1 files changed, 165 insertions, 0 deletions
diff --git a/prev/common_windows.c b/prev/common_windows.c
new file mode 100644
index 0000000..d1447f6
--- /dev/null
+++ b/prev/common_windows.c
@@ -0,0 +1,165 @@
+// 17 july 2014
+
+#include "winapi_windows.h"
+#include "_cgo_export.h"
+
+LRESULT getWindowTextLen(HWND hwnd)
+{
+	return SendMessageW(hwnd, WM_GETTEXTLENGTH, 0, 0);
+}
+
+void getWindowText(HWND hwnd, WPARAM n, LPWSTR buf)
+{
+	SetLastError(0);
+	if (SendMessageW(hwnd, WM_GETTEXT, n + 1, (LPARAM) buf) != (LRESULT) n)
+		xpanic("WM_GETTEXT did not copy the correct number of characters out", GetLastError());
+}
+
+void setWindowText(HWND hwnd, LPWSTR text)
+{
+	switch (SendMessageW(hwnd, WM_SETTEXT, 0, (LPARAM) text)) {
+	case FALSE:
+		xpanic("WM_SETTEXT failed", GetLastError());
+	}
+}
+
+void updateWindow(HWND hwnd)
+{
+	if (UpdateWindow(hwnd) == 0)
+		xpanic("error calling UpdateWindow()", GetLastError());
+}
+
+void *getWindowData(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT *lResult)
+{
+	CREATESTRUCTW *cs = (CREATESTRUCTW *) lParam;
+	void *data;
+
+	data = (void *) GetWindowLongPtrW(hwnd, GWLP_USERDATA);
+	if (data == NULL) {
+		// the lpParam is available during WM_NCCREATE and WM_CREATE
+		if (uMsg == WM_NCCREATE)
+			SetWindowLongPtrW(hwnd, GWLP_USERDATA, (LONG_PTR) (cs->lpCreateParams));
+		// act as if we're not ready yet, even during WM_NCCREATE (nothing important to the switch statement below happens here anyway)
+		*lResult = DefWindowProcW(hwnd, uMsg, wParam, lParam);
+	}
+	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
+*/
+
+/*
+all controls that have events receive the events themselves through subclasses
+to do this, all container windows (including the message-only window; see http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q104069) forward WM_COMMAND to each control with this function, WM_NOTIFY with forwardNotify, etc.
+*/
+static LRESULT forwardCommand(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+	HWND control = (HWND) lParam;
+
+	// don't generate an event if the control (if there is one) is unparented (a child of the message-only window)
+	if (control != NULL && IsChild(msgwin, control) == 0)
+		return SendMessageW(control, msgCOMMAND, wParam, lParam);
+	return DefWindowProcW(hwnd, uMsg, wParam, lParam);
+}
+
+static LRESULT forwardNotify(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+	NMHDR *nmhdr = (NMHDR *) lParam;
+	HWND control = nmhdr->hwndFrom;
+
+	// don't generate an event if the control (if there is one) is unparented (a child of the message-only window)
+	if (control != NULL && IsChild(msgwin, control) == 0)
+		return SendMessageW(control, msgNOTIFY, wParam, lParam);
+	return DefWindowProcW(hwnd, uMsg, wParam, lParam);
+}
+
+BOOL sharedWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT *lResult)
+{
+	switch (uMsg) {
+	case WM_COMMAND:
+		*lResult = forwardCommand(hwnd, uMsg, wParam, lParam);
+		return TRUE;
+	case WM_NOTIFY:
+		*lResult = forwardNotify(hwnd, uMsg, wParam, lParam);
+		return TRUE;
+	case WM_CTLCOLORSTATIC:
+	case WM_CTLCOLORBTN:
+		// read-only TextFields and Textboxes are exempt
+		// this is because read-only edit controls count under WM_CTLCOLORSTATIC
+		if (windowClassOf((HWND) lParam, L"edit", NULL) == 0)
+			if (textfieldReadOnly((HWND) lParam))
+				return FALSE;
+		if (SetBkMode((HDC) wParam, TRANSPARENT) == 0)
+			xpanic("error setting transparent background mode to Labels", GetLastError());
+		paintControlBackground((HWND) lParam, (HDC) wParam);
+		*lResult = (LRESULT) hollowBrush;
+		return TRUE;
+	}
+	return FALSE;
+}
+
+void paintControlBackground(HWND hwnd, HDC dc)
+{
+	HWND parent;
+	RECT r;
+	POINT p, pOrig;
+
+	parent = hwnd;
+	for (;;) {
+		parent = GetParent(parent);
+		if (parent == NULL)
+			xpanic("error getting parent control of control in paintControlBackground()", GetLastError());
+		// wine sends these messages early, yay...
+		if (parent == msgwin)
+			return;
+		// skip groupboxes; they're (supposed to be) transparent
+		if (windowClassOf(parent, L"button", NULL) != 0)
+			break;
+	}
+	if (GetWindowRect(hwnd, &r) == 0)
+		xpanic("error getting control's window rect in paintControlBackground()", GetLastError());
+	// the above is a window rect; convert to client rect
+	p.x = r.left;
+	p.y = r.top;
+	if (ScreenToClient(parent, &p) == 0)
+		xpanic("error getting client origin of control in paintControlBackground()", GetLastError());
+	if (SetWindowOrgEx(dc, p.x, p.y, &pOrig) == 0)
+		xpanic("error moving window origin in paintControlBackground()", GetLastError());
+	SendMessageW(parent, WM_PRINTCLIENT, (WPARAM) dc, PRF_CLIENT);
+	if (SetWindowOrgEx(dc, pOrig.x, pOrig.y, NULL) == 0)
+		xpanic("error resetting window origin in paintControlBackground()", GetLastError());
+}