Develop Reference

how to change textView repeatedly after pressing on a button until specific case

I'm trying to build a layout that has a textView that has a number, an editText that has a hint for the entered item and a button, and when i press on the button i'll get the entered text and put it inside a variable and then decrease the number that is inside the text view until it is 0
here's the piece of my code:
job = "";
adjective = "";
this.changeMyEditText(2, "job");
job = this.getMyText();
this.changeMyEditText(1, "adjective");
adjective = this.getMyText();
scan.close();
and here's the changeMyEditText function:
public void changeMyEditText(int num, String type) {
TextView numOfEnteredWords = (TextView) findViewById(R.id.numOfEnteredWords);
EditText enteredWord = (EditText) findViewById(R.id.enteredWord);
numOfEnteredWords.setText(num + " word(s) left");
enteredWord.setHint(type);
}
and the getMyText method:
public String getMyText() {
EditText enteredWord = (EditText) findViewById(R.id.enteredWord);
return enteredWord.getText().toString();
}

On button's click listener event, you can decrease textViewNumber -1.
and can check on every button's click if number = 0 then do whatever you want to do.
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (textViewNumber != 0) {
textViewNumber--; //I guess if you want to change number by -1
} else {
// Your action on textviewNumber become 0
}
}
});

Compare data from edit text with data from if statement

I'm making a quiz app. User has to finish the phrase shown on display and write the name of the car in the edittext, after pushing on button, if the answer right, edittext become green, if doesn't, become red. If all answers right (green), intent move on next activity.
I have some difficulties with if statement edit text become red even the answer was right. Also how to make INTENT to move on next activity if all right, if not it doesn't move?
public class MainActivity extends AppCompatActivity {
EditText et_one_one, et_one_two, et_one_three;
Button buttonCheck;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_one_one = (EditText) findViewById(R.id.et_one_one);
et_one_two = (EditText) findViewById(R.id.et_one_two);
et_one_three = (EditText) findViewById(R.id.et_one_three);
final String t1 = et_one_one.getText().toString();
final String t2 = et_one_two.getText().toString();
final String t3 = et_one_three.getText().toString();
buttonCheck = (Button) findViewById(R.id.buttonCheck);
buttonCheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (t1.equals("maserati")){
et_one_one.setBackgroundColor(Color.GREEN);
}
else {
et_one_one.setBackgroundColor(Color.RED);
}
if (t2.equals("mercedes")){
et_one_two.setBackgroundColor(Color.GREEN);
}
else{
et_one_two.setBackgroundColor(Color.RED);
}
if (t3.equals("bmw")){
et_one_three.setBackgroundColor(Color.GREEN);
}
else{
et_one_three.setBackgroundColor(Color.RED);
}
}
});
}
}

You're changing the color of just the et_one_one each time in your if else statements. Shouldn't it be for different edittexts?
buttonCheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
boolean allAnswersCorrect = true;
String t1 = et_one_one.getText().toString();
String t2 = et_one_two.getText().toString();
String t3 = et_one_three.getText().toString();
if (t1.equals("maserati")){
et_one_one.setBackgroundColor(Color.GREEN);
}
else {
allAnswersCorrect = false;
et_one_one.setBackgroundColor(Color.RED);
}
if (t2.equals("mercedes")){
et_one_two.setBackgroundColor(Color.GREEN);
}
else{
allAnswersCorrect = false;
et_one_two.setBackgroundColor(Color.RED);
}
if (t3.equals("bmw")){
et_one_three.setBackgroundColor(Color.GREEN);
}
else{
allAnswersCorrect = false;
et_one_three.setBackgroundColor(Color.RED);
}
if(allAnswersCorrect){
Intent intent = new Intent(YourActivity.this, YourSecondActivity.class);
startActivity(intent);
}
}
});
Maintain a allAnswersCorrect boolean to check whether your answers are correct or not. If all are correct the move to your next activity.

You should use t2.equals("maserati"), and it will be ok.

