From 78c909cc9ba87abc759767c11b34a9cccf8ef34c Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Fri, 30 May 2014 14:02:57 -0400
Subject: [PATCH] Added GetWindowLongPtr()/SetWindowLongPtr() generation to the
 windowsconstgen tool and the pregenerated files. This will be needed for when
 we get rid of creating a new window class for each Window/Area. Also did some
 minor cleanup to the windowsconstgen tool.

---
 tools/windowsconstgen.go    | 26 ++++++++++++++++++++++++--
 zconstants_windows_386.go   |  2 ++
 zconstants_windows_amd64.go |  2 ++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/tools/windowsconstgen.go b/tools/windowsconstgen.go
index 0617eb1..6be1b59 100644
--- a/tools/windowsconstgen.go
+++ b/tools/windowsconstgen.go
@@ -107,12 +107,31 @@ func preamble(pkg string) string {
 		"package " + pkg + "\n"
 }
 
+// for backwards compatibiilty reasons, Windows defines GetWindowLongPtr()/SetWindowLongPtr() as a macro which expands to GetWindowLong()/SetWindowLong() on 32-bit systems
+// we'll just simulate that here
+var gwlpNames = map[string]string{
+	"386":		"etWindowLong",
+	"amd64":		"etWindowLongPtr",
+}
+
+func printConst(f *os.File, goconst string, winconst string) {
+	fmt.Fprintf(f, "	fmt.Println(\"const %s =\", C.%s)\n", goconst, winconst)
+}
+
+func printGWLPName(f *os.File, which string, char string, targetarch string) {
+	fmt.Fprintf(f, "	fmt.Println(\"var %s = user32.NewProc(\\\"%s\\\")\")\n",
+		which, char + gwlpNames[targetarch])
+}
+
 func main() {
 	if len(os.Args) < 3 {
 		panic("usage: " + os.Args[0] + " path goarch [go-command-options...]")
 	}
 	pkgpath := os.Args[1]
 	targetarch := os.Args[2]
+	if _, ok := gwlpNames[targetarch]; !ok {
+		panic("unknown target windows/" + targetarch)
+	}
 	goopts := os.Args[3:]		// valid if len(os.Args) == 3; in that case this will just be a slice of length zero
 
 	pkg := getPackage(pkgpath)
@@ -163,12 +182,15 @@ func main() {
 	for _, ident := range consts {
 		if ident[0] == 'x' {
 			// hack name; strip the leading x (but not the _ after it) from the constant name but keep the value name unchanged
-			fmt.Fprintf(f, "	fmt.Println(\"const %s =\", C.%s)\n", ident[1:], ident)
+			printConst(f, ident[1:], ident)
 			continue
 		}
 		// not a hack name; strip the leading _ from the value name but keep the constant name unchanged
-		fmt.Fprintf(f, "	fmt.Println(\"const %s =\", C.%s)\n", ident, ident[1:])
+		printConst(f, ident, ident[1:])
 	}
+	// and now for _getWindowLongPtr/_setWindowLongPtr
+	printGWLPName(f, "_getWindowLongPtr", "G", targetarch)
+	printGWLPName(f, "_setWindowLongPtr", "S", targetarch)
 	fmt.Fprintf(f, "}\n")
 	f.Close()
 
diff --git a/zconstants_windows_386.go b/zconstants_windows_386.go
index 4427631..c1d88c2 100644
--- a/zconstants_windows_386.go
+++ b/zconstants_windows_386.go
@@ -162,3 +162,5 @@ const _IDC_ARROW = 32512
 const _IDI_APPLICATION = 32512
 const _INVALID_HANDLE_VALUE = 4294967295
 const _NULL = 0
+var _getWindowLongPtr = user32.NewProc("GetWindowLong")
+var _setWindowLongPtr = user32.NewProc("SetWindowLong")
diff --git a/zconstants_windows_amd64.go b/zconstants_windows_amd64.go
index 0274d3a..4d3c1c3 100644
--- a/zconstants_windows_amd64.go
+++ b/zconstants_windows_amd64.go
@@ -162,3 +162,5 @@ const _IDC_ARROW = 32512
 const _IDI_APPLICATION = 32512
 const _INVALID_HANDLE_VALUE = 18446744073709551615
 const _NULL = 0
+var _getWindowLongPtr = user32.NewProc("GetWindowLongPtr")
+var _setWindowLongPtr = user32.NewProc("SetWindowLongPtr")