More Windows window class logic simplification. This will be needed for read-only TextFields, next.

common_windows.c

@@ -45,6 +45,39 @@ void *getWindowData(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT
 	return data;
 }
 
+// this is a helper function that takes the logic of determining window classes and puts it all in one place
+// there are a number of places where we need to know what window class an arbitrary handle has
+// theoretically we could use the class atom to avoid a _wcsicmp()
+// however, raymond chen advises against this - http://blogs.msdn.com/b/oldnewthing/archive/2004/10/11/240744.aspx (and we're not in control of the Tab class, before you say anything)
+// usage: windowClassOf(hwnd, L"class 1", L"class 2", ..., NULL)
+int windowClassOf(HWND hwnd, ...)
+{
+// MSDN says 256 is the maximum length of a class name; add a few characters just to be safe (because it doesn't say whether this includes the terminating null character)
+#define maxClassName 260
+	WCHAR classname[maxClassName + 1];
+	va_list ap;
+	WCHAR *curname;
+	int i;
+
+	if (GetClassNameW(hwnd, classname, maxClassName) == 0)
+		xpanic("error getting name of window class in windowClassOf()", GetLastError());
+	va_start(ap, hwnd);
+	i = 0;
+	for (;;) {
+		curname = va_arg(ap, WCHAR *);
+		if (curname == NULL)
+			break;
+		if (_wcsicmp(classname, curname) == 0) {
+			va_end(ap);
+			return i;
+		}
+		i++;
+	}
+	// no match
+	va_end(ap);
+	return -1;
+}
+
 /*
 all container windows (including the message-only window, hence this is not in container_windows.c) have to call the sharedWndProc() to ensure messages go in the right place and control colors are handled properly
 */
@@ -100,7 +133,6 @@ void paintControlBackground(HWND hwnd, HDC dc)
 	HWND parent;
 	RECT r;
 	POINT p, pOrig;
-	WCHAR classname[maxClassName + 1] = L"";
 
 	parent = hwnd;
 	for (;;) {
@@ -110,10 +142,8 @@ void paintControlBackground(HWND hwnd, HDC dc)
 		// wine sends these messages early, yay...
 		if (parent == msgwin)
 			return;
-		if (GetClassNameW(parent, classname, maxClassName) == 0)
-			xpanic("error getting name of focused window class in paintControlBackground()", GetLastError());
 		// skip groupboxes; they're (supposed to be) transparent
-		if (_wcsicmp(classname, L"button") != 0)
+		if (windowClassOf(parent, L"button", NULL) != 0)
 			break;
 	}
 	if (GetWindowRect(hwnd, &r) == 0)

uitask_windows.c

@@ -59,7 +59,6 @@ void uimsgloop(void)
 	MSG msg;
 	int res;
 	HWND active, focus;
-	WCHAR classchk[maxClassName + 1];
 	BOOL dodlgmessage;
 
 	for (;;) {
@@ -80,12 +79,11 @@ void uimsgloop(void)
 		// as for Tabs, we can't have both WS_TABSTOP and WS_EX_CONTROLPARENT set at the same time, so we hotswap the two styles to get the behavior we want
 		focus = GetFocus();
 		if (focus != NULL) {
-			if (GetClassNameW(focus, classchk, maxClassName) == 0)
+			switch (windowClassOf(focus, areaWindowClass, WC_TABCONTROLW, NULL)) {
-				xpanic("error getting name of focused window class for Area check", GetLastError());
+			case 0:		// areaWindowClass
-			if (_wcsicmp(classchk, areaWindowClass) == 0) {
 				uimsgloop_area(active, focus, &msg);
 				continue;
-			} else if (_wcsicmp(classchk, WC_TABCONTROL) == 0) {
+			case 1:		// WC_TABCONTROLW
 				uimsgloop_tab(active, focus, &msg);
 				continue;
 			}

winapi_windows.h

@@ -23,6 +23,7 @@
 #include <windowsx.h>
 #include <vsstyle.h>
 #include <vssym32.h>
+#include <stdarg.h>
 
 // global messages unique to everything
 enum {
@@ -41,13 +42,6 @@ enum {
 	msgOpenFileDone,
 };
 
-// there are a number of places where we need to know what window class an arbitrary handle has
-// theoretically we could use the class atom to avoid a _wcsicmp()
-// however, raymond chen advises against this - http://blogs.msdn.com/b/oldnewthing/archive/2004/10/11/240744.aspx (and we're not in control of the Tab class, before you say anything)
-// MSDN says 256 is the maximum length of a class name; add a few characters just to be safe (because it doesn't say whether this includes the terminating null character)
-// TODO localize this to a helper function
-#define maxClassName 260
-
 // uitask_windows.c
 extern void uimsgloop(void);
 extern void issue(void *);
@@ -112,6 +106,7 @@ extern void getWindowText(HWND, WPARAM, LPWSTR);
 extern void setWindowText(HWND, LPWSTR);
 extern void updateWindow(HWND);
 extern void *getWindowData(HWND, UINT, WPARAM, LPARAM, LRESULT *);
+extern int windowClassOf(HWND, ...);
 extern BOOL sharedWndProc(HWND, UINT, WPARAM, LPARAM, LRESULT *);
 extern void paintControlBackground(HWND, HDC);