From 68e95eba382c972aafde02ead2cd2426a8a92480 Mon Sep 17 00:00:00 2001
From: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Date: Fri, 28 Feb 2020 12:24:31 +0900
Subject: [PATCH] Add EnableColorsStdout

---
 colorable_appengine.go |  8 ++++++++
 colorable_others.go    |  8 ++++++++
 colorable_windows.go   | 21 +++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/colorable_appengine.go b/colorable_appengine.go
index 0b0aef8..1f7806f 100644
--- a/colorable_appengine.go
+++ b/colorable_appengine.go
@@ -27,3 +27,11 @@ func NewColorableStdout() io.Writer {
 func NewColorableStderr() io.Writer {
 	return os.Stderr
 }
+
+// EnableColorsStdout enable colors if possible.
+func EnableColorsStdout(enabled *bool) func() {
+	if enabled != nil {
+		*enabled = true
+	}
+	return func() {}
+}
diff --git a/colorable_others.go b/colorable_others.go
index 3fb771d..08cbd1e 100644
--- a/colorable_others.go
+++ b/colorable_others.go
@@ -28,3 +28,11 @@ func NewColorableStdout() io.Writer {
 func NewColorableStderr() io.Writer {
 	return os.Stderr
 }
+
+// EnableColorsStdout enable colors if possible.
+func EnableColorsStdout(enabled *bool) func() {
+	if enabled != nil {
+		*enabled = true
+	}
+	return func() {}
+}
diff --git a/colorable_windows.go b/colorable_windows.go
index d172cc3..b9e9363 100644
--- a/colorable_windows.go
+++ b/colorable_windows.go
@@ -81,6 +81,7 @@ var (
 	procSetConsoleCursorInfo       = kernel32.NewProc("SetConsoleCursorInfo")
 	procSetConsoleTitle            = kernel32.NewProc("SetConsoleTitleW")
 	procGetConsoleMode             = kernel32.NewProc("GetConsoleMode")
+	procSetConsoleMode             = kernel32.NewProc("SetConsoleMode")
 	procCreateConsoleScreenBuffer  = kernel32.NewProc("CreateConsoleScreenBuffer")
 )
 
@@ -1010,3 +1011,23 @@ func n256setup() {
 		n256backAttr[i] = c.backgroundAttr()
 	}
 }
+
+// EnableColorsStdout enable colors if possible.
+func EnableColorsStdout(enabled *bool) func() {
+	var mode uint32
+	h := os.Stdout.Fd()
+	if r, _, _ := procGetConsoleMode.Call(h, uintptr(unsafe.Pointer(&mode))); r != 0 {
+		if r, _, _ = procSetConsoleMode.Call(h, uintptr(mode|cENABLE_VIRTUAL_TERMINAL_PROCESSING)); r != 0 {
+			if enabled != nil {
+				*enabled = true
+			}
+			return func() {
+				procSetConsoleMode.Call(h, uintptr(mode))
+			}
+		}
+	}
+	if enabled != nil {
+		*enabled = true
+	}
+	return func() {}
+}