Develop Reference

Changing the Color of the Dynamically loaded Buttons onclick

Android: I have created dynamic buttons based on my arraylist size,Lets consider 10 buttons. When a button is clicked, the color of the button will change to grey. When another one is clicked, the color of the previous button should be reset to the default color.
boolean iscolor = true;
final LinearLayout linearLayout = view.findViewById(R.id.total_count);
final LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
for (int j =1;j<=datalist.size()/2;j++) {
final Button btn = new Button(getContext());
final int id_ = j;
btn.setText("" + j);
btn.setTextColor(Color.WHITE);
btn.setMaxWidth(5);
btn.setId(id_);
btn.setPadding(8, 8, 8, 8);
btn.setBackgroundColor(getContext().getResources().getColor(R.color.DarkBlue));
linearLayout.addView(btn, params);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!iscolor ) {
btn.setBackgroundColor(getResources().getColor(R.color.DarkBlue));
iscolor =true;
}
else
{
btn.setBackgroundColor(getResources().getColor(R.color.gray));
iscolor = false;
}
}});
How to restore the color of the previous clicked Button in Android.

Try this :
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
/* you need to have already stored buttons in a data structure, something like : List<Button> btns; */
for(Button b : btns){
if(b.getId() == v.getId(){ b.setBackgroundColor(getResources().getColor(R.color.gray)); } else{ b.setBackgroundColor(getResources().getColor(R.color.yourdefaultcolor)); } //no need for isColor variable
}});
linearLayout.addView(btn, params);

Table with Radiobuttons in Android

I am looking for something similar in android where I can add radiobuttons to each cells in Table and get their position. Does anyone has worked on it before, if you can share the sample code would be helpful. Thanks

The following pseudocode should get you started:
//create a radio group
RadioGroup rg = new RadioGroup(context);
RadioGroup.LayoutParams rgParams = new RadioGroup.LayoutParams(
RadioGroup.LayoutParams.WRAP_CONTENT,
RadioGroup.LayoutParams.WRAP_CONTENT);
rg.setLayoutParams(rgParams);
//add the radio group to the row.
rowView.addView(rg);
//add radio buttons
for (i = 0; i < length; i++) {
RadioButton btn = new RadioButton(context);
btn.setText(description[i]);
//or save an object which will hold all information you need
btn.setTag(rowNumber);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Log.d(TAG, v.getTag());
}
});
if (<some condition>) {
btn.setChecked(true);
}
rg.addView(btn);
}

i made check box dynamically but i can not see them

i have an app that make check box dynamically.
A button and edit text,i insert some thing in the edit text then click button after that a check box with that text appear.
but i have problem with that.
i am completely confuse, i cannot see them!!!! and i do not have any error!!!!????
can some one help me ? :(
...
public int i2 = 0;
...
final EditText et1 = (EditText) findViewById(R.id.editText1);
final Button bnext = (Button) findViewById(R.id.button1);
//
final LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
//
bnext.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//getting text from edit text
String str_et1 = et1.getText().toString();
do {
CheckBox cb = new CheckBox(getApplicationContext());
cb.setId(i2);//set id to each checkbox
cb.setText(str_et1);//set text to each checkbox
ll.addView(cb);
} while (bnext.isDirty());//add when ever i clicked
i2++;//this the counter
}
});

Try this code -
final EditText et1 = (EditText) findViewById(R.id.editText1);
final Button bnext = (Button) findViewById(R.id.button1);
//
final LinearLayout ll = new LinearLayout(this);
LayoutParams params =
new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
ll.setOrientation(LinearLayout.VERTICAL);
ll.setLayoutParams(params);
//
bnext.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//getting text from edit text
String str_et1 = et1.getText().toString();
do {
CheckBox cb = new CheckBox(getApplicationContext());
cb .setLayoutParams(params);
cb.setId(i2);//set id to each checkbox
cb.setText(str_et1);//set text to each checkbox
ll.addView(cb);
} while (bnext.isDirty());//add when ever i clicked
i2++;//this the counter
}
});
Hope this code helps you!!
if its not working please let me know i will try to help more.

A check box alone is not a visible component. You will need to have a LayoutParam, then attach the checkbox to it to make it visible.

