I have created a custom cursor adapter which fetches the value from the database and displays it in my defined view.
I have one textview and imageview.
Depends on the text in the database image changes accordingly.
I have defined MyArrayAdapter as follows, but it gives an error.
public class MyArrayAdapter extends SimpleCursorAdapter {
private final Context context;
private final Cursor cursor;
private final String[] from;
static class ViewHolder {
public ImageView imageView;
public TextView textView;
}
public MyArrayAdapter(Context context, int layout, Cursor c, String[] from,
int[] to) {
super(context, layout, c, from, to);
this.context = context;
this.cursor = c;
this.from = from;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View rowView = convertView;
ViewHolder holder;
if (rowView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
rowView = inflater.inflate(R.layout.todo_row,null,true);
holder = new ViewHolder();
holder.textView = (TextView) rowView.findViewById(R.id.todo_edit_summary);
holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
rowView.setTag(holder);
}else{
holder = (ViewHolder) rowView.getTag();
}
String s = cursor.getString(cursor.getColumnIndex(from[0]));
holder.textView.setText(s);
if (cursor.getString(cursor.getColumnIndex("category")) == "Urgent"){
holder.imageView.setImageResource(R.drawable.urgent);
}else{
holder.imageView.setImageResource(R.drawable.reminder);
}
return rowView;
}
}
(Update from deleted answer)
The following code is working fine, but they are showing the same value in each and every entry in the ListView. I have extended SimpleCursorAdapter. Am I making any mistakes with managing the cursor?
public View getView(int position, View convertView, ViewGroup parent) {
View rowView = convertView;
ViewHolder holder;
if (rowView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
rowView = inflater.inflate(R.layout.todo_row,null,true);
holder = new ViewHolder();
holder.textView = (TextView) rowView.findViewById(R.id.label);
holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
rowView.setTag(holder);
}else{
holder = (ViewHolder) rowView.getTag();
}
String s = cursor.getString(cursor.getColumnIndex(from[0]));
holder.textView.setText(s);
if ((cursor.getString(cursor.getColumnIndex("category"))).equals("Urgent")){
holder.imageView.setImageResource(R.drawable.reminder);
}else{
holder.imageView.setImageResource(R.drawable.urgent);
}
return rowView;
}
As far as I can tell the only part of SimpleCursorAdapter you are using is the from parameter which you can easily substitute with a literal string since you are extending it. While I'm not familiar with the "guts" of the code it's pretty safe to assume that since getView is not mentioned in SimpleCursorAdapter documentation that it's not meant to be overridden lightly since doing so can break it like in your example.
Based on what you have, I've adapted it to extend CursorAdapter instead and by splitting the code you had in getView into newView and bindView, both of which are defined as abstract methods in CursorAdapter.
public class MyCursorAdapter extends CursorAdapter {
static class ViewHolder {
public ImageView imageView;
public TextView textView;
}
public MyArrayAdapter(Context context, Cursor c) {
super(context, c);
}
#Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.todo_row,null,true);
ViewHolder holder = new ViewHolder();
holder.textView = (TextView) rowView.findViewById(R.id.todo_edit_summary);
holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
rowView.setTag(holder);
return rowView;
}
#Override
public void bindView(View view, Context context, Cursor cursor) {
ViewHolder holder = (ViewHolder) view.getTag();
String s = cursor.getString(cursor.getColumnIndex("whatever from[] represented"));
holder.textView.setText(s);
if (cursor.getString(cursor.getColumnIndex("category")) == "Urgent"){
holder.imageView.setImageResource(R.drawable.urgent);
}else{
holder.imageView.setImageResource(R.drawable.reminder);
}
}
}
To compare between value of two strings use equals() of String class. Donot use == operator in this case
So use the following code
if ((cursor.getString(cursor.getColumnIndex("category"))).equals("Urgent")){
holder.imageView.setImageResource(R.drawable.urgent);
}else{
holder.imageView.setImageResource(R.drawable.reminder);
}
Related
I would like to display items with an adapter in a ListView but when getView is called in the ArrayAdapter, it displays the good image but not on the good item when I am scrolling. It is like if the findViewById didn't give me the good id of the layout.
