From a1fc18d0362202dee81392f9adb03820424aa9c1 Mon Sep 17 00:00:00 2001
From: Johan Reitan <johan.reitan@gmail.com>
Date: Fri, 9 Apr 2021 11:29:21 +0200
Subject: [PATCH] Add isNavigationBarContrastEnforced API

---
 .../systemuicontroller/SystemUiControllerTest.kt    | 11 +++++++++--
 .../systemuicontroller/SystemUiController.kt        | 13 +++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/systemuicontroller/src/androidTest/java/com/google/accompanist/systemuicontroller/SystemUiControllerTest.kt b/systemuicontroller/src/androidTest/java/com/google/accompanist/systemuicontroller/SystemUiControllerTest.kt
index 634e72328..817b19fb1 100644
--- a/systemuicontroller/src/androidTest/java/com/google/accompanist/systemuicontroller/SystemUiControllerTest.kt
+++ b/systemuicontroller/src/androidTest/java/com/google/accompanist/systemuicontroller/SystemUiControllerTest.kt
@@ -191,9 +191,13 @@ class SystemUiControllerTest {
         val view = composeTestRule.contentView
         val window = composeTestRule.activity.window
 
-        // Now create an AndroidSystemUiController() and set the navigation bar with dark icons
-        // and enforce contrast
+        // Now create an AndroidSystemUiController()
         val controller = AndroidSystemUiController(view)
+
+        // Assert that the contrast is not enforced initially
+        assertThat(controller.isNavigationBarContrastEnforced()).isFalse()
+
+        // and set the navigation bar with dark icons and enforce contrast
         controller.setNavigationBarColor(
             Color.Transparent,
             darkIcons = true,
@@ -209,6 +213,9 @@ class SystemUiControllerTest {
 
         // Assert that the system applied the contrast enforced property
         assertThat(window.isNavigationBarContrastEnforced).isTrue()
+
+        // Assert that the controller reflects that the contrast is enforced
+        assertThat(controller.isNavigationBarContrastEnforced()).isTrue()
     }
 }
 
diff --git a/systemuicontroller/src/main/java/com/google/accompanist/systemuicontroller/SystemUiController.kt b/systemuicontroller/src/main/java/com/google/accompanist/systemuicontroller/SystemUiController.kt
index 453aaa5ce..cfa7d7856 100644
--- a/systemuicontroller/src/main/java/com/google/accompanist/systemuicontroller/SystemUiController.kt
+++ b/systemuicontroller/src/main/java/com/google/accompanist/systemuicontroller/SystemUiController.kt
@@ -97,6 +97,14 @@ interface SystemUiController {
             transformColorForLightContent
         )
     }
+
+    /**
+     * Returns whether the system is ensuring that the navigation bar has enough contrast when a
+     * fully transparent background is requested.
+     *
+     * @return true, if API is 29+ and the system is ensuring contrast, false otherwise.
+     */
+    fun isNavigationBarContrastEnforced(): Boolean = false
 }
 
 /**
@@ -160,6 +168,11 @@ class AndroidSystemUiController(view: View) : SystemUiController {
         }
     }
 
+    override fun isNavigationBarContrastEnforced(): Boolean {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q
+            && window?.isNavigationBarContrastEnforced == true
+    }
+
     private fun Context.findWindow(): Window? {
         var context = this
         while (context is ContextWrapper) {