I have a RecyclerView inside that recyclerView I added two Sections Favorites, All Contacts. For adding the section I used SimpleSectionedRecyclerViewAdapter
now I have rows with section which is hardcoded (the index of rows and section), I want to add rows to favorite section by selecting the rows since there's nothing documented about what I want, I don't know where to start or what I have to do ?
If anybody knows how can I add a row from All Contacts section (which is default location for rows ) by selecting them. then please give me some hints for what I have to do
what I want is something like this :
add to favorite by pressing the button
any guidance will be so helpful for me , thanks
You can achieve it with the library SectionedRecyclerViewAdapter without having to hardcode header/rows indexes.
First create a Section class to group your items:
class MySection extends StatelessSection {
String title;
List<String> list;
public MySection(String title, List<String> list) {
// call constructor with layout resources for this Section header, footer and items
super(R.layout.section_header, R.layout.section_item);
this.title = title;
this.list = list;
}
#Override
public int getContentItemsTotal() {
return list.size(); // number of items of this section
}
#Override
public RecyclerView.ViewHolder getItemViewHolder(View view) {
// return a custom instance of ViewHolder for the items of this section
return new MyItemViewHolder(view);
}
#Override
public void onBindItemViewHolder(RecyclerView.ViewHolder holder, int position) {
MyItemViewHolder itemHolder = (MyItemViewHolder) holder;
// bind your view here
itemHolder.tvItem.setText(list.get(position));
}
#Override
public RecyclerView.ViewHolder getHeaderViewHolder(View view) {
return new SimpleHeaderViewHolder(view);
}
#Override
public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) {
MyHeaderViewHolder headerHolder = (MyHeaderViewHolder) holder;
// bind your header view here
headerHolder.tvItem.setText(title);
}
}
Then you set up the RecyclerView with your Sections:
// Create an instance of SectionedRecyclerViewAdapter
SectionedRecyclerViewAdapter sectionAdapter = new SectionedRecyclerViewAdapter();
// Create your sections with the list of data
MySection favoritesSection = new MySection("Favorites", favoritesList);
MySection contactsSection = new MySection("Add Favorites", contactsList);
// Add your Sections to the adapter
sectionAdapter.addSection(favoritesSection);
sectionAdapter.addSection(contactsSection);
// Set up your RecyclerView with the SectionedRecyclerViewAdapter
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setAdapter(sectionAdapter);
You can find an example of how to listen to the button click here.
You can also add new rows to your sections without having to recalculate indexes, just create a method like this in your Section class:
public void addRow(String item) {
this.list.add(item);
}
Then:
favoritesSection.addRow("new item");
sectionAdapter.notifyDataSetChanged();
Related
I am trying to implement a list of files that can be selected from the RecyclerView Adapter class. While I understand it is not a good idea, I feel if I am able to accomplish this from within said class, it would be really helpful in the future.
My list item (Each individual item view for the RecyclerView) has the following structure:
|--------|----------------|
| ICON | DATA |
|--------|----------------|
Problem:
When a file is selected (by touching the icon portion of a file item), I change the background of that item to another color to denote that it has been selected.
However, when I scroll down to about 25 items later, another file has the same background color even though it's not selected (it does not show up in Log.d as being selected, nor was it in the test ArrayList that was used to store selected files).
It seems as though the item is only retaining the background change of the previous occupant.
Solution attempts:
Previously, only the variables related to each list item were declared in the RecyclerView ViewHolder class and all changes were made in the onBindViewHolder method. Now, all changes to be made have been moved to the ViewHolder class inside a method called bind. There was no change in behavior.
If I set the default background image during the very first step in onBindViewHolder, the behavior changes such that the items do not retain changes of previous occupants. However, on scrolling back, the background change for the target item reverts to the default background image.