Dynamic Buttons and OnClickListener

Say I have buttons that are created dynamically:
for(int j = 0; j < spirits.length;
j++){
Button imgBtn = new Button(v.getContext());
imgBtn.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
imgBtn.setMinimumWidth(100);
imgBtn.setMinimumHeight(100);
imgBtn.setId(j+1);
imgBtn.setTag(spirits[j]);
imgBtn.setText(spirits[j]);
imgBtn.setOnClickListener(new SpiritsClickListener());
cabinet_layout.addView(imgBtn);
}
I want to change the text of the button every time it's pressed (On - Off)
How can I reference the buttons within the OnClickListener class?

in your onClickListener, you have a function called onClick(View v){} where v is the View that was clicked. You may use v to get details about the button, including its ID. You can also take this view, and if you know it is a button, cast it to a button.
Button clicked = (Button)v;
You can then use it in your javacode just as you would normally use a button.

Why don't you just call new OnClickListener() inside that loop like this
for(int j = 0; j < spirits.length;j++){
Button imgBtn = new Button(v.getContext());
imgBtn.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
imgBtn.setMinimumWidth(100);
imgBtn.setMinimumHeight(100);
imgBtn.setId(j+1);
imgBtn.setTag(spirits[j]);
imgBtn.setText(spirits[j]);
imgBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//do what you need to do here
}
});
cabinet_layout.addView(imgBtn);
}

Create an OnClickListener for dynamically created buttons as:
// Create Listener for Button
private OnClickListener SpiritsClickListener = new OnClickListener()
{
#Override
public void onClick(View view) {
// TODO Auto-generated method stub
Button btn = (Button) view;
String btnText = btn.getText();
if(btnText.equalsIgnoreCase("On")){
btn.setText("Off");
}else{
btn.setText("On");
}
}
};
add this Listener to dynamically created buttons as:
imgBtn.setOnClickListener(SpiritsClickListener);

Android OnClickListener throws NullPointerException

A table is being created such that:
TableLayout layout = new TableLayout(this);
layout.setLayoutParams(new TableLayout.LayoutParams(4,5));
layout.setPadding(1, 1, 1, 1);
for(int i=0; i<7; i++) {
TableRow tr = new TableRow(this);
for(int j=0; j<6; j++) {
Button b = new Button(this);
b.setText("0");
b.setOnClickListener(buttonListener);
tr.addView(b);
}
layout.addView(tr);
}
super.setContentView(layout);
The OnClickListener buttonListener is:
View.OnClickListener buttonListener = new View.OnClickListener() {
public void onClick(View v) {
Button thisButton = (Button) findViewById(((Button)v).getId());
//thisButton.setText(Integer.toString(Integer.parseInt((String) thisButton.getText()) + 1));
thisButton.getText();
}
};
The call to thisButton.getText() throws a NullPointerException, and I'm not sure why. Can anyone help me out?

TableLayout layout = new TableLayout(this);
layout.setLayoutParams(new TableLayout.LayoutParams(4,5));
layout.setPadding(1, 1, 1, 1);
for(int i=0; i<7; i++) {
TableRow tr = new TableRow(this);
for(int j=0; j<6; j++) {
Button b = new Button(this);
b.setText("0");
b.setOnClickListener(buttonListener);
tr.addView(b);
}
layout.addView(tr);
}
setContentView(layout);
}
View.OnClickListener buttonListener = new View.OnClickListener() {
public void onClick(View v) {
Button btn1 = (Button)v;
//thisButton.setText(Integer.toString(Integer.parseInt((String) thisButton.getText()) + 1));
String name = btn1.getText().toString();
}
};
I have tested this will work.
When you create view dynamically you don't to assgin an id to it.
you work using the object of the view.
I hope it makes sense to all the people who are curious to set id for dynamic buttons.

One problem in your code.
Have not set id of Button
b.setText("0");
b.setOnClickListener(buttonListener);
b.setId(i);

Assumption:
I can't see anything regarding setting id to button
The below line may causing exception:
Button thisButton = (Button) findViewById(((Button)v).getId());
Why are you doing? Instead you are already passing a view in click action: View v
So you can do straight way like:
String strText = ((Button) v).getText();

It mean your thisButton is probably null, because the statement before that was not successful.
Button thisButton = (Button) findViewById(((Button)v).getId());
does not look right. Usually the paramenter inside findViewById() should be a resource id.
such as
Button thisButton = (Button) findViewById(R.id.button);
R.id.button is defined by your layout xml.

You may simply get the text from the passed view, instead of recreating a button.
public void onClick(View v) {
if(v instanceof Button)
String text = ((Button) v).getText();
}