Add a simple GWIN window manager, Change the way GWIN visibility works

11 files changed, 461 insertions, 78 deletions

diff --git a/src/gfx.c b/src/gfx.c
index 2b307426..3856eea3 100644
--- a/src/gfx.c
+++ b/src/gfx.c
@@ -32,7 +32,7 @@ void DEPRECATED("Use gfxInit() instead") gdispInit() { gfxInit(); }
 
 /* These init functions are defined by each module but not published */
 extern void _gosInit(void);
-#if GFX_USE_GDISP && (GDISP_NEED_MULTITHREAD || GDISP_NEED_ASYNC)
+#if GFX_USE_GDISP
 	extern void _gdispInit(void);
 #endif
 #if GFX_USE_TDISP
diff --git a/src/gqueue/gqueue.c b/src/gqueue/gqueue.c
index d515a425..11d10c0a 100644
--- a/src/gqueue/gqueue.c
+++ b/src/gqueue/gqueue.c
@@ -21,6 +21,9 @@
  * @file    src/gqueue/gqueue.c
  * @brief   GQUEUE source file.
  */
+
+#include "gfx.h"
+
 #if GFX_USE_GQUEUE
 
 #if GQUEUE_NEED_ASYNC
@@ -34,7 +37,7 @@
 		gfxSystemLock();
 		if ((pi = pqueue->head))
 			pqueue->head = pi->next;
-		gfxSytemUnlock();
+		gfxSystemUnlock();
 		return pi;
 	}
 	void gfxQueueASyncPut(gfxQueueASync *pqueue, gfxQueueASyncItem *pitem) {
@@ -58,13 +61,15 @@
 		gfxSystemUnlock();
 	}
 	void gfxQueueASyncRemove(gfxQueueASync *pqueue, gfxQueueASyncItem *pitem) {
+		gfxQueueASyncItem *pi;
+
 		if (!pitem) return;
 		gfxSystemLock();
 		if (pqueue->head) {
 			if (pqueue->head == pitem) {
 				pqueue->head = pitem->next;
 			} else {
-				for(gfxQueueASyncItem *pi = pqueue->head; pi->next; pi = pi->next) {
+				for(pi = pqueue->head; pi->next; pi = pi->next) {
 					if (pi->next == pitem) {
 						pi->next = pitem->next;
 						if (pqueue->tail == pitem)
@@ -80,8 +85,10 @@
 		return pqueue->head == NULL;
 	}
 	bool_t gfxQueueASyncIsIn(gfxQueueASync *pqueue, gfxQueueASyncItem *pitem) {
+		gfxQueueASyncItem *pi;
+
 		gfxSystemLock();
-		for(gfxQueueASyncItem *pi = pqueue->head; pi; pi = pi->next) {
+		for(pi = pqueue->head; pi; pi = pi->next) {
 			if (pi == pitem) {
 				gfxSystemUnlock();
 				return TRUE;
@@ -132,13 +139,15 @@
 		gfxSemSignal(&pqueue->sem);
 	}
 	void gfxQueueGSyncRemove(gfxQueueGSync *pqueue, gfxQueueGSyncItem *pitem) {
+		gfxQueueGSyncItem *pi;
+
 		if (!pitem) return;
 		gfxSystemLock();
 		if (pqueue->head) {
 			if (pqueue->head == pitem) {
 				pqueue->head = pitem->next;
 			} else {
-				for(gfxQueueGSyncItem *pi = pqueue->head; pi->next; pi = pi->next) {
+				for(pi = pqueue->head; pi->next; pi = pi->next) {
 					if (pi->next == pitem) {
 						pi->next = pitem->next;
 						if (pqueue->tail == pitem)
@@ -154,8 +163,10 @@
 		return pqueue->head == NULL;
 	}
 	bool_t gfxQueueGSyncIsIn(gfxQueueGSync *pqueue, gfxQueueGSyncItem *pitem) {
+		gfxQueueGSyncItem *pi;
+
 		gfxSystemLock();
-		for(gfxQueueGSyncItem *pi = pqueue->head; pi; pi = pi->next) {
+		for(pi = pqueue->head; pi; pi = pi->next) {
 			if (pi == pitem) {
 				gfxSystemUnlock();
 				return TRUE;
@@ -214,6 +225,8 @@
 		return gfxSemWait(&pitem->sem, ms);
 	}
 	void gfxQueueFSyncRemove(gfxQueueFSync *pqueue, gfxQueueFSyncItem *pitem) {
+		gfxQueueFSyncItem *pi;
+
 		if (!pitem) return;
 		gfxSystemLock();
 		if (pqueue->head) {
@@ -225,7 +238,7 @@
 				gfxSemDestroy(&pitem->sem);
 				return;
 			}
-			for(gfxQueueFSyncItem *pi = pqueue->head; pi->next; pi = pi->next) {
+			for(pi = pqueue->head; pi->next; pi = pi->next) {
 				if (pi->next == pitem) {
 					pi->next = pitem->next;
 					if (pqueue->tail == pitem)
@@ -240,8 +253,10 @@
 		return pqueue->head == NULL;
 	}
 	bool_t gfxQueueFSyncIsIn(gfxQueueFSync *pqueue, gfxQueueFSyncItem *pitem) {
+		gfxQueueASyncItem *pi;
+
 		gfxSystemLock();
-		for(gfxQueueFSyncItem *pi = pqueue->head; pi; pi = pi->next) {
+		for(pi = pqueue->head; pi; pi = pi->next) {
 			if (pi == pitem) {
 				gfxSystemUnlock();
 				return TRUE;
diff --git a/src/gwin/button.c b/src/gwin/button.c
index 1ebc8ee5..83b81b03 100644
--- a/src/gwin/button.c
+++ b/src/gwin/button.c
@@ -40,6 +40,7 @@ static const gwidgetVMT buttonVMT = {
 	{
 		"Button",				// The classname
 		_gwidgetDestroy,		// The destroy routine
+		_gwidgetRedraw,			// The redraw routine
 		0,						// The after-clear routine
 	},
 	gwinButtonDraw_3D,		// The default drawing routine
@@ -94,14 +95,14 @@ static void SendButtonEvent(GWidgetObject *gw) {
 static void MouseDown(GWidgetObject *gw, coord_t x, coord_t y) {
 	(void) x; (void) y;
 	gw->g.flags |= GBUTTON_FLG_PRESSED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 }
 