Code:
public class RVA extends RecyclerView.Adapter<RVA.RVH>
{
private LayoutInflater inf;
private ArrayList<File> items;
// The var below is used to track the no. of selected items
// globally within the RVA class.
private int numberOfSelectedItems = 0;
public RVA(ArrayList<File> _items)
{
items = _items;
}
#Override
public RVA.RVH onCreateViewHolder(ViewGroup parent, int viewType)
{
inf = LayoutInflater.from(parent.getContext());
return new RVH(inf, parent);
}
#Override
public void onBindViewHolder(RVA.RVH holder, int position)
{
File listItem = items.get(position);
// 'binding' each file element to a respective host container.
holder.bind(listItem);
}
#Override
public int getItemCount()
{
return items.size();
}
#Override
public long getItemId(int position)
{
return position;
}
// The ViewHolder class.
// Initially it was just declared as class.
// There was no change observed after the 'final' modifier was added.
final class RVH extends RecyclerView.ViewHolder
{
private Context context;
private LinearLayout itemSelector;
private ImageView itemIcon;
private TextView itemName;
private TextView itemSize;
public RVH(LayoutInflater inf, ViewGroup parent)
{
super(inf.inflate(R.layout.list_item, parent, false));
context = parent.getContext();
// This is the SECOND outermost LinearLayout of each file item View.
// It was previously the parent Layout, but there was no difference due to change.
itemSelector = itemView.findViewById(R.id.item_selector);
// This is the icon ImageView.
itemIcon = itemView.findViewById(R.id.item_icon);
// These are the data TextViews.
itemName = itemView.findViewById(R.id.item_id);
itemSize = itemView.findViewById(R.id.item_size);
}
// The 'bind' method that registers changes.
public void bind(File fileItem)
{
String listItemName = fileItem.getName();
itemName.setText(listItemName);
//---- These are just changes to the icons depending on type. Works fine.
if(fileItem.isDirectory())
{
itemIcon.setImageResource(R.drawable.directory_icon);
itemSize.setText("Directory");
}
else
{
itemSize.setText(fileItem.length() + " B");
if(listItemName.endsWith(".jpg") || listItemName.endsWith(".jpeg") || listItemName.endsWith(".png") || listItemName.endsWith(".gif"))
{
Glide.with(context).load(fileItem).centerCrop().into(itemIcon);
}
else
{
itemIcon.setImageResource(R.drawable.file_icon);
}
}
//---- END
//---- This is the code which handles opening files according to type. Works fine.
itemSelector.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
if(numberOfSelectedItems == 0)
{
if(!itemSize.getText().toString().endsWith(" B"))
{
Intent loadListItemIntent = new Intent(context, DirectoryViewActivity.class);
loadListItemIntent.putExtra("ITEMPATH", fileItem.getPath());
context.startActivity(loadListItemIntent);
}
else
{
if(itemName.getText().toString().endsWith(".jpg") || itemName.getText().toString().endsWith(".jpeg") || itemName.getText().toString().endsWith(".png") || itemName.getText().toString().endsWith(".gif"))
{
Glide.with(context).load(fileItem).centerCrop().into(itemIcon);
Intent loadListItemIntent = new Intent(context, ImageActivity.class);
loadListItemIntent.putExtra("ITEMPATH", fileItem.getPath());
context.startActivity(loadListItemIntent);
}
else
{
Toast.makeText(context, "File needs proper application.", Toast.LENGTH_SHORT).show();
}
}
}
}
});
//---- END
//---- !!! THIS SECTION is where the problem manifests.
itemIcon.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
if(itemIcon.getTag().toString().equals("not_selected"))
{
// Incrementing based on selection.
++numberOfSelectedItems;
// Using a tag to identify/ denote whether item is selected.
itemIcon.setTag("selected");
// Changing the background & disabling file opening while in selection mode.
itemSelector.setBackgroundResource(R.drawable.list_item_selected);
itemSelector.setClickable(false);
itemSelector.setLongClickable(false);
// I use this odd method to send a message to the host Activity
// that we have entered selection mode & that the Activity should
// display some option buttons on the Action Bar.
if(context instanceof DirectoryViewActivity)
{
((DirectoryViewActivity)context).addSelectedItem(fileItem);
if(numberOfSelectedItems == 1)
{
((DirectoryViewActivity)context).setSelectionMode();
}
}
}
else
{
// Decrementing based on deselection.
