I get a NullPointerException on doing a swipe. What is wrong and how to correct? The exception is triggered in method onTouchEvent by statement return gestureDetector.onTouchEvent(event);
This activity (List8) is called as a TabActivity from class Tabs3 which is also provided for completess sake.
package myapp.tabnavui;
import myapp.tabnavui.R;
import android.app.ListActivity;
import android.content.Context;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.AbsListView;
import android.widget.Toast;
import java.util.ArrayList;
/**
* A list view that demonstrates the use of setEmptyView. This example alos uses
* a custom layout file that adds some extra buttons to the screen.
*/
public class List8 extends ListActivity {
private GestureDetector gestureDetector;
PhotoAdapter mAdapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Use a custom layout file
setContentView(R.layout.list_8);
// Tell the list view which view to display when the list is empty
getListView().setEmptyView(findViewById(R.id.empty));
// Set up our adapter
mAdapter = new PhotoAdapter(this);
setListAdapter(mAdapter);
// Wire up the clear button to remove all photos
Button clear = (Button) findViewById(R.id.clear);
clear.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mAdapter.clearPhotos();
} });
// Wire up the add button to add a new photo
Button add = (Button) findViewById(R.id.add);
add.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mAdapter.addPhotos();
} });
}
#Override
public boolean onTouchEvent(MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
/**
* A simple adapter which maintains an ArrayList of photo resource Ids.
* Each photo is displayed as an image. This adapter supports clearing the
* list of photos and adding a new photo.
*
*/
public class PhotoAdapter extends BaseAdapter {
private Integer[] mPhotoPool = {
R.drawable.sample_thumb_0, R.drawable.sample_thumb_1, R.drawable.sample_thumb_2,
R.drawable.sample_thumb_3, R.drawable.sample_thumb_4, R.drawable.sample_thumb_5,
R.drawable.sample_thumb_6, R.drawable.sample_thumb_7};
private ArrayList<Integer> mPhotos = new ArrayList<Integer>();
public PhotoAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mPhotos.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
// Make an ImageView to show a photo
ImageView i = new ImageView(mContext);
i.setImageResource(mPhotos.get(position));
i.setAdjustViewBounds(true);
i.setLayoutParams(new AbsListView.LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT));
// Give it a nice background
i.setBackgroundResource(R.drawable.picture_frame);
return i;
}
private Context mContext;
public void clearPhotos() {
mPhotos.clear();
notifyDataSetChanged();
}
public void addPhotos() {
int whichPhoto = (int)Math.round(Math.random() * (mPhotoPool.length - 1));
int newPhoto = mPhotoPool[whichPhoto];
mPhotos.add(newPhoto);
notifyDataSetChanged();
}
}
class MyGestureDetector extends SimpleOnGestureListener {
private static final int SWIPE_MAX_OFF_PATH = 200;
private static final int SWIPE_MIN_DISTANCE = 50;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
#Override
public boolean onDown (MotionEvent e) {
return true;
}
#Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
return false;
// left to right swipe and right to left swipe
if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
// left swipe
Toast t = Toast.makeText(List8.this, "Left swipe", Toast.LENGTH_LONG);
t.show();
startActivity(Tabs3.tab1);
return true;
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
// right swipe
Toast t = Toast.makeText(List8.this, "Right swipe", Toast.LENGTH_LONG);
t.show();
startActivity(Tabs3.tab3);
return true;
}
return false;
}
}
}
Here's Tabs3:
package myapp.tabnavui;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TabHost;
import android.widget.Toast;
import android.app.TabActivity;
import android.content.Intent;
/**
* An example of tab content that launches an activity via {#link android.widget.TabHost.TabSpec#setContent(android.content.Intent)}
*/
public class Tabs3 extends TabActivity {
private GestureDetector gestureDetector;
// View.OnTouchListener gestureListener;
// Intent go;
public static Intent tab1, tab2, tab3;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final TabHost tabHost = getTabHost();
tab1 = new Intent(this, List1.class);
tabHost.addTab(tabHost.newTabSpec("tab1")
.setIndicator("list")
.setContent(tab1));
tab2 = new Intent(this, List8.class);
tabHost.addTab(tabHost.newTabSpec("tab2")
.setIndicator("photo list")
.setContent(tab2));
// This tab sets the intent flag so that it is recreated each time
// the tab is clicked.
tab3 = new Intent(this, Controls2.class);
tabHost.addTab(tabHost.newTabSpec("tab3")
.setIndicator("destroy")
.setContent(tab3
.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));
}
}
Reason
Tabs3.gestureDetector and List8.gestureDetector are never set, so they are null.