Calculation goes wrong when I started using SeekBar

public class Main extends Activity implements OnClickListener {
TextView ePrice;
TextView InputPrice;
TextView InputPercent;
TextView ePercent;
private SeekBar volumeControl = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
/** Remove title bar */
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/** Hide Auto Keyboard */
getWindow().setSoftInputMode(
WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
/** Hide Auto Keyboard End here */
InputPrice = (TextView) findViewById(R.id.ePrice);
InputPercent = (TextView) findViewById(R.id.ePercents);
ePrice = (TextView) findViewById(R.id.ePrice);
ePercent = (TextView) findViewById(R.id.ePercents);
Here is my SeekBar. Before this SeekBar I have been using EditText and every thing was ok but after i started using this SeekBar the SECOND result is so weird!!
SeekBarPer = (SeekBar) findViewById(R.id.volume_bar);
SeekBarPer.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
int progressChanged = 0;
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser){
progressChanged = progress;
TextView label = (TextView) findViewById(R.id.ePercents);
label.setText(""+progressChanged);
}
public void onStartTrackingTouch(SeekBar seekBar) {
}
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
what I have:
One EditText up One TextView under the SeekBar and Two another TextView are down to show the result of calculating the Price and the Percent! The First result is going well but the second is NOT!
For example if i calculate 30 dollars minus 50% i got the first result 15 and the second one 35.
What I want:
Just to correct the second result
Here is the Calculation:
// show the price to get
final TextView tR = (TextView) findViewById(R.id.viewResult);
// show the price to pay
final TextView tRpay = (TextView) findViewById(R.id.viewResultPay);
Button buttonConvert = (Button) findViewById(R.id.buttonConvert);
buttonConvert.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
try {
double price = Double.parseDouble(ePrice.getText().toString());
double percent = Double.parseDouble(ePercent.getText().toString());
double pri = (price / 100.0f) * percent;;
double per = percent * ((100.0f - price)/100.0f);
tR.setText(String.valueOf(pri));
tRpay.setText(String.valueOf(per));
tR.setText("" + pri);
tRpay.setText("" + per);
// catch
} catch (NumberFormatException ex) {
// write a message to users
tR.setText("");
}
}
});
}
Update:
I am using the SeekBar as a percent. So when I move the SeekBar there will be numbers 0-100 in the second TextView.
Thanks in advance!

This should be what you want:
DiscountValue = price*discount/100.0f;
ValueToPay = price - DiscountValue;

Checking a Button exists in 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
}

Android Button setAlpha

There are a set of buttons, I want to get the result:
When I click one of them, first I divide them into two parts: the clicked one and the others. I'm trying to set different color or alpha value to different them.
Now I use setAlpha, but when I change the value from 0 to 255, it works, but when I change the value from 255 to 0 , it doesnot work. I don't know why.
Maybe after I invoke the methodButton.setAlpha(), I need invoke another method?
my code:
public class MainActivity extends Activity {
// button alpha value: minimize value
public static int BUTTON_ALPHA_MIN = 0;
// button alpha value: maximize value
public static int BUTTON_ALPHA_MAX = 255;
private LinearLayout centerRegion;
private LinearLayout bottomRegion;
private Button btnCheckIn;
private Button btnReview;
private Button btnMyCircles;
private Button btnSettings;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// get all the widgets
getAllWidgets();
// set buttons click response function
btnCheckIn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
centerRegion.setBackgroundColor(android.graphics.Color.RED);
btnReview.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX);
}
});
btnReview.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
centerRegion.setBackgroundColor(android.graphics.Color.BLUE);
btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MIN);
btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX);
}
});
btnMyCircles.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
centerRegion.setBackgroundColor(android.graphics.Color.YELLOW);
btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX);
btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX);
btnSettings.getBackground().setAlpha(BUTTON_ALPHA_MAX);
v.getBackground().setAlpha(BUTTON_ALPHA_MIN);
}
});
btnSettings.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
centerRegion.setBackgroundColor(android.graphics.Color.MAGENTA);
btnCheckIn.getBackground().setAlpha(BUTTON_ALPHA_MAX);
btnReview.getBackground().setAlpha(BUTTON_ALPHA_MAX);
btnMyCircles.getBackground().setAlpha(BUTTON_ALPHA_MAX);
v.getBackground().setAlpha(BUTTON_ALPHA_MIN);
}
});
}
/**
* get all the widgets
*/
public void getAllWidgets() {
this.centerRegion = (LinearLayout) this.findViewById(R.id.center_region);
this.bottomRegion = (LinearLayout) this.findViewById(R.id.bottom_region);
this.btnCheckIn = (Button) this.findViewById(R.id.button_check_in);
this.btnReview = (Button) this.findViewById(R.id.button_review);
this.btnMyCircles = (Button) this.findViewById(R.id.button_my_circles);
this.btnSettings = (Button) this.findViewById(R.id.button_setting);
}
}

