Android Tutorial Theme based on version Tutorial

What is this?
As the title suggests, this tutorial shows you how to select an android theme based on what version of Android your app is run on.

Why do I need this?
You don't, but after reading this tutorial you may think it is a useful technique that you wasn't previously aware of.

How could I use it?
There are many ways this can be used. For this tutorial I will use, what I believe will be the most common case study. Creating transparent activities whilst allowing the use of Holo based themes when available.

The problem
We want to create a transparent activity in our app but we also want our app to use a Holo theme when run on HoneyComb +. An example for a use of a transparent activity is to add a panel and some other views to create the effect of a 'popup window'.

Using the manifest editor, we can utilize the Holo dark theme simply by setting the targetSDK to 11 or higher or use the Light theme by setting a theme like this
B4X:
SetApplicationAttribute(android:theme, "@android:style/Theme.Holo.Light")

Many of us will have followed this advice to create said transparent activity
http://www.basic4ppc.com/forum/basic4android-updates-questions/14824-hiding-activity.html#post84047

BUT, there is a problem. Theme.Translucent.NoTitleBar does NOT utilize the nice new Holo theme. So your app would use Holo.Light, but your transparent activity would use the older default theme. This will look very unprofessional.

The Holo themes' Transparent effect can be gained by setting your application theme to
B4X:
@android:style/Theme.Holo.Light.Panel

But again, this has a problem. Run this on a device operating on an Android version less than HoneyComb (i.e. gingerbread) and you get an error as the theme simply doesn't exist.

So how do we stitch the 2 together? By setting the theme based on the version of Android in use. This does required creating some xml, but it's not too scary.

Here's what we do

After you have created your b4a project, open the projects' folder and navigate to the \res\ folder. within res create 2 new folders 'values' and 'values-v11'. Inside each of these folders we need a 'theme.xml' file. So we end up with

B4X:
\res\values\theme.xml
\res\values-v11\theme.xml

Anything added to the theme.xml in the values folder will be used as default. Anything added to the theme.xml in the values-v11 will be use when android v11 (honeycomb) or above is in use.

OK, what to put in them? essentially we are going to create a custom theme, so we need to give it a name. For this tutorial, we will call it 'MyThemeTransparent'. We need to add this text to the files

\res\values\theme.xml
B4X:
<?xml version="1.0" encoding="utf-8"?>

<resources>
    <style 
        name="MyThemeTransparent" parent="android:style/Theme.Translucent.NoTitleBar">
    </style>
</resources>

\res\values-v11\theme.xml
B4X:
<?xml version="1.0" encoding="utf-8"?>

<resources>
    <style 
        name="MyThemeTransparent" parent="@android:style/Theme.Holo.Light.Panel">
    </style>
</resources>

These files then need to be made read only!

Then in the b4a manifest editor, we use our custom theme like this:
B4X:
SetActivityAttribute(PopupWindow, android:theme, "@style/MyThemeTransparent")

PopupWindow being an activity we have created in b4a.

You may need to clean you b4a project for the theme resources to be recognized.

Advanced:
We can create more variants of our custom theme. Here is an example.

\res\values\theme.xml
B4X:
<?xml version="1.0" encoding="utf-8"?>

<resources>
    <style 
        name="MyTheme" parent="android:style/Theme.Light">
    </style>

    <style 
        name="MyThemeNoTitle" parent="android:style/Theme.Light.NoTitleBar">
    </style>

    <style 
        name="MyThemeTransparent" parent="android:style/Theme.Translucent.NoTitleBar">
    </style>
</resources>

\res\values-v11\theme.xml
B4X:
<?xml version="1.0" encoding="utf-8"?>

<resources>
    <style 
        name="MyTheme" parent="@android:style/Theme.Holo.Light">
    </style>

    <style 
        name="MyThemeNoTitle" parent="@android:style/Theme.Holo.Light.NoActionBar">
    </style>

    <style 
        name="MyThemeTransparent" parent="@android:style/Theme.Holo.Light.Panel">
    </style>
</resources>

This creates 3 variants.

MyTheme - A simple base theme that uses 'Theme.Light' on older versions of android and 'Theme.Holo.light' when available.

MyThemeNoTitle - As MyTheme but hides the titlebar (or ActionBar as it is now known)

MyThemeTransparent - Explained in tutorial above.

With this setup, i can set the base theme for the app using this in the manifest editor

B4X:
SetApplicationAttribute(android:theme, "@style/MyTheme")

Then use the other variants as explained above.

Hope this help some folks to make their apps look pretty.

Demo Project Below
This is a very simple demo to show you how things should look and feel after following this tutorial.
Hope it helps.

View attachment VersionThemeDemo.zip
 
Last edited:

Dave O

Well-Known Member
Licensed User
@barx , thanks for explaining this. I was testing an app on my 5.x phone, and everything was fine, then tried it on a 4.x device and saw that the theme was screwy. I fixed it using your tutorial, but I replaced the manual XML-file-editing with the CreateResource function in the manifest editor.

Here's how I made the same theme (based on Holo Light) for 4.x and 5.x:

B4X:
SetApplicationAttribute(android:theme, "@style/MyAppTheme")
CreateResource(values-v11, theme.xml,
<resources>
   <style name="MyAppTheme" parent="@android:style/Theme.Holo.Light">
     <item name="android:colorPrimary">#12DB00</item> <!-- action bar -->
     <item name="android:colorPrimaryDark">#096E00</item> <!-- status bar -->
     <item name="android:colorAccent">#12DB00</item> <!-- checkboxes,, switches,, msgbox buttons in Android 6.x -->
     <item name="android:textColor">#000000</item> <!-- ? -->
    <item name="android:textColorPrimary">#000000</item> <!-- msgbox text in Android 6.x -->
      <item name="android:textColorSecondary">#606060</item> <!-- inactive editText line,, scrollbar -->
     <item name="android:textColorLink">#096E00</item>
     <item name="android:textColorHighlight">#12DB00</item> <!-- menu text,, msgbox title -->
   </style>
</resources>
)
CreateResource(values-v21, theme.xml,
<resources>
   <style name="MyAppTheme" parent="@android:style/Theme.Material.Light.DarkActionBar">
     <item name="android:colorPrimary">#12DB00</item> <!-- action bar -->
     <item name="android:colorPrimaryDark">#096E00</item> <!-- status bar -->
     <item name="android:colorAccent">#12DB00</item> <!-- checkboxes,, switches,, msgbox buttons in Android 6.x -->
     <item name="android:textColor">#000000</item> <!-- ? -->
    <item name="android:textColorPrimary">#000000</item> <!-- msgbox text in Android 6.x -->
      <item name="android:textColorSecondary">#606060</item> <!-- inactive editText line,, scrollbar -->
     <item name="android:textColorLink">#096E00</item>
     <item name="android:textColorHighlight">#12DB00</item> <!-- menu text,, msgbox title -->
   </style>
</resources>
)

Thanks again!
 
Last edited:

Ederson Kerber

Member
Licensed User
Good evening, @Erel @barx

When trying to use the theme together as an attribute:

#Region Activity Attributes
#FullScreen: False
#IncludeTitle: false
#Extends: android.support.v7.app.AppCompatActivity
#End Region

I get the error below: java.lang.RuntimeException: Unable to start activity ComponentInfo{barxdroid.VersionThemeDemo/barxdroid.VersionThemeDemo.main}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.


When taking the attribute "Extends: android.support.v7.app.AppCompatActivity" the error does not happen, however, I must use the same in my application.


Thanks, I appreciate that you can help.
 

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