This is why you get NullPointerException whe you try to use it at gestureDetector.onTouchEvent(event);
Solution
Based on this question, you need to set it at creation time with GestureDetector:
#Override
public void onCreate(Bundle savedInstanceState) {
// code
gestureDetector = new GestureDetector(new MyGestureDetector());
// code
}
Related
When I create a custom card view in recycler view and click the increment button counter work properply. But when I crete another cardview then already created card counter value reset to 0. How to solve this issue?
Here's my Main Activity code
package com.example.muhasbaapp;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.util.ArrayList;
import com.example.muhasbaapp.CustomAdapter.ViewHolder.*;
public class MainActivity extends AppCompatActivity {
private static RecyclerView.Adapter mAdapter,countAdapter;
private RecyclerView.LayoutManager layoutManager,layoutManager2;
private static RecyclerView recyclerView,recyclerView2;
private ImageView imageView;
public CustomModel customModel;
public static ArrayList<String> input = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// myOnClickListener = new MyOnClickListener(this);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
recyclerView2=(RecyclerView)findViewById(R.id.recycler_view2);
recyclerView.setHasFixedSize(true);
recyclerView2.setHasFixedSize(true);
layoutManager2=new LinearLayoutManager(this);
recyclerView2.setLayoutManager(layoutManager2);
recyclerView2.setItemAnimator(new DefaultItemAnimator());
mAdapter= new CustomAdapter(input);
recyclerView2.setAdapter(mAdapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.more_action_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) { //add action2 kau kat sini
switch (item.getItemId()) {
case R.id.action_item_1:
openCustomDialoge();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void openCustomDialoge() {
final AlertDialog dialogBuilder = new AlertDialog.Builder(this).create();
LayoutInflater inflater = this.getLayoutInflater();
View dialogView = inflater.inflate(R.layout.user_generated_cards, null);
final EditText editText = (EditText) dialogView.findViewById(R.id.edt_comment);
Button button1 = (Button) dialogView.findViewById(R.id.buttonSubmit);
Button button2 = (Button) dialogView.findViewById(R.id.buttonCancel);
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialogBuilder.dismiss();
}
});
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String s=editText.getText().toString();
if (s.isEmpty()){
Toast.makeText(MainActivity.this, "You can't enter empty spaces", Toast.LENGTH_SHORT).show();
}else {
input.add(s);
recyclerView2.setAdapter(mAdapter);
dialogBuilder.dismiss();
}
}
});
dialogBuilder.setView(dialogView);
dialogBuilder.show();
}
}
And Here' my Adaptar Class code
package com.example.muhasbaapp;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {
public ArrayList<String> values;
final CustomModel customMdl=new CustomModel();
final MainActivity mainActivity=new MainActivity();
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView tv;
public View layout;
public TextView counter_value;
public ImageView increment,decrement, deleted;
public int counter;
public ViewHolder(View v) {
super(v);
layout = v;
tv = (TextView) v.findViewById(R.id.textViewName);
counter_value=(TextView) v.findViewById(R.id.counter);
increment=(ImageView)v.findViewById(R.id.increment);
decrement=(ImageView)v.findViewById(R.id.decrement);
deleted=(ImageView)v.findViewById(R.id.delbtn);
}
}
public void add(int position, String item) {
values.add(position, item);
notifyItemInserted(position);
}
public void remove(int position) {
values.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, values.size());
}
// Provide a suitable constructor (depends on the kind of dataset)
public CustomAdapter(ArrayList<String> myDataset) {
this.values = myDataset;
}
// Create new views (invoked by the layout manager)
#Override
public CustomAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
LayoutInflater inflater = LayoutInflater.from(
parent.getContext());
View v =
inflater.inflate(R.layout.custom_cards_layout, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
final String name = values.get(position);
holder.tv.setText(name);
final int[] counter={0};
holder.deleted.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
remove(position);
}
});
holder.decrement.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (counter[0] == 0) {
Toast.makeText(v.getContext(), "Can't add less than 0", Toast.LENGTH_SHORT).show();
} else {
counter[0] -= 1;
holder.counter_value.setText(String.valueOf(counter[0]));
}
}
});
holder.increment.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
holder.decrement.setEnabled(true);
counter[0] += 1;
holder.counter_value.setText(String.valueOf(counter[0]));
}
});
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return values.size();
}
}
If anyone knows this problem please inform me.
