Develop Reference

How to change several texts on button click in android studio

HELP ME PLEASE! I want to create 2 buttons ("Next" and "Previous") that will change the text in TextView. I made a switch and "systemcounter" to change the cases, which then will set another text in TextView. When I test my program in this window buttons do not change the pages. I think this is because the system cannot see the "systemcounter"
private Button next_button;
private Button previous_button;
private TextView Text_set1;
int systemcounter = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_learningpage);
next_button = (Button) findViewById(R.id.next_button);
previous_button = (Button) findViewById(R.id.previous_button);
Text_set1 = (TextView) findViewById(R.id.Text_set);
next_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
systemcounter = systemcounter + 1;
}
});
previous_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
systemcounter = systemcounter - 1;
}
});
switch (systemcounter) {
case (0):
Text_set1.setText("Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.");
previous_button.setVisibility(View.INVISIBLE);
break;
case (1):
Text_set1.setText("Hi there");
previous_button.setVisibility(View.VISIBLE);
break;
case (2):
Text_set1.setText("How are you");
previous_button.setVisibility(View.VISIBLE);
break;
case (3):
Text_set1.setText("How old are you?");
break;
default:
Text_set1.setText("OPS");
break;
}```

you have switch statement in oncreate method and so it executes it only once, make a seperate method like
setEditText(int systemcount) and create your switch tehre and call this methods from button onclick methods

private void setText() {
switch (systemcounter) {
case (0):
Text_set1.setText("Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.");
previous_button.setVisibility(View.INVISIBLE);
break;
case (1):
Text_set1.setText("Hi there");
previous_button.setVisibility(View.VISIBLE);
break;
case (2):
Text_set1.setText("How are you");
previous_button.setVisibility(View.VISIBLE);
break;
case (3):
Text_set1.setText("How old are you?");
break;
default:
Text_set1.setText("OPS");
break;
}
}
and call this method in your listeners (like this)
next_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
systemcounter = systemcounter + 1;
setText();
}
});

How to validate which checkbox is checked?

I am new to android ,Here I have 7 check boxes in my application and I have customized it as in the image .Each checkbox is represents a day of the week .
What I want to do is ,If a user clicked on a checkbox the text of the clicked checkbox should appear on the above TextView (by default if there is any checkbox is not clicked Textview text should be as "Never").
Here the Textview text should be in a ordered way ,I mean If I select all the check boxes randomly but the TextView text should be in a ordered way like Sun,Mon,.....Sat.
I know how to validate a checkbox is checked or not ,but When it comes to the above situation I don't know how it should be .
Can anyone help me to get this .
private TreeMap<Integer, String> mAlarmDays = new TreeMap<>();
public void onClick(View v) {
switch (v.getId()) {
case R.id.mSun:
if (mRepeat.getText().toString().contains("Sun")) {
mAlarmDays.remove(0);
Toast.makeText(getApplicationContext(),"Sun is clicked",Toast.LENGTH_LONG).show();
} else
mAlarmDays.put(0, "Sun");
break;
case R.id.mMon:
if (mRepeat.getText().toString().contains("Mon")) {
mAlarmDays.remove(1);
} else
mAlarmDays.put(1, "Mon");
break;
case R.id.mTue:
if (mRepeat.getText().toString().contains("Tue")) {
mAlarmDays.remove(2);
} else
mAlarmDays.put(2, "Tue");
break;
case R.id.mWed:
if (mRepeat.getText().toString().contains("Wed")) {
mAlarmDays.remove(3);
} else
mAlarmDays.put(3, "Wed");
break;
case R.id.mThu:
if (mRepeat.getText().toString().contains("Thu")) {
mAlarmDays.remove(4);
} else
mAlarmDays.put(4, "Thu");
break;
case R.id.mFri:
if (mRepeat.getText().toString().contains("Fri")) {
mAlarmDays.remove(5);
} else
mAlarmDays.put(5, "Fri");
break;
case R.id.mSat:
if (mRepeat.getText().toString().contains("Sat")) {
mAlarmDays.remove(6);
} else
mAlarmDays.put(6, "Sat");
break;
}
StringBuilder repeatDays = new StringBuilder();
if (mAlarmDays.size() == 0) {
repeatDays = new StringBuilder("Never");
} else {
for (String day:mAlarmDays.values()) {
repeatDays.append(day).append(" ");
}
}
mRepeat.setText(repeatDays.toString());
}

I suggest to create one checkbox listener for all checkboxes which will iterate over them and build string for textview
Something like this:
CheckBox sunday = ...;
CheckBox monday = ...;
//......
CheckBox saturday = ...;
TextView label = ...;
CompoundButton.OnCheckedChangeListener changeListener = new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
List<String> days = new ArrayList<>();
if (sunday.isChecked()) {
days.add("Sun");
}
if (monday.isChecked()) {
days.add("Mon");
}
//....
if (saturday.isChecked()) {
days.add("Sat");
}
if (days.size() != 0) {
label.setText(TextUtils.join(", ", days));
} else {
label.setText("Never");
}
}
};
sunday.setOnCheckedChangeListener(changeListener);
monday.setOnCheckedChangeListener(changeListener);
//......
saturday.setOnCheckedChangeListener(changeListener);