 // A mouse up has occurred (it may or may not be over the button)
 static void MouseUp(GWidgetObject *gw, coord_t x, coord_t y) {
 	(void) x; (void) y;
 	gw->g.flags &= ~GBUTTON_FLG_PRESSED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 
 	#if !GWIN_BUTTON_LAZY_RELEASE
 		// If the mouse up was not over the button then cancel the event
@@ -116,14 +117,14 @@ static void MouseUp(GWidgetObject *gw, coord_t x, coord_t y) {
 static void ToggleOff(GWidgetObject *gw, uint16_t instance) {
 	(void) instance;
 	gw->g.flags &= ~GBUTTON_FLG_PRESSED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 }
 
 // A toggle on has occurred
 static void ToggleOn(GWidgetObject *gw, uint16_t instance) {
 	(void) instance;
 	gw->g.flags |= GBUTTON_FLG_PRESSED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 	// Trigger the event on button down (different than for mouse/touch)
 	SendButtonEvent(gw);
 }
diff --git a/src/gwin/checkbox.c b/src/gwin/checkbox.c
index d35f271c..893dab9c 100644
--- a/src/gwin/checkbox.c
+++ b/src/gwin/checkbox.c
@@ -33,6 +33,7 @@ static const gwidgetVMT checkboxVMT = {
 	{
 		"Checkbox",				// The classname
 		_gwidgetDestroy,		// The destroy routine
+		_gwidgetRedraw,			// The redraw routine
 		0,						// The after-clear routine
 	},
 	gwinCheckboxDraw_CheckOnLeft,	// The default drawing routine
@@ -78,7 +79,7 @@ static void SendCheckboxEvent(GWidgetObject *gw) {
 static void MouseDown(GWidgetObject *gw, coord_t x, coord_t y) {
 	(void) x; (void) y;
 	gw->g.flags ^= GCHECKBOX_FLG_CHECKED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 	SendCheckboxEvent(gw);
 }
 