Thanks in advance
Well, I'm seeing some bad practices in your code:
Adapters hosted in main activity must be not static, what do you think if try accessing via recyclerView.getAdapter()
Please remove the next one in your adapter
final MainActivity mainActivity = new MainActivity();
So the problem that you are having is inside your click listener.
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String s = editText.getText().toString();
if (s.isEmpty()) {
Toast.makeText(MainActivity.this, "You can't enter empty spaces", Toast.LENGTH_SHORT).show();
} else {
input.add(s); // <-------------- HERE
recyclerView2.setAdapter(mAdapter);
dialogBuilder.dismiss();
}
}
});
You add the new item to the array, however, the adapter never knows that there is a new item has been added.
Access to the instanced adapter which has been attached to RecyclerView in onCreate() step and update their data.
I am trying to create a note-taking app focusing on color-changing.
In one of the activity, I am trying to implement item addition and deletion to the note
picture_of_the_activity.
Item addition obviously works as intended.
The problem is with the deletion, it is very inconsistent: when I delete all the item starting from the last one upward, everything work fine; if I delete items in another order the adapter mess up, do not always delete the correct one and crashes when removing the last item.
I looked it up and found some possible solution (here or in other websites) but couldn't find a solution, or, so I thought.
I created methods inside the adapter addItem() and removeItem() so any changes is done within the class.
Maybe I am misunderstanding a concept or missing something?
Thank you in advance!
some interfaces or protion of the code are missing because I didn't implement some features yet
Activity Code
package com.example.colornoteplus;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Objects;
public class CheckListNoteActivity extends AppCompatActivity{
// note editable views
private EditText titleView;
private TextView titleCharacterCount;
private ImageButton colorView;
private RecyclerView contentView;
private FloatingActionButton fab;
CheckListAdapter adapter;
// toolbar
private Toolbar toolbar;
// Current note
private CheckListNote note;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getNoteFromIntent();
note.getContent().add(new CheckListItem("ONE"));
note.getContent().add(new CheckListItem("TWO"));
note.getContent().add(new CheckListItem("THREE"));
note.getContent().add(new CheckListItem("FOUR"));
note.getContent().add(new CheckListItem("FIVE"));
changeViewsColor(0);
}
// Method used to add menus and configure button action
// like OnClickListeners ...
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Create a submenu for sorting purpose
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_check_list_activity,menu);
return super.onCreateOptionsMenu(menu);
}
// get note from the intent
private void getNoteFromIntent(){
if (!getIntent().getStringExtra(Statics.KEY_NOTE_ACTIVITY).equals(Statics.NOTE_DEFAULT_UID)){
note = MySharedPreferences.LoadCheckListNoteFromSharedPreferences(getIntent().getStringExtra(Statics.KEY_NOTE_ACTIVITY),getApplicationContext());
} else {
note = new CheckListNote();
}
}
private void changeViewsColor(int color){
// set the global theme
setTheme(StyleManager.getTheme(color));
// set the appropriate layout
setContentView(R.layout.activity_check_list_note);
// change status bar color
getWindow().setStatusBarColor(getResources().getColor(StyleManager.getThemeColor(color)));
// set up FAB action
fab = findViewById(R.id.fab_add_item);
fab.setOnClickListener(view -> onFabClickListener());
// setting the toolbar
toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setBackgroundColor(getResources().getColor(StyleManager.getThemeColor(color)));
Objects.requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
// setting the note title
titleView = findViewById(R.id.note_title_view);
titleView.setText("");
titleView.setTextColor(getResources().getColor(StyleManager.getThemeColorDark(color)));
titleView.setHintTextColor(getResources().getColor(StyleManager.getThemeColorLight(color)));
// setting the character counter for the note title
titleCharacterCount = findViewById(R.id.note_title_characters);
