Switch colors of search icon for the two search modes

CHANGELOG.md

@@ -55,6 +55,7 @@ The new default removes the linked file from the entry instead of deleting the f
 - We fixed an issue where linked files would be deleted from bibliography entries despite choosing the "Cancel" option in the dialog menu.
 - We fixed the name of the group editing window to "Add group" instead of "Edit Group" when adding a new group. [koppor#277](https://github.com/koppor/jabref/issues/277)
 - We fixed an issue where the "Copy linked files" dialog produced an error when the entry had no file [#3818](https://github.com/JabRef/jabref/issues/3818)
+- We fixed the coloring of the search box icon in case a user switches to advanced search mode [#3870](https://github.com/JabRef/jabref/issues/3870)
 
 ### Removed
 - We removed the [Look and Feels from JGoodies](http://www.jgoodies.com/freeware/libraries/looks/), because the open source version is not compatible with Java 9.

src/main/java/org/jabref/logic/search/SearchQuery.java

@@ -85,7 +85,7 @@ private String getLocalizedRegularExpressionDescription() {
     }
 
     public boolean isGrammarBasedSearch() {
-        return rule instanceof GrammarBasedSearchRule;
+        return rule instanceof GrammarBasedSearchRule || rule instanceof RegexBasedSearchRule;
     }
 
     public String getQuery() {

src/main/java/org/jabref/model/search/rules/SearchRules.java

@@ -2,16 +2,20 @@
 
 import org.jabref.model.strings.StringUtil;
 
+import java.util.regex.Pattern;
+
 public class SearchRules {
 
     private SearchRules() {
     }
 
+    private static final Pattern simpleExpression = Pattern.compile("(\\w|\\d|\\s)*");
+
     /**
      * Returns the appropriate search rule that fits best to the given parameter.
      */
     public static SearchRule getSearchRuleByQuery(String query, boolean caseSensitive, boolean regex) {
-        if (StringUtil.isBlank(query)) {
+        if (isSimpleQuery(query)) {
             return new ContainBasedSearchRule(caseSensitive);
         }
 
@@ -25,6 +29,10 @@ public static SearchRule getSearchRuleByQuery(String query, boolean caseSensitiv
         }
     }
 
+    private static boolean isSimpleQuery(String query) {
+        return StringUtil.isBlank(query) || simpleExpression.matcher(query).matches();
+    }
+
     private static SearchRule getSearchRule(boolean caseSensitive, boolean regex) {
         if (regex) {
             return new RegexBasedSearchRule(caseSensitive);

src/test/java/org/jabref/logic/search/SearchQueryTest.java

@@ -21,15 +21,15 @@ public void testToString() {
 
     @Test
     public void testIsContainsBasedSearch() {
-        assertFalse(new SearchQuery("asdf", true, false).isContainsBasedSearch());
-        assertFalse(new SearchQuery("asdf", true, true).isContainsBasedSearch());
+        assertTrue(new SearchQuery("asdf", true, false).isContainsBasedSearch());
+        assertTrue(new SearchQuery("asdf", true, true).isContainsBasedSearch());
         assertFalse(new SearchQuery("author=asdf", true, false).isContainsBasedSearch());
     }
 
     @Test
     public void testIsGrammarBasedSearch() {
-        assertTrue(new SearchQuery("asdf", true, false).isGrammarBasedSearch());
-        assertTrue(new SearchQuery("asdf", true, true).isGrammarBasedSearch());
+        assertFalse(new SearchQuery("asdf", true, false).isGrammarBasedSearch());
+        assertFalse(new SearchQuery("asdf", true, true).isGrammarBasedSearch());
         assertTrue(new SearchQuery("author=asdf", true, false).isGrammarBasedSearch());
     }
 
@@ -186,4 +186,13 @@ public void isMatchedForNormalAndFieldBasedSearchMixed() {
 
     }
 
+    @Test
+    public void testSimpleTerm() {
+        String query = "progress";
+
+        SearchQuery result = new SearchQuery(query, false, false);
+
+        assertFalse(result.isGrammarBasedSearch());
+    }
+
 }