Change bgcolor when click button

I'm using Android to create a Quiz application. So far, most of the things are done. Only one problem. When the answer button is clicked, its background color should be changed to a different color.

I implement in this way:

selectionBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
//                correct answer clicked
                if (checkChosen(questionProgress, selectionBtn.getText().toString())) {
//                    change the bg-color to green indicates user made correct choice
                    selectionBtn.setBackgroundResource(R.drawable.correct_button_selected);
//                    last the bg-color for 0.3s
                    selectionBtn.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            selectionBtn.setBackgroundResource(R.drawable.choice_button_border);
                        }
                    }, 300);
                } else {
//                    wrong answer clicked
                    selectionBtn.setBackgroundResource(R.drawable.wrong_button_selected);
                    selectionBtn.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            selectionBtn.setBackgroundResource(R.drawable.choice_button_border);
                        }
                    }, 300);
                }
//                progress added
                questionProgress++;
                /**
                 * progress equals the amount, means the last question
                 * show the submit button
                 */
                if (questionProgress == questionAmount) {
                    binding.submitBtn.setVisibility(View.VISIBLE);
                    binding.progressBar.setProgress(binding.progressBar.getMax());
                    binding.progressCount.setText(questionAmount + " / " + questionAmount);
                }
                /**
                 * progress < amount, remove answer buttons of the last question
                 * add new answer buttons and change progress bar
                 */
                if (questionProgress < questionList.length) {
                    Log.v("progress", String.valueOf(questionProgress));
                    binding.progressBar.setProgress(questionProgress);
                    binding.progressCount.setText(questionProgress + " / " + questionAmount);
                    binding.quizContent.setText(questionList[questionProgress]);
                    binding.selectionLayout.removeAllViews();
                    String[] anLi = answerMap.get(questionProgress);
                    for (int i = 0; i < anLi.length - 1; i++) {
                        addSelections(anLi[i]);
                    }
                }
            }
        });

However, in this way, only answer buttons for the last question will change bg-color when they are clicked.

How can I solve this problem? Thanks in advance.

You can use view from onClick method like in the code snippet below.

selectionBtn.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(final View view) {
		if (checkChosen(questionProgress, selectionBtn.getText().toString())) {
			view.setBackgroundResource(R.drawable.correct_button_selected);

			final Handler handler = new Handler();
			handler.postDelayed(new Runnable() {
				@Override
				public void run() {
					view.setBackgroundResource(R.drawable.choice_button_border);
				}
			}, 200);
		} else {
			// else condition
		}
	}
});

You seem to reuse selectionBtn variable while creating new button for each answer, when your delayed runnable starts, the value of selectionBtn will be different and it will be pointing the last button you created.

To fix that, use the onClick()'s argument, which actually is the view that triggered the event (which is your correct button):

selectionBtn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        final Button currentButton = (Button) view;
        
        if (checkChosen(questionProgress, currentButton.getText().toString())) {
            currentButton.setBackgroundResource(R.drawable.correct_button_selected);
        } else {
            currentButton.setBackgroundResource(R.drawable.wrong_button_selected);
        }

        currentButton.postDelayed(new Runnable() {
            @Override
            public void run() {
                currentButton.setBackgroundResource(R.drawable.choice_button_border);
            }
        }, 300);

        ....
    }

I have fixed it. The problem is removeAllViews(). It removes the whole views for answer buttons before add new buttons, and that makes the flash not visible cause it's removed.

if (questionProgress < questionList.length) {
                    Log.v("progress", String.valueOf(questionProgress));
                    binding.progressBar.setProgress(questionProgress);
                    binding.progressCount.setText(questionProgress + " / " + questionAmount);
                    binding.quizContent.setText(questionList[questionProgress]);
                    binding.selectionLayout.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            binding.selectionLayout.removeAllViews();
                            String[] anLi = answerMap.get(questionProgress);
                            for (int i = 0; i < anLi.length - 1; i++) {
                                addSelections(anLi[i]);
                            }
                        }
                    }, 300);

                }

This is how I fixed it.