String m = titleView.getText().toString().trim().length()+ getString(R.string.text_divider)+ getResources().getInteger(R.integer.title_max_length);
titleCharacterCount.setText(m);
titleCharacterCount.setTextColor(getResources().getColor(StyleManager.getThemeColor(color)));
titleView.addTextChangedListener(new TextWatcher()
{
#Override
public void onTextChanged(CharSequence s, int start, int before, int count)
{
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int aft)
{
}
#Override
public void afterTextChanged(Editable s)
{
// this will show characters remaining
String msg = titleView.getText().toString().length()+ getString(R.string.text_divider)+ getResources().getInteger(R.integer.title_max_length);
titleCharacterCount.setText(msg);
}
});
// setting the color view
colorView = findViewById(R.id.note_color_view);
colorView.setOnClickListener(view -> buildColorPickDialog());
colorView.setBackgroundResource(StyleManager.getBackground(color));
adapter = new CheckListAdapter(getApplicationContext(),note.getContent(),color);
adapter.setOnItemClickListener(new CheckListAdapter.OnItemClickListener() {
#Override
public void onChecked(int position) {
Toast.makeText(CheckListNoteActivity.this, "Checked item: " +position, Toast.LENGTH_SHORT).show();
}
#Override
public void onUnchecked(int position) {
Toast.makeText(CheckListNoteActivity.this, "Unchecked item: " +position, Toast.LENGTH_SHORT).show();
}
#Override
public void onSetPriority(int position) {
}
#Override
public void onSetReminder(int position) {
}
#Override
public void onDelete(int position) {
adapter.removeItem(position);
Toast.makeText(CheckListNoteActivity.this, "List has "+note.getContent().size()+" elements", Toast.LENGTH_SHORT).show();
}
});
contentView = findViewById(R.id.note_content_view);
contentView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
contentView.setAdapter(adapter);
}
private void switchColor(int color){
String tempTitle = titleView.getText().toString().trim();
changeViewsColor(color);
titleView.setText(tempTitle);
}
// build the color picker dialog
private void buildColorPickDialog(){
FragmentPickColor fragment = new FragmentPickColor(new ColorAdapter(),5,note.getColor());
fragment.show(getSupportFragmentManager(),Statics.TAG_FRAGMENT_COLOR_PICK);
fragment.setOnItemClickListener(new ColorAdapter.OnItemClickListener() {
#Override
public void OnClickListener(int position) {
note.setColor(position);
switchColor(position);
fragment.dismiss();
}
#Override
public void OnLongClickListener(int position) {
}
});
}
private void onFabClickListener(){
FragmentAddCheckListItem fragment = new FragmentAddCheckListItem(note.getColor());
fragment.show(getSupportFragmentManager(),Statics.TAG_FRAGMENT_ADD_CHECK_LIST_ITEM);
fragment.setOnClickListener(new FragmentAddCheckListItem.OnClickListener() {
#Override
public void onConfirmClickListener() {
fragment.getItem().setDescription(fragment.getInputText());
adapter.addItem(fragment.getItem(),0);
fragment.dismiss();
}
#Override
public void onSetPriorityClickListener() {
}
#Override
public void onSetDueTimeClickListener() {
FragmentDatePicker datePicker = new FragmentDatePicker();
datePicker.show(getSupportFragmentManager(),Statics.TAG_FRAGMENT_DATE_PICKER);
datePicker.setOnDateSet((year, month, day) -> {
Calendar c = Calendar.getInstance();
c.set(Calendar.YEAR,year);
c.set(Calendar.MONTH,month);
c.set(Calendar.DAY_OF_MONTH,day);
fragment.getItem().setDueDate(c.getTime().getTime());
fragment.setDueTimeText(DateFormat.getDateInstance().format(new Date(fragment.getItem().getDueDate())));
});
}
});
}
}
Adapter
package com.example.colornoteplus;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.recyclerview.widget.RecyclerView;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
public class CheckListAdapter extends RecyclerView.Adapter<CheckListAdapter.MyViewHolder> {
public CheckListAdapter(Context context,ArrayList<CheckListItem> list, int color) {
this.list = list;
this.color = color;
this.context = context;
}
final private ArrayList<CheckListItem> list;
final private int color;
final private Context context;
private OnItemClickListener listener;
#NonNull
#Override
public CheckListAdapter.MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new CheckListAdapter.MyViewHolder(LayoutInflater.