Using AlphaAnimation should work; verified on my device.
public class Test extends Activity implements OnClickListener {
private AlphaAnimation alphaDown;
private AlphaAnimation alphaUp;
private Button b1;
private Button b2;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout ll = (LinearLayout) findViewById(R.id.linear_layout);
b1 = new Button(this);
b1.setText("Button 1");
b1.setOnClickListener(this);
ll.addView(b1);
b2 = new Button(this);
b2.setText("Button 2");
b2.setOnClickListener(this);
ll.addView(b2);
alphaDown = new AlphaAnimation(1.0f, 0.3f);
alphaUp = new AlphaAnimation(0.3f, 1.0f);
alphaDown.setDuration(1000);
alphaUp.setDuration(1000);
alphaDown.setFillAfter(true);
alphaUp.setFillAfter(true);
}
public void onClick(View v) {
if (v == b1) {
b1.startAnimation(alphaUp);
b2.startAnimation(alphaDown);
} else {
b1.startAnimation(alphaDown);
b2.startAnimation(alphaUp);
}
}
}
The key is calling setFillAfter(true) so that the alpha change persists.

Thanks for the question and the answer. This really helped me out.
For my solution, I needed to set the alpha of a button without seeing any animation effect, but the button.setAlpha(x) was failing sporadically. Using animations instead did the trick, but I had to set the duration to zero to get the automatic effect.
alphaDown = new AlphaAnimation(1.0f, 0.3f);
alphaUp = new AlphaAnimation(0.3f, 1.0f);
alphaDown.setDuration(0);
alphaUp.setDuration(0);
alphaDown.setFillAfter(true);
alphaUp.setFillAfter(true);
I use this for player controls in a media application, so I had something like this:
boolean bInitPrevEnabled = m_btPrev.isEnabled();
boolean bInitNextEnabled = m_btNext.isEnabled();
boolean bInitPlayEnabled = m_btPlay.isEnabled();
m_btPrev.setEnabled(true);
m_btNext.setEnabled(true);
m_btPlay.setEnabled(true);
// Process enabling of the specific buttons depending on the state
if (bInitPrevEnabled != m_btPrev.isEnabled())
m_btPrev.startAnimation((m_btPrev.isEnabled()) ? alphaUp : alphaDown);
if (bInitNextEnabled != m_btNext.isEnabled())
m_btNext.startAnimation((m_btNext.isEnabled()) ? alphaUp : alphaDown);
if (bInitPlayEnabled != m_btPlay.isEnabled())
m_btPlay.startAnimation((m_btPlay.isEnabled()) ? alphaUp : alphaDown);

Button btn;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btn = (Button) findViewById(R.id.main_btn);
Drawable d = getResources().getDrawable(R.drawable.imagen);
d.setAlpha(60);
btn.setBackgroundDrawable(d);
}
This works for me :)

public void setAlpha (int alpha) - deprecated
public void setAlpha (float alpha) (0f < alpha < 1f)
Added in API level 11