public class ItemPackAdapter extends ArrayAdapter<Pack> {
Context context;
public ItemPackAdapter(Context context, ArrayList<Pack> pack) {
super(context, 0, pack);
this.context = context;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
// Check if an existing view is being reused, otherwise inflate the view
final Pack pack = getItem(position);
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.item_pack, parent, false);
holder = new ViewHolder();
holder.textView1 = (TextView) convertView.findViewById(R.id.textView1);
holder.textView2 = (TextView) convertView.findViewById(R.id.textView2);
holder.textView3 = (TextView) convertView.findViewById(R.id.textView3);
holder.imageView = (ImageView) convertView.findViewById(R.id.imageView);
if (!pack.getImageName().equals("null")) {
UrlGenerator urlGenerator = new UrlGenerator();
String url = urlGenerator.getDownloadPicture(pack.getImageName());
DownloadPicture downloadPicture = new DownloadPicture(holder.imageView, url, getContext());
downloadPicture.start();
}
convertView.setTag(holder);
}
else {
holder = (ViewHolder)convertView.getTag();
}
holder.textView1.setText(pack.getSomething1());
holder.textView2.setText(pack.getSomething2());
holder.textView3.setText(pack.getSomething3());
if (!pack.getImageName().equals("null")) {
UrlGenerator urlGenerator = new UrlGenerator();
String url = urlGenerator.getDownloadPicture(pack.getImageName());
DownloadPicture downloadPicture = new DownloadPicture(holder.imageView, url, getContext());
downloadPicture.start();
}
if(pack.getImageName().equals("null")){
holder.imageView.setImageBitmap(null);
}
return convertView;
}
static class ViewHolder {
TextView textView1;
TextView textView2;
TextView textView3;
ImageView imageView;
}
}
Actually I found a solution with :
if(pack.getImageName().equals("null")){
holder.imageView.setImageBitmap(null);
}
But when I am scrolling on the listView, I can see the image in the wrong item, and I need to scroll again to call getView to delete the image with the previous condition.
I would like something cleaner :p
Thank you in advance.
And sorry for my bad English.
Your code looks will work just fine with just a little tweak. I discovered that you were setting the ImageView twice, so I edit your code as shown below
public class ItemPackAdapter extends ArrayAdapter<Pack> {
Context context;
ArrayList<Pack> packs;
public ItemPackAdapter(Context context, ArrayList<Pack> packs) {
super(context, 0, packs);
this.context = context;
this.packs = packs;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
// Check if an existing view is being reused, otherwise inflate the view
final Pack pack = packs.get(position);
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.item_pack, parent, false);
holder = new ViewHolder();
holder.textView1 = (TextView) convertView.findViewById(R.id.textView1);
holder.textView2 = (TextView) convertView.findViewById(R.id.textView2);
holder.textView3 = (TextView) convertView.findViewById(R.id.textView3);
holder.imageView = (ImageView) convertView.findViewById(R.id.imageView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if (pack.getImageName().equals("null")) {
holder.imageView.setImageBitmap(null);
} else {
UrlGenerator urlGenerator = new UrlGenerator();
String url = urlGenerator.getDownloadPicture(pack.getImageName());
DownloadPicture downloadPicture = new DownloadPicture(holder.imageView, url, getContext());
downloadPicture.start();
}
holder.textView1.setText(pack.getSomething1());
holder.textView2.setText(pack.getSomething2());
holder.textView3.setText(pack.getSomething3());
return convertView;
}
static class ViewHolder {
TextView textView1;
TextView textView2;
TextView textView3;
ImageView imageView;
}
}
In this case if you don't caching your image that may give you like this problem.
Use Picasso library is highly recommended for avoiding this problem. Add the picasso library in your project then write your code some thing like this.
Picasso.with(getApplicationContext()).load(url).into(holder.imageView);
instead of this line
DownloadPicture downloadPicture = new DownloadPicture(holder.imageView, url, getContext());
downloadPicture.start();
my images get shuffled or changed when i scroll in list view.......
Images get shuffled when i scroll down and keep on changing own its own...............
public class CustomListAdapter extends BaseAdapter {
private ArrayList<NewsItem> listData;
private LayoutInflater layoutInflater;
public CustomListAdapter(Context context, ArrayList<NewsItem> listData) {
this.listData = listData;
layoutInflater = LayoutInflater.from(context);
}
#Override
public int getCount() {
return listData.size();
}
#Override
public Object getItem(int position) {
return listData.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.activity_list_search, null);
holder = new ViewHolder();
holder.headlineView = (TextView) convertView.findViewById(R.id.title);
holder.reporterNameView = (TextView) convertView.findViewById(R.id.reporter);
holder.reportedDateView = (TextView) convertView.findViewById(R.id.date);
holder.imageView = (ImageView) convertView.findViewById(R.id.thumbImage);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
NewsItem newsItem = (NewsItem) listData.get(position);
holder.headlineView.setText(newsItem.getHeadline());
holder.reporterNameView.setText("Model: " + newsItem.getReporterName());
holder.reportedDateView.setText(newsItem.getDate());
if (holder.imageView != null) {
new ImageDownloaderTask(holder.imageView).execute(newsItem.getUrl());
}
return convertView;
}
static class ViewHolder {
TextView headlineView;
TextView reporterNameView;
TextView reportedDateView;
ImageView imageView;
}
}
The problem is very generic for new Android developers.
