From 92e8732d6c14d5b1c4a6fc54071154726cdf7102 Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Mon, 4 Jul 2022 08:11:26 +0200
Subject: [PATCH] Added fake dark

---
 .../eu/faircode/email/AdapterMessage.java     | 60 +++++++++++--------
 .../faircode/email/FragmentOptionsMisc.java   | 14 ++++-
 .../java/eu/faircode/email/HtmlHelper.java    |  8 +++
 .../java/eu/faircode/email/WebViewEx.java     |  5 ++
 .../main/res/layout/fragment_options_misc.xml | 14 ++++-
 app/src/main/res/values/strings.xml           |  1 +
 6 files changed, 74 insertions(+), 28 deletions(-)

diff --git a/app/src/main/java/eu/faircode/email/AdapterMessage.java b/app/src/main/java/eu/faircode/email/AdapterMessage.java
index 1a7f2dddc7..f1c5f4ee05 100644
--- a/app/src/main/java/eu/faircode/email/AdapterMessage.java
+++ b/app/src/main/java/eu/faircode/email/AdapterMessage.java
@@ -300,6 +300,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     private static boolean debug;
     private int level;
     private boolean canDarken;
+    private boolean fake_dark;
     private boolean webview_legacy;
     private boolean show_recent;
 
@@ -2170,7 +2171,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     ibSearch.setVisibility(tools && !outbox && button_search && (froms > 0 || tos > 0) ? View.VISIBLE : View.GONE);
                     ibTranslate.setVisibility(tools && !outbox && button_translate && DeepL.isAvailable(context) && message.content ? View.VISIBLE : View.GONE);
                     ibForceLight.setVisibility(tools && full && dark && button_force_light && message.content ? View.VISIBLE : View.GONE);
-                    ibForceLight.setImageLevel(!canDarken || force_light ? 1 : 0);
+                    ibForceLight.setImageLevel(!(canDarken || fake_dark) || force_light ? 1 : 0);
                     ibImportance.setVisibility(tools && button_importance && !outbox && seen ? View.VISIBLE : View.GONE);
                     ibHide.setVisibility(tools && button_hide && !outbox ? View.VISIBLE : View.GONE);
                     ibSeen.setVisibility(tools && button_seen && !outbox && seen ? View.VISIBLE : View.GONE);
@@ -2663,6 +2664,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             float scale = (size == 0 || textSize == 0 ? 1.0f : size / (textSize * message_zoom / 100f));
             args.putFloat("scale", scale);
 
+            boolean dark = Helper.isDarkTheme(context);
+            args.putBoolean("fake_dark", !canDarken && fake_dark && dark && !force_light);
+
             new SimpleTask<Object>() {
                 @Override
                 protected void onPreExecute(Bundle args) {
@@ -2820,6 +2824,10 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                                 HtmlHelper.restorePre(document);
                         }
 
+                        boolean fake_dark = args.getBoolean("fake_dark");
+                        if (fake_dark)
+                            HtmlHelper.fakeDark(document);
+
                         boolean browser_zoom = prefs.getBoolean("browser_zoom", false);
                         int message_zoom = prefs.getInt("message_zoom", 100);
                         if (browser_zoom && message_zoom != 100) {
@@ -4902,7 +4910,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                 });
 
                 boolean isDark = Helper.isDarkTheme(context);
-                tvDark.setVisibility(isDark && !canDarken ? View.VISIBLE : View.GONE);
+                tvDark.setVisibility(isDark && !(canDarken || fake_dark) ? View.VISIBLE : View.GONE);
             } else {
                 boolean disable_tracking = prefs.getBoolean("disable_tracking", true);
 