from(parent.getContext()).
inflate(R.layout.item_check_list,parent,false));
}
#Override
public void onBindViewHolder(#NonNull CheckListAdapter.MyViewHolder holder, int position) {
CheckListItem currentItem = list.get(position);
holder.background.setBackgroundResource(StyleManager.getBackgroundLight(color));
holder.checkBox.setOnCheckedChangeListener((compoundButton, b) -> {
if (b) listener.onChecked(position);
else listener.onUnchecked(position);
});
holder.title.setTextColor(context.getResources().getColor(StyleManager.getThemeColorDark(color)));
holder.title.setHintTextColor(context.getResources().getColor(StyleManager.getThemeColor(color)));
assert currentItem != null;
holder.title.setText(currentItem.getDescription().trim());
holder.dueTimeText.setTextColor(context.getResources().getColor(StyleManager.getThemeColor(color)));
holder.dueTimeText.setText(currentItem.getDoneDate() != -1 ? DateFormat.getDateInstance().format(new Date(currentItem.getDueDate())) : context.getString(R.string.set_reminder));
holder.dueTimeText.setOnClickListener(view -> listener.onSetReminder(position));
holder.priorityText.setTextColor(context.getResources().getColor(StyleManager.getThemeColor(color)));
holder.priorityText.setText(currentItem.priorityToString(context));
holder.priorityText.setOnClickListener(view -> listener.onSetPriority(position));
holder.delete.setBackgroundResource(StyleManager.getBackground(color));
holder.delete.setOnClickListener(view -> {
// listener.onDelete(position);
removeItem(position);
});
}
#Override
public int getItemCount() {
return list.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder{
CheckBox checkBox;
ConstraintLayout background;
EditText title;
ImageButton delete;
TextView priorityText,dueTimeText;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
checkBox = itemView.findViewById(R.id.item_check_box);
title = itemView.findViewById(R.id.item_title);
dueTimeText = itemView.findViewById(R.id.item_due_time_text);
priorityText = itemView.findViewById(R.id.item_priority_text);
delete = itemView.findViewById(R.id.item_delete);
background = itemView.findViewById(R.id.item_background);
}
}
public void addItem(CheckListItem item,int position){
if (position < 0){
list.add(item);
notifyItemInserted(list.size()-1);
}
else {
list.add(position,item);
notifyItemInserted(position);
}
}
public void removeItem(int position){
list.remove(position);
notifyItemRemoved(position);
}
public void setOnItemClickListener(OnItemClickListener listener){
this.listener = listener;
}
public interface OnItemClickListener{
void onChecked(int position);
void onUnchecked(int position);
void onSetPriority(int position);
void onSetReminder(int position);
void onDelete(int position);
}
}
public void addItem(CheckListItem item, int position) {
if (position >= 0) {
list.add(position, item);
notifyItemInserted(position);
}
}
public void removeItem(int position) {
if (position >= 0) {
list.remove(position);
notifyItemRemoved(position);
}
}
And in onBindViewHolder use holder.getAdapterPosition() instead of position in your listeners like this:
holder.delete.setOnClickListener(view -> {
// listener.onDelete(position);
removeItem(holder.getAdapterPosition());
});
I've tried to set up a click and toch listener for my RecyclerView with tutorials. But every tutorial I've tried I finaly failed because I've set the RecyclerView up with an other tutorial and all tutorials are looking different. Please can you help me detect click for each row? For example when a user clicks my first row (which is a logout field) it should logout the user from the app. All of my logout actions are working but the click on RecyclerView don't.
My SettingsAdapter:
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
/**
* Created by Johannes on 19.01.2017.
