Use highlight span instead of background color span

app/src/main/java/eu/faircode/email/FragmentCompose.java

@@ -73,7 +73,6 @@ import android.text.Spanned;
 import android.text.TextUtils;
 import android.text.TextWatcher;
 import android.text.method.ArrowKeyMovementMethod;
-import android.text.style.BackgroundColorSpan;
 import android.text.style.ImageSpan;
 import android.text.style.QuoteSpan;
 import android.text.style.RelativeSizeSpan;
@@ -2831,7 +2830,7 @@ public class FragmentCompose extends FragmentBase {
                     args.putCharSequence("text", text);
 
                     new SimpleTask<DeepL.Translation>() {
-                        private Object highlightSpan;
+                        private HighlightSpan highlightSpan;
                         private Toast toast = null;
 
                         @Override
@@ -2840,7 +2839,7 @@ public class FragmentCompose extends FragmentBase {
                             boolean deepl_highlight = prefs.getBoolean("deepl_highlight", true);
                             if (deepl_highlight) {
                                 int textColorHighlight = Helper.resolveColor(getContext(), android.R.attr.textColorHighlight);
-                                highlightSpan = new BackgroundColorSpan(textColorHighlight);
+                                highlightSpan = new HighlightSpan(textColorHighlight);
                                 etBody.getText().setSpan(highlightSpan, paragraph.first, paragraph.second,
                                         Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
                             }
@@ -2960,7 +2959,7 @@ public class FragmentCompose extends FragmentBase {
 
         new SimpleTask<List<LanguageTool.Suggestion>>() {
             private Toast toast = null;
-            private BackgroundColorSpan highlightSpan = null;
+            private HighlightSpan highlightSpan = null;
 
             @Override
             protected void onPreExecute(Bundle args) {
@@ -2969,7 +2968,7 @@ public class FragmentCompose extends FragmentBase {
                     boolean lt_highlight = prefs.getBoolean("lt_highlight", !BuildConfig.PLAY_STORE_RELEASE);
                     if (lt_highlight) {
                         int textColorHighlight = Helper.resolveColor(getContext(), android.R.attr.textColorHighlight);
-                        highlightSpan = new BackgroundColorSpan(textColorHighlight);
+                        highlightSpan = new HighlightSpan(textColorHighlight);
                         etBody.getText().setSpan(highlightSpan, start, end,
                                 Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
                     }
@@ -7887,7 +7886,7 @@ public class FragmentCompose extends FragmentBase {
             Context context = etBody.getContext();
             int color = Helper.resolveColor(context, R.attr.colorHighlight);
             SpannableString ss = new SpannableString(etBody.getText());
-            ss.setSpan(new BackgroundColorSpan(color),
+            ss.setSpan(new HighlightSpan(color),
                     pos, pos + query.length(), Spannable.SPAN_COMPOSING);
             ss.setSpan(new RelativeSizeSpan(HtmlHelper.FONT_LARGE),
                     pos, pos + query.length(), Spannable.SPAN_COMPOSING);

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -83,7 +83,6 @@ import android.text.SpannableStringBuilder;
 import android.text.TextUtils;
 import android.text.TextWatcher;
 import android.text.format.DateUtils;
-import android.text.style.BackgroundColorSpan;
 import android.text.style.ForegroundColorSpan;
 import android.text.style.RelativeSizeSpan;
 import android.text.style.StyleSpan;
@@ -8121,7 +8120,7 @@ public class FragmentMessages extends FragmentBase
             Context context = searchView.getContext();
             int color = Helper.resolveColor(context, R.attr.colorHighlight);
             SpannableString ss = new SpannableString(searchView.getText());
-            ss.setSpan(new BackgroundColorSpan(color),
+            ss.setSpan(new HighlightSpan(color),
                     pos, pos + query.length(), Spannable.SPAN_COMPOSING);
             ss.setSpan(new RelativeSizeSpan(HtmlHelper.FONT_LARGE),
                     pos, pos + query.length(), Spannable.SPAN_COMPOSING);

app/src/main/java/eu/faircode/email/HighlightSpan.java

@@ -0,0 +1,18 @@
+package eu.faircode.email;
+
+import android.text.TextPaint;
+import android.text.style.CharacterStyle;
+import android.text.style.UpdateAppearance;
+
+public class HighlightSpan extends CharacterStyle implements UpdateAppearance {
+    private int color;
+
+    public HighlightSpan(int color) {
+        this.color = color;
+    }
+
+    @Override
+    public void updateDrawState(TextPaint tp) {
+        tp.bgColor = color;
+    }
+}

app/src/main/java/eu/faircode/email/StyleHelper.java

@@ -1272,12 +1272,12 @@ public class StyleHelper {
         args.putCharSequence("text", etBody.getText().subSequence(start, end));
 
         new SimpleTask<List<LanguageTool.Suggestion>>() {
-            private BackgroundColorSpan highlightSpan = null;
+            private HighlightSpan highlightSpan = null;
 
             @Override
             protected void onPreExecute(Bundle args) {
                 int textColorHighlight = Helper.resolveColor(context, android.R.attr.textColorHighlight);
-                highlightSpan = new BackgroundColorSpan(textColorHighlight);
+                highlightSpan = new HighlightSpan(textColorHighlight);
                 etBody.getText().setSpan(highlightSpan, start, end,
                         Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
             }