--numberOfSelectedItems;
// Overwiting the tag to identify/ denote item is now unselected.
itemIcon.setTag("not_selected");
// Background changed back to default & file opening re-enabled.
itemSelector.setClickable(true);
itemSelector.setLongClickable(true);
itemSelector.setBackgroundResource(R.drawable.list_item_background);
// I use this method to send a message to the host Activity
// that we have exited selection mode & that the Activity should
// remove related option buttons from the Action Bar.
if(context instanceof DirectoryViewActivity)
{
((DirectoryViewActivity)context).removeSelectedItem(fileItem);
if(numberOfSelectedItems == 0)
{
((DirectoryViewActivity)context).voidSelectionMode();
}
}
}
}
});
}
}
}
This is because RecyclerView does not create views for all of your items in the list it create enough ViewHolder to fill up the screen and few more and when you scroll the old ViewHolder are bind to some other data in the adapter that is when the onBindViewHolder() is called , so basically what is happening here is you are setting the background of current ViewHolder on the screen and when you scroll the same ViewHolder in bind to the new data.
I think you have to check in the onBindViewHolder whether or not this is the item to which you want to set the background and then take the decision remove it if the item is not selected in the dataset set background if it is selected.
I have a Child recyclerView nested in a parent recyclerView giving me the concept of topics in different Chapters as seen in the attached photo below.
MY CHALLENGE is highlighting a single selected child item (Topic) in any given section or Chapter(nested child RecyclerView).
As can be seen in the photo, items (or Topic) previously selected in any other section (chapter) does not de-select when a topic from another section is selected.
Can someone please give a hint on HOW best to highlight a selected item in a nested recyclerView.
HERE is my code snippet for the Child RecyclerView.
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
Topic topic = topicList.get(position);
holder.clearSelection();
if (currentItemPosition == position) {
holder.position.setTextColor(holder.itemView.getResources().getColor(R.color.red));
holder.title.setTextColor(holder.itemView.getResources().getColor(R.color.red));
holder.description.setTextColor(holder.itemView.getResources().getColor(R.color.blue));
} else {
holder.position.setTextColor(holder.itemView.getResources().getColor(R.color.black));
holder.title.setTextColor(holder.itemView.getResources().getColor(R.color.black));
holder.description.setTextColor(holder.itemView.getResources().getColor(R.color.black));
}
holder.position.setText(String.valueOf(topic.getPosition()));
holder.title.setText(topic.getTitle());
holder.description.setText(topic.getDescription());
holder.duration.setText(topic.getDuration());
if (downloadedTopics.contains(topic.getTitle())) {
holder.downloadIcon.setImageResource(R.drawable.downloaded_icon);
} else {
holder.downloadIcon.setImageResource(R.drawable.undownloaded_icon);
}
}
HERE is the OnBindViewHolder of the Parent (or Main RecyclerView)
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
ArrayList<View> topicViewList = new ArrayList<>();
RootTopic topicGroup = rootTopicsGroupList.get(position);
ArrayList<Topic>topicList = topicGroup.getTopicGroup();
String titleConstruct = "Chapter " + (position + 1) + "- " + topicGroup.getRootTopicName();
holder.SectionTitle.setText(titleConstruct);
setUpTopicGroupRec(topicList,downloadedTopicList,holder.groupedTopicsRV,holder.itemView.getContext());
}
Here Is the setUpTopicGroupRec method called
private void setUpTopicGroupRec(ArrayList<Topic> topicList, ArrayList<String>downloads, RecyclerView recyclerView, Context context, ArrayList<RootTopic> rootTopicsGroupList){
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context,RecyclerView.VERTICAL,false);
topicAdapter = new TopicAdapter(topicList, downloads);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setAdapter(topicAdapter);
topicAdapter.setOnItemClickListener(new TopicAdapter.OnItemClickListener() {
#Override
public void onTopicClick(int position, Topic topic) {
currentTopic = topic;
onTopicClickLD.postValue(currentTopic);
int currentTopicPos = topic.getPosition();
}
#Override
public void onDownloadIconClick(int position, Topic topic) {
currentTopic = topic;
onDownloadIconClickLD.postValue(currentTopic);
}
});
}
On child recycler view adapter add a code that listens the onClick event on the specific item and see its position and finally apply change in the item at that position.
