measuring and manual layouts in Android is mostly unnecessary if you design your layout properly in light of your business need.
EDIT:
As I mentioned this can be solved using some design decisions. I will use your Nodes/List example (hoping that this is your actual use case, but the solution can be expanded for a more general problem).
So if we think about your Header as a comment in a forum, and the List as replies to your comment, we can make the following assumption:
One list is enough, not two. Each item in the list can either be a header (comment) or a list item (reply). Each reply is a comment, but not all comments are replies.
For item n, I know if it's a comment or a reply (i.e. is it a header or an item in your list).
For item n, I have a boolean member isVisible (default false; View.GONE).
Now, you can use the following components:
One extended adapter class
Two Layout XMLs: One for your Comment, one for your reply. You can have unlimited comments and each comment can have unlimited replies. Both those satisfy your requirements.
Your fragment or activity container class that implements OnItemClickListener to show/hide your list.
So let's look at some code, shall we?
First, your XML files:
Comment row (your header)
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/overall"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:animateLayoutChanges="true">
<TextView
android:id="#+id/comment_row_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>
Now your reply row (an element in your list)
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/overall"
android:layout_width="match_parent"
android:layout_height="wrap_content"> <!-- this is important -->
<TextView
android:id="#+id/reply_row_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"/> <!-- important -->
</RelativeLayout>
Ok, now your adapter class
public class CommentsListAdapter extends BaseAdapter implements OnClickListener
{
public static String TAG = "CommentsListAdapter";
private final int NORMAL_COMMENT_TYPE = 0;
private final int REPLY_COMMENT_TYPE = 1;
private Context context = null;
private List<Comment> commentEntries = null;
private LayoutInflater inflater = null;
//All replies are comments, but not all comments are replies. The commentsList includes all your data. (Remember that the refresh method allows you to add items to the list at runtime.
public CommentsListAdapter(Context context, List<Comment> commentsList)
{
super();
this.context = context;
this.inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.commentEntries = commentsList;
}
//For our first XML layout file
public static class CommentViewHolder
{
public RelativeLayout overall;
public TextView label;
}
//For our second XML
public static class ReplyViewHolder
{
public RelativeView replyOverall;
public TextView replyLabel;
}
#Override
public int getViewTypeCount()
{
return 2; //Important. We have two views, Comment and reply.
}
//Change the following method to determine if the current item is a header or a list item.
#Override
public int getItemViewType(int position)
{
int type = -1;
if(commentEntries.get(position).getParentKey() == null)
type = NORMAL_COMMENT_TYPE;
else if(commentEntries.get(position).getParentKey() == 0L)
type = NORMAL_COMMENT_TYPE;
else
type = REPLY_COMMENT_TYPE;
return type;
}
#Override
public int getCount()
{
return this.commentEntries.size(); //all data
}
#Override
public Object getItem(int position)
{
return this.commentEntries.get(position);
}
#Override
public long getItemId(int position)
{
return this.commentEntries.indexOf(this.commentEntries.get(position));
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
CommentViewHolder holder = null;
ReplyViewHolder replyHolder = null;
int type = getItemViewType(position);
if(convertView == null)
{
if(type == NORMAL_COMMENT_TYPE)
{
convertView = inflater.inflate(R.layout.row_comment_entry, null);
holder = new CommentViewHolder();
holder.label =(TextView)convertView.findViewById(R.id.comment_row_label);
convertView.setTag(holder);
}
else if(type == REPLY_COMMENT_TYPE)
{
convertView = inflater.inflate(R.layout.row_comment_reply_entry, null);
replyHolder = new ReplyViewHolder();
replyHolder.replyLable = (TextView)convertView.findViewById(R.id.reply_row_label);
convertView.setTag(replyHolder);
}
}
else
{
if(type == NORMAL_COMMENT_TYPE)
{
holder = (CommentViewHolder)convertView.getTag();
}
else if(type == REPLY_COMMENT_TYPE)
{
replyHolder = (ReplyViewHolder)convertView.getTag();
}
}
//Now, set the values of your labels
if(type == NORMAL_COMMENT_TYPE)
{
holder.label.setTag((Integer)position); //Important for onClick handling
//your data model object
Comment entry = (Comment)getItem(position);
holder.label.setText(entry.getLabel());
}
else if(type == REPLY_COMMENT_TYPE)
{
replyHolder = (ReplyViewHolder)convertView.getTag(); //if you want to implement onClick for list items.
