Any idea how to illustrate backspace funtion in this code? I try to make some changes but it can't work the backspace function. So, i would like to help me, with the backspace button.
enter code here
public class MainActivity extends AppCompatActivity implements OnClickListener {
private TextView mCalculatorDisplay;
private Boolean userIsInTheMiddleOfTypingANumber = false;
private CalculatorBrain mCalculatorBrain;
private static final String DIGITS = "0123456789.";
DecimalFormat df = new DecimalFormat("############");
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
// hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
// hide the status bar and other OS-level chrome
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mCalculatorBrain = new CalculatorBrain();
mCalculatorDisplay = (TextView) findViewById(R.id.textView1);
df.setMinimumFractionDigits(0);
df.setMinimumIntegerDigits(1);
df.setMaximumIntegerDigits(8);
findViewById(R.id.button0).setOnClickListener(this);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
findViewById(R.id.button4).setOnClickListener(this);
findViewById(R.id.button5).setOnClickListener(this);
findViewById(R.id.button6).setOnClickListener(this);
findViewById(R.id.button7).setOnClickListener(this);
findViewById(R.id.button8).setOnClickListener(this);
findViewById(R.id.button9).setOnClickListener(this);
findViewById(R.id.buttonBackspace).setOnClickListener(this);
findViewById(R.id.buttonAdd).setOnClickListener(this);
findViewById(R.id.buttonSubtract).setOnClickListener(this);
findViewById(R.id.buttonMultiply).setOnClickListener(this);
findViewById(R.id.buttonDivide).setOnClickListener(this);
findViewById(R.id.buttonToggleSign).setOnClickListener(this);
findViewById(R.id.buttonDecimalPoint).setOnClickListener(this);
findViewById(R.id.buttonEquals).setOnClickListener(this);
findViewById(R.id.buttonClear).setOnClickListener(this);
// The following buttons only exist in layout-land (Landscape mode) and require extra attention.
// The messier option is to place the buttons in the regular layout too and set android:visibility="invisible".
if (findViewById(R.id.buttonSquareRoot) != null) {
findViewById(R.id.buttonSquareRoot).setOnClickListener(this);
}
if (findViewById(R.id.buttonSquared) != null) {
findViewById(R.id.buttonSquared).setOnClickListener(this);
}
if (findViewById(R.id.buttonInvert) != null) {
findViewById(R.id.buttonInvert).setOnClickListener(this);
}
if (findViewById(R.id.buttonSine) != null) {
findViewById(R.id.buttonSine).setOnClickListener(this);
}
if (findViewById(R.id.buttonCosine) != null) {
findViewById(R.id.buttonCosine).setOnClickListener(this);
}
if (findViewById(R.id.buttonTangent) != null) {
findViewById(R.id.buttonTangent).setOnClickListener(this);
}
}
#Override
public void onClick (View v) {
String buttonPressed = ((Button) v).getText().toString();
if (DIGITS.contains(buttonPressed)) {
// digit was pressed
if (userIsInTheMiddleOfTypingANumber) {
if (buttonPressed.equals(".") && mCalculatorDisplay.getText().toString().contains(".")) {
// ERROR PREVENTION
// Eliminate entering multiple decimals
} else {
mCalculatorDisplay.append(buttonPressed);
}
} else {
if (buttonPressed.equals(".")) {
// ERROR PREVENTION
// This will avoid error if only the decimal is hit before an operator, by placing a leading zero
// before the decimal
mCalculatorDisplay.setText(0 + buttonPressed);
} else {
mCalculatorDisplay.setText(buttonPressed);
}
}
userIsInTheMiddleOfTypingANumber = true;
}else{
// operation was pressed
if (userIsInTheMiddleOfTypingANumber) {
mCalculatorBrain.setOperand(Double.parseDouble(mCalculatorDisplay.getText().toString()));
userIsInTheMiddleOfTypingANumber = false;
}
mCalculatorBrain.performOperation(buttonPressed);
if (new Double(mCalculatorBrain.getResult()).equals(0.0)) {
mCalculatorDisplay.setText("" + 0);
} else {
mCalculatorDisplay.setText(df.format(mCalculatorBrain.getResult()));
}
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save variables on screen orientation change
outState.putDouble("OPERAND", mCalculatorBrain.getResult());
outState.putDouble("MEMORY", mCalculatorBrain.getMemory());
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState){
super.onRestoreInstanceState(savedInstanceState);
// Restore variables on screen orientation change
mCalculatorBrain.setOperand(savedInstanceState.getDouble("OPERAND"));
mCalculatorBrain.setMemory(savedInstanceState.getDouble("MEMORY"));
if (new Double(mCalculatorBrain.getResult()).equals(0.0)){
mCalculatorDisplay.setText("" + 0);
} else {
mCalculatorDisplay.setText(df.format(mCalculatorBrain.getResult()));
}
}
}
In your layout you can add a onClick attribute to each button, say onClick="function", and in your activity you just need to implement a method like this:
public void function(View v) {
switch(v.getId()) {
case R.id.buttonBackspace:
// handle the backspace button
break;
case R.id.xxx:
// handle the button
break;
...
