Develop Reference

how is an object created?

EditText text1;
text1 = (EditText) findViewById(R.id.editText1);
text1.getText().toString();
Hi im new to android programming an need a little help. :) I just want to clarify if text1 is an object? Because it can call a method. But if text1 is an object how come that there is no "new" keyword. Thanks in advance for any response. :)

It is not necessary that all variables do initialization with new keyword.
Like if you write
String s = "";
Your String has been initialized without new keyword.
Same like this EditText is provided initialization in findViewById(). Here findViewById returned Edittext instance.
I suggest you complete Java Tutorial before continue work on Android. Because Android is based on Java language.

EditText is derived from the Super class View. Here findViewById method is returning an an object of the View class. You are explicitly typecasting it to EditText and assigning it to text1. So new is not required. It is being managed in findViewById method. Alternatively you can do this as:
EditText text1;
text1 = new EditText(An instance of Context); //Create an object of Edittext class
Now do whatever with this object text1.

It's me 2 years after, Now I want to answer your question bud. I know you just started and had a dream of creating apps that will be used by others, and guess what? You already achieved that and you can now also create apps not just for android but for IOS since you're using flutter now, you also have your own account on google play store now. Listen Bud, on the first line you declare what type is the text1. on the second line that's where you declare the text1 as an object now, then on the third line you are then using that object's capabilities like getting text. You've learned so much in this journey, and still learning not just in programming but in life.

How to show the name of the widget on a TextView?

Let me explain:
I need to show the name of any building block either it is imagebutton, edittext in my textview field depending upon which of above written will be hover over by the user.
So that my textview could behave like some dynamic display plate.
Any help will highly be appreciated.
mrana..

So something that you can do. Since there it no "setText" for imageviews, you can do something like
String name = "imageview";
imageView.setTag(name);
Then in your onFocusedChangedListener call the following method
void displayInTextView(View selectedView) {
String viewName = (String) selectedView.getTag();
mDisplayText.setText(viewName);
}

Since this is a touch device, "hovering" will not be possible. One solution is to show the name on when long-press. See this solution https://stackoverflow.com/a/4433441/1227692
EDI: Thanks Frank and mrana for pointing out. I agree and take back my comment.

LInkify block onclick event

I have some TextView objects that I have onclick listeners assigned to. The onclick listeners work fine unless I run Linkify.addLinks on the TextView objects, at which point the onclick event never happens. This happens regardless of whether anything in the TextView is actually linkified. Is there a way to have both events happen, or at least be able to predict whether anything is or would be linkified in the text?

I don't know if you found an answer or not as this question is rather old, but I just found it while looking for another problem (not exactly similar) and I can help (a bit): there is an easy way to "detect" whether Linkify modifies the text: just compares it with the original. Something like:
String originalText = textView.getText().toString();
Linkify.addLinks(textView, Linkify.ALL);
String linkifiedText = textView.getText().toString();
if (originalText.equals(linkifiedText)) {
// linkify did not do anything...
}

Linkify.addLinks() returns a boolean which indicates if it found links in the text or not. There is no need to do a before/after comparison like Guillaume suggested.

TextView.setText() followed by TextView.invalidate() doesn't update text in view

I have no idea why this doesn't work. The TextView is defined from an tag in the view. The base TextView doesn't have text set and I want to set it in the View on display.
I have tried placing the below in onCreate and onStart but it doesn't seem to work. The last two lines are just for debugging. I can verify that the header does get the text. The thing is, the TextView doesn't actually get updated. Any ideas?
TextView header=(TextView) findViewById(R.id.acheader);
header.setText(R.string.accounts);
header.invalidate();
header=(TextView) findViewById(R.id.acheader);
String blah=(String) header.getText();

Try again removing the text in 4th line
header=(TextView) findViewById(R.id.acheader);

header.invalidate() is not needed.
Instead of String blah = (String) header.getText() try
String blah = heager.getText().toString();
And why are you verifying a "setText()" on text view using code? Why can't you check the
actual output?
The above code might not work the way you are trying to use it, because the redraw of text view is handled by the framework and generally it tries to group item updates (Dirty rectangles to be specific) and update them all at once. It may do it well after your function exits, Try to validate visually, thats the best way.

Setting textview text from a string resource held in an array problem

This should be simple, but driving my crazy.
I have the following in my layout, not problems.
<TextView
android:id="#+id/birdinfo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#00009c"
android:text="The Robin is a popular bird"
/>
Then I have these arrays which are set up with the list of string resources I have
private Integer[] DetailIds = {
R.string.barnaclegoose,
R.string.barnowl,
R.string.bewicksswan,
R.string.blackbird,
R.string.blackcap_male};
So I simply want to do this!
TextView detail = (TextView)findViewById(R.id.birdinfo);
detail.setText(DetailIds[0]);
setContentView(R.layout.main);
But this causes a force close error.
The string resource looks like this ( without header and footer info of course
<string name="barnaclegoose">What a wonderful goose!</string>
Added to this problem is if I use the resource directly to the resource
detail.setText(R.string.barnaclegoose);
For example, I still get a null exception! I'm sure I've done this before, but maybe I'm missing the obvious???
Any ideas appreciated.
( Eclipse, Android 1.5, Emulator with 1.5 )

I realize this is very old, but it came up in a search... Anyways, you need to call setContentView() before findViewById() etc:
setContentView(R.layout.main);
TextView detail = (TextView)findViewById(R.id.birdinfo);
detail.setText(DetailIds[0]);

your problem is for this line setContentView(R.layout.main);
at first you must define this this line then setText your textView

Thanks for the answer. but if you mean R.string.barnaclegoose for example, this is an integer value for the ID pointing to the string itself in the resource.
Anyway, I finally got it working by just creating the view inline instead of using an resource view.
For example
TextView t= new TextView(ctx);
t.setId(2);
t.setTextColor(Color.BLACK);
t.setText(DetailIds[bird]);
mLinearLayout.addView(t,params);
mLinearLayout.setBackgroundColor(Color.WHITE);
setContentView(mLinearLayout);
And that works perfectly.