Support regular expression search in game load/save activity

Standard Java regular expression syntax is supported. The search is
case insensitive.

DroidFishApp/src/main/java/org/petero/droidfish/activities/EditPGN.java

@@ -72,6 +72,7 @@ public abstract class EditPGN extends AppCompatActivity {
     private String lastSearchString = "";
     private String lastFileName = "";
     private long lastModTime = -1;
+    private boolean useRegExp = false;
 
     private Thread workThread = null;
     private boolean canceled = false;
@@ -95,11 +96,13 @@ public abstract class EditPGN extends AppCompatActivity {
             lastFileName = savedInstanceState.getString("lastFileName");
             if (lastFileName == null) lastFileName = "";
             lastModTime = savedInstanceState.getLong("lastModTime");
+            useRegExp = savedInstanceState.getBoolean("useRegExpSearch");
         } else {
             defaultFilePos = settings.getLong("defaultFilePos", 0);
             lastSearchString = settings.getString("lastSearchString", "");
             lastFileName = settings.getString("lastFileName", "");
             lastModTime = settings.getLong("lastModTime", 0);
+            useRegExp = settings.getBoolean("useRegExpSearch", false);
         }
 
         Intent i = getIntent();
@@ -131,14 +134,14 @@ public abstract class EditPGN extends AppCompatActivity {
             workThread = new Thread(() -> {
                 if (!readFile())
                     return;
+                GameAdapter.ItemMatcher<GameInfo> m =
+                    GameAdapter.getItemMatcher(lastSearchString, useRegExp);
                 int itemNo = getItemNo(gamesInFile, defaultFilePos) + (next ? 1 : -1);
                 if (next) {
-                    while (itemNo < gamesInFile.size() &&
+                    while (itemNo < gamesInFile.size() && !m.matches(gamesInFile.get(itemNo)))
-                        !GameAdapter.matchItem(gamesInFile.get(itemNo), lastSearchString))
                         itemNo++;
                 } else {
-                    while (itemNo >= 0 &&
+                    while (itemNo >= 0 && !m.matches(gamesInFile.get(itemNo)))
-                        !GameAdapter.matchItem(gamesInFile.get(itemNo), lastSearchString))
                         itemNo--;
                 }
                 final int loadItem = itemNo;
@@ -205,6 +208,7 @@ public abstract class EditPGN extends AppCompatActivity {
         outState.putString("lastSearchString", lastSearchString);
         outState.putString("lastFileName", lastFileName);
         outState.putLong("lastModTime", lastModTime);
+        outState.putBoolean("useRegExpSearch", useRegExp);
     }
 
     @Override
@@ -214,6 +218,7 @@ public abstract class EditPGN extends AppCompatActivity {
         editor.putString("lastSearchString", lastSearchString);
         editor.putString("lastFileName", lastFileName);
         editor.putLong("lastModTime", lastModTime);
+        editor.putBoolean("useRegExpSearch", useRegExp);
         editor.apply();
         super.onPause();
     }
@@ -234,6 +239,8 @@ public abstract class EditPGN extends AppCompatActivity {
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.edit_file_options_menu, menu);
+        MenuItem item = menu.findItem(R.id.regexp_search);
+        item.setChecked(useRegExp);
         return true;
     }
 
@@ -243,6 +250,14 @@ public abstract class EditPGN extends AppCompatActivity {
         case R.id.item_delete_file:
             reShowDialog(DELETE_PGN_FILE_DIALOG);
             break;
+        case R.id.regexp_search:
+            useRegExp = !useRegExp;
+            item.setChecked(useRegExp);
+            if (binding != null) {
+                String s = binding.selectGameFilter.getText().toString();
+                setFilterString(s);
+            }
+            break;
         }
         return false;
     }
@@ -480,17 +495,20 @@ public abstract class EditPGN extends AppCompatActivity {
     }
 
     private void setFilterString(String s) {
+        boolean regExp = useRegExp;
         Filter.FilterListener listener = (count) -> {
             ArrayList<GameInfo> arr = aa.getValues();
             int itemNo = getItemNo(arr, currentFilePos);
             if (itemNo < 0)
                 itemNo = 0;
-            while (itemNo < arr.size() &&
+            GameAdapter.ItemMatcher<GameInfo> m =
-                !GameAdapter.matchItem(arr.get(itemNo), lastSearchString))
+                GameAdapter.getItemMatcher(lastSearchString, regExp);
+            while (itemNo < arr.size() && !m.matches(arr.get(itemNo)))
                 itemNo++;
             if (itemNo < arr.size())
                 binding.listView.setSelectionFromTop(itemNo, 0);
         };
+        aa.setUseRegExp(regExp);
         aa.getFilter().filter(s, listener);
     }
 