}
}
And for digits, I suggest assign a tag to each digit button in the layout, and do your logic in java based on the tag, instead of the text on the button. Because the text is just a UI, it might change in the future due to other possible requirements.
Related
I have a quiz app that is working properly, but the thing is the user must answer all questions correctly in order to win the game(if the player gets it wrong the game will be over) .
What I wanted to do is have the questions answered and then at the end there will be an activity that will show how many the player has answered then there will be the options to retry and go back to menu
This is the code for the maingameactivity
public class MainGameActivity extends AppCompatActivity {
FButton buttonA, buttonB, buttonC, buttonD;
TextView questionText, triviaQuizText, timeText, resultText, coinText;
TriviaQuizHelper triviaQuizHelper;
TriviaQuestion currentQuestion;
List<TriviaQuestion> list;
int qid = 0;
int timeValue = 20;
int coinValue = 0;
CountDownTimer countDownTimer;
Typeface tb, sb;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game_main);
//Initializing variables
questionText = (TextView) findViewById(R.id.triviaQuestion);
buttonA = (FButton) findViewById(R.id.buttonA);
buttonB = (FButton) findViewById(R.id.buttonB);
buttonC = (FButton) findViewById(R.id.buttonC);
buttonD = (FButton) findViewById(R.id.buttonD);
triviaQuizText = (TextView) findViewById(R.id.triviaQuizText);
timeText = (TextView) findViewById(R.id.timeText);
resultText = (TextView) findViewById(R.id.resultText);
coinText = (TextView) findViewById(R.id.coinText);
//Setting typefaces for textview and buttons - this will give stylish fonts on textview and button etc
tb = Typeface.createFromAsset(getAssets(), "fonts/TitilliumWeb-Bold.ttf");
sb = Typeface.createFromAsset(getAssets(), "fonts/shablagooital.ttf");
triviaQuizText.setTypeface(sb);
questionText.setTypeface(tb);
buttonA.setTypeface(tb);
buttonB.setTypeface(tb);
buttonC.setTypeface(tb);
buttonD.setTypeface(tb);
timeText.setTypeface(tb);
resultText.setTypeface(sb);
coinText.setTypeface(tb);
//Our database helper class
triviaQuizHelper = new TriviaQuizHelper(this);
//Make db writable
triviaQuizHelper.getWritableDatabase();
//It will check if the ques,options are already added in table or not
//If they are not added then the getAllOfTheQuestions() will return a list of size zero
if (triviaQuizHelper.getAllOfTheQuestions().size() == 0) {
//If not added then add the ques,options in table
triviaQuizHelper.allQuestion();
}
//This will return us a list of data type TriviaQuestion
list = triviaQuizHelper.getAllOfTheQuestions();
//Now we gonna shuffle the elements of the list so that we will get questions randomly
Collections.shuffle(list);
//currentQuestion will hold the que, 4 option and ans for particular id
currentQuestion = list.get(qid);
//countDownTimer
countDownTimer = new CountDownTimer(22000, 1000) {
public void onTick(long millisUntilFinished) {
//here you can have your logic to set text to timeText
timeText.setText(String.valueOf(timeValue) + "\"");
//With each iteration decrement the time by 1 sec
timeValue -= 1;
//This means the user is out of time so onFinished will called after this iteration
if (timeValue == -1) {
//Since user is out of time setText as time up
resultText.setText(getString(R.string.timeup));
//Since user is out of time he won't be able to click any buttons
//therefore we will disable all four options buttons using this method
disableButton();
}
}
//Now user is out of time
public void onFinish() {
//We will navigate him to the time up activity using below method
timeUp();
}
}.start();
//This method will set the que and four options
updateQueAndOptions();
}
public void updateQueAndOptions() {
