Fix issue #4962, remove trailing whitespace in caption field when set to uploadMediaDetails (#5085)

* add methods to check and remove trailing whitespace

* fix filter to check and remove trailing whitespace

* fix filter to check and remove trailing space first

* add test and fix filter() and removeTrailingWhitespace()

* caption trailing whitespace: change solution to remove trailing whitespaces when set to uploadMediaDetails

* update code documentation

* add more tests include instance tab, carriage return and Japanese whitespace

* Caption field: Stop blocking Japanese Space, convert to English Space when set to uploadMediaDetails

* Change method name from convertJapSpaceToEngSpace to convertIdeographicSpaceToLatinSpace

* Change pattern name from JapSpacePattern to ideographicSpacePattern

app/src/main/java/fr/free/nrw/commons/upload/UploadMediaDetailAdapter.java

@@ -34,6 +34,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Objects;
+import java.util.regex.Pattern;
 import javax.inject.Inject;
 import timber.log.Timber;
 
@@ -197,7 +198,7 @@ public class UploadMediaDetailAdapter extends RecyclerView.Adapter<UploadMediaDe
 
             removeButton.setOnClickListener(v -> removeDescription(uploadMediaDetail, position));
             captionListener = new AbstractTextWatcher(
-                captionText -> uploadMediaDetails.get(position).setCaptionText(captionText));
+                captionText -> uploadMediaDetails.get(position).setCaptionText(convertIdeographicSpaceToLatinSpace(removeTrailingWhitespace(captionText))));
             descriptionListener = new AbstractTextWatcher(
                 descriptionText -> uploadMediaDetails.get(position).setDescriptionText(descriptionText));
             captionItemEditText.addTextChangedListener(captionListener);
@@ -418,10 +419,45 @@ public class UploadMediaDetailAdapter extends RecyclerView.Adapter<UploadMediaDe
                 languageHistoryListView.setAdapter(recentLanguagesAdapter);
             }
         }
+
+        /**
+         * Checks if the source string contains trailing whitespace
+         * @param source input string
+         * @return true if contains trailing whitespace and false otherwise
+         */
+        public Boolean checkTrailingWhitespace(String source) {
+            int len = source.length();
+            if (len == 0) {
+                return false;
+            }
+            return Character.isWhitespace(source.charAt(len - 1));
+        }
+
+        /**
+         * Removes any trailing whitespace from the source text.
+         * @param source input string
+         * @return a string without trailing whitespace
+         */
+        public String removeTrailingWhitespace(String source) {
+            while (checkTrailingWhitespace(source)) {
+                source = source.substring(0, source.length() - 1);
+            }
+            return source;
+        }
+
+        /**
+         * Convert Ideographic space to Latin space
+         * @param source the source text
+         * @return a string with Latin spaces instead of Ideographic spaces
+         */
+        public String convertIdeographicSpaceToLatinSpace(String source) {
+            Pattern ideographicSpacePattern = Pattern.compile("\\x{3000}");
+            return ideographicSpacePattern.matcher(source).replaceAll(" ");
+        }
+
     }
 
     public interface Callback {
-
         void showAlert(int mediaDetailDescription, int descriptionInfo);
     }
 

app/src/main/java/fr/free/nrw/commons/upload/UploadMediaDetailInputFilter.java

@@ -17,7 +17,7 @@ public class UploadMediaDetailInputFilter implements InputFilter {
      */
     public UploadMediaDetailInputFilter() {
         patterns = new Pattern[]{
-            Pattern.compile("[\\x{00A0}\\x{1680}\\x{180E}\\x{2000}-\\x{200B}\\x{2028}\\x{2029}\\x{202F}\\x{205F}\\x{3000}]"),
+            Pattern.compile("[\\x{00A0}\\x{1680}\\x{180E}\\x{2000}-\\x{200B}\\x{2028}\\x{2029}\\x{202F}\\x{205F}]"),
             Pattern.compile("[\\x{202A}-\\x{202E}]"),
             Pattern.compile("\\p{Cc}"),
             Pattern.compile("\\x{FEFF}"),

app/src/test/kotlin/fr/free/nrw/commons/upload/UploadMediaDetailAdapterUnitTest.kt

@@ -247,4 +247,51 @@ class UploadMediaDetailAdapterUnitTest {
         verify(adapterView, times(3)).adapter
     }
 
+    @Test
+    fun testRemoveTrailingWhitespace() {
+        // empty space
+        val test1 = "test  "
+        val expected1 = "test"
+        Assert.assertTrue(viewHolder.checkTrailingWhitespace(test1));
+        Assert.assertEquals(expected1, viewHolder.removeTrailingWhitespace(test1))
+
+        val test2 = "test test "
+        val expected2 = "test test"
+        Assert.assertTrue(viewHolder.checkTrailingWhitespace(test2));
+        Assert.assertEquals(expected2, viewHolder.removeTrailingWhitespace(test2))
+
+        // No whitespace
+        val test3 = "No trailing space";
+        val expected3 = "No trailing space";
+        Assert.assertFalse(viewHolder.checkTrailingWhitespace(test3))
+        Assert.assertEquals(expected3, viewHolder.removeTrailingWhitespace(test3))
+    }
+
+    @Test
+    fun testRemoveTrailingInstanceTab() {
+        val test = "test\t"
+        val expected = "test"
+        Assert.assertTrue(viewHolder.checkTrailingWhitespace(test));
+        Assert.assertEquals(expected, viewHolder.removeTrailingWhitespace(test))
+    }
+
+    @Test
+    fun testRemoveTrailingCarriageReturn() {
+        val test = "test\r"
+        val expected = "test"
+        Assert.assertTrue(viewHolder.checkTrailingWhitespace(test));
+        Assert.assertEquals(expected, viewHolder.removeTrailingWhitespace(test))
+    }
+
+    @Test
+    fun testCaptionJapaneseCharacters() {
+        val test1 = "テスト　テスト"
+        val expected1 = "テスト テスト"
+        Assert.assertEquals(expected1, viewHolder.convertIdeographicSpaceToLatinSpace(test1));
+
+        val test2 = "テスト　\r　\t　"
+        val expected2 = "テスト"
+        Assert.assertTrue(viewHolder.checkTrailingWhitespace(test2));
+        Assert.assertEquals(expected2, viewHolder.removeTrailingWhitespace(test2))
+    }
 }

app/src/test/kotlin/fr/free/nrw/commons/upload/UploadMediaDetailInputFilterTest.kt

@@ -33,7 +33,7 @@ class UploadMediaDetailInputFilterTest {
         builder.filters = arrayOf(UploadMediaDetailInputFilter())
 
         //All unusual space characters
-        val tests = intArrayOf(0x00A0, 0x1680, 0x180E, 0x2000, 0x2005, 0x200B, 0x2028, 0x2029, 0x202F, 0x205F, 0x3000)
+        val tests = intArrayOf(0x00A0, 0x1680, 0x180E, 0x2000, 0x2005, 0x200B, 0x2028, 0x2029, 0x202F, 0x205F)
         for (test: Int in tests) {
             builder.insert(0, String(Character.toChars(test)))
             Assert.assertEquals(builder.toString(), "")