@@ -86,7 +87,7 @@ static void MouseDown(GWidgetObject *gw, coord_t x, coord_t y) {
 static void ToggleOn(GWidgetObject *gw, uint16_t instance) {
 	(void) instance;
 	gw->g.flags ^= GCHECKBOX_FLG_CHECKED;
-	gwinDraw((GHandle)gw);
+	_gwidgetRedraw((GHandle)gw);
 	SendCheckboxEvent(gw);
 }
 
diff --git a/src/gwin/console.c b/src/gwin/console.c
index d9bda362..c4b2798d 100644
--- a/src/gwin/console.c
+++ b/src/gwin/console.c
@@ -61,11 +61,12 @@ static void AfterClear(GWindowObject *gh) {
 static const gwinVMT consoleVMT = {
 		"Console",				// The classname
 		0,						// The destroy routine
+		0,						// The redraw routine
 		AfterClear,				// The after-clear routine
 };
 
 GHandle gwinCreateConsole(GConsoleObject *gc, coord_t x, coord_t y, coord_t width, coord_t height) {
-	if (!(gc = (GConsoleObject *)_gwinInit((GWindowObject *)gc, x, y, width, height, sizeof(GConsoleObject), &consoleVMT)))
+	if (!(gc = (GConsoleObject *)_gwindowInit((GWindowObject *)gc, x, y, width, height, sizeof(GConsoleObject), &consoleVMT, GWIN_FLG_VISIBLE)))
 		return 0;
 	#if GFX_USE_OS_CHIBIOS && GWIN_CONSOLE_USE_BASESTREAM
 		gc->stream.vmt = &GWindowConsoleVMT;
diff --git a/src/gwin/graph.c b/src/gwin/graph.c
index 0ae9822b..393297e7 100644
--- a/src/gwin/graph.c
+++ b/src/gwin/graph.c
@@ -32,6 +32,7 @@ static const GGraphStyle GGraphDefaultStyle = {
 static const gwinVMT graphVMT = {
 		"Graph",				// The classname
 		0,						// The destroy routine
+		0,						// The redraw routine
 		0,						// The after-clear routine
 };
 
@@ -164,7 +165,7 @@ static void lineto(GGraphObject *gg, coord_t x0, coord_t y0, coord_t x1, coord_t
 }
 
 GHandle gwinCreateGraph(GGraphObject *gg, coord_t x, coord_t y, coord_t width, coord_t height) {
-	if (!(gg = (GGraphObject *)_gwinInit((GWindowObject *)gg, x, y, width, height, sizeof(GGraphObject), &graphVMT)))
+	if (!(gg = (GGraphObject *)_gwindowInit((GWindowObject *)gg, x, y, width, height, sizeof(GGraphObject), &graphVMT, GWIN_FLG_VISIBLE)))
 		return 0;
 	gg->xorigin = gg->yorigin = 0;
 	gg->lastx = gg->lasty = 0;
diff --git a/src/gwin/gwidget.c b/src/gwin/gwidget.c
index 3f23140c..773a715d 100644
--- a/src/gwin/gwidget.c
+++ b/src/gwin/gwidget.c
@@ -7,7 +7,7 @@
 
 #include "gfx.h"
 