//Or another data model if you decide to use multiple Lists
Comment entry = (Comment)getItem(position);
replyHolder.replyLabel.setText(entry.getLabel()));
//This is the key
if(entry.getVisible() == true)
replyHolder.replyLabel.setVisibility(View.VISIBLE);
else
replyHolder.replyLabel.setVisibility(View.GONE);
}
return convertView;
}
//You can use this method to add items to your list. Remember that if you are using two data models, then you will have to send the correct model list here and create another refresh method for the other list.
public void refresh(List<Comment> commentsList)
{
try
{
this.commentEntries = commentsList;
notifyDataSetChanged();
}
catch(Exception e)
{
e.printStackTrace();
Log.d(TAG, "::Error refreshing comments list.");
}
}
//Utility method to show/hide your list items
public void changeVisibility(int position)
{
if(this.commentEntries == null || this.commentEntries.size() == 0)
return;
Comment parent = (Comment)getItem(position);
for(Comment entry : this.commentEntries)
{
if(entry.getParent().isEqual(parent))
entry.setVisible(!entry.getVisible()); //if it's shown, hide it. Show it otherwise.
}
notifyDataSetChanged(); //redraw
}
}
Ok great, now we have a list of headers with hidden children (remember, we set the default visibility of children to 'gone'). Not what we wanted, so let's fix that.
Your container class (fragment or activity) you will have the following XML definition
<!-- the #null divider means transparent -->
<ListView
android:id="#+id/comments_entries_list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="#null"
android:dividerHeight="5dp" />
And your onCreateView will implement OnItemClickListener and have the following
private ListView commentsListView = null;
private List<Comment>comments = null;
private static CommentsListAdapter adapter = null;
....
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
...
//comments list can be null here, and you can use adapter.refresh(data) to set the data
adapter = new CommentsListAdapter(getActivity(), comments);
this.commentsListView.setAdapter(adapter);
this.commentsListView.setOnClickListener(this); //to show your list
}
Now to show your list when you click a header
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id)
{
adapter.changeVisibility(position);
}
Now, if an item is clicked and that item has a parent (i.e. list item), it will be shown/hidden according to its current state.
Some comments about the code:
I wrote this on WordPad as I don't have a dev environment handy. Sorry for any compilation errors.
This code can be optimized: If you have a very large data set, this code would be slow since you're redrawing the entire list on every call to changeVisibility(). You can maintain two lists (one for headers, one for list items) and in changeVisibility you can query over the list items only).
I re-enforce that idea that some design decisions would make your life a lot easier. For example, if your list items were actually just a list of labels, then you can have one custom XML file (for your header) and a ListView view within it that you can set to View.GONE. This will make all other views pretend that it's not even there and your layout will work properly.
Hope this helps.

ListView: how to access Item's elements programmatically from outside?

I have the following situation.
I have a ListView, each item of the ListView is comprised of different widgets (TextViews, ImageViews, etc...) inflated form a Layout in the getView() method of the custom adapter.
Now, I would like to achieve the following:
when a certain event is triggered I want to change the background of a View which is inside the item.
Please how do I do it?
This is the the Item Layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/cardlayout"
android:layout_width="320dp"
android:layout_height="130dp"
android:background="#android:color/transparent"
android:orientation="vertical"
android:paddingBottom="5dp"
android:paddingRight="5dp"
android:paddingTop="5dp" >
<FrameLayout
android:layout_width="320dp"
android:layout_height="117dp" >
<View
android:id="#+id/card"
android:layout_width="320dp"
android:layout_height="117dp"
android:background="#drawable/card_selector" />
</FrameLayout>
</LinearLayout>
I need to change the background of card
I have tried doing this:
View v=lv.getAdapter().getView(index, null, lv);
View card =(View)v.findViewById(R.id.card);
card.setBackgroundResource(R.drawable.pressed_background_card);
But no success :-((
When your event is triggered you should just call a notifyDataSetChanged on your adapter so that it will call again getView for all your visible elements.