DroidFishApp/src/main/java/org/petero/droidfish/activities/GameAdapter.java

@@ -28,6 +28,8 @@ import android.widget.Filterable;
 import android.widget.TextView;
 
 import java.util.ArrayList;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
 
 /**
  * An adapter for displaying an ArrayList<GameInfo> in a ListView.
@@ -38,6 +40,7 @@ public class GameAdapter<T> extends BaseAdapter implements Filterable {
     private final LayoutInflater inflater;
     private int resource;
     private GameFilter filter;         // Initialized at first use
+    private boolean useRegExp = false; // If true, use regular expression in filter
 
     public GameAdapter(Context context, int resource, ArrayList<T> objects) {
         origValues = objects;
@@ -83,6 +86,10 @@ public class GameAdapter<T> extends BaseAdapter implements Filterable {
         return filter;
     }
 
+    public void setUseRegExp(boolean regExp) {
+        useRegExp = regExp;
+    }
+
     private class GameFilter extends Filter {
         @Override
         protected FilterResults performFiltering(CharSequence constraint) {
@@ -91,10 +98,10 @@ public class GameAdapter<T> extends BaseAdapter implements Filterable {
                 res.values = origValues;
                 res.count = origValues.size();
             } else {
-                String s = constraint.toString().toLowerCase();
+                ItemMatcher<T> m = getItemMatcher(constraint.toString(), useRegExp);
                 ArrayList<T> newValues = new ArrayList<>();
                 for (T item : origValues)
-                    if (matchItem(item, s))
+                    if (m.matches(item))
                         newValues.add(item);
                 res.values = newValues;
                 res.count = newValues.size();
@@ -110,10 +117,27 @@ public class GameAdapter<T> extends BaseAdapter implements Filterable {
         }
     }
 
-    /** Return true if matchStr matches item.
+    interface ItemMatcher<U> {
-     * @param item The item to check. The toString() value converted to lowercase is used.
+        /** Return true if item matches the search criteria. */
-     * @param matchStr The match string. Must be lowercase. */
+        boolean matches(U item);
-    static <U> boolean matchItem(U item, String matchStr) {
+    }
-        return item.toString().toLowerCase().contains(matchStr);
+
+    /** Return an object that determines if an item matches given search criteria.
+     *  @param matchStr  The match string.
+     *  @param useRegExp If true matchStr is interpreted as a regular expression. */
+    static <U> ItemMatcher<U> getItemMatcher(String matchStr, boolean useRegExp) {
+        if (useRegExp) {
+            Pattern tmp;
+            try {
+                tmp = Pattern.compile(matchStr, Pattern.CASE_INSENSITIVE);
+            } catch (PatternSyntaxException ex) {
+                tmp = null;
+            }
+            Pattern p = tmp;
+            return item -> p == null || p.matcher(item.toString()).find();
+        } else {
+            String s = matchStr.toLowerCase();
+            return item -> item.toString().toLowerCase().contains(s);
+        }
     }
 }

DroidFishApp/src/main/res/menu/edit_file_options_menu.xml

@@ -1,6 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<menu xmlns:android="http://schemas.android.com/apk/res/android">
+<menu xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:android="http://schemas.android.com/apk/res/android">
     <item
         android:id="@+id/item_delete_file"
         android:title="@string/delete_file" />
+    <item
+        android:id="@+id/regexp_search"
+        android:title="@string/regexp_search"
+        android:checkable="true"
+        app:showAsAction="never" />
 </menu>

DroidFishApp/src/main/res/values/strings.xml

@@ -196,6 +196,7 @@ If you are running on battery power, it is recommended that you change settings
     <string name="delete_file">Delete file</string>
     <string name="delete_file_question">Delete file?</string>
     <string name="delete_named_file">Delete file %s?</string>
+    <string name="regexp_search">Regular Expression Search</string>
     <string name="game_saved">Game saved</string>
     <string name="failed_to_save_game">Failed to save game</string>
     <string name="failed_to_delete_game">Failed to delete game</string>