-#if GFX_USE_GWIN
+#if GFX_USE_GWIN && GWIN_NEED_WIDGET
 
 #include <string.h>
 
@@ -24,7 +24,7 @@ static void gwidgetCallback(void *param, GEvent *pe) {
 	#define pde		((GEventDial *)pe)
 
 	// check if widget is disabled
-	if (!(gw->g.flags & GWIN_FLG_ENABLED))
+	if ((gw->g.flags & (GWIN_FLG_ENABLED|GWIN_FLG_VISIBLE)) != (GWIN_FLG_ENABLED|GWIN_FLG_VISIBLE))
 		return;
 
 	// Process via AllEvents() if it is defined
@@ -87,10 +87,9 @@ static void gwidgetCallback(void *param, GEvent *pe) {
 }
 
 GHandle _gwidgetInit(GWidgetObject *pgw, coord_t x, coord_t y, coord_t width, coord_t height, size_t size, const gwidgetVMT *vmt) {
-	if (!(pgw = (GWidgetObject *)_gwinInit((GWindowObject *)pgw, x, y, width, height, size, (const gwinVMT *)vmt)))
+	if (!(pgw = (GWidgetObject *)_gwindowInit((GWindowObject *)pgw, x, y, width, height, size, (const gwinVMT *)vmt, GWIN_FLG_WIDGET|GWIN_FLG_ENABLED)))
 		return 0;
 
-	pgw->g.flags |= (GWIN_FLG_WIDGET|GWIN_FLG_ENABLED);
 	pgw->txt = "";
 	pgw->fnDraw = vmt->DefaultDraw;
 	pgw->fnParam = 0;
@@ -101,9 +100,6 @@ GHandle _gwidgetInit(GWidgetObject *pgw, coord_t x, coord_t y, coord_t width, co
 }
 
 void _gwidgetDestroy(GHandle gh) {
-	if (!(gh->flags & GWIN_FLG_WIDGET))
-		return;
-
 	// Deallocate the text (if necessary)
 	if ((gh->flags & GWIN_FLG_ALLOCTXT)) {
 		gh->flags &= ~GWIN_FLG_ALLOCTXT;
@@ -112,21 +108,10 @@ void _gwidgetDestroy(GHandle gh) {
 	// Untangle the listeners (both on us and to us).
 	geventDetachSource(&gw->listener, 0);
 	geventDetachSourceListeners((GSourceHandle)gh);
-	gh->flags &= ~GWIN_FLG_WIDGET;
-}
-
-void gwinSetEnabled(GHandle gh, bool_t enabled) {
-	if (!(gh->flags & GWIN_FLG_WIDGET))
-		return;
-
-	if (enabled)
-		gh->flags |= GWIN_FLG_ENABLED;
-	else
-		gh->flags &= ~GWIN_FLG_ENABLED;
 }
 
-void gwinDraw(GHandle gh) {
-	if (!(gh->flags & GWIN_FLG_WIDGET))
+void _gwidgetRedraw(GHandle gh) {
+	if (!(gh->flags & GWIN_FLG_VISIBLE))
 		return;
 
 	#if GDISP_NEED_CLIP
@@ -136,6 +121,23 @@ void gwinDraw(GHandle gh) {
 	gw->fnDraw(gw, gw->fnParam);
 }
 
+void gwinSetEnabled(GHandle gh, bool_t enabled) {
+	if (!(gh->flags & GWIN_FLG_WIDGET))
+		return;
+
+	if (enabled) {
+		if (!(gh->flags & GWIN_FLG_ENABLED)) {
+			gh->flags |= GWIN_FLG_ENABLED;
+			_gwidgetRedraw(gh);
+		}
+	} else {
+		if ((gh->flags & GWIN_FLG_ENABLED)) {
+			gh->flags &= ~GWIN_FLG_ENABLED;
+			_gwidgetRedraw(gh);
+		}
+	}
+}
+
 void gwinSetText(GHandle gh, const char *txt, bool_t useAlloc) {
 	if (!(gh->flags & GWIN_FLG_WIDGET))
 		return;
@@ -162,6 +164,7 @@ void gwinSetText(GHandle gh, const char *txt, bool_t useAlloc) {
 	}
 
