Develop Reference

Getting a view's index in a LinearLayout

So I have a LinearLayout set up in my XML file, and I dynamically add a bunch of CardViews to it through code upon startup of my activity. How can I make it so that when I click on any of the CardViews, I am able to obtain its position?
I tried setting up on an onClickListener for the LinearLayout, as well as an OnClickLIstener for each individual card, but couldn't find a way to obtain the index of the card that was clicked.
I'd really like to know where to put the onClickListener, and how to obtain the position that was clicked so that I can start a new activity based on what was clicked.
Here is my code:
private LinearLayout sLinearLayout;
private CardView[] cardViews;
private Workout[] workouts;
private ViewGroup.LayoutParams params;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.saved_workouts);
Intent intent = getIntent();
Parcelable[] parcelableArrayExtra = intent.getParcelableArrayExtra(MainActivity.EXTRA_WORKOUTS);
workouts = new Workout[parcelableArrayExtra.length];
System.arraycopy(parcelableArrayExtra, 0, workouts, 0, parcelableArrayExtra.length);
sLinearLayout = findViewById(R.id.viewList);
// Set the CardView layoutParams
params = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT
);
populateCardViews();
populateLayout();
}
//TODO: this method will populate the linear layout, filling the list.
private void populateLayout() {
for (CardView cardView : cardViews) {
sLinearLayout.addView(cardView);
}
}
//TODO: this method will fill up the CardViews array with an array of workouts.
private void populateCardViews() {
cardViews = new CardView[workouts.length];
for(int i = 0; i < workouts.length; i++) {
CardView card = new CardView(this);
card.setClickable(true);
card.setLayoutParams(params);
// Set CardView corner radius
card.setRadius(9);
// Set cardView content padding
card.setContentPadding(15, 15, 15, 15);
// Set a background color for CardView
card.setCardBackgroundColor(Color.BLUE);
// Set the CardView maximum elevation
card.setMaxCardElevation(50);
// Set CardView elevation
card.setCardElevation(25);
// Initialize a new TextView to put in CardView
TextView tv = new TextView(this);
tv.setLayoutParams(params);
tv.setText("Workout WorkTime: " + workouts[i].getWorkTime());
tv.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 30);
tv.setTextColor(Color.WHITE);
card.setTag(workouts[i].getWorkTime());
card.addView(tv);
cardViews[i] = card;
}
}

I think you can setOnClickListener for each individual card. The index of clicked card is i
for (int i = 0; i < workouts.length; i++) {
...
final int finalI = i;
card.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Log.i("TAG", "You click at card: " + finalI);
}
});
}

I not good to add so much layout programmatically. You can use a recycler view and an adapter to show a list of items. You can read this: https://developer.android.com/guide/topics/ui/layout/recyclerview
By the way, in your case: when you create a Cardview, just add onClickListener to it and the index of your Cardview is the index of it in Cardview list.
CardView cardView = new CardView(this);
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//handle click here
}
});

See if this works.
cardview.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
int index = linearLayout.indexOfChild(v);
}
});

How to remove dynamically created imageview from another button onclick?

I have created an ImageView dynamically like below image.It works fine. Now I want to remove view when top cross ImageView is clicked. When I click, it crashes .Please help how to achieve it.
here is what i have done
private void postImage(List<Uri> urilist) {
for(int i=0; i< urilist.size(); i++) {
imgView = new ImageView(getActivity());
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(150, 150);
lp.setMargins(20,10,20,10);
imgView.setLayoutParams(lp);
imgView.setId(i);
Log.d("uri list in loop",""+urilist.get(0));
Glide.with(getActivity())
.load(urilist.get(i))
.into(imgView);
layout.addView(imgView);
imgView1 = new ImageView(getActivity());
LinearLayout.LayoutParams lp1 = new LinearLayout.LayoutParams(50, 50);
lp1.setMargins(0,5,1,80);
imgView1.setLayoutParams(lp1);
imgView1.setId(i);
Log.d("uri list in loop",""+urilist.get(0));
Glide.with(getActivity())
.load(R.drawable.ic_action_cross)
.into(imgView1);
layout.addView(imgView1);
}
imgView1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
layout.removeViewAt(v.getId());
}
});
}

If it is because of the index (which definitely will crash in deletion of the 2nd item) then you can try below
imgView1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ViewGroup parentView = (ViewGroup) v.getParent();
parentView.removeView(v);
}
});
Note: You should not set id of two views as same. Rather use some mathematical formula.

