Checking a Button exists in Android - android

Need some advice again.
I am 99% done with this module I'm working on, although I'm stuck at the last hurdle. I'm dynamically publishing a button on the screen at runtime. This button will take it to a new activity view when pressed. I got that working perfectly.
However, I have another button which randomly changes the view so it effectively needs to reset itself, if that makes sense. What's happening is each time the button is clicked (the dynamic one) it then adds another button to the stack. Effectively I have buttons each time I click running down the screen. Is my logic wrong or is there a way to check and prevent the button to show each time? i.e. Just once...Below is the code.
public void ButtonOnClick(View v) {
Random rnd = new Random();
int randomListIndex = rnd.nextInt(2);
Animation myFadeInAnimation = AnimationUtils.loadAnimation(Page1.this, R.anim.fadein);
int firstRun = 0;
switch (randomListIndex) {
case 0:
//get the image your going to muck with
image = (ImageView) findViewById(R.id.cardImageView);
//set the image with what it should be
image.setImageResource(R.drawable.storm);
//apply the transition effect so it looks correct
image.startAnimation(myFadeInAnimation);
button = (Button)findViewById(R.id.dynamicButton);
button.setText("Need another question?");
Button myButton = new Button(this);
myButton.setText("Press Me");
LinearLayout layout = (LinearLayout) findViewById(R.id.nextPageContainer);
layout.addView(myButton);
final Button myButton1 = myButton;
myButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View arg0) {
String activityName = "Storm";
Intent intent = new Intent(Page1.this, Page2.class);
intent.putExtra(ACTIVITYNAME,activityName);
startActivity(intent);
}
});
break;
}
}

EDIT: How about this? Add a new class field member (a class variable, not a method's local variable) that indicates whether the button was actually added in the layout.
private boolean buttonShown = false; /* Here changed */
public void ButtonOnClick(View v) {
Random rnd = new Random();
int randomListIndex = rnd.nextInt(2);
Animation myFadeInAnimation = AnimationUtils.loadAnimation(Page1.this, R.anim.fadein);
int firstRun = 0;
switch (randomListIndex) {
case 0:
//get the image your going to muck with
image = (ImageView) findViewById(R.id.cardImageView);
//set the image with what it should be
image.setImageResource(R.drawable.storm);
//apply the transition effect so it looks correct
image.startAnimation(myFadeInAnimation);
button = (Button)findViewById(R.id.dynamicButton);
button.setText("Need another question?");
if (buttonShown == false) { /* Here changed */
Button myButton = new Button(this);
myButton.setText("Press Me");
LinearLayout layout = (LinearLayout) findViewById(R.id.nextPageContainer);
layout.addView(myButton);
final Button myButton1 = myButton;
myButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View arg0) {
String activityName = "Storm";
Intent intent = new Intent(Page1.this, Page2.class);
intent.putExtra(ACTIVITYNAME,activityName);
startActivity(intent);
}
});
buttonShown = true; /* Here changed */
} /* Here changed */
break;
}
}
Edited again: Instead of local variable myButton, I used class field member pressMeButton.
private Button pressMeButton;
public void ButtonOnClick(View v) {
Random rnd = new Random();
int randomListIndex = rnd.nextInt(2);
Animation myFadeInAnimation = AnimationUtils.loadAnimation(Page1.this, R.anim.fadein);
int firstRun = 0;
switch (randomListIndex) {
case 0:
//get the image your going to muck with
image = (ImageView) findViewById(R.id.cardImageView);
//set the image with what it should be
image.setImageResource(R.drawable.storm);
//apply the transition effect so it looks correct
image.startAnimation(myFadeInAnimation);
button = (Button)findViewById(R.id.dynamicButton);
button.setText("Need another question?");
if (pressMeButton == null) {
pressMeButton = new Button(this);
pressMeButton.setText("Press Me");
LinearLayout layout = (LinearLayout) findViewById(R.id.nextPageContainer);
layout.addView(pressMeButton);
}
/* If the pressMeButton is already in the layout, all you need to do is just changing the onClickListener. */
pressMeButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View arg0) {
String activityName = "Storm";
Intent intent = new Intent(Page1.this, Page2.class);
intent.putExtra(ACTIVITYNAME,activityName);
startActivity(intent);
}
});
break;
}
}

