Using Vector Drawable Safely on pre-lollipop version

Want to see more about docs and how to use vector drawable, please come and read here

I want to show what we need to handle all cases for using Vector Drawable via XML resources

build.gradle

 android {
   defaultConfig {
     vectorDrawables.useSupportLibrary = true
    }
 }

Application class

override fun onCreate() {
    super.onCreate()
    // App crashes when selector with using vector-drawable
    // So, keep using this line + AppCompatImageView for android 4.4
    AppCompatDelegate.setCompatVectorFromResourcesEnabled(true)
    // Your other logic code ...
}

Way to get Drawable

// using ContextCompat
ContextCompat.getDrawable(@NonNull Context context, @DrawableRes int resId)
// using ResourcesCompat
ResourcesCompat.getDrawable(@NonNull Resources res, @DrawableRes int id, @Nullable Theme theme)
// using AppCompatResources
AppCompatResources.getDrawable(@NonNull Context context, @DrawableRes int resId)
// using VectorDrawableCompat
VectorDrawableCompat.create(@NonNull Resources res, @DrawableRes int resId, @Nullable Theme theme)

Here is the comparision table when using one of these above ways. This is StackOverflow link

For normal image resource:

For vector drawable image resource:

For custom view

Here is the sample for custom view with drawable using vector

const val INVALID_RES_ID = -1
private fun initAttrs(attrs: AttributeSet?) {
    if (isInEditMode || attrs == null) return
    var drawableStart: Drawable? = null
    var ta: TypedArray? = null
    try {
        ta = context.obtainStyledAttributes(attrs, R.styleable.YourCustomView)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            // Directly call getDrawable is safely
            drawableStart = typedArray.getDrawable(...)
        } else {
            val drawableStartId = typedArray.getResourceId(..., INVALID_RES_ID)
            if (drawableStartId != INVALID_RES_ID)
                drawableStart = AppCompatResources.getDrawable(context, drawableStartId)
        }
        // other logic
    } finally {
        ta?.recycle()
    }
}

For using selector or DrawableStateList in custom view, you must using AppCompat... kind like AppCompatImageView, AppCompatImageButton… if not your app will be crashed on pre-lollipop android version

Example: Your selector

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/your_vector_drawable" android:state_pressed="true" />
    <item android:drawable="@drawable/your_vector_drawable" android:state_enabled="true" />
    <item android:drawable="@drawable/your_vector_drawable" android:state_enabled="false" />
    <item android:drawable="@drawable/your_vector_drawable" />
</selector>

Your layout

<android.support.v7.widget.AppCompatImageView
    android:id="@+id/img_id"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:contentDescription="@null"
    />

Your code

val resId = typedArray.getResourceId(stylable, -1)
img_id.setImageResource(resId)