Implemented Tab on Windows.

redo/comctl32_windows.c

@@ -35,7 +35,7 @@ DWORD initCommonControls(LPCWSTR manifest, char **errmsg)
 
 	ZeroMemory(&icc, sizeof (INITCOMMONCONTROLSEX));
 	icc.dwSize = sizeof (INITCOMMONCONTROLSEX);
-	icc.dwICC = ICC_PROGRESS_CLASS;
+	icc.dwICC = ICC_PROGRESS_CLASS | ICC_TAB_CLASSES;
 
 	comctl32 = LoadLibraryW(L"comctl32.dll");
 	if (comctl32 == NULL) {

redo/containers_windows.c

@@ -0,0 +1,64 @@
+/* 25 july 2014 */
+
+#include "winapi_windows.h"
+#include "_cgo_export.h"
+
+/* provided for cgo's benefit */
+LPCWSTR xWC_TABCONTROL = WC_TABCONTROL;
+
+static LRESULT CALLBACK tabSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR id, DWORD_PTR data)
+{
+	NMHDR *nmhdr = (NMHDR *) lParam;
+	LRESULT r;
+
+	switch (uMsg) {
+	case msgNOTIFY:
+		switch (nmhdr->code) {
+		case TCN_SELCHANGING:
+			r = SendMessageW(hwnd, TCM_GETCURSEL, 0, 0);
+			if (r == (LRESULT) -1)	/* no tab currently selected */
+				return FALSE;
+			tabChanging((void *) data, r);
+			return FALSE;			/* allow change */
+		case TCN_SELCHANGE:
+			tabChanged((void *) data, SendMessageW(hwnd, TCM_GETCURSEL, 0, 0));
+			return 0;
+		}
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	case WM_NCDESTROY:
+		if ((*fv_RemoveWindowSubclass)(hwnd, tabSubProc, id) == FALSE)
+			xpanic("error removing Tab subclass (which was for its own event handler)", GetLastError());
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	default:
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
+	}
+	xmissedmsg("Tab", "tabSubProc()", uMsg);
+	return 0;		/* unreached */
+}
+
+void setTabSubclass(HWND hwnd, void *data)
+{
+	if ((*fv_SetWindowSubclass)(hwnd, tabSubProc, 0, (DWORD_PTR) data) == FALSE)
+		xpanic("error subclassing Tab to give it its own event handler", GetLastError());
+}
+
+void tabAppend(HWND hwnd, LPCWSTR name)
+{
+	TCITEM item;
+	LRESULT n;
+
+	ZeroMemory(&item, sizeof (TCITEM));
+	item.mask = TCIF_TEXT;
+	/* TODO the C means const; change everything to use LPWSTR instead */
+	item.pszText = name;
+	/* MSDN's example code uses the first invalid index directly for this */
+	n = SendMessageW(hwnd, TCM_GETITEMCOUNT, 0, 0);
+	if (SendMessageW(hwnd, TCM_INSERTITEM, (WPARAM) n, (LPARAM) (&item)) == (LRESULT) -1)
+		xpanic("error adding tab to Tab", GetLastError());
+}
+
+extern void tabGetContentRect(HWND hwnd, RECT *r)
+{
+	/* not &r; already a pointer (thanks MindChild in irc.efnet.net/#winprog for spotting my failure) */
+	SendMessageW(hwnd, TCM_ADJUSTRECT, FALSE, (LPARAM) r);
+}

redo/containers_windows.go

@@ -0,0 +1,93 @@
+// 25 july 2014
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "winapi_windows.h"
+import "C"
+
+/*
+On Windows, container controls are just regular controls; their children have to be children of the parent window, and changing the contents of a switching container (such as a tab control) must be done manually. Mind the odd code here.
+
+TODO
+- make sure all tabs cannot be deselected (that is, make sure the current tab can never have index -1)
+*/
+
+type tab struct {
+	*widgetbase
+	tabs			[]Control
+	curparent		*window
+}
+
+func newTab() Tab {
+	w := newWidget(C.xWC_TABCONTROL,
+		C.TCS_TOOLTIPS | C.WS_TABSTOP,
+		0)
+	t := &tab{
+		widgetbase:	w,
+	}
+	C.controlSetControlFont(w.hwnd)
+	C.setTabSubclass(w.hwnd, unsafe.Pointer(t))
+	return t
+}
+
+func (t *tab) unparent() {
+	t.widgetbase.unparent()
+	for _, c := range t.tabs {
+		c.unparent()
+	}
+	t.curparent = nil
+}
+
+func (t *tab) parent(win *window) {
+	t.widgetbase.parent(win)
+	for _, c := range t.tabs {
+		c.parent(win)
+	}
+	t.curparent = win
+}
+
+func (t *tab) Append(name string, control Control) {
+	t.tabs = append(t.tabs, control)
+	if t.curparent == nil {
+		control.unparent()
+	} else {
+		control.parent(t.curparent)
+	}
+	C.tabAppend(t.hwnd, toUTF16(name))
+}
+
+//export tabChanging
+func tabChanging(data unsafe.Pointer, current C.LRESULT) {
+	t := (*tab)(data)
+	t.tabs[int(current)].containerHide()
+}
+
+//export tabChanged
+func tabChanged(data unsafe.Pointer, new C.LRESULT) {
+	t := (*tab)(data)
+	t.tabs[int(new)].containerShow()
+}
+
+// a tab control contains other controls; size appropriately
+func (t *tab) allocate(x int, y int, width int, height int, d *sizing) []*allocation {
+	var r C.RECT
+
+	// first, append the tab control itself
+	a := t.widgetbase.allocate(x, y, width, height, d)
+	// now figure out what the rect for each child is
+	r.left = C.LONG(x)				// load rect with existing values
+	r.top = C.LONG(y)
+	r.right = C.LONG(x + width)
+	r.bottom = C.LONG(y + height)
+	C.tabGetContentRect(t.hwnd, &r)
+	// and allocate
+	// don't allocate to just hte current tab; allocate to all tabs!
+	for _, c := range t.tabs {
+		a = append(a, c.allocate(int(r.left), int(r.top), int(r.right - r.left), int(r.bottom - r.top), d)...)
+	}
+	return a
+}

