Improve XRay implementation

android/libraries/rib-android/src/main/kotlin/com/uber/rib/core/ViewRouter.kt

@@ -34,7 +34,7 @@ abstract class ViewRouter<V : View, I : Interactor<*, *>> : Router<I> {
   ) : super(interactor, component) {
     this.view = view
     if (XRay.isEnabled()) {
-      XRay.apply(this, view)
+      XRay.apply(getName(), view)
     }
   }
 
@@ -44,7 +44,7 @@ abstract class ViewRouter<V : View, I : Interactor<*, *>> : Router<I> {
   ) : super(null, interactor, RibRefWatcher.getInstance(), getMainThread()) {
     this.view = view
     if (XRay.isEnabled()) {
-      XRay.apply(this, view)
+      XRay.apply(getName(), view)
     }
   }
 

android/libraries/rib-android/src/main/kotlin/com/uber/rib/core/XRay.kt

@@ -23,70 +23,76 @@ import android.graphics.drawable.BitmapDrawable
 import android.graphics.drawable.Drawable
 import android.view.Gravity
 import android.view.View
+import androidx.annotation.VisibleForTesting
 
 /** Utility class that shows riblets name in its background. */
 class XRay private constructor() {
-  private var isEnabled = false
-  private var textPaint: Paint? = null
-  private fun writeOnBitmap(bitmap: Bitmap, text: String) {
-    val canvas = Canvas(bitmap)
-    val textPaint = getTextPaint()
-    val xStartPoint = (bitmap.width - textPaint.measureText(text)) / 2f
-    val yStartPoint = bitmap.height / 2f
-    canvas.drawText(text, xStartPoint, yStartPoint, textPaint)
+  private var config = XRayConfig()
+  private val textPaint: Paint by lazy {
+    Paint().apply {
+      textSize = TEXT_SIZE.toFloat()
+      color = TEXT_COLOR
+    }
   }
 
-  private fun getTextPaint(): Paint {
-    if (textPaint == null) {
-      textPaint =
-        Paint().apply {
-          textSize = TEXT_SIZE.toFloat()
-          color = TEXT_COLOR
-        }
+  private fun writeOnBitmap(bitmap: Bitmap, text: String) {
+    Canvas(bitmap).run {
+      val xStartPoint = (bitmap.width - textPaint.measureText(text)) / 2f
+      val yStartPoint = bitmap.height / 2f
+      drawText(text, xStartPoint, yStartPoint, textPaint)
     }
-    return textPaint!!
   }
 
   companion object {
     private val INSTANCE = XRay()
     private const val FRAME_WIDTH = 500
     private const val FRAME_HEIGHT = 150
-    private const val XRAY_ALFA = 0.9f
+    private const val XRAY_ALPHA = 0.9f
     private const val TEXT_SIZE = 30
     private const val TEXT_COLOR = Color.RED
 
-    /** Toggles state of XRay. */
+    /** Setup XRay using a [XRayConfig] */
     @JvmStatic
-    fun toggle() {
-      INSTANCE.isEnabled = !INSTANCE.isEnabled
+    public fun setup(config: XRayConfig) {
+        INSTANCE.config = config
+    }
+
+    /** Toggles state of XRay. */
+    public fun toggle() {
+      val config = INSTANCE.config
+      setup(config.copy(enabled = !config.enabled))
     }
 
     /** @return `true` if XRay is enabled, `false` otherwise. */
     @JvmStatic
-    fun isEnabled(): Boolean {
-      return INSTANCE.isEnabled
+    public fun isEnabled(): Boolean {
+      return INSTANCE.config.enabled
     }
 
     /**
      * Puts [ViewBuilder]s riblet name in the background of the [View]
      *
-     * @param viewRouter a [ViewRouter] which riblets name should be written.
+     * @param routerName the riblets name to be written.
      * @param view a [View] to put the name behind.
      */
     @JvmStatic
-    fun apply(viewRouter: ViewRouter<*, *>, view: View) {
+    internal fun apply(routerName: String, view: View) {
       val oldBackground = view.background
       val bitmap: Bitmap =
         if (oldBackground != null) {
           drawableToBitmap(oldBackground)
         } else {
           Bitmap.createBitmap(FRAME_WIDTH, FRAME_HEIGHT, Bitmap.Config.ARGB_8888)
         }
-      INSTANCE.writeOnBitmap(bitmap, getRibletName(viewRouter))
-      val newBackground = BitmapDrawable(view.context.resources, bitmap)
-      newBackground.gravity = Gravity.CENTER
-      view.background = newBackground
-      view.alpha = XRAY_ALFA
+      INSTANCE.writeOnBitmap(bitmap, getShortRibletName(routerName))
+      view.background =
+        BitmapDrawable(view.context.resources, bitmap).apply {
+          gravity = Gravity.CENTER
+        }
+
+      if (INSTANCE.config.alphaEnabled) {
+        view.alpha = XRAY_ALPHA
+      }
     }
 
     private fun drawableToBitmap(drawable: Drawable): Bitmap {
@@ -110,8 +116,13 @@ class XRay private constructor() {
       return bitmap
     }
 
