So i was developing a bmi calculator activity in android studio. And i ran into a problem where i got a value of two variable inside from two methods for different TextView which was defined in the class. That shouldn't be problem but once i switch to another TextView in app. The first one sends a zero value, which is the problem, Anyone knows how to fix it? Thanks !
The two methods in onCreate which give value:
inheight.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
height = Double.parseDouble(inheight.getText().toString());
if(KeyEvent.KEYCODE_DEL== keyCode)
{
if(inheight.getText().length() != 0)
inheight.setText(inheight.getText().subSequence(0,inheight.getText().length()-1));
}
return true;
}
});
inweight.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
weight = Integer.parseInt(inweight.getText().toString());
if(KeyEvent.KEYCODE_DEL == keyCode)
{
if(inweight.getText().length() != 0)
inweight.setText(inweight.getText().subSequence(0,inweight.getText().length()-1));
}
return true;
}
});
And the Calculate method where i try to calulate
public void calculate()
{
if(height!=0 && weight !=0)
{
// do this
}
else
{
Toast.makeText(this, "Error: Values Cannot Be Zero!", Toast.LENGTH_LONG).show();
}
So when i run it always shows the toast message :(. Please Help!
As stated in the android documentation, View.OnKeyListener is useful only for hardware keyboards , and a software input method (like the one android uses), has no obligation to trigger this listener.
So instead of using View.OnKeyListener to get your values i would try a different approach (i.e getting the values after pressing a button, implementing View.OnClickListener )
Also are you sure that only the first TextView gives you the zero value, or both ?
Related
we got homework to make convertor of weights where the fields are updated while typing the number (no need to click "calculate" or anything). one of the students offered the code below.
the code works: when putting a number in field 1, field 2 changes while typing.
what i dont understand is how does that work?
in the onKey method, no value is given to View int and keyEvent
so how does the listener "knows" on which view to and what keys to listen to or what event to activate ?
public class Screen extends Activity {
double weight = 2.20462;
EditText kgEdit, lbsEdit;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
kgEdit = (EditText) findViewById(R.id.kgEdit);
lbsEdit = (EditText) findViewById(R.id.lbsEdit);
kgEdit.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
String kg = kgEdit.getText().toString();
if (kg.isEmpty()) {
lbsEdit.setText("");
} else {
double num = Double.valueOf(kgEdit.getText().toString()) * weight;
lbsEdit.setText(num + "");
}
return false;
}
});
lbsEdit.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
String lbs = lbsEdit.getText().toString();
if (lbs.isEmpty()) {
kgEdit.setText("");
} else {
double num = Double.valueOf(lbsEdit.getText().toString()) / weight;
kgEdit.setText(num + "");
}
return false;
}
});
}
}
I'm going to focus on just 1 of the text fields to answer this. Look at this first line:
kgEdit = (EditText) findViewById(R.id.kgEdit);
All this does is get a reference to the EditText for entering kg. Now that there is a reference, we can call methods on that object.
Next, we have this:
kgEdit.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
// ...
}
}
What the above does is the following. Take our reference to the EditText for kilograms that we retrieved in our first line. The method setOnKeyListener does the following (from here): "Register a callback to be invoked when a hardware key is pressed in this view."
What this means is that you've now told the view that you want to be informed every time the user presses a key while this EditText has the focus. You make this call to the Android API and in the background Android handles everything you're asking. It will call the method with the View view, int keyCode and KeyEvent event. You give it a method that then handles those inputs. So nowhere in your code do you need to call the method, Android calls it in the background where you'll never have to see or worry about it.
Now, because you called the method on kgEdit, that means the following code will ONLY be called when kgEdit is focused and keys are typed, so there's no confusion with the other EditText. It gets its own method call later, just below. Here's the rest of the code inside the setOnKeyListener:
String kg = kgEdit.getText().toString();
if (kg.isEmpty()) {
lbsEdit.setText("");
} else {
double num = Double.valueOf(kgEdit.getText().toString()) * weight;
lbsEdit.setText(num + "");
}
return false;
What this does is get the current text in kgEdit, which has already been updated with the key the user pressed. And it just checks if the text is empty, and if so remove the text in lbsEdit. If it's not empty, then get the text, convert it to a number, convert the number from kg to lbs and update lbsEdit
You have to use addTextChangedListener like this-
EditText editText = (EditText) findViewById(R.id.editText1);
editText.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
//do here your calculation
String data = s.toString();
}
});
I am new to Android. I am trying to make a text box and on pressing done key, it should take the value to the java code. For this I am using setOnEditorActionListener.. I searched on how to do this and got many answers on how to implement it. Example:
EditText editText = (EditText) findViewById(R.id.search);
editText.setOnEditorActionListener(new OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
sendMessage();
handled = true;
}
return handled;
}
});
I need to ask where should I write this thing? In which method? I tried doing it in onCreate but it threw some error. I somehow made it work using this code:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.unlock);
Log.i(TAG, "onCreate");
editText= (EditText) findViewById(R.id.editText);
editText.setOnEditorActionListener(this);
}
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
Log.i(TAG, "button pressed");
Toast.makeText(this, "Hey you just clicked the DONE button", Toast.LENGTH_SHORT).show();
handled = true;
}
return handled;
}
Here I used this keyword, and I don't understand why have I used it.