//This method will setText for que and options
questionText.setText(currentQuestion.getQuestion());
buttonA.setText(currentQuestion.getOptA());
buttonB.setText(currentQuestion.getOptB());
buttonC.setText(currentQuestion.getOptC());
buttonD.setText(currentQuestion.getOptD());
timeValue = 20;
//Now since the user has ans correct just reset timer back for another que- by cancel and start
countDownTimer.cancel();
countDownTimer.start();
//set the value of coin text
coinText.setText(String.valueOf(coinValue));
//Now since user has ans correct increment the coinvalue
coinValue++;
}
//Onclick listener for first button
public void buttonA(View view) {
//compare the option with the ans if yes then make button color green
if (currentQuestion.getOptA().equals(currentQuestion.getAnswer())) {
buttonA.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.lightGreen));
//Check if user has not exceeds the que limit
if (qid < list.size() - 1) {
//Now disable all the option button since user ans is correct so
//user won't be able to press another option button after pressing one button
disableButton();
//Show the dialog that ans is correct
correctDialog();
}
//If user has exceeds the que limit just navigate him to GameWon activity
else {
gameWon();
}
}
//User ans is wrong then just navigate him to the PlayAgain activity
else {
gameLostPlayAgain();
}
}
//Onclick listener for sec button
public void buttonB(View view) {
if (currentQuestion.getOptB().equals(currentQuestion.getAnswer())) {
buttonB.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.lightGreen));
if (qid < list.size() - 1) {
disableButton();
correctDialog();
} else {
gameWon();
}
} else {
gameLostPlayAgain();
}
}
//Onclick listener for third button
public void buttonC(View view) {
if (currentQuestion.getOptC().equals(currentQuestion.getAnswer())) {
buttonC.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.lightGreen));
if (qid < list.size() - 1) {
disableButton();
correctDialog();
} else {
gameWon();
}
} else {
gameLostPlayAgain();
}
}
//Onclick listener for fourth button
public void buttonD(View view) {
if (currentQuestion.getOptD().equals(currentQuestion.getAnswer())) {
buttonD.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.lightGreen));
if (qid < list.size() - 1) {
disableButton();
correctDialog();
} else {
gameWon();
}
} else {
gameLostPlayAgain();
}
}
//This method will navigate from current activity to GameWon
public void gameWon() {
Intent intent = new Intent(this, GameWon.class);
startActivity(intent);
finish();
}
//This method is called when user ans is wrong
//this method will navigate user to the activity PlayAgain
public void gameLostPlayAgain() {
Intent intent = new Intent(this, PlayAgain.class);
startActivity(intent);
finish();
}
//This method is called when time is up
//this method will navigate user to the activity Time_Up
public void timeUp() {
Intent intent = new Intent(this, Time_Up.class);
startActivity(intent);
finish();
}
//If user press home button and come in the game from memory then this
//method will continue the timer from the previous time it left
#Override
protected void onRestart() {
super.onRestart();
countDownTimer.start();
}
//When activity is destroyed then this will cancel the timer
#Override
protected void onStop() {
super.onStop();
countDownTimer.cancel();
}
//This will pause the time
#Override
protected void onPause() {
super.onPause();
countDownTimer.cancel();
}
//On BackPressed
#Override
public void onBackPressed() {
Intent intent = new Intent(this, HomeScreen.class);
startActivity(intent);
finish();
}
//This dialog is show to the user after he ans correct
public void correctDialog() {
final Dialog dialogCorrect = new Dialog(MainGameActivity.this);
dialogCorrect.requestWindowFeature(Window.FEATURE_NO_TITLE);