Your ImageDownloaderTask should take care of whether the downloaded image should still be posted on screen.
For example, after ImageDownloaderTask finishes one image downloading task (e.g. for index 15), it should make sure the 15th item is still displaying on screen. Since ListView is reusing all the item views, if you directly set the bit map to the original referenced view, your imageview will be shuffled.
I have made a custom adapter for a autocompletetextview, but it's not filtering on the text and inputting weird strings when you select a item. Like this string:
listadapters.LocatieRowItem#BSE433q4e30
I have made this adapter so the first item of the autocompletetextview could have a image and a different color then the rest.
Here is my custom adapter:
public class LocatieAdapter extends ArrayAdapter<LocatieRowItem> {
Context context;
private List<LocatieRowItem> items;
public LocatieAdapter(Context context, int resourceId, List<LocatieRowItem> items) {
super(context, resourceId, items);
this.context = context;
this.items = items;
}
/*private view holder class*/
private class ViewHolder {
ImageView imageView;
TextView txtTitle;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
LocatieRowItem rowItem = items.get(position);
LayoutInflater mInflater = (LayoutInflater) context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
convertView = mInflater.inflate(R.layout.locatieitem, null);
holder = new ViewHolder();
holder.txtTitle = (TextView) convertView.findViewById(R.id.text1);
holder.imageView = (ImageView) convertView.findViewById(R.id.logo);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if(rowItem.getTitle().equals("huidige locatie")) {
if (holder.imageView.getVisibility() != View.VISIBLE) {
holder.imageView.setVisibility(View.VISIBLE);
holder.txtTitle.setTextColor(Color.parseColor("#33B5E5"));
holder.txtTitle.setPadding(40, 10, 5, 5);
}
} else {
holder.imageView.setVisibility(View.GONE);
holder.txtTitle.setTextColor(Color.parseColor("#333333"));
holder.txtTitle.setPadding(10, 10, 10, 10);
}
holder.txtTitle.setText(rowItem.getTitle());
//convertView.setBackgroundColor(position % 2 == 0 ? Color.WHITE : Color.parseColor("#F8F8F8"));
return convertView;
}
}
Is it possible to get an item view based on its position in the adapter and not in the visible views in the ListView?
I am aware of functions like getChildAt() and getItemIdAtPosition() however they provide information based on the visible views inside ListView. I am also aware that Android recycles views which means that I can only work with the visible views in the ListView.
My objective is to have a universal identifier for each item since I am using CursorAdapter so I don't have to calculate the item's position relative to the visible items.
Here's how I accomplished this. Within my (custom) adapter class:
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = null;
if (convertView == null) {
LayoutInflater inflater = context.getLayoutInflater();
view = inflater.inflate(textViewResourceId, parent, false);
final ViewHolder viewHolder = new ViewHolder();
viewHolder.name = (TextView) view.findViewById(R.id.name);
viewHolder.button = (ImageButton) view.findViewById(R.id.button);
viewHolder.button.setOnClickListener
(new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = (int) viewHolder.button.getTag();
Log.d(TAG, "Position is: " +position);
}
});
view.setTag(viewHolder);
viewHolder.button.setTag(items.get(position));
} else {
view = convertView;
((ViewHolder) view.getTag()).button.setTag(items.get(position));
}
ViewHolder holder = (ViewHolder) view.getTag();
return view;
}
Essentially the trick is to set and retrieve the position index via the setTag and getTag methods. The items variable refers to the ArrayList containing my custom (adapter) objects.
Also see this tutorial for in-depth examples. Let me know if you need me to clarify anything.