Your getView method should take into account that some elements may have different background colors (and not forget to set it to normal color if the element doesn't need the changed background, else with recycling you would have many elements with changed background when you scroll)
edit :
I would try something like this :
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null)
{
convertView = LayoutInflater.from(getContext()).inflate(R.layout.card, parent, false);
}
//This part should also be optimised with a ViewHolder
//because findViewById is a costly operation, but that's not the point of this example
CardView cardView =(CardView)convertView .findViewById(R.id.card);
//I suppose your card should be determined by your adapter, not a new one each time
Card card = getItem(position);
//here you should check sthg like the position presence in a map or a special state of your card object
if(mapCardWithSpecialBackground.contains(position))
{
card.setBackgroundResource(specialBackground);
}
else
{
card.setBackgroundResource(normalBackground);
}
cardView.setCard(card);
return convertView;
}
And on the special event i would add the position of the item into the map and call notifyDataSetChanged.
Use the onitemclicklistener which has method onclicksomething..that takes four or five parameters. (View parent, View view, int position, int id). Use the view parameter to customize your background.
Update
Here's some of my code, If you don't understand I recommend to read about recycling and ViewHolder pattern.
#Override
public View getView(int position, View convertView, ViewGroup parent) {
{
ViewHolder viewHolder;
// If convertView isn't a recycled view, create a new.
if(convertView == null){
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.row_gallery_frame, parent, false);
viewHolder = new ViewHolder();
// Here you must be able to find your Widget inside convertView and set a listener to it I guess?
viewHolder.nameHolder = (TextView) convertView.findViewById(R.id.nameTv);
// Set a reference to newly inflated view
convertView.setTag(viewHolder);
}
// If it is, then get the ViewHolder by tag
else{
viewHolder = (ViewHolder)convertView.getTag();
}
// Set the data
GalleryFrame galleryFrame = galleryFrameArrayList.get(position);
viewHolder.nameHolder.setText(galleryFrame.getName());
return convertView;
}
}
// Viewholder pattern which holds all widgets used
public static class ViewHolder{
public TextView nameHolder;
}
I assume you have a model object that you use to "draw" the list item , and for example the background color is determined based on a boolean or something.
All you need to do, is change the value on which you base your decision which background color should that TextView have.
Your getView() method should have code like that
if (myModelObj.isBrown()) {
myTextView.setBackgroundResource(R.drawable.brown_bg);
else
myTextView.setBackgroundResource(R.drawable.not_brown_bg);
All you should do when ur event is triggered, is set the value of the brown boolean in your model
and call notifyDataSetChanged() on your adapter
EDIT
If for some reason you don't wanna call nofitfyDataSetChanged(), althought it won't move the scroll position of your list and with the right recyclying it won't cause bad performance
You can find the View object that represent the list item you want to edit-if it's visisble-, and simply change the background in it, without refreshing the list at all.
int wantedPosition = 10; // Whatever position you're looking for
int firstPosition = listView.getFirstVisiblePosition() - listView.getHeaderViewsCount();
int wantedChild = wantedPosition - firstPosition
if (wantedChild < 0 || wantedChild >= listView.getChildCount()) {
// Wanted item isn't displayed
return;
}
View wantedView = listView.getChildAt(wantedChild);
then use wantedView to edit your background
This answer can be found here
try this one:
View v=lv.getAdapter().getView(index, null, lv);
View card =(View)v.findViewById(R.id.card);
card.setBackgroundResource(R.drawable.pressed_background_card);
card.invalidate();
v.invalidate();
those function force your views to redraw itself and they will render again.
look at invalidate()
What I normally do is this:
public static class EventDetailsRenderer {
private TextView title;
private TextView description;
private Event item;
public EventDetailsRenderer(View view) {
extractFromView(view);
}
private final void extractFromView(View view) {
title = (TextView) view.findViewById(R.id.EventTitle);
description = (TextView) view.findViewById(R.id.Description);
}
public final void render() {
render(item);
}
public final void render(Event item) {
this.item= item;
title.setText(item.getTitle());
description.setText(item.getDescription());
}
}
private class EventsAdapter
extends ArrayAdapter<Event> {
public EventsAdapter(Context context) {
super(context, R.layout.list_node__event_details, 0);
}
public void addAllItems(Event... services) {
for (int i = 0; i < services.length; i++) {
add(services[i]);
}
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
Event event = getItem(position);
EventDetailsRenderer eventRenderer;
if (convertView != null && convertView.getTag() != null) {
eventRenderer = (EventDetailsRenderer) convertView.getTag();
} else {
convertView = getActivity().getLayoutInflater().inflate(R.layout.list_node__event_details, null);
eventRenderer = new EventDetailsRenderer(convertView);
convertView.setTag(eventRenderer);
}
eventRenderer.render(event);
return convertView;
}
}
NOTE: that this example might not compile I pasted it from some code I have and deleted some lines to show an example but the logic it the same.