-    private fun getRibletName(viewRouter: ViewRouter<*, *>): String {
-      return viewRouter.javaClass.simpleName.replace("Router", "")
+    @VisibleForTesting
+    internal fun getShortRibletName(originalName: String): String {
+      return if (originalName != "Router") {
+        originalName.replace("Router", "")
+      } else {
+        originalName
+      }
     }
   }
 }

android/libraries/rib-android/src/main/kotlin/com/uber/rib/core/XRayConfig.kt

@@ -0,0 +1,11 @@
+package com.uber.rib.core
+
+/**
+ * Configuration for XRay.
+ * @property enabled `true` to enable XRay. By default it is disabled.
+ * @property alphaEnabled `true` to enable alpha changes when XRay is enabled.
+ */
+public data class XRayConfig(
+    val enabled: Boolean = false,
+    val alphaEnabled: Boolean = true,
+)

android/libraries/rib-android/src/test/kotlin/com/uber/rib/core/XRayTest.kt

@@ -16,27 +16,62 @@
 package com.uber.rib.core
 
 import android.view.View
-import com.uber.rib.core.XRay.Companion.apply
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.kotlin.any
 import org.mockito.kotlin.doReturn
 import org.mockito.kotlin.mock
+import org.mockito.kotlin.never
 import org.mockito.kotlin.verify
-import org.mockito.kotlin.verifyNoMoreInteractions
 import org.robolectric.RobolectricTestRunner
 import org.robolectric.RuntimeEnvironment
 
 @RunWith(RobolectricTestRunner::class)
 class XRayTest {
+  @Before
+  fun setup() {
+    XRay.setup(XRayConfig(enabled = true))
+  }
+
+  @Test
+  fun test_initial_value() {
+    XRay.setup(XRayConfig())
+    assertFalse("XRay must be disabled by default", XRay.isEnabled())
+  }
 
   @Test
   fun apply_changesViewBackground() {
-    XRay.toggle()
-    val viewRouter: ViewRouter<*, *> = mock()
     val view: View = mock { on { context } doReturn (RuntimeEnvironment.application.baseContext) }
-    apply(viewRouter, view)
+    XRay.apply("Test", view)
+    verify(view).background = any()
+    verify(view).alpha = 0.9f
+  }
+
+  @Test
+  fun apply_changesViewBackground_alphaDisabled() {
+    XRay.setup(XRayConfig(enabled = true, alphaEnabled = false))
+    val view: View = mock { on { context } doReturn (RuntimeEnvironment.application.baseContext) }
+    XRay.apply("Test", view)
     verify(view).background = any()
-    verifyNoMoreInteractions(viewRouter)
+    verify(view, never()).alpha = any()
+  }
+
+  @Test
+  fun getShortRibletName_mustShortRouterName() {
+    assertEquals("Test", XRay.getShortRibletName("TestRouter"))
+    assertEquals("Router", XRay.getShortRibletName("Router"))
+  }
+
+  @Test
+  fun xray_toggle() {
+    XRay.toggle()
+    assertFalse(XRay.isEnabled())
+
+    XRay.toggle()
+    assertTrue(XRay.isEnabled())
   }
 }

android/libraries/rib-base/src/main/kotlin/com/uber/rib/core/Router.kt

@@ -62,6 +62,13 @@ protected constructor(
     interactorGeneric.setRouterInternal(this)
   }
 
+  /**
+   * @return the name of the router. This is used for logging and debugging purposes.
+   */
+  protected fun getName(): String {
+    return javaClass.simpleName
+  }
+
   /**
    * Dispatch back press to the associated interactor. Do not override this.
    *
@@ -125,8 +132,8 @@ protected constructor(
 
     ribRefWatcher.logBreadcrumb(
       "ATTACHED",
-      childRouter.javaClass.simpleName,
-      this.javaClass.simpleName,
+      childRouter.getName(),
+      this.getName(),
     )
     RibEvents.emitRouterEvent(RibEventType.ATTACHED, childRouter, this)
     var childBundle: Bundle? = null
@@ -153,8 +160,8 @@ protected constructor(
     ribRefWatcher.watchDeletedObject(interactor)
     ribRefWatcher.logBreadcrumb(
       "DETACHED",
-      childRouter.javaClass.simpleName,
-      this.javaClass.simpleName,
+      childRouter.getName(),
+      this.getName(),
     )
     if (savedInstanceState != null) {
       val childrenBundles = savedInstanceState?.getBundleExtra(KEY_CHILD_ROUTERS)