Passing a value via Button ( maybe hidden) - android

This code was working until last night, but now now. I'm wanting a value to be record that is linked to the buttons, I have used set and get tag but is only returning last value.
//create a layout
LinearLayout layout = (LinearLayout)findViewById(R.id.linearlayout);
// create a list of buttons
for(x=0; x<3; x++)
{
newBut = new Button(this);
newBut.setText("("TEXT");
newBut.setTextColor(Color.parseColor("#FFFFFF"));
newBut.setTag(x); //hide job id within the button.
newBut.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
int newValue = Integer.parseInt(newBut.getTag().toString());
System.out.println(newValue); //this just a test to display the value
}
});
layout.addView(newBut);
}
Is the error obvious - not to me.

It is returning the last value, because in all the created listeners you always reference the same button (last value of newBut variable), ignoring the actual click source view you have as the argument. Is should be:
newBut.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
int newValue = Integer.parseInt(v.getTag().toString());
System.out.println(newValue);
}
});

Related

Changing the background image of Text View whenever the button is pressed

Whenever the user presses the button, the text of the TextView, as well as the background image of TextView, is changed. I have created an int[] array to store the id of drawable to use in TextView.setBackgroundResource(array[index]) . But on incrementing the index the background is not changed. I even tried hardcoded index for array[] but it still sets first element image.
//j and drawable array are global variable.
int j=1;
int[] drawablearray=new int[]{R.drawable.girl,R.drawable.beach,R.drawable.flower};
nextButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(j<drawablearray.length-1){
j++;
quoteTextView.setBackgroundResource(drawablearray[j]);
quoteTextView.getBackground().setAlpha(150);
}else{
j=0;
quoteTextView.setBackgroundResource(drawablearray[j]);
quoteTextView.getBackground().setAlpha(150);
}
});
It seems everthing OK in your code.
Did you initialised nextButton properly?
Probably your click is not working.
UPDATE
I have updated your code:
nextButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(j<drawablearray.length){
quoteTextView.setBackgroundResource(drawablearray[j]);
quoteTextView.getBackground().setAlpha(150);
j++;
}else{
quoteTextView.setBackgroundResource(R.drawable.girl);
quoteTextView.getBackground().setAlpha(150);
}
}
});
For the first 3 clicks it will show three different images then sets to default image
Your j variable must be 'global'. It means that it must a member of your Activity or Fragment but not a variable inside your method
Instead of the "if" condition I suggest you to use:
j = (j+1) % drawablearray.length;
Then the variable j must be a field of your java class (declare it outside every method)

TextView set multiple string into a setText(int resid)

Good morning,
How can I put multiple string ressources inside the setText to display them in order ?
I have a layout with a TextView (id: TxtDisp) and a Button (id: NextSentence) that change the text when I click on it.
NextSentence.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TxtDisp.setText(R.string.sentence_2);
}
});
Where or how can I put four to six string ressources to be display in order when the button is clicked ?
Thanks in advance !
You could put the string resources in an array, and get the string from that. So add a class member to track the which sentence is next
private int nextSentenceId = 0;
then in onCreate use code like this
final int[] sentences = new int[]{R.string.sentence_1, R.string.sentence_2, R.string.sentence_3};
NextSentence.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if( nextSentenceId < sentences.length ) {
TxtDisp.setText(sentences[nextSentenceId]);
++nextSentenceId;
}
}
});
Make sure to catch when you are at the last sentence or you will get an array out of bounds error.
You can do it easily when you hold these strings in an array or something and have a counter that hold which string is displayed right now like so
in onCreate() method put your sentences in an ArrayList
ArrayList<Integer> strings = new ArrayList();
strings.add(R.string.sentence1);
strings.add(R.string.sentence2);
strings.add(R.string.sentence3);
then on the button click you can use the counter and track which is selected
NextSentence.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TxtDisp.setText(strings.get(count++));
}
});
I hope this would help you

