FadingActionBar error in Android appcompat v7 21 library

Question

I am trying to appcompat v7 21 library for the first time today.

Also I am using FadingActionBar library in my application. That link to library https://github.com/ManuelPeinado/FadingActionBar

App had been working excellent before I used to appcompat v7 21 library. But now I get this error.

Caused by: java.lang.NullPointerException
            at com.manuelpeinado.fadingactionbar.FadingActionBarHelper.setActionBarBackgroundDrawable(FadingActionBarHelper.java:48)
            at com.manuelpeinado.fadingactionbar.FadingActionBarHelperBase.initActionBar(FadingActionBarHelperBase.java:173)
            at com.manuelpeinado.fadingactionbar.FadingActionBarHelper.initActionBar(FadingActionBarHelper.java:31)
            at olkunmustafa.example.parallax.medyasef.com.parallaxanimationexample.MyActivity.onCreate(MyActivity.java:23)
            at android.app.Activity.performCreate(Activity.java:5231)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
            at android.app.ActivityThread.access$800(ActivityThread.java:135)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5017)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
            at dalvik.system.NativeStart.main(Native Method)

If I change appcompat from v21 to v20 everything is fixed. But I want to use v21.

It is my values/style.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light">
        <item name="android:windowActionBarOverlay">true</item>
    </style>

</resources>

MyActivity.java

public class MyActivity extends ActionBarActivity {

    @Override
    protected void onCreate( Bundle savedInstanceState ) {
        super.onCreate( savedInstanceState );

        FadingActionBarHelper helper = new FadingActionBarHelper()
                .actionBarBackground( R.color.green_ms )
                .headerLayout( R.layout.header )
                .contentLayout( R.layout.activity_my );
        setContentView( helper.createView( this ) );
        helper.initActionBar( this );
    }
}

build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 21
    buildToolsVersion "21.0.1"

    defaultConfig {
        applicationId "olkunmustafa.example.parallax.medyasef.com.parallaxanimationexample"
        minSdkVersion 14
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.+'
    compile 'com.github.manuelpeinado.fadingactionbar:fadingactionbar:3.1.2'
}

Sorry bad english. Thanks for helps

Answer 1

Strangely, i'm using fadingactionbar library and it works well with appcompat v7 21 library. Here it is my build

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "23.0.0 rc3"

    defaultConfig {
        applicationId "com.test.aprido.testfadedactionbar"
        minSdkVersion 15
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.+'
    compile    'com.github.manuelpeinado.fadingactionbar:fadingactionbar:3.1.2'
}

amd this is my res/value/style.xml

    <resources>

        <!-- Base application theme. -->
        <style name="AppTheme" parent="@android:style/Theme.Holo.Light.DarkActionBar">
            <item name="android:actionBarStyle">@style/Widget.ActionBar</item>
        </style>

        <style name="AppTheme.TranslucentActionBar">
            <item name="android:actionBarStyle">@style/Widget.ActionBar.Transparent</item>
            <item name="android:windowActionBarOverlay">true</item>
            <item name="android:windowContentOverlay">@null</item>
        </style>

        <style name="AppTheme.Light.TranslucentActionBar" parent="@android:style/Theme.Holo.Light">
            <item name="android:actionBarStyle">@style/Widget.Light.ActionBar.Transparent</item>
            <item name="android:windowActionBarOverlay">true</item>
            <item name="android:windowContentOverlay">@null</item>
        </style>

        <style name="Widget" />

        <style name="Widget.ActionBar" parent="@android:style/Widget.Holo.Light.ActionBar.Solid.Inverse" />

        <style name="Widget.Light" />

        <style name="Widget.Light.ActionBar" parent="@android:style/Widget.Holo.Light.ActionBar.Solid" />

        <style name="Widget.ActionBar.Transparent">
            <item name="android:background">@android:color/transparent</item>
        </style>

        <style name="Widget.Light.ActionBar.Transparent">
            <item name="android:background">@android:color/transparent</item>
        </style>

    </resources>

Answer 2

This library is not compatible with the new AppCompat. An issue has been opened on its Github page here: Fading ActionBar Issues. The developer is aware of the issue, but in the meantime, he published a gist that shows how to implement this effect with the new Toolbar widget here: Toolbar fading effect