Develop Reference

Android: Dynamically create image button with click event

I'm new to android and I require to have a list of image buttons in an activity which are created based on the data in a database. I haven't created anything like this in android before and so far I've been using HTML tables to show my data in a grid view. I'm not asking for any special code, I'm just clueless on how to implement this. I wanna know what the best approach is.
One problem I've faced is with the click events(in the way I've been doing them so far) which do not take in any EventArg, so I can't get the name of the button out of them.

If you're sure that the OnClickListener instance is applied to a Button, then you could just cast the received view to a Button and get the text:
public void onClick(View v) {
// 1) Possibly check for instance of first
Button b = (Button)v;
String buttonText = b.getText().toString();
}

// create the layout params that will be used to define how your button will be displayed
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
// Create Button
final Button btn = new Button(this);
// Give button an ID
btn.setId(someinteger);
btn.setText("Add Text");
// set the layoutParams on the button
btn.setLayoutParams(params);

How can I change Text of Textview from other funcion?

this is my first question so I hope to make it clear.
I have one textView with some numerical text and next to it one button with one click listener and what I want is that when you click on the button the numerical value (>=0) of the TextView decrements in one.
Here is part of my code:
TextView Counter = new TextView(this);
if (intSeries != 0)
Counter.setText(Integer.toString(intSeries));
else
Counter.setText("0");
Counter.setId(4);
tablaContador.addView(Counter,Tr);
Button Done = new Button(this);
Done.setText("-1");
if (intSeries != 0)
Done.setVisibility(View.VISIBLE);
else
Done.setVisibility(View.GONE);
Done.setId(6);
Done.setOnClickListener(this);
And this is the onClick funcion (part of it):
#Override
public void onClick(final View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case 6:{
TextView text = (TextView)findViewById(4);
int series = Integer.parseInt(text.getText().toString());
series--;
text.setText(series);
if (series==0){
Button boton = (Button)findViewById(6);
boton.setVisibility(View.GONE);
}
}
}
}
The error is when I try to make the setText inside the onClick function, I hope it can be fixed or maybe recieve other idea to do it.
Thank you so much.

I would avoid all this hardcoding of Ids, use resources instead.
Your call to
text.setText(series)
is passing an int. The only valid setText(int resId) overload expects a resource associated with the int value, i.e. a string resource.
Convert your series value to a string.
Something like:
text.setText(Integer.toString(series));

You should setup series as an integer. And increase/descrease it as you wish. When you want to change the button's text convert the int to String.
Instead of:
text.setText(series);
use:
text.setText(String.valueOf(series));

Variablenames in java can't start with a capital letter. That is reserved for classnames.
Counter -> counter
Done -> done

I tried this and it worked:
//Create onClickListener
OnClickListener pickChoice = new OnClickListener()
{
public void onClick(View v)
{
TextView txt = (TextView) findViewById(4);
int number = Integer.valueOf(txt.getText().toString());
txt.setText(String.valueOf(number -1));
}
};
//Create layout
LinearLayout lnLayout = new LinearLayout(this);
lnLayout.setOrientation(LinearLayout.VERTICAL);
TextView txt = new TextView(this);
txt.setId(4);
txt.setText("0");
lnLayout.addView(txt);
Button Done = new Button(this);
Done.setText("-1");
Done.setId(6);
Done.setOnClickListener(pickChoice);
lnLayout.addView(Done);
setContentView(lnLayout);
Where are you creating your button inside? an activity? the part where you pass the onClickListener to the button doesn't make sense, maybe the button is getting a wrong listener and gets you an error every time you press the button ?
The code should be easy to understand, if there is anything you need me to explain please ask :)

List Of Text And Clickable

I want to ask how to make a list of text that we can tap in each of the text and then get the selected text to editText.
I just added the screenshot
http://i.stack.imgur.com/ddZSg.png
I have been searching it since yesterday, but I can not find exact solution. I also tried with listview, but I don't know how it's possible with horizontal, and flow list item.

I am also new in android. But I can think of the logic what you want. You can try this out if you want.
First of all, you can make your list of texts EditText by list of buttons Buttons
You can dynamically add as many Buttons with their respective text as you want to show.
set their corresponding onClickListener
In their onClickListener , create an object of the EditText you are using to add texts.
Store the value of EditText into a String Variable first.
Add the text of the clicked Button to the variable.
and now again set the text in EditText with the variable you created to store the values.
Your task will be done.
Try referring this code.
and change the code accordingly as your needs.
// Adding EditText and a button in a new linear layout and then adding
// the new linearLayout to the main layout
String[] valuesToBeAdded={"A","B","C","D"};
String selectedValues=null;
LinearLayout mainLayout=(LinearLayout) findViewById(R.id.mainLayout);
LinearLayout localLayout = new LinearLayout(context);
localLayout.setOrientation(LinearLayout.VERTICAL);
localLayout.setLayoutParams(new LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
EditText editText=new EditText(context);
editText.setText(selectedValues);
editText.setId(5000);
localLayout.addView(editText);
for(int i=0;i<valuesToBeAdded.length();i++){
Button button = new Button(context);
button.setText(R.string.scanDocument);
button.setId(i);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
EditText ed=(EditText) findViewById(5000);
selectedValues=ed.getText();
selectedValues=selectedValues +" " + this.getText();
ed.setText(selectedValues);
}
});
localLayout.addView(button);
}
mainLayout.addView(localLayout);
Thank You

Could you not make as many buttons as you need and then in the button_Click method for all buttons add:
Buttonwithtext_Click(object sender, EventArgs e)
{
editTextBox.Text = editTextBox.Text + Buttonwithtext.text + ", ":
}

Creating texts and buttons with listeners successively?

