Android button state files

The docs say to put XML state files for bu开发者_JAVA技巧ttons in "the" "drawable" folder - which one of at least three?! (Putting it in res/drawable gives an out of sync filesystem error and putting it in each of the drawable-*dpi where * is l, m, h is an error too.)

res/drawable is ok and default.

The "fs out of sync" is probably from your IDE when you put the files e.g. via command line or into the folder. IDEs usually try to remember the state of files and report external changes this way. Try issuing a "refresh" command in the IDE.

res/drawable is a fallback that is taken if you do not provide more specific images in res/drawable-*dpi or also some orientation counterparts.

Have a look at the docs: http://developer.android.com/guide/topics/resources/providing-resources.html#AlternativeResources

drawable-nodpi is a special directory for files you don't want scaled, which makes no sense at all for buttons, as you want buttons to scale according to screen size/dpi.

You should use res/drawable for your XML state list drawables. If you get the "out of sync filesystem" error just refresh the Eclipse project (select it in the projects pane and hit F5).

XML state lists are (in most cases) not DPI-independent. However, their content will not change across different DPI environments. Basically, this means that if you reference a raw drawable called, for example, @drawable/btn_pressed, from within a state list, Android will look for the appropriate file for that drawable, according to the environment (drawable-*dpi/btn_pressed.png).

As you can see, although the state list is the same on LDPI, MDPI and HDPI, the drawables referenced within it could change.

I propose drawable-nodpi because it works.

However this is not made obvious in the docs when it needs to be.

How to make something trivial complicated? Make it ambiguous.