From 9bb9eda302ba20ce875ba702003458807da2003e Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Thu, 4 Apr 2013 19:09:34 +0200
Subject: [PATCH] Dynamically change prompt color for regex prompt depending on
 regex validity

---
 src/input_handler.cc | 16 ++++++++++++++++
 src/input_handler.hh |  1 +
 src/main.cc          | 15 +++++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/src/input_handler.cc b/src/input_handler.cc
index 1222b379..a8b161cb 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -433,6 +433,15 @@ public:
         m_callback(line, PromptEvent::Change, context());
     }
 
+    void set_prompt_colors(ColorPair colors)
+    {
+        if (colors != m_prompt_colors)
+        {
+            m_prompt_colors = colors;
+            display();
+        }
+    }
+
 private:
     void display() const
     {
@@ -799,6 +808,13 @@ void InputHandler::prompt(const String& prompt, ColorPair prompt_colors,
                                         completer, callback));
 }
 
+void InputHandler::set_prompt_colors(ColorPair prompt_colors)
+{
+    InputModes::Prompt* prompt = dynamic_cast<InputModes::Prompt*>(m_mode.get());
+    if (prompt)
+        prompt->set_prompt_colors(prompt_colors);
+}
+
 void InputHandler::menu(const memoryview<String>& choices,
                         MenuCallback callback)
 {
diff --git a/src/input_handler.hh b/src/input_handler.hh
index d4509752..7b2d771f 100644
--- a/src/input_handler.hh
+++ b/src/input_handler.hh
@@ -49,6 +49,7 @@ public:
     // not change the mode itself
     void prompt(const String& prompt, ColorPair prompt_colors,
                 Completer completer, PromptCallback callback);
+    void set_prompt_colors(ColorPair prompt_colors);
 
     // enter menu mode, callback is called on each selection change,
     // abort or validation with corresponding MenuEvent value
diff --git a/src/main.cc b/src/main.cc
index dd2f7f1b..cd89515d 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -326,6 +326,11 @@ void do_select_regex(Context& context)
                 if (not ex.empty())
                     context.editor().multi_select(std::bind(select_all_matches, _1, ex));
             }
+            else if (event == PromptEvent::Change)
+            {
+                const bool ok = Regex{str, boost::regex_constants::no_except}.status() == 0;
+                context.input_handler().set_prompt_colors(get_color(ok ? "Prompt" : "Error"));
+            }
         });
 }
 
@@ -343,6 +348,11 @@ void do_split_regex(Context& context)
                 if (not ex.empty())
                     context.editor().multi_select(std::bind(split_selection, _1, ex));
             }
+            else if (event == PromptEvent::Change)
+            {
+                const bool ok = Regex{str, boost::regex_constants::no_except}.status() == 0;
+                context.input_handler().set_prompt_colors(get_color(ok ? "Prompt" : "Error"));
+            }
         });
 }
 
@@ -393,6 +403,11 @@ void do_keep(Context& context)
                     throw runtime_error("no selections remaining");
                 editor.select(std::move(keep));
             }
+            else if (event == PromptEvent::Change)
+            {
+                const bool ok = Regex{str, boost::regex_constants::no_except}.status() == 0;
+                context.input_handler().set_prompt_colors(get_color(ok ? "Prompt" : "Error"));
+            }
         });
 }