[fenix] For https://github.com/mozilla-mobile/fenix/issues/22851: Add logo animation for wallpapers.

app/src/main/java/org/mozilla/fenix/home/HomeFragment.kt

@@ -17,6 +17,7 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.View.AccessibilityDelegate
 import android.view.ViewGroup
+import android.view.ViewTreeObserver
 import android.view.accessibility.AccessibilityEvent
 import android.widget.Button
 import android.widget.LinearLayout
@@ -821,6 +822,26 @@ class HomeFragment : Fragment() {
         // triggered to cause an automatic update on warm start (no tab selection occurs). So we
         // update it manually here.
         requireComponents.useCases.sessionUseCases.updateLastAccess()
+
+        if (shouldEnableWallpaper()) {
+            _binding?.sessionControlRecyclerView?.viewTreeObserver?.addOnGlobalLayoutListener(
+                homeLayoutListenerForLogoAnimation
+            )
+        }
+    }
+
+    // To try to find a good time to show the logo animation, we are waiting until all
+    // the sub-recyclerviews (recentBookmarks, collections, recentTabs,recentVisits
+    // and pocketStories) on the home screen have been layout.
+    private val homeLayoutListenerForLogoAnimation = object : ViewTreeObserver.OnGlobalLayoutListener {
+        override fun onGlobalLayout() {
+            _binding?.let { safeBindings ->
+                requireComponents.wallpaperManager.animateLogoIfNeeded(safeBindings.wordmark)
+                safeBindings.sessionControlRecyclerView.viewTreeObserver.removeOnGlobalLayoutListener(
+                    this
+                )
+            }
+        }
     }
 
     override fun onPause() {

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -431,6 +431,16 @@ class Settings(private val appContext: Context) : PreferencesHolder {
         featureFlag = FeatureFlags.inactiveTabs
     )
 
+    /**
+     * Indicates if the Firefox logo on the home screen should be animated,
+     * to show users that they can change the wallpaper by tapping on the Firefox logo.
+     */
+    var shouldAnimateFirefoxLogo by featureFlagPreference(
+        appContext.getPreferenceKey(R.string.pref_key_show_logo_animation),
+        default = FeatureFlags.showWallpapers,
+        featureFlag = FeatureFlags.showWallpapers
+    )
+
     /**
      * Indicates if the user has enabled the search term tab groups feature.
      */

app/src/main/java/org/mozilla/fenix/wallpapers/WallpaperManager.kt

@@ -4,7 +4,11 @@
 
 package org.mozilla.fenix.wallpapers
 
+import android.animation.AnimatorSet
+import android.animation.ObjectAnimator
 import android.content.Context
+import android.os.Handler
+import android.os.Looper
 import android.view.View
 import androidx.appcompat.app.AppCompatDelegate
 import mozilla.components.support.base.log.logger.Logger
@@ -96,4 +100,41 @@ class WallpaperManager(private val settings: Settings) {
             Wallpaper.valueOf(currentWallpaper)
         }
     }
+
+    /**
+     * Animates the Firefox logo, if it hasn't been animated before, otherwise nothing will happen.
+     * After animating the first time, the [Settings.shouldAnimateFirefoxLogo] setting
+     * will be updated.
+     */
+    @Suppress("MagicNumber")
+    fun animateLogoIfNeeded(logo: View) {
+        if (!settings.shouldAnimateFirefoxLogo) {
+            return
+        }
+        Handler(Looper.getMainLooper()).postDelayed(
+            {
+                val animator1 = ObjectAnimator.ofFloat(logo, "rotation", 0f, 10f)
+                val animator2 = ObjectAnimator.ofFloat(logo, "rotation", 10f, 0f)
+                val animator4 = ObjectAnimator.ofFloat(logo, "rotation", 10f, 0f)
+                val animator3 = ObjectAnimator.ofFloat(logo, "rotation", 0f, 10f)
+
+                animator1.duration = 200
+                animator2.duration = 200
+                animator3.duration = 200
+                animator4.duration = 200
+
+                val set = AnimatorSet()
+
+                set.play(animator1).before(animator2).after(animator3).before(animator4)
+                set.start()
+
+                settings.shouldAnimateFirefoxLogo = false
+            },
+            ANIMATION_DELAY_MS
+        )
+    }
+
+    companion object {
+        private const val ANIMATION_DELAY_MS = 1500L
+    }
 }

app/src/main/res/values/preference_keys.xml

@@ -189,6 +189,7 @@
 
     <!-- Wallpaper Settings -->
     <string name="pref_key_current_wallpaper" translatable="false">pref_key_current_wallpaper</string>
+    <string name="pref_key_show_logo_animation" translatable="false">pref_key_show_logo_animation</string>
 
     <string name="pref_key_encryption_key_generated" translatable="false">pref_key_encryption_key_generated</string>