And then when you want to render it, just get the children from the list, iterate over them, check if the renderer contains the card you want to flip and call its render method... then you render a specific item in the list without effecting the rest of the items.
Let me know if this works...
Adam.
User EasyListViewAdapters library https://github.com/birajpatel/EasyListViewAdapters
Features
Easier than implementing your own Adapter (ie handling
BaseAdaper#getView).Very Easier to provide multi-row support.
Library takes care of recycling all views, that ensures performance
& helps your list view scroll smoothly.
Cleaner code. By keeping different RowViewSetter classes for
different row-types makes your code easy to manage & easy to reuse.
No data browsing, Library takes care of browsing data through
data-structure when View is being drawn or event occurs so that
Users does not have to look for their data to take actions.
Just by passing correct row-types library will Auto-map your
data-types to row-types to render views. Row views can be created by
using XML or Java (doesn't restrict to XML-Only Approach).
Load More callbacks can be registered to implement paginatation
support to your list.
Handling children viewclicks, you can also register for
Children(present inside your rows) view click events.
All these Views are registered with single OnClickListner so that
this mechanism is very memory efficient when click event occurs
users you gets clickedChildView, rowData,int eventId as callback
params.

Combination of adapter and template views in Android ListView

I just want to start off by saying the list view works fine, there's no problem with this code.
All I want to know is how I can expand on it. I want to have a label (a bit of text to describe what the items in the list view represent) at the top of the list view before all of the items from the adapter appear. But obviously, because I want it inside the list view I want the label to go out of view when the user starts scrolling through the list.
How do I achieve that?
ListView listView = (ListView) findViewById(R.id.list_task_summary);
TasksSummaryListViewHelper adapter = new TasksSummaryListViewHelper(this, getTasks());
listView.setAdapter(adapter);
listView.setEmptyView(findViewById(R.id.text_empty_list));
And my template:
<ListView
android:layout_marginRight="5dp"
android:layout_marginLeft="5dp"
android:id="#+id/list_task_summary"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="#android:color/transparent"
android:dividerHeight="15sp"
android:listSelector="#drawable/list_task_summary_selector_unselected">
</ListView>
In your custom List Adapter , When getView is called, create a title view for position 0 and other position you own list item layout
#Override
public View getView(int position, View contentView , ViewGroup parent){
View row = null;
if(position == 0) {
// inflate any custom layout or just a textView
TextView titleView = new TextView();
titleView.setText("TITLE");
row = titleView;
}
else {
row = mContext.getLayoutInflater().inflate(R.layout.list_item, null);
}
return row;
}
And ,You will see the recyle issue with ListView since it uses the same child view for other items,
So to that you need to Override the getViewTypeCount and return the view type count as 2
#Override
public int getViewTypeCount() {
return 2;
}
Also, Override getItemViewType and return a unique id for position 0 and other views same id.
#Override
public int getItemViewType(int position){
// return a unique number
if(position == 0){
return 0;
}
else {
return 1;
}
}
You can do as Libin suggests, but if it's one static view that needs to scroll with the rest of the list, I think it's better to use listView.addHeaderView() instead. This way you don't need to make any changes to your adapter at all. Note that the position reported in any OnListItemClickListeners will be offset by the number of header views.

How use ArrayAdapter<T> with complex Layout?

This is the first time I need to use the ArrayAdapter<T> to show a multi-item Row-Layout. After a lot of successful work with different adapters this one is driving me crazy.
getView(..., position, ...) always returns 0-7[EDIT] so I never see elements in my ArrayList that are on position >= 7[/EDIT]. I know, this is the visible position, but how do I select the correct object in the ArrayList?
EDIT: Currently I only get the first 8 elements out of my array because position only comes in from 0-7 - even on a 50 element ArrayList. I don't see a way to position within the ArrayList without a "real" position.
The docs say the following - but I don't get it. Did somebody successfully implement an ArrayAdapter<T> with a complex layout? What do the doc mean and how should I implement it?