Your code is fine but the way it is it will always add a button to the screen. Whats the desired behavior your looking for? If its a conditional thing than you need to account for that in the onclick call.
EDIT:
So what you need to do then is to create some kind of flag or id for the button and set it as the button's view.tag like this:
Button b = new Button(context);
b.setTag(flagTag);
Then when you want to check if the button exists you check it like:
if((LinearLayout) findViewById(R.id.nextPageContainer))
.findViewById(tagFlag)==null){
Button b = new Button(context);
b.setTag(flagTag);
}else{
//do nothing or something :p
}

Related

Changing the Color of the Dynamically loaded Buttons onclick

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How to restore the color of the previous clicked Button in Android.
Try this :
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#Override
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/* you need to have already stored buttons in a data structure, something like : List<Button> btns; */
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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
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I'm new to android and I'm having a hard time finding solutions to my problem on my app.
My app is a wordsearch game that uses tapping on the tiles as an input. This is the code for the onClick() of the dynamic textviews on the tablelayout:
text.setOnClickListener(new View.OnClickListener() {
#Override
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w.setVisibility(View.VISIBLE);
//change the color of tapped textview
text.setTextColor(Color.WHITE);
text.setBackgroundColor(Color.parseColor(mColors[randomNum]));
String b = text.getText().toString();
uTxt.setText(""+uTxt.getText().toString() + b);
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if(checkAns(uTxt, list))
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t.cancel();
Context mContext = getApplicationContext();
Activity mActivity = GameScreen.this;
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RelativeLayout.LayoutParams.MATCH_PARENT,
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Typeface font = Typeface.createFromAsset(getAssets(), "raw2.ttf");
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cattxt.setTypeface(font);
cattxt.setText(ctg);
Button yesB = (Button) customView.findViewById(R.id.maglaro2);
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#Override
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Intent intent = new Intent(GameScreen.this, Category.class);
startActivity(intent);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
GameScreen.this.finish();
}
});
Button noB = (Button) customView.findViewById(R.id.hindi);
noB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(GameScreen.this, MainActivity.class);
startActivity(intent);
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
GameScreen.this.finish();
}
});
mPopupWindow.showAtLocation(table, Gravity.CENTER,0,0);
}
uTxt.setText("");
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}
});
Now my problem is I want an UNDO Button that will delete the last character on the uTxt and will change back the color of the last touched textView
Does anyone have any ideas on how to do that?
If yes leave a comment, answer, or suggestion below. TIA!
Typical solution for this problem is the usage of the command pattern (excellent for undo redo functionality).
See https://en.wikipedia.org/wiki/Command_pattern

how to make a button do multiple things?

I have a question regarding android development. I am trying to make an app that changes the screen color from red to blue and then green. I have asigned an onClickListener to a relativeLayout, that turns the screen from white to red. How do I make that same onClickListener do multiple things in an order, so that when I click the screen once it turns it to red and when I click it again it will turn the screen to blue etc.
Here is my code so far:
final RelativeLayout layout = (RelativeLayout) findViewById(R.id.view);
layout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
layout.setBackgroundColor(Color.parseColor("#ff0000"));
}
});
Store the list of desired colors in an array. Keep track of the current color index and increment after each click like so:
final RelativeLayout layout = (RelativeLayout) findViewById(R.id.view);
layout.setOnClickListener(new View.OnClickListener() {
String[] colors = new String[]{"#ff0000", "#00ff00", "#0000ff"};
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#Override
public void onClick(View view) {
String color = colors[colorIndex];
colorIndex = colorIndex++ % colors.length;
layout.setBackgroundColor(Color.parseColor(color));
}
});
The modulo operator (%) ensures we don't index past the end of the array.
track the state of your click. Like this
private int colorState =0;
final RelativeLayout layout = (RelativeLayout) findViewById(R.id.view);
layout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
switch(colorState){
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layout.setBackgroundColor(Color.parseColor("#ff0000"));
break;
case 1:
layout.setBackgroundColor(Color.parseColor("#000000"));
break;
case 2:
layout.setBackgroundColor(Color.parseColor("#FFFFFF"));
break;
colorState++;
}

How to check which ImageButton was prssed?