It really depends how you have the text set... but you can do something like.
if (checkBox.isChecked()) {
System.out.println("checkBox clicked");
}

try this for every checkbox.
CheckBox checkBox = (CheckBox)v;
if(checkBox.isChecked()){
Log.i("Checkbox", "Checkbox selected.");
}else{
Log.i("Checkbox", "Checkbox Not selected.");
}

click a button for diffrent time

I've a Button for 8 CheckBoxs and i want when i click on button a piece of my code running for example case 1 in this code for showing tick on chk1 (note.done1) .and for second time when i clicked on button,my app recognize chk1 is checked and now checking chk2(note.done2) and too for 6 another CheckBoxs.
but this code is wrong because when i click on button, chk1 and chk3 and chk5 are true.also I'm trying else if and Sharedpreferences and array .
i can't use ischecked() method because i use listview with 1000(in less) item.just i can use note.done where link to checkboxs in each item .i can use array where link to each checkboxs and sqlite too!
so can anyone help me?
btnOk.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
switch (G.result_s1[position]) {
case 0: {
note.done1 = true;
note.c = Color.RED;
G.database_s.execSQL("UPDATE mystate SET s1='1' WHERE s_id=" + (position + 1));
G.result_s1[position] = 1;
//AdapterNote.img.setBackgroundColor(Color.CYAN);
}
break;
case 1:
{
note.done2 = true;
note.c = Color.GREEN;
G.database_s.execSQL("UPDATE mystate SET s2='1' WHERE s_id=" + (position + 1));
G.result_s2[position] = 1;
}
break;
}
switch (G.result_s3[position]) {
case 0: {
note.done3 = true;
note.c = Color.MAGENTA;
G.database_s.execSQL("UPDATE mystate SET s3='1' WHERE s_id=" + (position + 1));
G.result_s3[position] = 1;
}
break;
case 1: {
note.done4 = true;
note.c = Color.YELLOW;
G.database_s.execSQL("UPDATE mystate SET s4='1' WHERE s_id=" + (position + 1));
G.result_s4[position] = 1;
}
break;
}
dialog.dismiss();
finish();
}
});

Why don't you use ischecked()?
Whenever you click the button you check another checkbox
btnOk.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
if(!checkbox1.ischecked()){
// check checkbox1
}else if(checkbox1.ischecked()){
// check checkbox2
}else if(checkbox1.ischecked() && checkbox2.ischecked()){
// check checkbox3
}....
}
}

Multiple OnClickListeners Android

I have 10 buttons set up which are the answers to ten questions. When a certain button is clicked, I have a switch statement set up in my onClick method shown below. My question is what is the best way to set up the OnClickListeners for all the buttons seeing that I need to pass 2 arrays to the onClick method in order to tell if it is correct or not? Also, I need to return and integer value. Thanks
public void onClick(View v, int[] qaarray, int questionorder) {
int x=0;
switch(v.getId())
{
case R.id.imageButton0:
if(qaarray[0] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton1:
if(qaarray[1] == questionorder){
// correct
}else{
//incorrect
}
break;
case R.id.imageButton2:
if(qaarray[2] == questionorder){
// correct
}else{
//incorrect
}
break;
case R.id.imageButton3:
if(qaarray[3] == questionorder){
// correct
}else{
//incorrect
}
break;
case R.id.imageButton4:
if(qaarray[4] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton5:
if(qaarray[5] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton6:
if(qaarray[6] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton7:
if(qaarray[7] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton8:
if(qaarray[8] == questionorder){
//correct
}else{
//incorrect
}
break;
case R.id.imageButton9:
if(qaarray[9] == questionorder){
//correct
}else{
//incorrect
}
break;
default:
throw new RuntimeException("Unknown button ID");
}
}

The OnClickListener only gives you one parameter, which is the View:
void onClick(View v);
But you don't have to pass the questions and 'order' to the method to have what you want. One of the technique you can use is the setTag() method of View:
int[] button = new int[] { R.id.imageButton1, R.id.imageButton2.... };
private class AnswerPair{
public int questionOrder;
public int answer;
}
public void onCreate(Bundle bundle){
for(int i=0; i<NO_OF_BUTTON; i++){
AnswerPair ans = new AnswerPair();
ans.questionOrder = i;
ans.answer = 0; // SET this
getViewById(button[i]).setTag(ans);
getViewById(button[i]).setOnClickListener(this);
}
}
public void onClick(View v){
if (v.getTag() == null) return;
try{
AnswerPair answer = (ans)v.getTag();
// Check answer == question order? index?
}catch(exception e) return;
}

You can implement as many OnClickListeners as you want and assign different listeners for each button.
public void onCreate(Bundle bundle){
setContentView(R.layout.main);
Button b = (Button) findViewById(R.id.myButton)
b.setOnClickListener(new MyListener());
}
private class MyListener implements OnClickListener {
#Override
public void onClick(View v) {
// Your code here
}
}

i think a lot of people know this already, but there's a shortcut you can use instead of having different instances of onClickListeners and assigning them in code using setOnClickListener(x).
In your button XML, give it the android:onClick property, and assign it a string you like, for example,
android:onClick="clickOne"
In the activity the sets this xml as its content view, create a method named clickOne with a View parameter.
public void clickOne(View view)
Whatever you place on this method will be executed when you click the button.