See below code:
public static class ViewHolder
{
public TextView nm;
public TextView tnm;
public TextView tr;
public TextView re;
public TextView membercount;
public TextView membernm;
public TextView email;
public TextView phone;
public ImageView ii;
}
class ImageAdapter extends ArrayAdapter<CoordinatorData>
{
private ArrayList<CoordinatorData> items;
public FoodDriveImageLoader imageLoader;
public ImageAdapter(Context context, int textViewResourceId,ArrayList<CoordinatorData> items)
{
super(context, textViewResourceId, items);
this.items = items;
}
public View getView(int position, View convertView, ViewGroup parent)
{
View v = convertView;
ViewHolder holder = null;
if (v == null)
{
try
{
holder=new ViewHolder();
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader = new FoodDriveImageLoader(FoodDriveModule.this);
v = vi.inflate(R.layout.virtual_food_drive_row, null);
//System.out.println("layout is null.......");
holder.nm = (TextView) v.findViewById(R.id.name);
holder.tnm = (TextView) v.findViewById(R.id.teamname);
holder.tr = (TextView) v.findViewById(R.id.target);
holder.re = (TextView) v.findViewById(R.id.received);
holder.membercount = new TextView(FoodDriveModule.this);
holder.membernm = new TextView(FoodDriveModule.this);
holder.email = new TextView(FoodDriveModule.this);
holder.phone = new TextView(FoodDriveModule.this);
holder.ii = (ImageView) v.findViewById(R.id.icon);
v.setTag(holder);
}
catch(Exception e)
{
System.out.println("Excption Caught"+e);
}
}
else
{
holder=(ViewHolder)v.getTag();
}
CoordinatorData co = items.get(position);
holder.nm.setText(co.getName());
holder.tnm.setText(co.getTeamName());
holder.tr.setText(co.getTarget());
holder.re.setText(co.getReceived());
holder.ii.setTag(co.getImage());
imageLoader.DisplayImage(co.getImage(), FoodDriveModule.this , holder.ii);
if (co != null)
{
}
return v;
}
}
A better option is to identify using the data returned by the CursorAdapter rather than visible views.
For example if your data is in a Array , each data item has a unique index.
Here, Its very short described code, you can simple re-use viewholder pattern to increase listview performance
Write below code in your getview() method
ViewHolder holder = new ViewHolder();
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.skateparklist, null);
holder = new ViewHolder();
holder.headlineView = (TextView) convertView
.findViewById(R.id.textView1);
holder.DistanceView = (TextView) convertView
.findViewById(R.id.textView2);
holder.imgview = (NetworkImageView) convertView
.findViewById(R.id.imgSkatepark);
convertView.setTag(holder); //PLEASE PASS HOLDER AS OBJECT PARAM , CAUSE YOU CAN NOY PASS POSITION IT WILL BE CONFLICT Holder and Integer can not cast
//BECAUSE WE NEED TO REUSE CREATED HOLDER
} else {
holder = (ViewHolder) convertView.getTag();
}
// your controls/UI setup
holder.DistanceView.setText(strDistance);
......
return convertview
Listview lv = (ListView) findViewById(R.id.previewlist);
final BaseAdapter adapter = new PreviewAdapter(this, name, age);
confirm.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
View view = null;
String value;
for (int i = 0; i < adapter.getCount(); i++) {
view = adapter.getView(i, view, lv);
Textview et = (TextView) view.findViewById(R.id.passfare);
value=et.getText().toString();
Toast.makeText(getApplicationContext(), value,
Toast.LENGTH_SHORT).show();
}
}
});
How do I refresh the content of a ListActivity using the custom ListAdapter that I created? I have in the arrayadapter a method that calls "notifyDataSetChanged();". That does not work. Neither have any of the related solutions on this site. Here's the code thus far:
private final Activity context;
private Message[] messages;
public RamRSSAdapter(Activity context, Message[] messages) {
super(context, R.layout.ram_rss_row);
this.context = context;
this.messages = messages;
}
// static to save the reference to the outer class and to avoid access to
// any members of the containing class
static class ViewHolder {
public ImageView imageView;
public TextView textView;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
// ViewHolder will buffer the assess to the individual fields of the row
// layout
ViewHolder holder;
// Recycle existing view if passed as parameter
// This will save memory and time on Android
// This only works if the base layout for all classes are the same
View rowView = convertView;
//string code goes here
if (rowView == null) {
LayoutInflater inflater = context.getLayoutInflater();
rowView = inflater.inflate(R.layout.ram_rss_row, null, true);
holder = new ViewHolder();
holder.textView = (TextView) rowView.findViewById(R.id.label);
holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
rowView.setTag(holder);
} else {
holder = (ViewHolder) rowView.getTag();
}
holder.textView.setText(messages[position].getTitle());
//code for image here
holder.imageView.setImageResource(getImageResID(getType(messages[position].getTitle())));
return rowView;
}
private String getType(String title){
int i1 = title.indexOf("[");
int i2 = title.indexOf("]");
if((i1==-1)||(i2==-1)){
return "";
}else{
return title.substring(i1+1, i2);
}
}
public void changeData(Message[] newData){
messages = newData;
notifyDataSetChanged();
}
/*
private int getImageResID(String type){
}
}
I have yet to see a case where notifyDataSetChanged() does anything. I've just gotten a new adapter based on the latest information, and changed the scroll position on the ListView to make it appear it's simply updated.
You should not overwrite the array of data directly- instead use the clear/insert/add/addAll/remove methods that are provided by the ArrayAdapter.