if (dialogCorrect.getWindow() != null) {
ColorDrawable colorDrawable = new ColorDrawable(Color.TRANSPARENT);
dialogCorrect.getWindow().setBackgroundDrawable(colorDrawable);
}
dialogCorrect.setContentView(R.layout.dialog_correct);
dialogCorrect.setCancelable(false);
dialogCorrect.show();
//Since the dialog is show to user just pause the timer in background
onPause();
TextView correctText = (TextView) dialogCorrect.findViewById(R.id.correctText);
FButton buttonNext = (FButton) dialogCorrect.findViewById(R.id.dialogNext);
//Setting type faces
correctText.setTypeface(sb);
buttonNext.setTypeface(sb);
//OnCLick listener to go next que
buttonNext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//This will dismiss the dialog
dialogCorrect.dismiss();
//it will increment the question number
qid++;
//get the que and 4 option and store in the currentQuestion
currentQuestion = list.get(qid);
//Now this method will set the new que and 4 options
updateQueAndOptions();
//reset the color of buttons back to white
resetColor();
//Enable button - remember we had disable them when user ans was correct in there particular button methods
enableButton();
}
});
}
//This method will make button color white again since our one button color was turned green
public void resetColor() {
buttonA.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.white));
buttonB.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.white));
buttonC.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.white));
buttonD.setButtonColor(ContextCompat.getColor(getApplicationContext(),R.color.white));
}
//This method will disable all the option button
public void disableButton() {
buttonA.setEnabled(false);
buttonB.setEnabled(false);
buttonC.setEnabled(false);
buttonD.setEnabled(false);
}
//This method will all enable the option buttons
public void enableButton() {
buttonA.setEnabled(true);
buttonB.setEnabled(true);
buttonC.setEnabled(true);
buttonD.setEnabled(true);
}
}
Edited
Just remove the wrapper if else inside all the buttons better to keep it as, don't repeat the code. I am assuming the screen that shows result is handled inside gameWon and you have implemented functionality for inCorrectDialog
public void buttonA(View view) {
Button button = (Button) view;
buttonPressed(button);
}
public void buttonB(View view) {
Button button = (Button) view;
buttonPressed(button);
}
public void buttonC(View view) {
Button button = (Button) view;
buttonPressed(button);
}
public void buttonD(View view) {
Button button = (Button) view;
buttonPressed(button);
}
public void buttonPressed(Button button) {
button.setButtonColor(ContextCompat.getColor(getApplicationContext(), R.color.lightGreen));
if (qid < list.size() - 1) {
disableButton();
if (currentQuestion.getOptA().equals(currentQuestion.getAnswer())) {
correctDialog();
} else {
inCorrectDialog();
}
} else {
gameWon();
}
}
I'm playing with a drawing activity in Java converted/decompiled from this Kotlin sample.
I'm simplifying its functionalities and, as it is now, it allows me to click on "Save" button and a preview pops up with a text saying "Saved!", but I'd like to know what needs to be done to simply throw the resulting image to the Android photo gallery anytime the button is clicked (let's say, after saved, the image must become a standalone picture inside the camera gallery).
It seems it has to do with FileOutputStream/Bitmap.CompressFormat/MediaStore.Images
and I can foresee some difficulties in terms of naming files in a way they don't overwrite and I'm reading a lot of answers around here, but I still didn't get the logic so any idea is appreciated.
It's the first time I'm trying to do something similar so I'm sort of lost and I come here to ask for some directions.
