TextView background is black when setting colour from xml?

I had a colour defined in a 'colours.xml' file in my project's 'values' folder like so:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="tvBackground">#337700</color>
</resources>

Which, for those of you who cannot transpose directly from hex, looks like this:

My code looked like this:

   TextView tv = new TextView(getApplicationContext());
       
   tv.setBackgroundColor(R.color.tvBackground);

Seems reasonable doesn't it?

But when I ran my code, my shiny new little TextView came out with the background colour of this:

(that's #000000 in hex, or 'black' btw)

What was going on here?
Turns out, I wasn't using the correct method to set the background colour so that it comes out correctly, what I should have used was either of these:

   tv.setBackgroundResource(R.color.tvBackground);

- or -

   tv.setBackgroundColor(getResources().getColor(R.color.tvBackground));

.. Not especially well documented, but easily fixed.


Anyhow, now my TextView shows with the background colour of:

.. So all is now well with the world. Thought I'd just post this in case it helps someone out there (or myself when I forget next time)


until that next time, bye bye.

Spinner down arrow stretching?

.. Styling the inner and outer views of a Spinner individually.


I was working with a Spinner with a lot of rows fetched from a database, and wanted to put a bit of padding around each item to make it easier for the user to select them.

So I went into my res\layout\spinner_view_row.xml (which controls how the Spinner rows display) and added this:

android:padding="5dip"

Then, when I went and re-ran my app, what used to look like this:

.. now looks like this:



.. Ooops. 


Looks like a condom doesn't it. Not what I was trying to achieve, really. If I made the padding large enough, it will also look like that before I've even selected anything.

Not what I wanted at all.

But I do want that padding around each item in my Spinner, otherwise my users will have too much trouble choosing items from my latest super-dooper, take-the-world-by-storm, #1 in the world market app, and it might not stay #1 for long at all.

Luckily, the answer is really, really simple.

You might recogise the below as the piece of code that binds a cursor from the database (containing all the items we want to display), to the xml view spinner_view_row, located at  res\layout\spinner_view_row.xml (this is the xml file in which we put the extra padding, above).

  final SimpleCursorAdapter ingredientAdapter =
  new SimpleCursorAdapter(this, android.R.layout.simple_spinner_item, ingredientsCursor, from, to); 
  ingredientAdapter.setDropDownViewResource(R.layout.spinner_view_row);

  spnIngredients.setAdapter(ingredientAdapter);

All we need to do to avoid the stretchy condom spinner arrow is to define another xml view in res\layout\ and call it something like spinner_view_closed, then paste into it the same code that you have in spinner_view_row.
Simply then customise this xml to have less padding, or a smaller text size for instance, then replace the reference to

simple_spinner_item

with a reference to this new xml file, like this:

  final SimpleCursorAdapter ingredientAdapter =
  new SimpleCursorAdapter(this, R.layout.spinner_view_row_closed, ingredientsCursor, from, to); 
  ingredientAdapter.setDropDownViewResource(R.layout.spinner_view_row);

  spnIngredients.setAdapter(ingredientAdapter);

.. and your new Spinner will look like this when open:

.. and this when closed.

Easy eh?
.. Told you so.

The difference between @+id and @android:id

Sometimes you see references in your layout files like:

<listview id="@+id/android:list">

and

<listview id="@android:id/list">

What's the difference?
.. I'm glad you asked ☺

@+id/foo means you are creating an id named foo in the namespace of your application.
You can refer to it using @id/foo.
@android:id/foo means you are referring to an id defined in the android namespace.

The '+' means to create the symbol if it doesn't already exist. You don't need it (and shouldn't use it) when referencing android: symbols, because those are already defined for you by the platform and you can't make your own in that namespace anyway.

This namespace is the namespace of the framework.
for example, you need to use @android:id/list because this the id the framework expects to find.. (the framework knows only about the ids in the android namespace.)