Add & delete item from LinearLayout using ArrayAdapter

I am doing bubble display of selected contacts. Each telephone bubble is a LinearLayout, which contains ImageView and TextView. These bubbles are then displayed in another LinearLayout which is child of HorizontalScrollView.
It child/parent tree looks like this:
- HorizontalScrollView
|- LinearLayout (id="#+id/telField")
|- LinearLayout (id="#+id/telBox") <- is programmatically added to parent
|- TextView (id="#+id/telNumber")
|- ImageView (id="#+id/delNumber")
In my .java class I call this method to display "telBox" LinearLayout in "telField" LinearLayout:
public void createAdapter() {
telList = new ArrayAdapter<>(this, R.layout.text_buble, R.id.telNumber, telNumList);
telField = (LinearLayout) findViewById(R.id.telField);
telField.removeAllViews();
final int adapterCount = telNumList.size();
for (ik = 0; ik < adapterCount; ik++) {
final View item = telList.getView(ik, null, null);
telField.addView(item);
item.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
telField.removeView(item);
telNumList.remove(ik-1);
telList.notifyDataSetChanged();
refresh();
}
});
}
}
Method refresh(); – is custom method which helps to "reload" Activity: it gets App values, refreshes warning ImageViews and cals createAdapter() method.
Big button "SELECT" calls an Intent which returns a selected phone number from a contacts book. I call this code to update my LinearLayout with id "telField":
telNumList.add(cursor.getString(cursor.getColumnIndexOrThrow(ContactsContract.CommonDataKinds.Phone.NUMBER)));
createAdapter();
Problem I face is:
After I click on LinearLayout with id "telNumber" it one by one deletes every bubble (no matter which I clicked) until it reaches first added bubble. It also crashes 50/50 when reaches first added element, I have not figured out a dependency. The error it returns is "out of bounds error", so I think it is connected with ik - 1 line.
My question is: How do I better construct my ArrayAdapter?
In your code you are trying to remove the view by ik which is getting change continuously because of which your coding is removing last view I have modified your code as given below
for (ik = 0; ik < adapterCount; ik++) {
final int position=ik;
final View item = telList.getView(ik, null, null);
telField.addView(item);
item.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
telField.removeView(item);
telNumList.remove(position);
telList.notifyDataSetChanged();
//refresh();
createAdapter();
}
});
}
Here position will help you to remove the particular view which you want to remove. I hope this is what you are asking for.
Inside your for loop, write these line of code:
for (ik = 0; ik < adapterCount; ik++) {
final View item = telList.getView(ik, null, null);
item.setTag(ik);
telField.addView(item);
item.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
int index = Integer.parseInt(v.getTag().toString());
telNumList.remove(index);
refresh();
}
});
}
Hope it will help you out.

onClickListener only working for the last element

In my onCreate, I insert every buttons of my Activity in a ArrayList and I loop on them to bind a clickListener. Only the last element gets the bind. Why is that?
for(Button bouton: tousLesBoutons) {
bouton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
resultat.setText(((Button) v).getText());
}
});
}
i do something similar but in the layout i set the onClick value to the same function for each button and then have a function like below. All 10 buttons hit this function,maybe you can try this approach
public void onButtonClick( View v )
{
Button but = (Button) findViewById( v.getId() );
String input = but.getText().toString();

ParseInt Exception

I am creating a small calc app with EditText views and Im running into an runtime exception when the user leaves an EditText view empty causing the ParseInt to try and Parse nothing. Ive read that I need to 'Try' and 'Catch' this error before it occurs, but Im unsure of where and how to do this!
Any advice is much appreciated!
Here is my code:
public class HandlerExamples extends Activity implements OnClickListener {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button = (Button)findViewById(R.id.testButton);
button.setOnClickListener(this);
public void onClick(View v) {
String a,b,t;
double vis;
EditText txtbox1 = (EditText)findViewById(R.id.A);
EditText txtbox2 = (EditText)findViewById(R.id.B);
EditText txtbox3 = (EditText)findViewById(R.id.t);
TextView tv = (TextView) findViewById(R.id.Answer);
a = txtbox1.getText().toString();
b = txtbox2.getText().toString();
t = txtbox3.getText().toString();
vis = ((Integer.parseInt(a)*1) + (Integer.parseInt(b)*2)) / (Double.parseDouble(t));
tv.setText(double.toString(vis));
}
}
Thanks so much!
public void onClick(View v) {
int id = v.getId();
switch(id){
case R.id.xx:
//do things xx click
break;
case R.id.yy:
//do things yy click
break;
}
}
you can get the view id to know whick widget was clicked.
Changwei Yao defined one way you can do this, but here's the way most Android programmers would do this (programmatically), since it's a little easier to read and figure out what your widgets are doing:
But first, remove the implements OnClickListener from your Activity, as it's not needed.
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// what you want your button to do when clicked
}
}
editText.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// what you want your EditText to do when clicked
// (such as editText.setText(""))
}
}
Another way to do the same thing is to define android:onClick="insert_method_name_here" for the widgets that you want perform an action when clicked. In your case, in your main.xml (since that's what you're using in your Activity), you could write something like...
<Button android:id="#+id/testButton"
(other attributes you wish to apply to the button)
android:onClick="buttonAction" />
<EditText
(other attributes)
android:onClick="textAction" />
And then, in your Activity, you define the methods buttonAction(View v) and textAction(View v). Note that these methods must be public void, and must take the sole argument View v.
(One advantage of the XML method is that you don't necessarily have to define an android:id attribute for these widgets, unless you need to be able to manipulate them or extract information from them in your code (which means you will need to define an android:id for your EditText since you'll likely want the user's input))
If you only need to exclude the empty text field then hotveryspicy's solution is probably the quickest. For a secure solution: catching the NumberFormatException will filter anything that can not be converted to an integer.
int vis;
try {
vis = Integer.parseInt(a);
}
catch(NumberFormatException nfe) {
Log.e(TAG,"trying to convert:"+a+" to integer failed");
vis = 0;
}

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