Here is the single activity:
public final class SampleActivity extends AppCompatActivity implements OnSeekBarChangeListener, OnClickListener {
private HashMap _$_findViewCache;
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.activity_sample);
(this._$_findCachedViewById(id.close)).setOnClickListener(this);
(this._$_findCachedViewById(id.save)).setOnClickListener(this);
(this._$_findCachedViewById(id.undo)).setOnClickListener(this);
(this._$_findCachedViewById(id.clear)).setOnClickListener(this);
((SeekBar)this._$_findCachedViewById(id.red)).setOnSeekBarChangeListener(this);
((SeekBar)this._$_findCachedViewById(id.green)).setOnSeekBarChangeListener(this);
((SeekBar)this._$_findCachedViewById(id.blue)).setOnSeekBarChangeListener(this);
((SeekBar)this._$_findCachedViewById(id.width)).setOnSeekBarChangeListener(this);
}
public void onProgressChanged(#Nullable SeekBar seekBar, int progress, boolean fromUser) {
int var10000;
SeekBar var10001;
label58: {
label50: {
if (seekBar != null) {
var10000 = seekBar.getId();
var10001 = (SeekBar)this._$_findCachedViewById(id.red);
Intrinsics.checkExpressionValueIsNotNull(var10001, "red");
if (var10000 == var10001.getId()) {
break label50;
}
}
if (seekBar != null) {
var10000 = seekBar.getId();
var10001 = (SeekBar)this._$_findCachedViewById(id.green);
Intrinsics.checkExpressionValueIsNotNull(var10001, "green");
if (var10000 == var10001.getId()) {
break label50;
}
}
if (seekBar == null) {
break label58;
}
var10000 = seekBar.getId();
var10001 = (SeekBar)this._$_findCachedViewById(id.blue);
Intrinsics.checkExpressionValueIsNotNull(var10001, "blue");
if (var10000 != var10001.getId()) {
break label58;
}
}
SeekBar var8 = (SeekBar)this._$_findCachedViewById(id.red);
Intrinsics.checkExpressionValueIsNotNull(var8, "red");
int r = var8.getProgress();
var8 = (SeekBar)this._$_findCachedViewById(id.green);
Intrinsics.checkExpressionValueIsNotNull(var8, "green");
int g = var8.getProgress();
var8 = (SeekBar)this._$_findCachedViewById(id.blue);
Intrinsics.checkExpressionValueIsNotNull(var8, "blue");
int b = var8.getProgress();
int color = Color.argb(255, r, g, b);
((FingerPaintImageView)this._$_findCachedViewById(id.finger)).setStrokeColor(color);
(this._$_findCachedViewById(id.colorPreview)).setBackgroundColor(color);
return;
}
if (seekBar != null) {
var10000 = seekBar.getId();
var10001 = (SeekBar)this._$_findCachedViewById(id.width);
Intrinsics.checkExpressionValueIsNotNull(var10001, "width");
if (var10000 == var10001.getId()) {
((FingerPaintImageView)this._$_findCachedViewById(id.finger)).setStrokeWidth((float)progress);
}
}
}
public void onClick(#Nullable View v) {
if (Intrinsics.areEqual(v, this._$_findCachedViewById(id.undo))) {
((FingerPaintImageView)this._$_findCachedViewById(id.finger)).undo();
} else if (Intrinsics.areEqual(v, this._$_findCachedViewById(id.clear))) {
((FingerPaintImageView)this._$_findCachedViewById(id.finger)).clear();
} else if (Intrinsics.areEqual(v, this._$_findCachedViewById(id.close))) {
this.hidePreview();
} else if (Intrinsics.areEqual(v, this._$_findCachedViewById(id.save))) {
this.showPreview();
}
}
private final void showPreview() {
RelativeLayout var10000 = (RelativeLayout)this._$_findCachedViewById(id.previewContainer);
Intrinsics.checkExpressionValueIsNotNull(var10000, "previewContainer");
var10000.setVisibility(View.VISIBLE);
ImageView var1 = (ImageView)this._$_findCachedViewById(id.preview);
FingerPaintImageView var10001 = (FingerPaintImageView)this._$_findCachedViewById(id.finger);
Intrinsics.checkExpressionValueIsNotNull(var10001, "finger");
var1.setImageDrawable(var10001.getDrawable());
}
private final void hidePreview() {
RelativeLayout var10000 = (RelativeLayout)this._$_findCachedViewById(id.previewContainer);
Intrinsics.checkExpressionValueIsNotNull(var10000, "previewContainer");
var10000.setVisibility(View.GONE);
}
public void onStartTrackingTouch(#Nullable SeekBar seekBar) {
}
public void onStopTrackingTouch(#Nullable SeekBar seekBar) {
}