What I want to do is to show the same selected items on a recycler view even after the activity has been closed and only change items color when I again click on it. For now I have achieved changing the color on click but the state doesn't get saved?
This is my adapter:
public class LightsRecyclerViewAdapter extends
RecyclerView.Adapter<LightsRecyclerViewAdapter.ViewHolder> {
// private List<Integer> mViewColors;
private List<String> mAnimals;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;
// data is passed into the constructor
LightsRecyclerViewAdapter(Context context, List<String>
animals) {
this.mInflater = LayoutInflater.from(context);
this.mAnimals = animals;
}
// inflates the row layout from xml when needed
#Override
#NonNull
public ViewHolder onCreateViewHolder(#NonNull ViewGroup
parent, int viewType) {
View view = mInflater.inflate(R.layout.item, parent,
false);
return new ViewHolder(view);
}
// binds the data to the view and textview in each row
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int
position) {
// int color = mViewColors.get(position);
String animal = mAnimals.get(position);
// holder.myView.setBackgroundColor(color);
holder.myTextView.setText(animal);
}
// total number of rows
#Override
public int getItemCount() {
return mAnimals.size();
}
// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder
implements View.OnClickListener {
View myView;
TextView myTextView;
ViewHolder(View itemView) {
super(itemView);
// myView = itemView.findViewById(R.id.colorView);
myTextView =
itemView.findViewById(R.id.tvAnimalName);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
if (mClickListener != null)
mClickListener.onItemClick(view, getAdapterPosition());
}
}
// convenience method for getting data at click position
public String getItem(int id) {
return mAnimals.get(id);
}
// allows clicks events to be caught
public void setClickListener(ItemClickListener
itemClickListener) {
this.mClickListener = itemClickListener;
}
// parent activity will implement this method to respond to click events
public interface ItemClickListener {
void onItemClick(View view, int position);
}
}
And this is my activity:
public class DevicesList extends AppCompatActivity implements
LightsRecyclerViewAdapter.ItemClickListener{
private LightsRecyclerViewAdapter adapter,adapter1;
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_devices_list);
title = (TextView)findViewById(R.id.textGrid);
// data to populate the RecyclerView with
ArrayList<Integer> viewColors = new ArrayList<>();
viewColors.add(Color.BLUE);
viewColors.add(Color.YELLOW);
viewColors.add(Color.MAGENTA);
viewColors.add(Color.RED);
viewColors.add(Color.BLACK);
ArrayList<String> Lab1LightsList = new ArrayList<>();
Lab1LightsList.add("Light 1");
Lab1LightsList.add("Light 2");
Lab1LightsList.add("Light 3");
Lab1LightsList.add("Light 4");
Lab1LightsList.add("Light 5");
ArrayList<String> Lab1ACList = new ArrayList<>();
Lab1ACList.add("AC 1");
Lab1ACList.add("AC 2");
Lab1ACList.add("AC 3");
Lab1ACList.add("AC 4");
Lab1ACList.add("AC 5");
ArrayList<String> Lab2LightsList = new ArrayList<>();
Lab2LightsList.add("Light 1");
Lab2LightsList.add("Light 2");
Lab2LightsList.add("Light 3");
Lab2LightsList.add("Light 4");
Lab2LightsList.add("Light 5");
Lab2LightsList.add("Light 6");
ArrayList<String> Lab2ACList = new ArrayList<>();
Lab2ACList.add("AC 1");
Lab2ACList.add("AC 2");
Lab2ACList.add("AC 3");
Lab2ACList.add("AC 4");
// set up the RecyclerView
RecyclerView recyclerView = findViewById(R.id.list1);
RecyclerView recyclerView1 =findViewById(R.id.list2);
LinearLayoutManager horizontalLayoutManagaer
= new LinearLayoutManager(DevicesList.this, LinearLayoutManager.HORIZONTAL, false);
LinearLayoutManager horizontalLayoutManager
= new LinearLayoutManager(DevicesList.this, LinearLayoutManager.HORIZONTAL, false);
recyclerView.setLayoutManager(horizontalLayoutManagaer);
recyclerView1.setLayoutManager(horizontalLayoutManager);
Intent mIntent = getIntent();
int intValue = mIntent.getIntExtra("labno", 0);
if(intValue==0) {
adapter = new LightsRecyclerViewAdapter(this, Lab1LightsList);
adapter1 = new LightsRecyclerViewAdapter(this, Lab1ACList);
