From c5e5fbd909ed4bd3e788cb84cec85aee7302dedf Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Wed, 6 May 2015 18:05:07 -0400
Subject: [PATCH] Laid the foundation for proper tab navigation in uiTabs.

---
 ui_windows.h             |  6 ++++++
 windows/newcontrol.c     |  4 ++++
 windows/tab.c            | 10 +++++++++-
 windows/uipriv_windows.h |  4 ++++
 windows/util.c           | 20 ++++++++++++++++++++
 5 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/ui_windows.h b/ui_windows.h
index 7c24a4d1..de8dcec9 100644
--- a/ui_windows.h
+++ b/ui_windows.h
@@ -56,6 +56,7 @@ extern void uiWindowsControlSetText(uiControl *, const char *);
 
 struct uiControlSysFuncParams {
 	int Func;
+	BOOL HasTabStops;
 };
 
 enum {
@@ -63,6 +64,11 @@ enum {
 	// These are needed because while disabling a parent window does cause children to stop receiving events, they are not shown as disabled, which is not what we want.
 	uiWindowsSysFuncContainerEnable,
 	uiWindowsSysFuncContainerDisable,
+	// This is interpreted by controls that are tab stops; the control should set HasTabStops to TRUE if so, and *LEAVE IT ALONE* if not.
+	// You only need this if implementing your own uiControl.
+	// Controls created with uiWindowsMakeControl() check for the presence of WS_TABSTOP.
+	// The name is "has tab stops" because it is used by uiTabs to say "does the current tab page have tab stops?".
+	uiWindowsSysFuncHasTabStops,
 };
 
 #endif
diff --git a/windows/newcontrol.c b/windows/newcontrol.c
index a19b8cc8..5fe97b71 100644
--- a/windows/newcontrol.c
+++ b/windows/newcontrol.c
@@ -118,6 +118,10 @@ static void singleSysFunc(uiControl *c, uiControlSysFuncParams *p)
 		s->containerDisabled = 1;
 		EnableWindow(s->hwnd, FALSE);
 		return;
+	case uiWindowsSysFuncHasTabStops:
+		if ((getStyle(s->hwnd) & WS_TABSTOP) != 0)
+			p->HasTabStops = TRUE;
+		return;
 	}
 	complain("unknown p->Func %d in singleSysFunc()", p->Func);
 }
diff --git a/windows/tab.c b/windows/tab.c
index 2a9e407f..0c5874ae 100644
--- a/windows/tab.c
+++ b/windows/tab.c
@@ -131,6 +131,14 @@ static void tabSysFunc(uiControl *c, uiControlSysFuncParams *p)
 	struct tabPage *page;
 	uintmax_t i;
 
+	// we handle tab stops specially
+	if (p->Func == uiWindowsSysFuncHasTabStops) {
+		// if there are no tabs, it is not a tab stop
+		if (t->pages->len != 0)
+			p->HasTabStops = TRUE;
+		return;
+	}
+	// otherwise distribute it throughout all pages
 	(*(t->baseSysFunc))(uiControl(t), p);
 	for (i = 0; i < t->pages->len; i++) {
 		page = ptrArrayIndex(t->pages, struct tabPage *, i);
@@ -324,7 +332,7 @@ uiTab *uiNewTab(void)
 	p.dwExStyle = 0;		// don't set WS_EX_CONTROLPARENT yet; we do that dynamically in the message loop (see main_windows.c)
 	p.lpClassName = WC_TABCONTROLW;
 	p.lpWindowName = L"";
-	p.dwStyle = TCS_TOOLTIPS | WS_TABSTOP;
+	p.dwStyle = TCS_TOOLTIPS | WS_TABSTOP;		// start with this; we will alternate between this and WS_EX_CONTROLPARENT as needed (see main.c and msgHasTabStops above)
 	p.hInstance = hInstance;
 	p.useStandardControlFont = TRUE;
 	p.onWM_COMMAND = onWM_COMMAND;
diff --git a/windows/uipriv_windows.h b/windows/uipriv_windows.h
index 1d1fa4a4..26345c18 100644
--- a/windows/uipriv_windows.h
+++ b/windows/uipriv_windows.h
@@ -52,6 +52,10 @@ extern HBRUSH hollowBrush;
 // util.c
 extern int windowClassOf(HWND, ...);
 extern void mapWindowRect(HWND, HWND, RECT *);
+extern DWORD getStyle(HWND);
+extern void setStyle(HWND, DWORD);
+extern DWORD getExStyle(HWND);
+extern void setExStyle(HWND, DWORD);
 
 // text.c
 extern WCHAR *toUTF16(const char *);
diff --git a/windows/util.c b/windows/util.c
index 8cb48837..caac4dd8 100644
--- a/windows/util.c
+++ b/windows/util.c
@@ -95,3 +95,23 @@ void mapWindowRect(HWND from, HWND to, RECT *r)
 			logLastError("error calling MapWindowRect() in mapWindowRect()");
 	}
 }
+
+DWORD getStyle(HWND hwnd)
+{
+	return (DWORD) GetWindowLongPtrW(hwnd, GWL_STYLE);
+}
+
+void setStyle(HWND hwnd, DWORD style)
+{
+	SetWindowLongPtrW(hwnd, GWL_STYLE, (LONG_PTR) style);
+}
+
+DWORD getExStyle(HWND hwnd)
+{
+	return (DWORD) GetWindowLongPtrW(hwnd, GWL_EXSTYLE);
+}
+
+void setExStyle(HWND hwnd, DWORD exstyle)
+{
+	SetWindowLongPtrW(hwnd, GWL_EXSTYLE, (LONG_PTR) exstyle);
+}