public void onBackPressed() {
RelativeLayout var10000 = (RelativeLayout)this._$_findCachedViewById(id.previewContainer);
Intrinsics.checkExpressionValueIsNotNull(var10000, "previewContainer");
if (var10000.getVisibility() == View.VISIBLE) {
this.hidePreview();
} else {
super.onBackPressed();
}
}
public View _$_findCachedViewById(int var1) {
if (this._$_findViewCache == null) {
this._$_findViewCache = new HashMap();
}
View var2 = (View)this._$_findViewCache.get(var1);
if (var2 == null) {
var2 = this.findViewById(var1);
this._$_findViewCache.put(var1, var2);
}
return var2;
}
public void _$_clearFindViewByIdCache() {
if (this._$_findViewCache != null) {
this._$_findViewCache.clear();
}
}
}
Thanks in advance!
I was able to overcome this issue by taking another paint-like sample (a simpler one and in Java) called Android Drawable View.
This different sample and tips from previous answers available here on StackOverflow like this one and this other one were enough to put the project together so I'll try to explain how to.
First, you need to add permission to WRITE_EXTERNAL_STORAGE in your Manifest.xml:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Later, you just need to add a save button to your activity_main.xml:
<Button
android:id="#+id/saveButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Save" />
Then, you initialize the button view onCreate and associate the new saveButton with a setOnClickListener and don't forget to request permission in realtime:
Button saveButton = findViewById(R.id.saveButton);
saveButton.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
if (ContextCompat.checkSelfPermission(getBaseContext(), Manifest.permission.CAMERA) ==
PackageManager.PERMISSION_GRANTED) {
drawableView.setEnabled(true);
}
else {
ActivityCompat.requestPermissions(MainActivity.this, new String[]
{ Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
}
Bitmap bm = drawableView.obtainBitmap();
MediaStore.Images.Media.insertImage(getContentResolver(), bm, "title" , "description");
}
});
By using the method described above, I've been able to save a new media file inside a folder in the default gallery app on the emulator as you can see below:
However, it's still getting an unintended black background that I must overcome now, but I consider the initial issue solved as it answers my own original question.
I'm a beginner in Android Studio, and I want to make a C button in calc with 2 functions.
How do I do that on one tap the C button erases only one number, and on hold erase all numbers in TextView?
findViewById(R.id.btnClear).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
txtScreen.setText(""); // Clear the screen
// Reset all the states and flags
lastNumeric = false;
stateError = false;
lastDot = false;
You can set an onClickListener and onLongClickListener to achieve this.
cButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String currentText = textView.getText().toString();
if(currentText.length >= 2){
currentText = currentText.substring(0, currentText.length - 2);
}else{
currentText = "";
}
textView.setText(currentText);
}
});
cButton.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
textView.setText("");
return true;
}
});
Have you looked in to the onClick() and onLongPress() methods?
cancelButton.setOnLongClickListener(new OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
myTextView.setText("");
return true;
}
});
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
removeOneCharacter();
}
});
private void removeOneCharacter()
{
String textViewValue = myTextView.getText().toString();
if (textViewValue != null && textViewValue.length >= 2)
{
myTextView.setText(textViewValue.substring(0, textViewValue.length() - 2);
}
}
The onClick() method removes on char from the TextView at a time. The onClick() method however removes the entire String from the TextView but only considering if there is already 2 or more characters to prevent an Exception from occurring due to the upper-bound of the substring.
