Develop Reference

Hide Keyboard and show it by button

I am creating a program that write in EditText by barcode reader so I don't want to show the keyboard immediately even if I focused on it I don't wanna it to be visible , I need to press a button to show keyboard only to Edit sometimes .
and thanks

I would disable the EditText button from the beginning:
editText.setEnabled(false);
And to answer your question, yes. Even if it is disabled, you can change the text. Disabled only means user can't change it. You can programmatically edit it.
Then when the button is pressed:
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
editText.setEnabled(true);
editText.requestFocus();
}
});
This should automatically show the keyboard when the button is pressed.
Bonus:
If you want to disable the EditText once the editing is done, you can do this:
editText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View v, boolean hasFocus) {
if(!hasFocus) {
editText.setEnabled(false);
}
}
});

Software debounce for Android buttons

I have a simple ImageButton in my Android program which, when clicked, appends a "0" in a TextView. When this button is long clicked, it is supposed to append "+" in that TextView. The program works fine but I'm facing a typical key bouncing effect. When I long press the button, it do appends a "+", but when I release the button, it also appends a "0". It seems like Android registers a second single click when long click ends. How can I eliminate this? Here's what I'm doing:
ImageButton button0=(ImageButton)V.findViewById(R.id.imageButtonzero);
button0.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
enterNumber.append("0");
}
});
button0.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
enterNumber.append("+");
return false;
}
});
Thanks for your help!

You need to return true in the OnLongClickListener, to inform other listeners that the event has been consumed and does not need to be actioned upon further down the line :
button0.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
enterNumber.append("+");
return true;
}
});
Source of information : Android javadoc

Android single button multiple functions

I am beginner to Android development. I have 3 edit boxes and one "Edit" button. When I launch the activity all the edit boxes should be disabled. When I click on the Edit button all the 3 edit boxes should get enabled and button text should change to "Save". After updating the data in the edit boxes, when I click on the "Save" button, I should be able to send the updated data to the backend.
My problem is how can I make use of a single button for two function "Edit" and "Save".
Please help me.

You can do it this way:
button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
String ButtonText = button.getText().toString();
if(ButtonText.equals("Save"){
//code for save
button.setText("Edit");
}
else{
//code for edit
button.setText("Save");
}
}
});

If I were you I would actually use two buttons one for edit, and one for save. Make them the same size and in the same position, when you want to switch between them make one invisible, and the other visible. Doing it that way would let you keep your onClickListeners separate which would make your code more understandable in my mind.
That being said you could technically achieve it with a single button as well. Just change the text on the button when you want to switch between them, and add an if statement into your click listener to check which "mode" your button is currently in to determine which action it should take.

I am not sure there is an easy way to do this or not. but you can sure use different behaviors of button clicks like
// When you press it for long time.
dummyButton.setOnLongClickListener(new OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
return true; // Can do lot more stuff here I am just returning boolean
}
});
// Normal click of button
dummyButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
//do lot more stuff here.
}
});

Do it this way :
Make a public boolean variable
public boolean isClickedFirstTime = true;
make your 3 editTexts enabled false in xml and
onClick of your button
#Override
public void onClick(View v) {
if (v.getId() == R.id.edit_button_id) { //whatever your id of button
Button button = (Button) findViewById(R.id.edit_button_id);
if(isClickedFirstTime)
{
edit1.setEnabled(true);
edit2.setEnabled(true);
edit3.setEnabled(true);
butt.setText("Save");
isClickedFirstTime = false;
}
else
{
....//Get your values from editText and update your database
isClickedFirstTime = true;
}
}

Single click edittext

How can make an EditText have a onClick event so that on single click an action is done.
private void addListenerOnButton() {
dateChanger = (EditText) findViewById(R.id.date_iWant);
dateChanger.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
showDialog(DATE_DIALOG_ID);
}
});
}
this is not working as excepted....single click gives just the onscreen keypad but not the datepicker dialog which appears only if i double click

if we just add android:focusableInTouchMode="false" in edittext on layout page it should work in a singleclick on its onclicklistener. no need to handle onFocusChangeListener.

Change your code from an onClickListener to an OnFocusChangeListener.
private void addListenerOnButton() {
dateChanger = (EditText) findViewById(R.id.date_iWant);
dateChanger.setOnFocusChangeListener(new OnFocusChangeListener() {
public void onFocusChange(View v, boolean hasFocus) {
if(hasFocus) {
showDialog(DATE_DIALOG_ID);
}
}
});
}

EditText is not meant for singleClick.
I mean you should not use Click Listener with it.
rather you can do like,
Use onFocusChangeListener which is also not 100% correct approach.
Best would be instead the EditText use one TextView write onClick of that and if needed give a background image to that TextView.

Rewrite
I have an EditText that launches a dialog when the user either clicks it once or navigates to it with a trackball / directional pad. I use this approach:
Use an OnFocusChangeListener for gaining focus to open the dialog.
Override dismissDialog() to clear the focus from the EditText when the user closes the dialog, preventing the user from entering text without the dialog (as far as I can tell)
.
I have also tried this (however I now remember this method did respond to trackball movement):
Use an OnClickListener for touch events.
Set setFocusable(false) to prevent user input.
Hope that helps.

Android: What's the difference between a boolean for a click and button.isPressed()?

There are a lot of options on how to define a click/tap on the touchscreen. One of them for example is setting a boolean.
Example for boolean:
boolean buttonClicked = true;
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (buttonClicked) {
//do that and this
}
}
});
And there's a isPressed() method:
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (button.isPressed()) {
//do that and this
}
}
});
What exactly is the difference between them? And when and why do I use boolean and the method isPressed()?

Because you are referring to a button in both of your examples, I assume that you are referring to the user tapping on a button, not just a random touch on the screen.
That being said, both of the examples you provided are not good.
In your first example, the boolean is useless because it is always true, so //do that and this will always be reached.
In your second example, your if statement is useless, because the onClick method by its nature is only reached when the button is tapped.
A good way to listen for a button press is using a click listener like this:
Button button = (Button) findViewById(R.id.buttonId);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Code placed here will run every time the button is tapped
}
});
...where R.id.buttonId is the ID of your button in the layout.

If you need to define click event for a View you can use onClickListener, onTouchListener.
For more information check for Android official Documentation.
onTouchListener
onTouchListener
When considering your first code snippet, You can use boolean to perform another operation on button click event. as example something like this ,
boolean buttonClicked = false;
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//true after button clicked
buttonClicked = true;
}
});
//if buttonClicked equals true
if (buttonClicked){
//perform operation only after button clicked
}
when considering your second code snippet, no need of button.isPressed() inside
button's onClick() callback. Because what you want to do by checking button.isPressed() is done without it inside button's onClick() callback.
Keep in mind these things.
isPressed() is a public method of View Class
Button is a subclass of View Class
isPressed() is a public method of Button Class as well.
About isPressed() from Android official documentation.
Indicates whether the view is currently in pressed state. Unless
setPressed(boolean) is explicitly called, only clickable views can
enter the pressed state.
Returns true if the view is currently pressed, false otherwise.