If you want to use a more complex
layout, use the constructors that also
takes a field id. That field id should
reference a TextView in the larger
layout resource. However the TextView
is referenced, it will be filled with
the toString() of each object in the
array. You can add lists or arrays of
custom objects. Override the
toString() method of your objects to
determine what text will be displayed
for the item in the list. To use
something other than TextViews for the
array display, for instance,
ImageViews, or to have some of data
besides toString() results fill the
views, override getView(int, View,
ViewGroup) to return the type of view
you want.
Many thanks in advance
hjw
Here's the code so far:
public class HappyAdapter extends ArrayAdapter<Happy> {
static class ViewHolder {
private ImageView imageView;
private TextView textViewBottom;
private TextView textViewTop;
}
private ArrayList<Happy> arrayListHappy;
private DrawableCache drawableCache = DrawableCache.getInstance();
private int layout;
#Override
public int getCount() {
return arrayListHappy.size();
}
#Override
public View getView(int position, View contentView, ViewGroup viewGroup) {
// position always 0-7
View view = null;
ViewHolder viewHolder = null;
if (contentView == null) {
LayoutInflater layoutInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = layoutInflater.inflate(layout, null);
if (view != null) {
viewHolder = new ViewHolder();
viewHolder.imageView = (ImageView) view.findViewById(R.id.happyactivity_row_image_left);
viewHolder.textViewBottom = (TextView) view.findViewById(R.id.happyactivity_row_text_bottom);
viewHolder.textViewTop = (TextView) view.findViewById(R.id.happyactivity_row_text_top);
view.setTag(viewHolder);
}
} else {
view = contentView;
viewHolder = (ViewHolder) contentView.getTag();
}
if (viewHolder != null) {
Happy happy = arrayListHappy.get(position);
if (happy != null) {
viewHolder.imageView.setUrl(happy.getImageThumbnail());
drawableCache.fetchDrawable(happy.getImageThumbnail(), viewHolder.imageView);
viewHolder.textViewBottom.setText(String.valueOf(position));
viewHolder.textViewTop.setText(String.valueOf(viewHolder.position));
}
}
return view;
}
public HappyAdapter(Context context, int layout, ArrayList<Happy> arrayListHappy) {
super(context, layout, arrayListHappy);
this.arrayListHappy = arrayListHappy;
this.layout = layout;
}
}
This is part of the Row-Layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:orientation="horizontal" >
<ImageView
android:id="#+id/happyactivity_row_image_left"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_width="fill_parent" />
<TextView
style="#style/TextViewStandard"
android:id="#+id/happyactivity_row_text_top"
android:layout_weight="1" />
<TextView
style="#style/TextViewStandard"
android:id="#+id/happyactivity_row_text_bottom"
android:layout_weight="1" />
</LinearLayout>
</LinearLayout>
I can't add comments yet so have to answer. As others have noted it isn't really clear what's not working. However, you are only seeing positions 0-7 being inflated as this is the only portion of the list that is currently visible, as you noted yourself. Other rows (with higher position numbers) won't be inflated until you scroll down the list.
Although it uses the BaseAdapter class, rather than ArrayAdapter that you are using, you could look at List14.java in the ApiDemos sample code (ApiDemos/src/com/example/android/apis/view/List14.java) as the principle is the same. When using ArrayAdapter though, you don't need to override all the methods that this sample code does (just getView).

Android: How to hide a ListView Item

How can you hide an item in a ListView or at least set its height to zero?
I have tried setting the visibility of the View to GONE but it still maintains the item's space (height).
Ressurecting an old question, but I just had this issue where I wanted to hide list items temporarily based upon criteria outside of the list data. What I ended up doing was creating a "null item" layout in xml and returned that based upon my criteria instead of the convert view in getView()...
instead of returning the convertView, I returned my null_item...
return inflater.inflate(R.layout.null_item, null);
null_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</LinearLayout>
if you want to hide the item like this:
convertView.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,1));
convertView.setVisibility(View.GONE);
can't be AbsListView.LayoutParams(-1,0);
if convertview are reused you should add this below to set it height back:
if(convertView.getVisibility() == View.GONE) {
convertView.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, AbsListView.LayoutParams.WRAP_CONTENT));
convertView.setVisibility(View.VISIBLE);
}
When it comes to ListView, to make it efficient, we use ViewHolder pattern. The way to use ViewHolder Pattern and R.layout.row_null of the following xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</LinearLayout>
is to use with getViewTypeCount() and getItemViewType(int position) as follow.