redo/controls_windows.c

@@ -50,6 +50,17 @@ LRESULT forwardCommand(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 	return DefWindowProcW(hwnd, uMsg, wParam, lParam);
 }
 
+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);
+}
+
 static LRESULT CALLBACK buttonSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR id, DWORD_PTR data)
 {
 	switch (uMsg) {

redo/uitask_windows.c

@@ -37,6 +37,8 @@ static LRESULT CALLBACK msgwinproc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM l
 	switch (uMsg) {
 	case WM_COMMAND:
 		return forwardCommand(hwnd, uMsg, wParam, lParam);
+	case WM_NOTIFY:
+		return forwardNotify(hwnd, uMsg, wParam, lParam);
 	case msgRequest:
 		doissue((void *) lParam);
 		return 0;

redo/uitask_windows.go

@@ -8,7 +8,7 @@ import (
 	"unsafe"
 )
 
-// #cgo LDFLAGS: -luser32 -lkernel32 -lgdi32
+// #cgo LDFLAGS: -luser32 -lkernel32 -lgdi32 -luxtheme
 // #include "winapi_windows.h"
 import "C"
 

redo/winapi_windows.h

@@ -17,11 +17,13 @@
 #include <windows.h>
 #include <commctrl.h>
 #include <stdint.h>
+#include <uxtheme.h>
 
 /* global messages unique to everything */
 enum {
 	msgRequest = WM_APP + 1,		/* + 1 just to be safe */
 	msgCOMMAND,				/* WM_COMMAND proxy; see forwardCommand() in controls_windows.go */
+	msgNOTIFY,					/* WM_NOTIFY proxy */
 };
 
 /* uitask_windows.c */
@@ -42,6 +44,7 @@ extern HWND newWidget(LPCWSTR, DWORD, DWORD);
 extern void controlSetParent(HWND, HWND);
 extern void controlSetControlFont(HWND);
 extern LRESULT forwardCommand(HWND, UINT, WPARAM, LPARAM);
+extern LRESULT forwardNotify(HWND, UINT, WPARAM, LPARAM);
 extern void setButtonSubclass(HWND, void *);
 extern void setCheckboxSubclass(HWND, void *);
 extern BOOL checkboxChecked(HWND);
@@ -77,4 +80,10 @@ extern void setWindowText(HWND, LPCWSTR);
 extern void updateWindow(HWND);
 extern void storelpParam(HWND, LPARAM);
 
+/* containers_windows.go */
+extern LPCWSTR xWC_TABCONTROL;
+extern void setTabSubclass(HWND, void *);
+extern void tabAppend(HWND, LPCWSTR);
+extern void tabGetContentRect(HWND, RECT *);
+
 #endif

redo/window_windows.c

@@ -25,6 +25,8 @@ static LRESULT CALLBACK windowWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARA
 	switch (uMsg) {
 	case WM_COMMAND:
 		return forwardCommand(hwnd, uMsg, wParam, lParam);
+	case WM_NOTIFY:
+		return forwardNotify(hwnd, uMsg, wParam, lParam);
 	case WM_SIZE:
 		if (GetClientRect(hwnd, &r) == 0)
 			xpanic("error getting client rect for Window in WM_SIZE", GetLastError());

redo/window_windows.go

@@ -44,6 +44,11 @@ func newWindow(title string, width int, height int) *window {
 	if hwnd != w.hwnd {
 		panic(fmt.Errorf("inconsistency: hwnd returned by CreateWindowEx() (%p) and hwnd stored in window (%p) differ", hwnd, w.hwnd))
 	}
+	// TODO keep?
+	hresult := C.EnableThemeDialogTexture(w.hwnd, C.ETDT_ENABLE | C.ETDT_USETABTEXTURE)
+	if hresult != C.S_OK {
+		panic(fmt.Errorf("error setting tab background texture on Window; HRESULT: 0x%X", hresult))
+	}
 	return w
 }
 

redo/zz_test.go

@@ -20,7 +20,8 @@ func init() {
 		Do(func() {
 			w := NewWindow("Hello", 320, 240)
 			b := NewButton("There")
-			w.SetControl(b)
+			t := NewTab()
+			w.SetControl(t)
 			if *closeOnClick {
 				b.SetText("Click to Close")
 			}
@@ -40,14 +41,14 @@ func init() {
 					w.Close()
 					Stop()
 					done <- struct{}{}
-				} else {
+				}
+			})
+			t.Append("Button", b)
 			c := NewCheckbox("You Should Now See Me Instead")
-					w.SetControl(c)
+			t.Append("Checkbox", c)
 			c.OnClicked(func() {
 				w.SetTitle(fmt.Sprint(c.Checked()))
 			})
-				}
-			})
 			w.Show()
 		})
 		<-done