Failed attempt to fix scroll lag

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

@@ -402,7 +402,10 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             ibHelp = itemView.findViewById(R.id.ibHelp);
             pbLoading = itemView.findViewById(R.id.pbLoading);
 
-            if (compact && tvSubject != null)
+            if (tvSubject != null) {
+                tvSubject.setTextColor(colorRead);
+
+                if (compact)
                     if ("start".equals(subject_ellipsize))
                         tvSubject.setEllipsize(TextUtils.TruncateAt.START);
                     else if ("end".equals(subject_ellipsize))
@@ -410,6 +413,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     else
                         tvSubject.setEllipsize(TextUtils.TruncateAt.MIDDLE);
             }
+        }
 
         private void ensureExpanded() {
             if (vsBody != null)
@@ -751,18 +755,28 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             tvCount.setTypeface(typeface);
 
             int colorUnseen = (message.unseen > 0 ? colorUnread : colorRead);
+            if (tvFrom.getTag() == null || (int) tvFrom.getTag() != colorUnseen) {
+                tvFrom.setTag(colorUnseen);
                 tvFrom.setTextColor(colorUnseen);
                 tvSize.setTextColor(colorUnseen);
                 tvTime.setTextColor(colorUnseen);
-            tvSubject.setTextColor(colorRead);
+            }
 
             // Account color
-            vwColor.setVisibility(View.VISIBLE);
-            vwColor.setBackgroundColor(message.accountColor == null || !ActivityBilling.isPro(context)
+            int colorBackground =
+                    (message.accountColor == null || !ActivityBilling.isPro(context)
                             ? colorSeparator : message.accountColor);
+            vwColor.setVisibility(View.VISIBLE);
+            if (vwColor.getTag() == null || (int) vwColor.getTag() != colorBackground) {
+                vwColor.setTag(colorBackground);
+                vwColor.setBackgroundColor(colorBackground);
+            }
 
             // Expander
+            if (ibExpander.getTag() == null || (boolean) ibExpander.getTag() != expanded) {
+                ibExpander.setTag(expanded);
                 ibExpander.setImageLevel(expanded ? 0 /* less */ : 1 /* more */);
+            }
             if (viewType == ViewType.THREAD)
                 ibExpander.setVisibility(EntityFolder.DRAFTS.equals(message.folderType) ? View.INVISIBLE : View.VISIBLE);
             else
@@ -788,17 +802,22 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                             Boolean.FALSE.equals(message.mx));
 
             // Line 3
+            int icon;
             if (outgoing && !EntityFolder.SENT.equals(message.folderType)) {
-                ivType.setImageResource(EntityFolder.getIcon(EntityFolder.SENT));
+                icon = EntityFolder.getIcon(EntityFolder.SENT);
                 ivType.setVisibility(View.VISIBLE);
             } else {
-                ivType.setImageResource(message.drafts > 0
+                icon = (message.drafts > 0
                         ? R.drawable.baseline_edit_24 : EntityFolder.getIcon(message.folderType));
                 ivType.setVisibility(message.drafts > 0 ||
                         (viewType == ViewType.UNIFIED && type == null && !inbox) ||
                         (viewType == ViewType.THREAD && EntityFolder.SENT.equals(message.folderType))
                         ? View.VISIBLE : View.GONE);
             }
+            if (ivType.getTag() == null || (int) ivType.getTag() != icon) {
+                ivType.setTag(icon);
+                ivType.setImageResource(icon);
+            }
 
             ivPriority.setVisibility(EntityMessage.PRIORITIY_HIGH.equals(message.priority) ? View.VISIBLE : View.GONE);
             ibAuth.setVisibility(authentication && !authenticated ? View.VISIBLE : View.GONE);
@@ -832,7 +851,11 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             bindFlagged(message, expanded);
 
             // Message text preview
-            tvPreview.setTextColor(contrast ? textColorPrimary : textColorSecondary);
+            int textColor = (contrast ? textColorPrimary : textColorSecondary);
+            if (tvPreview.getTag() == null || (int) tvPreview.getTag() != textColor) {
+                tvPreview.setTag(textColor);
+                tvPreview.setTextColor(textColor);
+            }
             tvPreview.setTypeface(
                     monospaced ? Typeface.MONOSPACE : Typeface.DEFAULT,
                     preview_italic ? Typeface.ITALIC : Typeface.NORMAL);

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

@@ -46,11 +46,15 @@ public class ViewCardOptional extends CardView {
         setCardBackgroundColor(Color.TRANSPARENT);
     }
 
+    private boolean initialized = false;
 
     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();
 
+        if (!initialized) {
+            initialized = true;
+
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
             boolean cards = prefs.getBoolean("cards", true);
             boolean compact = prefs.getBoolean("compact", false);
@@ -69,9 +73,15 @@ public class ViewCardOptional extends CardView {
 
             setCardElevation(0);
         }
+    }
+
+    private Integer color = null;
 
     @Override
     public void setCardBackgroundColor(int color) {
+        if (this.color == null || this.color != color) {
+            this.color = color;
+
             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
             boolean cards = prefs.getBoolean("cards", true);
             if (cards && color == Color.TRANSPARENT)
@@ -79,4 +89,5 @@ public class ViewCardOptional extends CardView {
 
             super.setCardBackgroundColor(color);
         }
+    }
 }