[ui] Make customization functions in GroupedComboBoxRenderer not abstract

If we override customize then getText, getSecondaryText and getIcon don't need to be overridden.

GitOrigin-RevId: e8aa2f06aa628ed8aa1d973d52a185753917b077

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/LanguageLevelCombo.java

@@ -20,7 +20,6 @@ import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import javax.swing.*;
 import java.text.MessageFormat;
 import java.util.Arrays;
 
@@ -77,12 +76,6 @@ public abstract class LanguageLevelCombo extends ComboBox<Object> {
         }
         return null;
       }
-
-      @Nullable
-      @Override
-      public Icon getIcon(Object value) {
-        return null;
-      }
     });
   }
 

platform/platform-impl/src/com/intellij/ui/GroupedComboBoxRenderer.kt

@@ -34,12 +34,12 @@ abstract class GroupedComboBoxRenderer<T>(private val combo: ComboBox<T>) : Grou
   }
 
   @NlsContexts.ListItem
-  abstract fun getText(value: T): String
+  open fun getText(value: T): String = ""
   @Nls
-  abstract fun getSecondaryText(value: T): String?
-  abstract fun getIcon(value: T): Icon?
+  open fun getSecondaryText(value: T): String? = null
+  open fun getIcon(value: T): Icon? = null
 
-  open fun customize(item: SimpleColoredComponent, value: T) {
+  open fun customize(item: SimpleColoredComponent, value: T, index: Int) {
     val text = getText(value)
     item.append(text)
 
@@ -86,7 +86,7 @@ abstract class GroupedComboBoxRenderer<T>(private val combo: ComboBox<T>) : Grou
                                             cellHasFocus: Boolean): Component {
     coloredComponent.apply {
       clear()
-      customize(this, value)
+      customize(this, value, index)
     }
 
     mySeparatorComponent.apply {