Highlight found text

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

@@ -1866,6 +1866,7 @@ public class ActivityView extends ActivityBilling implements FragmentManager.OnB
         args.putInt("lpos", intent.getIntExtra("lpos", -1));
         args.putBoolean("filter_archive", intent.getBooleanExtra("filter_archive", true));
         args.putBoolean("found", found);
+        args.putString("searched", intent.getStringExtra("searched"));
         args.putBoolean("pinned", intent.getBooleanExtra("pinned", false));
         args.putString("msgid", intent.getStringExtra("msgid"));
 

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

@@ -203,6 +203,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     private Fragment parentFragment;
     private String type;
     private boolean found;
+    private String searched;
     private ViewType viewType;
     private boolean compact;
     private int zoom;
@@ -2540,6 +2541,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     HtmlHelper.cleanup(document);
                     HtmlHelper.removeRelativeLinks(document);
 
+                    if (!TextUtils.isEmpty(searched))
+                        HtmlHelper.highlightSearched(context, document, searched);
+
                     // Check for inline encryption
                     boolean iencrypted = HtmlHelper.contains(document, new String[]{
                             Helper.PGP_BEGIN_MESSAGE,
@@ -3529,7 +3533,8 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                             .putExtra("id", message.id)
                             .putExtra("lpos", getAdapterPosition())
                             .putExtra("filter_archive", !EntityFolder.ARCHIVE.equals(message.folderType))
-                            .putExtra("found", viewType == ViewType.SEARCH);
+                            .putExtra("found", viewType == ViewType.SEARCH)
+                            .putExtra("searched", searched);
 
                     boolean doubletap = prefs.getBoolean("doubletap", true);
 
@@ -5894,13 +5899,14 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     }
 
     AdapterMessage(Fragment parentFragment,
-                   String type, boolean found, ViewType viewType,
+                   String type, boolean found, String searched, ViewType viewType,
                    boolean compact, int zoom, String sort, boolean ascending,
                    boolean filter_duplicates, boolean filter_trash,
                    final IProperties properties) {
         this.parentFragment = parentFragment;
         this.type = type;
         this.found = found;
+        this.searched = searched;
         this.viewType = viewType;
         this.compact = compact;
         this.zoom = zoom;

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

@@ -290,6 +290,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
     private int lpos;
     private boolean filter_archive;
     private boolean found;
+    private String searched;
     private boolean pinned;
     private String msgid;
     private BoundaryCallbackMessages.SearchCriteria criteria = null;
@@ -413,9 +414,12 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
         lpos = args.getInt("lpos", RecyclerView.NO_POSITION);
         filter_archive = args.getBoolean("filter_archive", true);
         found = args.getBoolean("found", false);
+        searched = args.getString("searched");
         pinned = args.getBoolean("pinned", false);
         msgid = args.getString("msgid");
         criteria = (BoundaryCallbackMessages.SearchCriteria) args.getSerializable("criteria");
+        if (criteria != null)
+            searched = criteria.query;
         pane = args.getBoolean("pane", false);
         primary = args.getLong("primary", -1);
         connected = args.getBoolean("connected", false);
@@ -849,7 +853,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             filter_trash = false;
 
         adapter = new AdapterMessage(
-                this, type, found, viewType,
+                this, type, found, searched, viewType,
                 compact, zoom, sort, ascending,
                 filter_duplicates, filter_trash,
                 iProperties);
@@ -5921,6 +5925,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                     else
                         nargs.putInt("lpos", forward ^ reversed ? lpos + 1 : lpos - 1);
                 nargs.putBoolean("found", found);
+                nargs.putString("searched", searched);
                 nargs.putBoolean("pane", pane);
                 nargs.putLong("primary", primary);
                 nargs.putBoolean("connected", connected);

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

@@ -36,6 +36,7 @@ import android.os.Build;
 import android.text.Html;
 import android.text.Layout;
 import android.text.Spannable;
+import android.text.SpannableString;
 import android.text.SpannableStringBuilder;
 import android.text.Spanned;
 import android.text.TextDirectionHeuristics;
@@ -2400,6 +2401,56 @@ public class HtmlHelper {
         return ssb;
     }
 
+    static Document highlightSearched(Context context, Document document, String searched) {
+        String find = searched.toLowerCase();
+        int color = Helper.resolveColor(context, R.attr.colorHighlight);
+
+        NodeTraversor.traverse(new NodeVisitor() {
+            @Override
+            public void head(Node node, int depth) {
+                if (node instanceof TextNode) {
+                    TextNode tnode = (TextNode) node;
+                    String text = tnode.getWholeText();
+
+                    int start = text.toLowerCase().indexOf(find);
+                    if (start < 0)
+                        return;
+
+                    int prev = 0;
+                    Element holder = document.createElement("span");
+
+                    while (start >= 0) {
+                        if (start > prev)
+                            holder.appendText(text.substring(prev, start));
+
+                        Element span = document.createElement("span");
+                        span.attr("style", mergeStyles(
+                                span.attr("style"),
+                                "font-size:larger; background-color:" + encodeWebColor(color)
+                        ));
+                        span.text(text.substring(start, start + find.length()));
+                        holder.appendChild(span);
+
+                        prev = start + find.length();
+                        start = text.toLowerCase().indexOf(find, prev);
+                    }
+
+                    if (prev < text.length())
+                        holder.appendText(text.substring(prev));
+
+                    tnode.before(holder);
+                    tnode.text("");
+                }
+            }
+
+            @Override
+            public void tail(Node node, int depth) {
+            }
+        }, document);
+
+        return document;
+    }
+
     static void cleanup(Document d) {
         // https://www.chromestatus.com/feature/5756335865987072
         // Some messages contain 100 thousands of Apple spaces