*/
public class SettingsAdapter extends RecyclerView.Adapter<SettingsAdapter.MySettingHolder> {
private List<Settings> settingList;
public class MySettingHolder extends RecyclerView.ViewHolder {
public ImageView settingImage;
public TextView settingTitle, settingSubtitle;
public MySettingHolder(View view) {
super(view);
settingImage = (ImageView) view.findViewById(R.id.settingImage);
settingTitle = (TextView) view.findViewById(R.id.settingTitle);
settingSubtitle = (TextView) view.findViewById(R.id.settingSubtitle);
}
}
public SettingsAdapter (List<Settings> settingList) {
this.settingList = settingList;
}
#Override
public MySettingHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.settings_list_row, parent, false);
return new MySettingHolder(itemView);
}
#Override
public void onBindViewHolder(MySettingHolder holder, int position) {
// Setting for one entry
Settings setting = settingList.get(position);
holder.settingImage.setImageResource(setting.getSettingImageUrl());
// If the settingSubtitle is empty it should be not visible and just the settingTitle
if (setting.getSettingSubtitle().equals("")) {
holder.settingTitle.setText(setting.getSettingTitle());
holder.settingSubtitle.setVisibility(View.GONE);
} else {
holder.settingTitle.setText(setting.getSettingTitle());
holder.settingSubtitle.setText(setting.getSettingSubtitle());
}
}
#Override
public int getItemCount() {
return settingList.size();
}
}
This is my SettingsFragment where I implement the RecyclerView
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CalendarView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import static android.content.Context.MODE_PRIVATE;
/**
* A simple {#link Fragment} subclass.
* Activities that contain this fragment must implement the
* {#link SettingsFragment.OnFragmentInteractionListener} interface
* to handle interaction events.
* Use the {#link SettingsFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class SettingsFragment extends Fragment {
// Variables
private OnFragmentInteractionListener mListener;
// Variables for Recycler View
private List<Settings> settingList = new ArrayList<>();
private RecyclerView accountRecyclerView;
private SettingsAdapter aAdapter;
public SettingsFragment() {
// Required empty public constructor
}
//Change the title in action bar
public void onResume(){
super.onResume();
String titleString = getResources().getString(R.string.title_activity_navigation_drawer_settings);
// Set title bar
((NavigationDrawerActivity) getActivity())
.setActionBarTitle(titleString);
}
public static SettingsFragment newInstance() {
SettingsFragment fragment = new SettingsFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_settings, container, false);
accountRecyclerView = (RecyclerView) view.findViewById(R.id.account_recycler_view);
aAdapter = new SettingsAdapter(settingList);
RecyclerView.LayoutManager aLayoutManager = new LinearLayoutManager(getActivity().getApplicationContext()) {
// Disable scrolling in the RecyclerView
#Override
public boolean canScrollVertically() {
return false;
}
};
// Setup account RecyclerView
accountRecyclerView.setLayoutManager(aLayoutManager);
accountRecyclerView.setItemAnimator(new DefaultItemAnimator());
prepareAccountData();
accountRecyclerView.setAdapter(aAdapter);
return view;
}
private void prepareAccountData() {
// Create new setting
Settings setting = new Settings(R.drawable.ic_menu_logout, "Abmelden", "Deine Daten bleibe erhalten");
// Add Object to list
settingList.add(setting);
// Notify data changes
aAdapter.notifyDataSetChanged();
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
}
#Override
public void onStart() {
super.onStart();
try {
mListener = (OnFragmentInteractionListener) getActivity();
} catch (ClassCastException e) {
throw new ClassCastException(getActivity().toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
#Override
public void onBindViewHolder(MySettingHolder holder, int position) {
// Setting for one entry
Settings setting = settingList.get(position);
holder.settingImage.setImageResource(setting.getSettingImageUrl());
// If the settingSubtitle is empty it should be not visible and just the settingTitle
if (setting.getSettingSubtitle().equals("")) {
holder.settingTitle.setText(setting.getSettingTitle());
holder.settingSubtitle.setVisibility(View.GONE);
} else {
holder.settingTitle.setText(setting.getSettingTitle());
holder.settingSubtitle.setText(setting.getSettingSubtitle());
}
holder.type = setting.getType();
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MySettingHolder holder = (MySettingHolder )(v.getTag());
switch (holder.type) {
case 1:
// do logout
break;
case 2:
// do other stuff
break;
default:
break;
}
}
});
// set viewholder
holder.itemView.setTag(holder);
}
Also remind to update your ViewHolder like this and to add a type variable into Settings.class
public class MySettingHolder extends RecyclerView.ViewHolder {
public int type;
public ImageView settingImage;
public TextView settingTitle, settingSubtitle;
public MySettingHolder(View view) {
super(view);
settingImage = (ImageView) view.findViewById(R.id.settingImage);
settingTitle = (TextView) view.findViewById(R.id.settingTitle);
settingSubtitle = (TextView) view.findViewById(R.id.settingSubtitle);
}
}
Im new to android programming so can you provide me the right code.