adapter.setClickListener(this);
adapter1.setClickListener(this);
recyclerView.setAdapter(adapter);
recyclerView1.setAdapter(adapter1);
}
if(intValue==1) {
adapter = new LightsRecyclerViewAdapter(this, Lab2LightsList);
adapter1 = new LightsRecyclerViewAdapter(this, Lab2ACList);
adapter.setClickListener(this);
adapter1.setClickListener(this);
recyclerView.setAdapter(adapter);
recyclerView1.setAdapter(adapter1);
}
}
#Override
public void onItemClick(View view, int position) {
Toast.makeText(this, "You clicked " +
adapter.getItem(position) + " on item position " + position,
Toast.LENGTH_SHORT).show();
view.setBackgroundColor(getResources().getColor(R.color.colorPrimaryDark));
}
}
Please help on this.
Create one selected item position list and store it in prefs when an app goes to background or closed. Load that list when launching an app and compare that list in an adapter's onBindViewHolder's position parameter and marks it selected/unselected based on a comparison.
As per my understandings about your question, you want to save the state of the selected items even after the app is closed, and then you want to reload it whenever the app is launched again. You need to refer to this link Android Save Data
For the above solution, there can be various ways to save state, I am mentioning a few below:
Use SQLite Database to save the selected items. Then, whenever the app is loaded, fetch all the selected data from the DB and then mark them selected with whatever colour you want on the list.
You can also use Shared Preferences, to store the selection. And, same as above, you can reload the data when the app is launched.
You can also store the data in a specific format, maybe CSV, JSON, XML etc., in a file and save it either in Internal Storage or External Storage of the device. And when the app is launched, fetch all the selected values from the file and process accordingly.
You can also use a web server, Firebase Storage, or other cloud storage services to save the data and then fetch the data on new app launch.
Do note: All these techniques require you to save the state before the app is closed. So it is better to store the states, either on click of the item, or onPause method of the activity.
If you face any problems with these solutions, you can post another comment and I will give it a look.
Save these clicked item position in a hashmap in Shareprefence. suppose u close the activity after u coming back the activity just pass the saved list with ur data in adapter and compare the shareprefence list with ur data list if position or data match than make the itemview layout colored.
// save clicked item is a list and save it sharePreference.
List<Integer> clikedList = new ArrayList<>();
if (clicked item){
ClikedList.add(position)
}
String value = gson.toJson(list);
SharedPreferences prefs = context.getSharedPreferences("mylist",
Context.MODE_PRIVATE);
Editor e = prefs.edit();
e.putString("list", value);
e.commit();
// for getting cliked position list from SharePreference
SharedPreferences prefs = context.getSharedPreferences("mylist",
Context.MODE_PRIVATE);
String value = prefs.getString("list", null);
GsonBuilder gsonb = new GsonBuilder();
Gson gson = gsonb.create();
MyObject[] list = gson.fromJson(value, MyObject[].class);
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
// suppose clicked position 4 u get from shaved cliked list
in here u neddd to retreive cliked list position and clored those item
int select = 4;
if (select == position) {
holder.itemView.setBackgroundColor(Color.BLUE);
Toast.makeText(context, "" + position, Toast.LENGTH_SHORT).show();
} else {
holder.itemView.setBackgroundColor(Color.parseColor("#214F4B"));
Toast.makeText(context, "" + position, Toast.LENGTH_SHORT).show();
}
holder.tv_title.setText(data.get(position));
}
I have multiple variables, we'll call them varA, varB, varC, and varD. When a button is pressed these 4 variables are to be stored in an ArrayList, together. This creates a single entry which can be viewed by variable varA. All the entries can be viewed in a ListView which is done through an ArrayAdapter.