@@ -6248,35 +6256,34 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
         }
 
         private void onActionForceLight(TupleMessageEx message) {
-            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
-                View view = LayoutInflater.from(context).inflate(R.layout.dialog_dark, null);
-                final Button btnIssue = view.findViewById(R.id.btnIssue);
-
-                btnIssue.setOnClickListener(new View.OnClickListener() {
-                    @Override
-                    public void onClick(View v) {
-                        Uri uri = Uri.parse("https://issuetracker.google.com/issues/237785596");
-                        Helper.view(v.getContext(), uri, true);
-                    }
-                });
-
-                new AlertDialog.Builder(context)
-                        .setView(view)
-                        .setNegativeButton(android.R.string.cancel, null)
-                        .show();
-                return;
-            }
-
-            if (canDarken) {
+            if (canDarken || fake_dark) {
                 boolean force_light = !properties.getValue("force_light", message.id);
                 properties.setValue("force_light", message.id, force_light);
                 ibForceLight.setImageLevel(force_light ? 1 : 0);
                 bindBody(message, false);
             } else {
-                Intent update = new Intent(Intent.ACTION_VIEW)
-                        .setData(Uri.parse(Helper.PACKAGE_WEBVIEW))
-                        .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-                context.startActivity(update);
+                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
+                    View view = LayoutInflater.from(context).inflate(R.layout.dialog_dark, null);
+                    final Button btnIssue = view.findViewById(R.id.btnIssue);
+
+                    btnIssue.setOnClickListener(new View.OnClickListener() {
+                        @Override
+                        public void onClick(View v) {
+                            Uri uri = Uri.parse("https://issuetracker.google.com/issues/237785596");
+                            Helper.view(v.getContext(), uri, true);
+                        }
+                    });
+
+                    new AlertDialog.Builder(context)
+                            .setView(view)
+                            .setNegativeButton(android.R.string.cancel, null)
+                            .show();
+                } else {
+                    Intent update = new Intent(Intent.ACTION_VIEW)
+                            .setData(Uri.parse(Helper.PACKAGE_WEBVIEW))
+                            .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+                    context.startActivity(update);
+                }
             }
         }
 
@@ -7113,6 +7120,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
         level = prefs.getInt("log_level", Log.getDefaultLogLevel());
 
         this.canDarken = WebViewEx.isFeatureSupported(context, WebViewFeature.ALGORITHMIC_DARKENING);
+        this.fake_dark = prefs.getBoolean("fake_dark", false);
         this.webview_legacy = prefs.getBoolean("webview_legacy", false);
         this.show_recent = prefs.getBoolean("show_recent", false);
 
diff --git a/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java b/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
index b320ff86a7..1355c52175 100644
--- a/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
+++ b/app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java
@@ -161,6 +161,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
     private SwitchCompat swUndoManager;
     private SwitchCompat swWebViewLegacy;
     private SwitchCompat swBrowserZoom;
+    private SwitchCompat swFakeDark;
     private SwitchCompat swShowRecent;
     private SwitchCompat swModSeq;
     private SwitchCompat swUid;
@@ -216,7 +217,9 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             "test2", "test3", "test4", "test5",
             "work_manager", // "external_storage",
             "query_threads", "wal", "sqlite_checkpoints", "sqlite_analyze", "sqlite_cache",
-            "chunk_size", "thread_range", "undo_manager", "webview_legacy", "browser_zoom", "show_recent",
+            "chunk_size", "thread_range", "undo_manager",
+            "webview_legacy", "browser_zoom", "fake_dark",
+            "show_recent",
             "use_modseq", "uid_command", "perform_expunge", "uid_expunge",
             "auth_plain", "auth_login", "auth_ntlm", "auth_sasl", "auth_apop",
             "keep_alive_poll", "empty_pool", "idle_done", "logarithmic_backoff",
@@ -338,6 +341,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swUndoManager = view.findViewById(R.id.swUndoManager);
         swWebViewLegacy = view.findViewById(R.id.swWebViewLegacy);
         swBrowserZoom = view.findViewById(R.id.swBrowserZoom);
+        swFakeDark = view.findViewById(R.id.swFakeDark);
         swShowRecent = view.findViewById(R.id.swShowRecent);
         swModSeq = view.findViewById(R.id.swModSeq);
         swUid = view.findViewById(R.id.swUid);
@@ -1050,6 +1054,13 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
             }
         });
 