this is my code. the data is from sqlite. my problem is . How can i get the 3 textview from recyclerview and pass it to dialogbox when clicked? i finally made dialogbox but i can get only the position of the item i want to get all of the three textview data. please help me.
FragmentMeal.java
package inncharge.poy.madrigal.innchargev1.fragments;
import android.app.Dialog;
import android.content.Context;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import inncharge.poy.madrigal.innchargev1.R;
import inncharge.poy.madrigal.innchargev1.database.DatabaseHelper;
import inncharge.poy.madrigal.innchargev1.adapters.VivzAdapter;
/**
* A simple {#link Fragment} subclass.
* Use the {#link FragmentMeal#newInstance} factory method to
* create an instance of this fragment.
*/
public class FragmentMeal extends Fragment {
private DatabaseHelper db;
private RecyclerView recyclerView;
private VivzAdapter adapter;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment FragmentMeal.
*/
// TODO: Rename and change types and number of parameters
public static FragmentMeal newInstance(String param1, String param2) {
FragmentMeal fragment = new FragmentMeal();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public FragmentMeal() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
db = new DatabaseHelper(getActivity());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_meal, container, false);
recyclerView = (RecyclerView) view.findViewById(R.id.mealList);
adapter = new VivzAdapter(getActivity(),db.getMealData());
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.addOnItemTouchListener(new RecyclerTouchListener(getActivity(), recyclerView, new ClickListener() {
#Override
public void onClick(View view, int postion) {
final Dialog dialog = new Dialog(getActivity());
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
dialog.setContentView(R.layout.custom_dialog);
dialog.show();
final EditText editText = (EditText)dialog.findViewById(R.id.editText_pin);
Button submitButton = (Button)dialog.findViewById(R.id.submit_button);
Button cancelButton = (Button)dialog.findViewById(R.id.cancel_button);
submitButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String text = editText.getText().toString();
Toast.makeText(getActivity(), "Pin submitted is : " + text, Toast.LENGTH_SHORT).show();
dialog.cancel();
}
});
cancelButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.cancel();
}
});
}
#Override
public void onLongClick(View view, int position) {
Toast.makeText(getActivity(), "onLongClick" + position, Toast.LENGTH_SHORT).show();
}
}));
return view;
}
class RecyclerTouchListener implements RecyclerView.OnItemTouchListener {
private GestureDetector gestureDetector;
private ClickListener clickListener;
public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener){
Log.d("VIVZ", "constructor invoked ");
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener(){
#Override
public boolean onSingleTapUp(MotionEvent e) {
Log.d("VIVZ","onSingleTapUp " + e);
return true;
}
#Override
public void onLongPress(MotionEvent e) {
View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null){
clickListener.onLongClick(child, recyclerView.getChildAdapterPosition(child));
}
Log.d("VIVZ", "onLongPress " + e);
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child = rv.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)){
clickListener.onClick(child, rv.getChildAdapterPosition(child));
}
return false;
}
#Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
Log.d("VIVZ","onTouchEvent "+ e);
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
public static interface ClickListener {
public void onClick(View arg1, int arg2);
public void onLongClick(View view, int position);
}
}
VivzAdapter.java
package inncharge.poy.madrigal.innchargev1.adapters;
import android.content.ClipData;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Collections;
import java.util.List;
import inncharge.poy.madrigal.innchargev1.R;
import inncharge.poy.madrigal.innchargev1.fragments.FragmentMeal;
import inncharge.poy.madrigal.innchargev1.pojo.Contact;
import inncharge.poy.madrigal.innchargev1.pojo.Information;
/**
* Created by Madrigal on 7/18/2015.
