From f131ac432bceb9129bf62af88cdf6e301e85a488 Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Mon, 18 Aug 2014 22:45:40 -0400
Subject: [PATCH] Implemented the beginning of a potential solution to the
 Windows modality issue.

---
 redo/winapi_windows.h  |  2 ++
 redo/window_windows.c  |  8 +++++++-
 redo/window_windows.go | 19 +++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/redo/winapi_windows.h b/redo/winapi_windows.h
index e888c99..199f838 100644
--- a/redo/winapi_windows.h
+++ b/redo/winapi_windows.h
@@ -32,6 +32,8 @@ enum {
 	msgAreaSizeChanged,
 	msgAreaRepaintAll,
 	msgTabCurrentTabHasChildren,
+	msgBeginModal,
+	msgEndModal,
 };
 
 // uitask_windows.c
diff --git a/redo/window_windows.c b/redo/window_windows.c
index 0db16bb..8a042e0 100644
--- a/redo/window_windows.c
+++ b/redo/window_windows.c
@@ -11,12 +11,18 @@ static LRESULT CALLBACK windowWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARA
 	RECT r;
 	LRESULT lResult;
 
-	data = getWindowData(hwnd, uMsg, wParam, lParam, &lResult, storeWindowHWND);
+	data = (void *) getWindowData(hwnd, uMsg, wParam, lParam, &lResult, storeWindowHWND);
 	if (data == NULL)
 		return lResult;
 	if (sharedWndProc(hwnd, uMsg, wParam, lParam, &lResult))
 		return lResult;
 	switch (uMsg) {
+	case msgBeginModal:
+		windowBeginModal(data);
+		return 0;
+	case msgEndModal:
+		windowEndModal(data);
+		return 0;
 	case WM_SIZE:
 		if (GetClientRect(hwnd, &r) == 0)
 			xpanic("error getting client rect for Window in WM_SIZE", GetLastError());
diff --git a/redo/window_windows.go b/redo/window_windows.go
index 60f89d1..5789df8 100644
--- a/redo/window_windows.go
+++ b/redo/window_windows.go
@@ -14,6 +14,7 @@ import "C"
 type window struct {
 	hwnd		C.HWND
 	shownbefore	bool
+	modallevel	int
 
 	closing		*event
 
@@ -99,3 +100,21 @@ func windowClosing(data unsafe.Pointer) {
 		C.windowClose(w.hwnd)
 	}
 }
+
+//export windowBeginModal
+func windowBeginModal(data unsafe.Pointer) {
+	w := (*window)(data)
+	C.EnableWindow(w.hwnd, C.FALSE)
+	w.modallevel++
+}
+
+//export windowEndModal
+func windowEndModal(data unsafe.Pointer) {
+	w := (*window)(data)
+	w.modallevel--
+	if w.modallevel == 0 {
+		C.EnableWindow(w.hwnd, C.TRUE)
+	} else if w.modallevel < 0 {
+		panic("window begin/end modal mismatch")
+	}
+}