From bccd1fcd3afa52f2831622d1817fdc7d9fee77f0 Mon Sep 17 00:00:00 2001
From: Brayan Oliveira <69634269+brayandso@users.noreply.github.com>
Date: Thu, 14 Mar 2024 10:50:49 -0300
Subject: [PATCH] UI: match navbar with previewers' background

---
 .../ichi2/anki/previewer/PreviewerFragment.kt | 10 +++++++
 .../previewer/TemplatePreviewerFragment.kt    | 10 +++++++
 .../java/com/ichi2/anki/utils/Resources.kt    | 26 +++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/previewer/PreviewerFragment.kt b/AnkiDroid/src/main/java/com/ichi2/anki/previewer/PreviewerFragment.kt
index 7eb7daa4905a..33bf0fe91019 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/previewer/PreviewerFragment.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/previewer/PreviewerFragment.kt
@@ -24,6 +24,7 @@ import android.view.MenuItem
 import android.view.View
 import android.webkit.WebView
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.appcompat.widget.ThemeUtils
 import androidx.appcompat.widget.Toolbar
 import androidx.core.os.bundleOf
 import androidx.core.view.isVisible
@@ -42,6 +43,7 @@ import com.ichi2.anki.browser.PreviewerIdsFile
 import com.ichi2.anki.snackbar.BaseSnackbarBuilderProvider
 import com.ichi2.anki.snackbar.SnackbarBuilder
 import com.ichi2.anki.utils.ext.sharedPrefs
+import com.ichi2.anki.utils.navBarNeedsScrim
 import com.ichi2.annotations.NeedsTest
 import com.ichi2.compat.CompatHelper.Companion.getSerializableCompat
 import com.ichi2.utils.performClickIfEnabled
@@ -174,6 +176,14 @@ class PreviewerFragment :
         if (sharedPrefs().getBoolean("safeDisplay", false)) {
             view.findViewById<MaterialCardView>(R.id.webview_container).elevation = 0F
         }
+
+        with(requireActivity()) {
+            // use the screen background color if the nav bar doesn't need a scrim when using a
+            // transparent background. e.g. when navigation gestures are enabled
+            if (!navBarNeedsScrim) {
+                window.navigationBarColor = ThemeUtils.getThemeAttrColor(this, R.attr.alternativeBackgroundColor)
+            }
+        }
     }
 
     override fun onMenuItemClick(item: MenuItem): Boolean {
diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/previewer/TemplatePreviewerFragment.kt b/AnkiDroid/src/main/java/com/ichi2/anki/previewer/TemplatePreviewerFragment.kt
index caff8ef19404..f8eb22fa6339 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/previewer/TemplatePreviewerFragment.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/previewer/TemplatePreviewerFragment.kt
@@ -20,6 +20,7 @@ import android.content.Intent
 import android.os.Bundle
 import android.view.View
 import android.webkit.WebView
+import androidx.appcompat.widget.ThemeUtils
 import androidx.core.os.BundleCompat
 import androidx.core.os.bundleOf
 import androidx.fragment.app.viewModels
@@ -33,6 +34,7 @@ import com.ichi2.anki.R
 import com.ichi2.anki.snackbar.BaseSnackbarBuilderProvider
 import com.ichi2.anki.snackbar.SnackbarBuilder
 import com.ichi2.anki.utils.ext.sharedPrefs
+import com.ichi2.anki.utils.navBarNeedsScrim
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
@@ -97,6 +99,14 @@ class TemplatePreviewerFragment :
         if (sharedPrefs().getBoolean("safeDisplay", false)) {
             view.findViewById<MaterialCardView>(R.id.webview_container).elevation = 0F
         }
+
+        with(requireActivity()) {
+            // use the screen background color if the nav bar doesn't need a scrim when using a
+            // transparent background. e.g. when navigation gestures are enabled
+            if (!navBarNeedsScrim) {
+                window.navigationBarColor = ThemeUtils.getThemeAttrColor(this, R.attr.alternativeBackgroundColor)
+            }
+        }
     }
 
     companion object {
diff --git a/AnkiDroid/src/main/java/com/ichi2/anki/utils/Resources.kt b/AnkiDroid/src/main/java/com/ichi2/anki/utils/Resources.kt
index 1075cae1db85..900a60c78266 100644
--- a/AnkiDroid/src/main/java/com/ichi2/anki/utils/Resources.kt
+++ b/AnkiDroid/src/main/java/com/ichi2/anki/utils/Resources.kt
@@ -15,10 +15,14 @@
  */
 package com.ichi2.anki.utils
 
+import android.annotation.SuppressLint
 import android.content.Context
 import android.content.res.Resources
 import androidx.annotation.PluralsRes
 import androidx.annotation.StringRes
+import androidx.fragment.app.FragmentActivity
+import com.ichi2.anki.CrashReportService
+import com.ichi2.annotations.NeedsTest
 
 /**
  * @param resId must be a [StringRes] or a [PluralsRes]
@@ -37,3 +41,25 @@ fun Resources.getFormattedStringOrPlurals(resId: Int, quantity: Int): String {
 fun Context.getFormattedStringOrPlurals(resId: Int, quantity: Int): String {
     return resources.getFormattedStringOrPlurals(resId, quantity)
 }
+
+@SuppressLint("DiscouragedApi") // Resources.getIdentifier: Use of this function is discouraged
+// because resource reflection makes it harder to perform build optimizations and compile-time
+// verification of code. It is much more efficient to retrieve resources by identifier
+// (e.g. `R.foo.bar`) than by name (e.g. `getIdentifier("bar", "foo", null)`)
+private fun Context.getSystemBoolean(resName: String, fallback: Boolean): Boolean {
+    return try {
+        val id = Resources.getSystem().getIdentifier(resName, "bool", "android")
+        if (id != 0) {
+            createPackageContext("android", 0).resources.getBoolean(id)
+        } else {
+            fallback
+        }
+    } catch (e: Exception) {
+        CrashReportService.sendExceptionReport(e, "Context::getSystemBoolean")
+        fallback
+    }
+}
+
+@NeedsTest("true if the navbar is transparent and needs a scrim, false if not")
+val FragmentActivity.navBarNeedsScrim: Boolean
+    get() = getSystemBoolean("config_navBarNeedsScrim", true)