Question 1. Please help me understand, why have we used this keyword..
Question 2. Why wasn't it working in the below code?
public void checkInput() {
Log.i(TAG, "Enter checkInput method");
final EditText editText= (EditText) findViewById(R.id.editText);
editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
Log.i(TAG, "Enter onEditorAction");
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
Log.i(TAG, "button pressed")
handled = true;
}
return handled;
}
});
}
I called this checkInput method from onCreate.
To answer Question 1:
Here I used this keyword, and I don't understand why have I used it. Question 1. Please help me understand, why have we used this keyword..
You're telling Java to look into the Activity class for implementations of methods required by the TextView.OnEditorActionListener interface. So for all interactions with your soft keyboard, Java would look into your class for the method: onEditorAction
In order for the above to work, your activity needs to defined like:
public class MyActivity implements TextView.OnEditorActionListener {}
For question 2:
Question 2. Why wasn't it working in the below code?
To check for the "Done" action, your if statement should be:
if (actionId == EditorInfo.IME_ACTION_DONE) { ... }
Hope that helps.
I have an activity where the whole screen is dedicated to sending one message. Being one EditText on the top half, and the SoftKeyboard always visible on the bottom half.
When i press back, the SoftKeyboard hides and i have to press back again to leave the activity.
The behavior that i'm struggling to get is : finishing the activity right away when i press the back button, instead of hiding the keyboard.
You can find this behavior in the twitter app for example, when writing a new tweet.
I tried with overriding the onBackPressed() function, but seems like when the keyboard is visible, the function is not called.
#Override
public void onBackPressed() {
finish();
}
Any help would be really appreciated!
So after trying many things, here something that worked :
Subclass EditText and override the onKeyPreIme() function to send a call back.
Here's the code for the subclass :
OnKeyPreImeListener onKeyPreImeListener;
public void setOnKeyPreImeListener(OnKeyPreImeListener onKeyPreImeListener) {
this.onKeyPreImeListener = onKeyPreImeListener;
}
#Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_UP) {
if(onKeyPreImeListener != null)
onKeyPreImeListener.onBackPressed();
Log.d(TAG, "HIDING KEYBOARD");
return false;
}
return super.dispatchKeyEvent(event);
}
public interface OnKeyPreImeListener {
void onBackPressed();
}
Then in your activity for each of your TextView :
EditTextGraphee.OnKeyPreImeListener onKeyPreImeListener =
new EditTextGraphee.OnKeyPreImeListener() {
#Override
public void onBackPressed() {
Log.d(TAG, "CALL BACK RECEIVED");
MyActivity.this.onBackPressed();
}
};
editText.setOnKeyPreImeListener(onKeyPreImeListener);
new answer:
so apparently you don't receive the onBackPressed callback, but that doesn't mean you can't detect the keyboard closing.
Using the technique described here: How to check visibility of software keyboard in Android?
you can detect when the keyboard open/close, so when the keyboard closes you call finish();
deprecated, original answer:
simply override the back press event in the activity:
#Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
I assume that since the soft keyboard is visible probably an edittext has a focus. So you can catch the back pressed event by adding an OnEditorActionListener on that EditText and finish activity.
yourEditText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_UP){
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK){
finish();
}
}
return false;
}
});
You nee to extend EdtText class and implement onKeyPreIme method.
public class MyEditText extends EditText {
/* Must use this constructor in order for the layout files to instantiate the class properly */
public MyEditText(Context context, AttributeSet attrs)
{
super(context, attrs);
// TODO Auto-generated constructor stub
}
#Override
public boolean onKeyPreIme (int keyCode, KeyEvent event)
{
// do your stuff here.
return true;
}
}
Override onBackPressed() method like this :
#Override
public void onBackPressed() {
hideKeyboard();
finish();
}
For hideKeyboard() function please search in the Internet .