+        swFakeDark.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
+                prefs.edit().putBoolean("fake_dark", checked).apply();
+            }
+        });
+
         swShowRecent.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
@@ -1772,6 +1783,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         swUndoManager.setChecked(prefs.getBoolean("undo_manager", false));
         swWebViewLegacy.setChecked(prefs.getBoolean("webview_legacy", false));
         swBrowserZoom.setChecked(prefs.getBoolean("browser_zoom", false));
+        swFakeDark.setChecked(prefs.getBoolean("fake_dark", false));
         swShowRecent.setChecked(prefs.getBoolean("show_recent", false));
         swModSeq.setChecked(prefs.getBoolean("use_modseq", true));
         swUid.setChecked(prefs.getBoolean("uid_command", false));
diff --git a/app/src/main/java/eu/faircode/email/HtmlHelper.java b/app/src/main/java/eu/faircode/email/HtmlHelper.java
index 0547b46b63..39b5e418cb 100644
--- a/app/src/main/java/eu/faircode/email/HtmlHelper.java
+++ b/app/src/main/java/eu/faircode/email/HtmlHelper.java
@@ -2372,6 +2372,14 @@ public class HtmlHelper {
         document.select("head").append(sb.toString());
     }
 
+    static void fakeDark(Document document) {
+        // https://developer.mozilla.org/en-US/docs/Web/CSS/filter-function/invert
+        // https://developer.mozilla.org/en-US/docs/Web/CSS/filter-function/hue-rotate
+        document.head().appendElement("style").html(
+                "body { filter: invert(100%) hue-rotate(180deg) !important; background: black !important; }" +
+                        "img { filter: invert(100%) hue-rotate(180deg) !important; }");
+    }
+
     static String getLanguage(Context context, String subject, String text) {
         try {
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
diff --git a/app/src/main/java/eu/faircode/email/WebViewEx.java b/app/src/main/java/eu/faircode/email/WebViewEx.java
index 633f25726e..72a5ca6908 100644
--- a/app/src/main/java/eu/faircode/email/WebViewEx.java
+++ b/app/src/main/java/eu/faircode/email/WebViewEx.java
@@ -369,6 +369,11 @@ public class WebViewEx extends WebView implements DownloadListener, View.OnLongC
 
     public static boolean isFeatureSupported(Context context, String feature) {
         if (WebViewFeature.ALGORITHMIC_DARKENING.equals(feature)) {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            boolean fake_dark = prefs.getBoolean("fake_dark", false);
+            if (fake_dark)
+                return false;
+
             if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q)
                 return false;
 
diff --git a/app/src/main/res/layout/fragment_options_misc.xml b/app/src/main/res/layout/fragment_options_misc.xml
index e7d8dd4a7b..8aa065d195 100644
--- a/app/src/main/res/layout/fragment_options_misc.xml
+++ b/app/src/main/res/layout/fragment_options_misc.xml
@@ -1030,6 +1030,18 @@
                     app:layout_constraintTop_toBottomOf="@id/swWebViewLegacy"
                     app:switchPadding="12dp" />
 
+                <androidx.appcompat.widget.SwitchCompat
+                    android:id="@+id/swFakeDark"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:checked="true"
+                    android:text="@string/title_advanced_fake_dark"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/swBrowserZoom"
+                    app:switchPadding="12dp" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swShowRecent"
                     android:layout_width="0dp"
@@ -1039,7 +1051,7 @@
                     android:text="@string/title_advanced_show_recent"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/swBrowserZoom"
+                    app:layout_constraintTop_toBottomOf="@id/swFakeDark"
                     app:switchPadding="12dp" />
 
                 <androidx.appcompat.widget.SwitchCompat
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index a952dd8f8a..4b7ad0d078 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -760,6 +760,7 @@
     <string name="title_advanced_undo_manager" translatable="false">Use Android\'s undo manager</string>
     <string name="title_advanced_webview_legacy" translatable="false">Old WebView behavior</string>
     <string name="title_advanced_browser_zoom" translatable="false">Use browser zoom</string>
+    <string name="title_advanced_fake_dark" translatable="false">Fake dark</string>
     <string name="title_advanced_show_recent" translatable="false">Show recent flag</string>
     <string name="title_advanced_modseq" translatable="false">MODSEQ</string>
     <string name="title_advanced_uid" translatable="false">UID command</string>