An improvement here could be to add another if function that checks the character length within the Long press and performs a clear if there is only one character remaining.
If the user clicks the "go" button, the application should check if the EditText's value is "Settings" or not? How can I do this?
Something like this:
Button buttn1;
EditText Text1;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttn1 = (Button)findViewById(R.id.Button111);
Text1 = (EditText)findViewById(R.id.Text111);
buttn1.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
if (Text1 == "Settings") {
//CODE
}else {
//CODE
}
}
});
}
You can get the content of an EditText field like this: Text1.getText().toString() and you can check String equality using .equals().
So combined, this would be Text1.getText().toString().equals("Settings")
Try This:
if (Text1.getText().toString().equals("Settings")) {
//CODE
}else {
//CODE
}
This is my code: here some edit texts are there.
public class MainActivity extends ActionBarActivity {
#InjectView(R.id.edt_fname) protected EditText account_fname;
#InjectView(R.id.edt_lnames) protected EditText account_lname;
#InjectView(R.id.edt_userid) protected EditText account_userid;
#InjectView(R.id.edt_pwd) protected EditText account_password;
#InjectView(R.id.edt_reenter) protected EditText account_reenter_pswd;
#InjectView(R.id.nxt_btn1) protected Button next_acct;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.inject(this);
next_acct.setEnabled(false);
if(( !account_fname.getText().toString().equals("")) &&
( !account_lname.getText().toString().equals("")) &&
( !account_userid.getText().toString().equals("")) &&
( !account_password.getText().toString().equals("")) &&
( !account_reenter_pswd.getText().toString().equals("")) )
{
next_acct.setEnabled(true);
next_acct.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivity(new Intent(getApplicationContext(), PersonalInfo.class));
overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left);
}
});
} }
My aim is that when the fields are empty, then the submit button is disabled.
If all fields are filled with some text, then the submit button is enabled.
How can I do this?
this is very simple...
if(edttext.getText().toString().equals(edttext2.getText().toString()))
{
submit_button.setEnabled(true);
}
else
{
submit_button.setEnabled(true);
}
try this
if((account_fname.getText() != null ) &&
( account_lname.getText() != null) &&
( account_userid.getText() != null) &&
( account_password.getText() != null) &&
( account_reenter_pswd.getText() != null) )
{
next_acct.setEnabled(true);
}
You're doing it inside the onCreate method. You need to add a textChangeListener on the EditText then place your if statement in the textChangeListener or create a method then put the if statement in the method then call the method in the TextChangeListener.
For reference on TextChangeListener: Counting Chars in EditText Changed Listener
The challenge here is really in gathering the content of the EditText fields. That is, once you have a simple call to retrieve all interesting TextView or EditText fields, then the problem becomes trivial.
I tested this, seems to work. I believe it's less fragile to changes in the structure or nesting of the EditText fields of the layout.
To answer the question in the topic, the submit button can be enabled if the array contains no "null" entries from the result of the "gatherEditTextContent(View root)" method.
public static String[] gatherEditTextContent(View root) {
final Vector<String> v = new Vector();
Boolean stop = false;
scanEditText(root, new ETCallback() {
#Override
public boolean onEditText(EditText editText) {
v.add((editText.getText() == null ? "null" : editText.getText().toString()));
return false;
}
});
return v.toArray(new String[v.size()]);
}
/** initiate by passing v= root, callback non-null */
public static boolean scanEditText(View v, ETCallback callback) {
boolean stop = false;
if (v instanceof EditText) {
if (callback != null) stop = callback.onEditText((EditText)v);
}
else if (v instanceof ViewGroup) {
ViewGroup vg = (ViewGroup) v;
for (int i=0; (!stop && i < vg.getChildCount()); i++) {
View child = vg.getChildAt(i);
stop = scanEditText(child, callback);
}
}
return stop;
}
private interface ETCallback {
public boolean onEditText(EditText editText);
}