Added message boxes and adjusted init() accordingly to display one on failure.

1 files changed, 98 insertions, 0 deletions

diff --git a/dialog_windows.go b/dialog_windows.go
new file mode 100644
index 0000000..d741c53
--- /dev/null
+++ b/dialog_windows.go
@@ -0,0 +1,98 @@
+// 7 february 2014
+package main
+
+import (
+	"fmt"
+	"syscall"
+	"unsafe"
+)
+
+// MessageBox button types.
+const (
+	_MB_ABORTRETRYIGNORE = 0x00000002
+	_MB_CANCELTRYCONTINUE = 0x00000006
+	_MB_HELP = 0x00004000
+	_MB_OK = 0x00000000
+	_MB_OKCANCEL = 0x00000001
+	_MB_RETRYCANCEL = 0x00000005
+	_MB_YESNO = 0x00000004
+	_MB_YESNOCANCEL = 0x00000003
+)
+
+// MessageBox icon types.
+const (
+	_MB_ICONEXCLAMATION = 0x00000030
+	_MB_ICONWARNING = 0x00000030
+	_MB_ICONINFORMATION = 0x00000040
+	_MB_ICONASTERISK = 0x00000040
+	_MB_ICONQUESTION = 0x00000020
+	_MB_ICONSTOP = 0x00000010
+	_MB_ICONERROR = 0x00000010
+	_MB_ICONHAND = 0x00000010
+)
+
+// MessageBox default button types.
+const (
+	_MB_DEFBUTTON1 = 0x00000000
+	_MB_DEFBUTTON2 = 0x00000100
+	_MB_DEFBUTTON3 = 0x00000200
+	_MB_DEFBUTTON4 = 0x00000300
+)
+
+// MessageBox modality types.
+const (
+	_MB_APPLMODAL = 0x00000000
+	_MB_SYSTEMMODAL = 0x00001000
+	_MB_TASKMODAL = 0x00002000
+)
+
+// MessageBox miscellaneous types.
+const (
+	_MB_DEFAULT_DESKTOP_ONLY = 0x00020000
+	_MB_RIGHT = 0x00080000
+	_MB_RTLREADING = 0x00100000
+	_MB_SETFOREGROUND = 0x00010000
+	_MB_TOPMOST = 0x00040000
+	_MB_SERVICE_NOTIFICATION = 0x00200000
+)
+
+// MessageBox return values.
+const (
+	_IDABORT = 3
+	_IDCANCEL = 2
+	_IDCONTINUE = 11
+	_IDIGNORE = 5
+	_IDNO = 7
+	_IDOK = 1
+	_IDRETRY = 4
+	_IDTRYAGAIN = 10
+	_IDYES = 6
+)
+
+var (
+	_messageBox = user32.NewProc("MessageBoxW")
+)
+
+func msgBox(lpText string, lpCaption string, uType uint32) (result int) {
+	r1, _, err := _messageBox.Call(
+		uintptr(_NULL),
+		uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(lpText))),
+		uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(lpCaption))),
+		uintptr(uType))
+	if r1 == 0 {		// failure
+		panic(fmt.Sprintf("error displaying message box to user: %v\nstyle: 0x%08X\ntitle: %q\ntext:\n%s", err, uType, lpCaption, lpText))
+	}
+	return int(r1)
+}
+
+// MsgBox displays an informational message box to the user with just an OK button.
+func MsgBox(title string, textfmt string, args ...interface{}) {
+	// TODO add an icon?
+	msgBox(fmt.Sprintf(textfmt, args...), title, _MB_OK)
+}
+
+// MsgBoxError displays a message box to the user with just an OK button and an icon indicating an error.
+func MsgBoxError(title string, textfmt string, args ...interface{}) {
+	// TODO add an icon?
+	msgBox(fmt.Sprintf(textfmt, args...), title, _MB_OK | _MB_ERROR)
+}