I will try to explain my problem. The code below as you can see try to add some textviews and buttons as the array get from another class.
public class Breakfast extends Activity {
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
ScrollView sv = new ScrollView(this);
LinearLayout ll = new LinearLayout(this);
sv.addView(ll);
if (extras != null) {
String food[]=extras.getStringArray("food");
String foodCateg[]=extras.getStringArray("foodCateg");
int K=0;
for (int i = 0; i < food.length/3; i++) {
TextView foodDay = new TextView(this);
foodDay.setText("Day "+ (i+1));
ll.addView(foodDay);
for (int j=K;j<K+3;j++){
Button contfood= new Button(this);
contfood.setText(food[j]);
ll.addView(contfood);
}
K=K+3;
}
this.setContentView(sv);
}
}
My question is how can I know what of this buttons are clicked on the screen?? Because in the case of what one of them are clicked (getting the text that have write before), I will do something or other thing.
ahhhhhhhhhhhhhhhhh yes I know how to do a ListActivity. But first I think in doing by hand because I don´t think how to symplify this...
Thank you for the answers of trying to build with everything a listview and then the method OnListItemClick, but I think that isn´t the solution.
I said that because when I insert the day for example (I Don´t put hear all the code...) but I do .setgravity .setSize .setbackgroundResource etc. And with the food for that day I use a diferent .setgravity and more parameters. So I think that with listview everything would have the same specifications... and that´s what I don´t like.
so... to know what button is pressed on the screen?

You could use contfood.setId(i) and work your way from there.
But what you are doing looks like you really want to create a ListActivity and use it's OnItemClickListener.

What you should do is put an id to each button "contfood". And then when you click on a button retrieve the id back to do the action you want.
Another way is to create the button and attach the method public void onClick(View view):
for (int j=K;j<K+3;j++){
Button contfood= new Button(this);
contfood.setText(food[j]);
ll.addView(contfood);
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), xxx.class);
startActivityForResult(myIntent, 0);
}
}
and add the parameters within the method.

I need to add onClickListener to a bunch of ImageButtons

I have created a bunch of ImageButtons programmatically while in a for loop. They have worked fine as the data displayed in a HorizontalScrollView. Now I need each one to go dim or bright when clicked. First click will setAlpha(45); second click will setAlpha(255);.
I don't think I fully understand how the Views and onClickListener works yet. It seems the onClick function examples I find take a View. How would that function know which button is clicked? Perhaps there is an easier way to do what I want?
Here are the ImageButtons.
TableRow tr0 = new TableRow(this);
tr0.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setBackgroundResource(0);
clueBut.setImageBitmap(ClueList.get(but).btmp);
//clueBut.setOnClickListener(this);
tr0.addView(clueBut);
}
Is there something I need to do to make the buttons identifiable? And how would that pass in through into the onClick function to be used?
-: Added Information :-
I am starting to wonder if the problem isn't with the buttons, but with the way I built the screen. More information added.
The Game activity is the main game, which uses the PuzzleView for the upper part of the screen holding the game grid. The lower part is where the ImageButtons are and I built them in place in the Game class.
public class Game extends Activity{
//various variables and stuff
private PuzzleView puzzleView; // The PuzzleView is from another .java file
// public class PuzzleView extends View
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
LinearLayout mainPanel = new LinearLayout(this);
mainPanel.setOrientation(LinearLayout.VERTICLE);
puzzleView = new PuzzleView(this);
mainPanel.addView(puzzleView);
HorizontalScrollView bottom = new HorizontalScrollView(this);
mainPanel.addView(bottom);
TableLayout clues = new TableLayout(this);
bottom.addView(clues);
TableRow tr0 = new TableRow(this);
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setImageBitmap(ClueList.get(but).btmp);
tr0.addView(clueBut);
}
When I try to add the ClickListener(this) I get errors about this not being able to be a Game. I have similar problems in the onClick(View v) function referencing the View. Are these problems because I am building the buttons in the Game Activity instead of a View class?
Thanks

When you set up an OnClickListener and implement the onClick(View v) callback, it's the Dalvik VM the one that will call that method each time the View is clicked, and it will pass the View instance as a parameter. Thus, the code you write inside that method will be applied only to the View that received the click and not to any other View. Add something like this to your loop:
clueBut.setOnClickListener(new OnClickListener() {
public void onClick (View v) {
if (v.getAlpha() == 1f)
v.setAlpha(0.2f);
else
v.setAlpha(1f);
}
});

In the onClick event:
public void onClick(View currentView)
{
Button currentButton = (Button)CurrentView;
//Do whatever you need with that button here.
}

To identify each view uniquely use the property
View. setId(int)
In your case the code would look something like this
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setBackgroundResource(0);
clueBut.setImageBitmap(ClueList.get(but).btmp);
clueBut.setId(but);
//clueBut.setOnClickListener(this);
tr0.addView(clueBut);
}
Inside the onclick listener match the id of the view using findViewByID()