#Override
public int getViewTypeCount() {
return 2;
}
#Override
public int getItemViewType(int position) {
return (hideStatusCheck(position)) ? 1 : 0;
}
#Override
public View getView(int pos, View convertView, ViewGroup parent) {
View rowView = convertView;
if (hideStatusCheck(pos)) {
if (rowView == null || rowView.getTag() != null) {
LayoutInflater inflater = mActivity.getLayoutInflater();
rowView = inflater.inflate(R.layout.row_null, parent, false);
}
} else {
if (rowView == null) {
rowView = inflateNormalView(parent);
} else if (rowView.getTag() == null) {
rowView = inflateNormalView(parent);
} else {
ViewHolder holderToCheck = (ViewHolder) rowView.getTag();
Integer storedPos = (Integer) holderToCheck.getTag(POSITION);
if (storedPos == null || storedPos != pos)
rowView = inflateNormalView(parent);
}
ViewHolder holder = (ViewHolder) rowView.getTag();
holder.setTag(POSITION,pos);
/*
Populate data
*/
return rowView;
}
private View inflateNormalView(ViewGroup parent) {
View rowView;
LayoutInflater inflater = mActivity.getLayoutInflater();
rowView = inflater.inflate(R.layout.normal_item, parent, false);
ViewHolder viewHolder = new ViewHolder();
assert rowView != null;
/* Initiate normal findViewById thing*/
rowView.setTag(viewHolder);
return rowView;
}
We do the checking of the item's View type and if it meets the hide check, it will return 1, otherwise 0. The ListView knows that there will be 2 types of View from getViewTypeCount. Now, the getView will return the approriate View depending on the hideStatusCheck. To make a robust ListView, we want to use the ViewHolder pattern. We don't need to use ViewHolder when it is hidden. We simply inflate the R.layout.row_null and return it. We will use the ViewHolder for the R.layout.normal_item. Here is the tricky part assuming the hiding check is not static. The first check of rowView==null is standard. The second check of rowView.getTag()==null is to see if the View is coming back to normal
from hiding. The third check in the last else clause is to check if the ViewHolder retained in the tag is the right ViewHolder. If these conditions are met, we always inflate the view again. Yes, it is true that, the ViewHolder pattern is not used throughout but it uses to certain extends. It is better than nothing.
I did some tinkering with a drag and drop list from here. When an item is popped out of the list to be moved around the cell space it occupied has it's height set to 1px (see line 238) so it appears "gone". I couldn't find a way to handle this better as setting height to 0 fails as does visibility GONE.
That said, If you really want to get rid of a row less temporarily, it might be a good idea to change the backing of the Adapter and call notifyDataSetChanged() on it.
I have look at source code. And there is only one way to hide item without notifyDataSetChanged(). You must set visibility GONE for all inner views and remove background image and paddings for item's view.
Note: Row with such invisible element will be selectable.
P.S: This is very usefull for ExpandableListView if you want to hide group view it self.
add to your ListView object:
android:dividerHeight="0px"
android:divider="#FFFFFF"
Divider color doesn't matter
only setting dividerHeight doesn't work
This does remove the divider though...
I think I have a much easier / safer solution: you just have to "embed" your item in a Layout, and change the visibility of this parent layout.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- Embed ListView Item into a "parent" Layout -->
<LinearLayout
android:id="#+id/parentLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<!-- This is the normal content of your ListView Item -->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="World" />
</LinearLayout>
</LinearLayout>
Then in your code just do:
public View getView(int position, View view, ViewGroup parent) {
if (view == null) {
LayoutInflater li = mActivity.getLayoutInflater();
view = li.inflate(R.layout.my_listview_item, null);
}
LinearLayout parentLayout = (LinearLayout) view.findViewById(R.id.parentLayout);
if (shouldDisplayItem(position)) {
parentLayout.setVisibility(View.VISIBLE);
} else {
parentLayout.setVisibility(View.GONE);
}
return view;
}
This way you always use/reuse the same item, and just hide/show it.
To Hide whole raw from listview in android:-
RelativeLayout parentLayout = (RelativeLayout) view.findViewById(R.id.relative);
if (productPojoList.get(position).getSERSERVICETYPE().toString().equals("Group|Promotional")){
view.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,1));
view.setVisibility(View.GONE);
} else {
if(view.getVisibility() == View.GONE) {
view.setLayoutParams(new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, AbsListView.LayoutParams.WRAP_CONTENT));
view.setVisibility(View.VISIBLE);
}
}

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