How to disable button click?

In my android application, there are number of images in drawable folder. In my layout there are two buttons: Back and Next buttons. On clicking next and back buttons 2 different images get loaded on the same layout(common for all images).
Problem:I am able to load images on Next/Back button's click but after reaching the last image, I want to make my Next button disable and same for the back button.As the user is on the first image the back button should be disabled. Code is as:
public class SequencerActivity extends Activity implements OnClickListener
{
private int imageCounter = 0;
private ImageView imageLoader;
private int[] imageList = {R.drawable.image_wo_lbl_0, R.drawable.image_wo_lbl_1, R.drawable.image_wo_lbl_2, R.drawable.image_wo_lbl_3, R.drawable.image_wo_lbl_4, R.drawable.image_wo_lbl_5,
R.drawable.image_wo_lbl_6, R.drawable.image_wo_lbl_8, R.drawable.image_wo_lbl_9,R.drawable.image_wo_lbl_10, R.drawable.image_wo_lbl_11};
#Override
public void onCreate(Bundle savedInstanceState)
{
setContentView(R.layout.parent_frame);//this one is the common parent layout for all image views
super.onCreate(savedInstanceState);
/*requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);*/
//int image1 = R.drawable.image_w_lbl_0;
imageLoader = (ImageView) findViewById(R.id.imageLoader);
//imageLoader.setImageResource(image1);
ImageButton next = (ImageButton) findViewById(R.id.next);
ImageButton back = (ImageButton) findViewById(R.id.back);
next.setOnClickListener(this);
back.setOnClickListener(this);
//show the default image
this.loadImage(imageList[imageCounter]);
}
#Override
public void onClick(View v)
{
int imagePath = 0;
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.next:
Log.i("Tag","tag");
if(imageCounter < imageList.length)
{
imageCounter++;
imagePath = imageList[imageCounter];
if (imageCounter==(imageList.length)-1)
{
//how to make my next button disable
}
}
break;
case R.id.back:
if(imageCounter > 0)
{
imageCounter--;
imagePath = imageList[imageCounter];
if (imageCounter==0)
{
//how to make my back button disable
}
}
break;
}
this.loadImage(imagePath);
}
private void loadImage(int imagePath)
{
imageLoader.setImageResource(imagePath);
}
}

KOTLIN:
next.isClickable = false
JAVA:
next.setClickable(false);

case R.id.next:
Log.i("Tag","tag");
if(imageCounter < imageList.length)
{
imageCounter++;
imagePath = imageList[imageCounter];
if (imageCounter==(imageList.length)-1)
{
ImageButton next=(ImageButton)findViewBYId(R.id.next);
next.setEnabled(false);
}
}
break;
case R.id.back:
if(imageCounter > 0)
{
imageCounter--;
imagePath = imageList[imageCounter];
if (imageCounter==0)
{
ImageButton back=(ImageButton)findViewBYId(r.id.back);
back.setEnabled(false);
}
}
break;

more preferred solution is,
onclick(){
btn.setEnabled(false);
btn.setClickable(false);
//yourwork
myWork();
}
myWork(){
//your tasks.
btn.setEnabled(true);
btn.setClickable(true);
}
As a link can be ignored easily, I had to repeat this again and again

With kotlin you can disable a button with
button.isEnabled = false
or to disable clicking on it
button.isClickable = false

For Kotlin you can use this
override fun onClick(v: View) {
when (v.id) {
R.id.cancel_button -> {
button.isClickable = false
button.isEnabled = false
}
}
}

just insert two extra images in your drawable folder one for disabled right arrow and one for disabled left arrow.
now try this
case R.id.next:
Log.i("Tag","tag");
if(imageCounter < imageList.length)
{
imageCounter++;
imagePath = imageList[imageCounter];
if (imageCounter==(imageList.length)-1)
{
//disabling right button by changing image from following code
next.setImageDrawable(getResources().getDrawable(R.drawable.right_disabled));
}
}
break;
case R.id.back:
if(imageCounter > 0)
{
imageCounter--;
imagePath = imageList[imageCounter];
if (imageCounter==0)
{
back.setImageDrawable(getResources().getDrawable(R.drawable.left_disabled));
}
}
break;