From 0bd3a9a573b599aef1a61c371e1b1f166bcb7e3c Mon Sep 17 00:00:00 2001
From: Konstantin Kolosovsky <konstantin.kolosovsky@jetbrains.com>
Date: Mon, 8 Jan 2018 02:10:31 +0300
Subject: [PATCH] Show option button popup on down arrow pressed

---
 .../com/intellij/ui/components/JBOptionButton.java    | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/platform/platform-api/src/com/intellij/ui/components/JBOptionButton.java b/platform/platform-api/src/com/intellij/ui/components/JBOptionButton.java
index b6dcf1bcf89d..b1871d81adac 100644
--- a/platform/platform-api/src/com/intellij/ui/components/JBOptionButton.java
+++ b/platform/platform-api/src/com/intellij/ui/components/JBOptionButton.java
@@ -16,6 +16,8 @@
 package com.intellij.ui.components;
 
 import com.intellij.icons.AllIcons;
+import com.intellij.openapi.actionSystem.CustomShortcutSet;
+import com.intellij.openapi.project.DumbAwareAction;
 import com.intellij.openapi.ui.GraphicsConfig;
 import com.intellij.openapi.ui.JBMenuItem;
 import com.intellij.openapi.ui.JBPopupMenu;
@@ -31,6 +33,7 @@ import javax.swing.*;
 import javax.swing.event.PopupMenuEvent;
 import javax.swing.event.PopupMenuListener;
 import java.awt.*;
+import java.awt.event.KeyEvent;
 import java.awt.event.MouseEvent;
 import java.util.HashSet;
 import java.util.Set;
@@ -54,6 +57,8 @@ public class JBOptionButton extends JButton implements Weighted {
 
     myOptions = options;
     applyOptions();
+
+    installShowPopupShortcut();
   }
 
   @Override
@@ -179,6 +184,11 @@ public class JBOptionButton extends JButton implements Weighted {
     repaint();
   }
 
+  private void installShowPopupShortcut() {
+    DumbAwareAction.create(e -> showPopup(null, true))
+      .registerCustomShortcutSet(new CustomShortcutSet(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0)), this);
+  }
+
   private void applyOptions() {
     myPopup = fillMenu();
   }
@@ -187,7 +197,6 @@ public class JBOptionButton extends JButton implements Weighted {
     return myOptions == null || myOptions.length == 0;
   }
 
-
   private JPopupMenu fillMenu() {
     final JPopupMenu result = new JBPopupMenu();
     if (isSimpleButton()) {