Develop Reference

Action bar size in custom xml file

I'm not able to find a way to insert the action bar size attribute in my own xml file. Since I'm using Google maps in my activity, I can't use the built-in xml attribute at all in my layout, but I have to call setPadding() on the map using the action bar size. Now, I found the way to retrieve the actionBarSize at runtime, but I wonder if I could skip this code completly, inserting the android attribute in my onw xml, for example:
<resources xmlns:android="http://schemas.android.com/apk/res/android">
<dimen name="myownsize">#android:attr/actionBarSize</dimen>
</resources>
But in this way it doesn't work. Is there a way to do it?

Define a attr in your own project. Create res/values/attrs.xml and add this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<attr name="myownsize" format="dimension"></attr>
</resources>
In your res/values/styles.xml, under your parent theme definition, initialize this attribute:
<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="myownsize">?android:attr/actionBarSize</item>
</style>
Once this is done, you can use ?attr/myownsize as a dimension:
android:padding="?attr/myownsize"
Sorry if I too, misunderstood the question.

Put View styles in resource files

I have some customized Views like:
public class CustomizedTextView extends TextView {
...
public CustomizedTextView(Context context) {
this.setText(TEXT_COLOR);
this.setTextSize(TEXT_SIZE);
this.setTypeFace(TYPE_FACE);
this.setPadding(LEFT, TOP, RIGHT, BOTTOM);
...
}
}
As you can see, these style settings and corresponding constants takes many lines of code. So I want to separate it out in resource files.
I have gone through the Android documentation, it says you could defined a style file like:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="CodeFont" parent="#android:style/TextAppearance.Medium">
<item name="android:layout_width">fill_parent</item>
<item name="android:layout_height">wrap_content</item>
<item name="android:textColor">#00FF00</item>
<item name="android:typeface">monospace</item>
</style>
</resources>
But I didn't find an API like setStyle(R.style.style001) to set the style in code. I also found a post here: android set style in code
Basically it says you can't do it in code. However this post is three years ago I am not sure what's the situation in API 19. Because defining a customized View is so common in Android that I don't understand why this is not possible.

You can set the textview style using setTextAppearance like this
textView.setTextAppearance(context, R.style.CodeFont);

Style item name not being recognized despite being used in Android's own styles.xml

Here's a resource of mine:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="MyTheme">
<item name="editTextStyle">#android:style/Widget.EditText</item>
</style>
</resources>
Eclipse doesn't like it: "No resource found that matches the given name: attr 'editTextStyle'"
At the same time, if I open Android's own platforms/android-3/data/res/values/themes.xml, I see that this is clearly being used there:
<resources>
...
<style name="Theme">
...
<item name="editTextStyle">#android:style/Widget.EditText</item>
...
Android documentation encourages to read that very same file to learn about the ins and outs of styling. But how can I actually do the same cool things they do there?

You need to specify the android namespace:
<item name="android:editTextStyle">#android:style/Widget.EditText</item>
Also, you probably only want to list the items you are overriding, there is really no point in setting it to the default.

Is it possible to add a custom property into a style in an android resource?

I'm a using a view flow component into my project, which allows the dev to override some attributes, like that :
<org.taptwo.android.widget.TitleFlowIndicator
...
app:footerTriangleHeight="0dip"
... />
I am reusing this component into several layouts, and I would like to put the properties into a style.
But when I'm doing this, the parser says Error: No resource found that matches the given name: attr 'app:footerTriangleHeight', even if I add the namespace in the styles file.
Is there a way to do that in android ?
Thanks.

Android Application
If you are not using Android Libraries, then here is what you can do:
Define custom styleable attribute (I guess you've already done that).
Do not use your namespace prefix in style items (namespace defaults to current app's namespace).
Example:
In attrs.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<attr name="testAttr" format="string"/>
</resources>
In styles.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="TestStyle" >
<item name="testAttr">asdf</item>
</style>
</resources>
Android Library
If custom attribute comes from Android Library, you can still use described approach. It theoretically should work, because Android Library's namespace is the same as application's (from aapt tool perspective during the build). But I haven't test this myself.
If you're specifying namespace, it will show error. As far as I know, styles do not support xml namespaces. So this will fail:
In styles.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:app="http://schemas.android.com/apk/res/app.package.name">
<style name="TestStyle" >
<item name="app:testAttr">asdf</item>
</style>
</resources>
Parser automatically defaults to current app's AndroidManifest namespace, though you can not specify this namespace explicitly.

You can define the style in terms of your namespace, i've used it myself
i.e
<style name="whatever">
<item name="YourPackage.YourSubPackage:parametername">#drawable_or_anything/bla</item>
</style>

Custom attrs parameter used in styles.xml

I have a set of custom Android layout parameters defined in attrs.xml. Now I would like to use some tags in my styles.xml file.
At the moment I get this error:
error: Error: No resource found that matches the given name: attr 'custom:tag'
I have tried declaring custom XML namespace as follows:
<resources
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res/com.my.project"
>
hoping, that the same logic used in every layout declaration can be applied here, but with no success.

The XML namespace mechanism is used to namespace tags and attributes. When you define a style like this:
<?xml version="1.0" encoding="utf-8"?>
<resources
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res/com.my.project">
<style name="my_style"> <item name="custom:tag">some_value</item> </style>
</resources>
you are trying to apply XML namespacing to an attribute value, which won't work. In this case, you should specify the package name directly, like this:
<style name="my_style"> <item name="com.my.project:tag">some_value</item> </style>
Now Android will be able to resolve where the attribute is defined.

The accepted solution did not work for me, but it shed some light upon the situation.
The custom attributes are resolved and can be referenced in a global project's package name, like "com.ltst.project". Even if you have multiple modules (with the same base package name) the resources would be resolved in a project's package name.
So for me it was enough to just omit any prefixes for custom attributes in a style.
Custom attribute:
<declare-styleable name="SampleView">
<attr name="sample_color" format="reference" />
</declare-styleable>
Style:
<style name="SampleStyle">
<item name="sample_color">#color/sample_color</item>
</style>

You can use the link
xmlns: app = "http://schemas.android.com/apk/res-auto
and define the prefix for each tag as app