I have ImageViews inside of a GridView, I had been using an OnItemClickListener along with an OnItemLongClickListener set on the GridView to open the image on a larger page and to delete the item respectively. Now, I have to implement rearranging of the ImageViews in the GridView, so I plan to move the deletion function to a double tap gesture, (please do not lecture me on android style guidelines (including the possibility of contextual actionbars, which I suggested), as this is what my boss asks for to emulate functions inside our ios app) in order to reserve long click for the drag and drop. I set an OnTouchListener on each view in the getView of my custom adapter, feeding a GestureDetecter with a listener extending SimpleOnGestureListener the given MotionEvent with onTouchEvent. I know what to do up to that point, but when I included (onDown of course, to get other callbacks) onDoubleTap, onSingleTapConfirmed, and onLongPressed all taps were interpreted as long clicks. And when I removed the both callback methods to be replaced with their listener counterparts once again (ie OnItemClickListeners) I received those two gestures but not the double tap, which makes sense, as double taps start out as a single tap unless you wait for a bit less than a second to confirm them as singles rather than potential doubles. I also tried placing the OnItemClickListener, but not the OnItemLongClickListener, with the callback in the extended SimpleOnGestureListener. In this case, only long presses were ever interpreted, but other gestures caused no response. Here is my code as it stands now, and do note that I returned false in the onTouchEvent in order to allow others (itemclicklisteners) to consume the events following the attempts made in the GestureDetector.
public class MainBoardGridAdapter extends GenericBoardGridAdapter implements OnItemLongClickListener {
private class Ges extends GestureDetector.SimpleOnGestureListener {
int pos;
public Ges(View v) {
pos = (Integer) v.getTag();
}
#Override
public boolean onDown(MotionEvent me) {
//this does get called but none of these methods below
return true;
}
#Override
public boolean onDoubleTap(MotionEvent me) {
new DeleteConfirmationPrompt(c, "board") {
#Override
protected boolean onDeleteConfirmed() {
// delete the visionboard
return deleteBoard(pos);
}
}; // Constructor shows dialog
return false;
}
#Override
public boolean onSingleTapConfirmed(MotionEvent e) {
MainBoardGridAdapter.super.flagForUpdate(pos);
if (listener != null) {
listener.onBoardClick(pos, getName(pos));
} else {
Intent intent = new Intent(c, VisionBoardActivity.class);
intent.putExtra(VisionBoardActivity.EXTRA_VISION_BOARD_NAME, getName(pos));
frag.startActivityForResult(intent, MyBoardsFragment.REQUEST_EDIT);
}
return false;
}
}
#Override
public boolean onItemLongClick(AdapterView<?> parent, View v,
final int pos, long id) {
Toast.makeText(c, "Long", Toast.LENGTH_LONG).show();
return false;
}
// called by getView of extended adapter
#Override
public void onImageLoaded(ImageView iv, String data, View root) {
iv.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
(new GestureDetector(c, (new Ges(v)))).onTouchEvent(event);
return false;
}
});
}
}
And in the Activity, gv is my GridView:
gv.setOnItemLongClickListener(gridAdapter);
Also note that I had been using true in the return value in the GestureDetector methods, until trying the current configuration.There was no difference to be seen.
Thank you for your valuable time and help, I hope that someone will be able to point out what I am doing incorrectly.
-Jackson
I have 3 EditTexts in a row but on 3 different layouts. I set them up so when i click enter,it will jump to the next EditText from that row,on the next layout.The problem is that when i click enter from the first EditText on the row,it goes to the third.From the third it goes to the second and from the second to the first.It's like i press enter on the first EditText,it goes to the second and then to the third on the same enter.
How can i stop it from jumping for example from the first EditText to the second and then the third on the same press of the enter key?
Here's some of my code :
et.setOnKeyListener(new OnKeyListener() {
public boolean onKey(View v1, int keyCode, KeyEvent KEYCODE_ENTER) {
l2.getChildAt(localizarer).requestFocus();
return true;
}
});
et2.setOnKeyListener(new OnKeyListener() {
public boolean onKey(View v2, int keyCode, KeyEvent KEYCODE_ENTER) {
l3.getChildAt(localizarer).requestFocus();
return true;
}
});
et3.setOnKeyListener(new OnKeyListener() {
public boolean onKey(View v3, int keyCode, KeyEvent KEYCODE_ENTER) {
l1.getChildAt(localizarer).requestFocus();
return true;
}
});
It's like i need some kind of break function,lol.
How can i fix this ?
Thanks and have a nice day/night !
Fixed by doing this :
et.setOnKeyListener(new OnKeyListener() {
public boolean onKey(View v, int keyCode, KeyEvent event) {
// If the event is a key-down event on the "enter" button
if ((event.getAction() == KeyEvent.ACTION_DOWN) &&
(keyCode == KeyEvent.KEYCODE_ENTER))
{
// Perform action on key press
l2.getChildAt(localizarer).requestFocus();
return true;
}
return false;
}
});
But now an older issue is back,it jumps to my second row of edittexts instead of going to the first child in the layout it goes to the second..
Are your edit texts defined in your xml do you have them in the corrent order there?
if that doesn't work you can use
android:nextFocusDown
to set the order
Why don't you use:
et1.requestFocus();
Instead of
l1.getChildAt(localizarer).requestFocus();