*/
public class VivzAdapter extends RecyclerView.Adapter<VivzAdapter.MyViewHolder> {
private Context context;
private final LayoutInflater inflater;
List<Contact> data = Collections.emptyList();
public VivzAdapter(Context context, List<Contact> data){
this.context=context;
inflater = LayoutInflater.from(context);
this.data=data;
}
public void delete(int position){
data.remove(position);
notifyItemRemoved(position);
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.custom_row, parent, false);
Log.d("VIVZ","onCreateHolder called ");
MyViewHolder holder = new MyViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Contact current = data.get(position);
Log.d("VIVZ", "onBindViewHolder called " + position);
holder.itemId.setText(String.valueOf(current.getId()));
holder.title.setText(current.getName());
holder.email.setText(current.getEmail());
}
#Override
public int getItemCount() {
return data.size();
}
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView title;
public TextView email;
public TextView itemId;
public MyViewHolder(View itemView) {
super(itemView);
title = (TextView) itemView.findViewById(R.id.listTextName);
email = (TextView) itemView.findViewById(R.id.listTextUname);
itemId = (TextView) itemView.findViewById(R.id.listTextId);
}
#Override
public void onClick(View v) {
}
}
}
Slidenerd makes some great videos, he helped me a lot as well when I started.
You might want to reconsider what you're trying to do and approach it differently... Why would you want to pass 3 textview from your UI into a dialog?
This is going to be painful.
Seems like you're going to have to extend DialogFragment (i'm assuming that's what you're using for a dialog, maybe an alert?). Create a static factory method inside the DialogFragment like this...
public class MyDialog extends DialogFragment {
private static tv1, tv2, tv3;
public static MyDialog newInstance(TextView tv1, TextView tv2, TextView tv3){
MyDialog.tv1 = tv1;
MyDialog.tv2 = tv2;
MyDialog.tv3 = tv3;
return new MyDialog();
}
}
Once you have this complete, create this dialog fragment inside that onClick method in the ViewHolder class. Instantiate the DialogFragment by doing this...
MyDialog.newInstance(title,email,itemId).show(getFragmentManager(),"dialog_tag");
Like i said before, it's seems sloppy and is probably error prone. There may be a better way of doing this but this is all I can think of off the top of my head. Let me know how it works out for you.. or perhaps revise your question so we can better help you reach a better solution to what you're trying to do.
For demonstration, I have a ListView displaying a list of numbers. I would like to achieve the effect that when the user scrolls the ListView and the scrolling ends, it will only stop at certain positions so that the first visible item is always shown completely. I've attached my attempted code below. It works when users drag to scroll the ListView. But when there's fling, the normal acceleration is interrupted, causing an unnatural stop. My question is, how can I take acceleration caused by fling into account while achieving the same effect?
package com.example.snaptest;
import android.content.Context;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
private static class TestListViewAdapter extends BaseAdapter {
private Context mContext;
public TestListViewAdapter(Context context) {
mContext = context;
}
#Override
public int getCount() {
return 100;
}
#Override
public Object getItem(int position) {
return Integer.toString(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView textView = new TextView(mContext);
textView.setText(Integer.toString(position));
AbsListView.LayoutParams params = new AbsListView.LayoutParams(ViewGroup.LayoutParams
.MATCH_PARENT, 180);
textView.setLayoutParams(params);
return textView;
}
}
private static class TestListView extends ListView {
public TestListView(Context context) {
super(context);
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_UP || ev.getAction() == MotionEvent.ACTION_CANCEL) {
View itemView = getChildAt(0);
int top = Math.abs(itemView.getTop()); // top is a negative value
int bottom = Math.abs(itemView.getBottom());
if (top >= bottom){
smoothScrollToPositionFromTop
(getFirstVisiblePosition() + 1, 0);
} else {
smoothScrollToPositionFromTop
(getFirstVisiblePosition(), 0);
}
}
return super.onTouchEvent(ev);
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TestListView listView = new TestListView(this);
listView.setAdapter(new TestListViewAdapter(this));
setContentView(listView);
}
}
I would try with an OnScrollListener rather than extending ListView.
Something like this:
listView.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (scrollState == AbsListView.SCROLL_STATE_IDLE) {
// snap the listview according to the top/bottom items' visibility
}
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
}
});