I have lots of image buttons. User can press any of those button and i need to know which button is pressed. These buttons appears dynamically so i don't know how much of them will be.
For one image button i would write this listener:
ImageButton ib = new ImageButton(this);
ib.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(TravelBite.this, "test", Toast.LENGTH_SHORT).show();
}
});
But how to do one listener for all my Images Buttons? Can i recognize which button was pressed by it's tag ? Like tag would be ID from sqlite.
Also i put image to button with this code:
button.setImageDrawable( testPic );
button is ImageButton and testPict is drawable (image)
But when i press this button it don't show that it is pressed if i do this:
button.setBackgroundColor(R.color.transparent_background);
I had to do this because i just want to see Buuton image which i could press and recognize what i pressed.
Thanks.
ok what you can do is that you can write a single callback function and then set it to each and every button it will allow you to handle each button with a sing function like :
View.OnClickListener btn_listener = View.OnClickListener() {
#Override
public void onClick(View v) {
// Do whatever work you want.
int id = v.getid();
// check for id and do you task.
}
Arraylist<Button> btn_group = new Arraylist<Button>;
or
Arraylist<int> btn_id_group = new ArrayList<int>;
for (int i =0; i < 10; i++) {
Button btn = new Button(getApplicationContext());
btn.setId(i);
btn_id_group.add(i) or btn_group.add(btn);
btn.SetOnClickListener(btn_listener);
}
I think it will work for you.
You can use View.setTag(object) and View.getTag() and store in it sqlite id. Something like this:
View.OnClickListener listener = View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(TravelBite.this, (String)v.getTag(), Toast.LENGTH_SHORT).show();
//or some function that do somthing useful
//if( ((String)v.getTag).equals("image1") ){} or anything else
}
And in for loop:
String tagFromSqlite = "image1";
ImageButton ib = new ImageButton(this);
ImageButton.setTag(tagFromSqlite);
ib.setOnClickListener(listener);
final OnClickLisener listener = new OnClickListener() {
public void onClick(View v){
switch((Integer)v.getTag()){
case R.id.zero:
break;
case R.id.one:
break;
case R.id.two:
break;
}
}
}
//when init the Buttom
ImageButton btn = new ImageButton(Context);
btn.setTag(NUMBER);
you'll have to manually assign ID's to keep them separated - I had to do something similar (1000 was the base ID I chose to add upon as well)
Although View v in the listener refers to the button pressed, when you programmatically create buttons the id's are not unique and caused me issues, so that's why I set them specifically
View.OnClickListener btn_listener = View.OnClickListener()
{
#Override
public void onClick(View v)
{
//you can use v.getID() here
}
}
for (int i =0; i < 10; i++)
{
Button btn = new Button(getApplicationContext());
btn.setID( 1000 + i );
btn.SetOnClickListener(btn_listener);
}

Animating (moving) ImageView works one way but not the other

I creating a "Add" button by using sdk, so i wan it to move it to left when i press that "Add" button, and come back to original place when i press again. The problem i have is the button only can go to the left when press, and cannot come back to the original place after i trying to press it again. Does it i having some problem on the if...else function there? any help would appreciate.
public class TestImage2 extends Activity {
/** Called when the activity is first created. */
ImageView image_plus;
ImageView image_subtract;
ImageView image_multiply;
ImageView image_div;
String op;
boolean pergi = false;
final Animation animation = new TranslateAnimation(0,100,0,0);
final Animation animation2 = new TranslateAnimation(100,0,0,0);
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
image_plus = (ImageView)findViewById(R.id.test_image);
image_subtract = (ImageView)findViewById(R.id.test_image2);
image_multiply = (ImageView)findViewById(R.id.test_image3);
image_div = (ImageView)findViewById(R.id.test_image4);
image_plus.setOnClickListener(new OnClickListener(){
public void onClick(View view) {
if(pergi == false)
{
animation.setDuration(1000);
image_plus.startAnimation(animation);
pergi= true;
animation.setFillAfter(true);
}
else
{
animation2.setDuration(1000);
image_plus.startAnimation(animation2);
pergi = false;
animation2.setFillAfter(true);
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}});
i think that there is something wrong in
final Animation animation2 = new TranslateAnimation(100,0,0,0);
it should be
final Animation animation2 = new TranslateAnimation(0,-100,0,0);
:)

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