I mean #shakac, you can try like that;
for(int i = 0; i<layout.getChildCount(); i++)
{
if (layout.getChildAt(i).getId() == v.getId()){
layout.removeView(layout.getChildAt(i));
break;
}
}
But as I said on the comment, you will remove the cross button like that.

Blur TextView on click, Android

I am trying to blur out a TextView, when a button is clicked. So far my code looks likes this:
#Override
public void onClick(View v) {
float radius = pdf.getTextSize() / 3;
BlurMaskFilter filter = new BlurMaskFilter(radius, BlurMaskFilter.Blur.NORMAL);
if (v==pause){
if (paused){
paused=false;
pdf.getPaint().setMaskFilter(null);
}
else{
paused=true;
pdf.getPaint().setMaskFilter(filter);
}
}
}
What am I doing wrong?

just set this
pdf.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
befor line: pdf.getPaint().setMaskFilter(filter);

Loop through each child element and compare its text in java

I am trying to build an android app that gets some questions from a database and its possible answers (the answers are created dynamically as UI buttons). What I have managed so far is that once the user clicks on an answer, if the answer is right the button's colour becomes green, and if the answer is wrong the colour becomes red. What I want to achieve is in case the answer was wrong, change the button's colour to red and find the button with the correct answer and change it's colour to green. I am currently trying to do this by looping through every child element of the clicked button's parent, and comparing its text with the right answer given from the database. This is what my code looks like:
final TableRow textRow = new TableRow(this);
textRow.addView(questionText, rowParamsQuestions);
layout.addView(textRow, layoutParams);
for(final String option : currentQuestion.getOptions())
{
final Button button = new Button(this);
button.setText(option);
button.setTextSize(16);
button.setBackgroundResource(R.drawable.rounded_shape);
button.setTextColor(Color.WHITE);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Button clicked = (Button) v;
if (!answeredQuestions.containsKey(currentQuestion)) {
answeredQuestions.put(currentQuestion, clicked.getText().toString());
if (clicked.getText().equals(currentQuestion.getAnswer())) {
clicked.setBackgroundResource(R.drawable.right_answer);
} else {
clicked.setBackgroundResource(R.drawable.wrong_answer);
for (int i = 0; i < textRow.getChildCount(); i++) {
View child = textRow.getChildAt(i);
if (child instanceof Button) {
if (((Button) child).getText().equals(currentQuestion.getAnswer())) {
child.setBackgroundResource(R.drawable.right_answer);
}
}
}
}
Thank you very much!

Array of Buttons (Android)

I have an array of buttons in my Android app. I want pressing a button to cause a different button to turn white. I have code like this:
final Button [][] button = new Button[5][3];
for(int i = 0; i < tableRow.length; i++) {
for(int j = 0; j < button[i].length; j++) {
button[i][j] = new Button(this);
button[i][j].getBackground().setColorFilter(new LightingColorFilter(0x00000000, 0xFF000000));
}
}
button[0][0].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
button[0][0].getBackground().setColorFilter(new LightingColorFilter(0x00000000, 0x00FFFFFF));
}
});
This works fine, but it turns button[0][0] white when it is pressed, while I want pressing button[0][0] to turn button[0][1] white. If I change it to this:
button[0][0].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
button[0][1].getBackground().setColorFilter(new LightingColorFilter(0x00000000, 0x00FFFFFF));
}
});
nothing happens when I press button[0][0]. Why?

button[0][1].invalidate();
will force the view to get redrawn.