onCreate
ArrayAdapter<String> profileAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, arrayList);
profileList.setAdapter(profileAdapter);
When a button is pressed
// Add data to a new profile in #+id/profileList ListView
ArrayList<String> arrayList= new ArrayList<>();
arrayList.add(varA);
System.out.println("varA's");
System.out.println(arrayList);
((ArrayAdapter)profileList.getAdapter()).notifyDataSetChanged();
Layout
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/overviewLayout">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/profileList"/>
</RelativeLayout>
I am having issues with the ListView showing the items that were added. Also, I was trying to use TinyDB to store these items so they can be referenced later since that ArrayList used on button press is just temporary. I also I'm having trouble figuring out how to set this up so that each time the button is pressed those 4 vars will stay together in a "profile" so they don't get mixed up with some other data that might be added later.
To avoid repeated values from getting stored check if it already exists :
if(!arrayList.contains(varA)){
arrayList.add(varA);
}
For listview updation problem ,use notifyItemInserted(position) instead of notifyDataSetChanged()
yourAdapter.notifyItemInserted(position);
As I understand, you want to display a list which contains 4 datas in one entry and showing just the first of them.
If it is, you could create a custom Model, it will be easier. This will store your datas in one object:
ProfileModel
|
|-- varA
|-- varB
|-- varC
'-- varD
Your custom model could look like something like this:
public class ProfileModel {
private String varA;
private float varB;
private int varC;
private String varD;
// getters
...
// setters
...
public ProfileModel() { }
}
Initialize the list of profiles at start:
ArrayList<ProfileModel> list = new ArrayList<>();
To populate the main list do as follows:
// create a list of object to the datas
ProfileModel profile = new ProfileModel();
profile.setVarA(varA);
profile.setVarB(varB);
profile.setVarC(varC);
profile.setVarD(varD);
// then fill the first list
list.add(profile);
Since you want to fill the adapter with other datas than a simple String but a custom model, I'd prefer to use a custom adapter. It's not that hard to create one, and because sometimes, you maybe want a different behavior on an update, I'd also prefer to use a custom notifyDataSetChanged method.
So, here's a simple adapter with the same layout as the one you used:
public class ProfileAdapter extends BaseAdapter {
private Context context;
private ArrayList<ProfileModel> listProfiles;
public ProfileAdapter(Context context, ArrayList<ProfileModel> listProfiles) {
super();
this.context = context;
this.listProfiles = listProfiles;
}
private class ViewHolder {
private TextView textVarA;
}
#Override
public int getCount() {
return listProfiles != null ? listProfiles.size() : 0;
}
#Override
public Object getItem(int i) {
return listProfiles.get(i); // will return the profile model from position
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int position, View view, ViewGroup viewGroup) {
ViewHolder holder;
if (view == null) {
holder = new ViewHolder();
view = LayoutInflater.from(context)
.inflate(android.R.layout.simple_list_item_1, null);
holder.textVarA = (TextView) view.findViewById(android.R.id.text1);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
ProfileModel profile = listProfiles.get(i);
holder.textVarA.setText(profile.getVarA()); // get varA value
return view;
}
public void addEntry(ProfileModel newEntry) {
listProfiles.add(newEntry);
this.notifyDataSetChanged();
}
}
Then, you can set the adapter as follows:
ProfileAdapter profileAdapter = new ProfileAdapter(this, list);
profileList.setAdapter(profileAdapter);
To update this adapter:
// create a list of object to the datas
ProfileModel profile = new ProfileModel();
profile.setVarA(varA);
profile.setVarB(varB);
profile.setVarC(varC);
profile.setVarD(varD);
profileAdapter.addEntry(profile); // this will call notifyDataSetChanged
Finally, I'm not very aware about TinyDB, but I saw it's using some JSON file to store data. So you could create a method to convert your datas to JSONArray which its name is varA and has values varB, varC, varD. There is many examples how to convert datas to JSON (as using Gson to convert your model to a JSON format).
Hope this will be useful.
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.
}
}