 	gw->txt = txt ? txt : "";
+	_gwidgetRedraw(gh);
 }
 
 const char *gwinGetText(GHandle gh) {
@@ -177,6 +180,7 @@ void gwinSetCustomDraw(GHandle gh, CustomWidgetDrawFunction fn, void *param) {
 
 	gw->fnDraw = fn ? fn : wvmt->DefaultDraw;
 	gw->fnParam = param;
+	_gwidgetRedraw(gh);
 }
 
 bool_t gwinAttachListener(GHandle gh, GListener *pl, unsigned flags) {
@@ -249,6 +253,6 @@ bool_t gwinAttachListener(GHandle gh, GListener *pl, unsigned flags) {
 	}
 #endif
 
-#endif /* GFX_USE_GWIN */
+#endif /* GFX_USE_GWIN && GWIN_NEED_WIDGET */
 /** @} */
 
diff --git a/src/gwin/gwin.c b/src/gwin/gwin.c
index 163e821d..3e790d38 100644
--- a/src/gwin/gwin.c
+++ b/src/gwin/gwin.c
@@ -11,90 +11,247 @@
 
 #include "gwin/class_gwin.h"
 
+// Needed if there is no window manager
+#define MIN_WIN_WIDTH	1
+#define MIN_WIN_HEIGHT	1
+
+/*-----------------------------------------------
+ * Data
+ *-----------------------------------------------*/
+
 static const gwinVMT basegwinVMT = {
 		"GWIN",					// The classname
 		0,						// The destroy routine
+		0,						// The redraw routine
 		0,						// The after-clear routine
 };
 
-static font_t	defaultFont;
 static color_t	defaultFgColor = White;
 static color_t	defaultBgColor = Black;
+#if GDISP_NEED_TEXT
+	static font_t	defaultFont;
+#endif
+#if GWIN_NEED_WINDOWMANAGER
+	gfxQueueASync			_GWINList;
+	extern GWindowManager	GNullWindowManager;
+	static GWindowManager *	cwm;
+#endif
+
+/*-----------------------------------------------
+ * Helper Routines
+ *-----------------------------------------------*/
+
+#if !GWIN_NEED_WINDOWMANAGER
+	static void _gwm_vis(GHandle gh) {
+		if (gh->vmt->Redraw) {
+			#if GDISP_NEED_CLIP
+				gdispSetClip(gh->x, gh->y, gh->width, gh->height);
+			#endif
+			gh->vmt->Redraw(gh);
+		} else
+			gwinClear(gh);
+	}
+	static void _gwm_redim(GHandle gh, coord_t x, coord_t y, coord_t w, coord_t h) {
+		if (x < 0) { w += x; x = 0; }
+		if (y < 0) { h += y; y = 0; }
+		if (x > gdispGetWidth()-MIN_WIN_WIDTH)		x = gdispGetWidth()-MIN_WIN_WIDTH;
+		if (y > gdispGetHeight()-MIN_WIN_HEIGHT)	y = gdispGetHeight()-MIN_WIN_HEIGHT;
+		if (w < MIN_WIN_WIDTH) { w = MIN_WIN_WIDTH; }
+		if (h < MIN_WIN_HEIGHT) { h = MIN_WIN_HEIGHT; }
+		if (x+w > gdispGetWidth()) w = gdispGetWidth() - x;
+		if (y+h > gdispGetHeight()) h = gdispGetHeight() - y;
+		gh->x = x; gh->y = y;
+		gh->width = w; gh->height = h;
+	}
+#endif
+
+/*-----------------------------------------------
+ * Class Routines
+ *-----------------------------------------------*/
+
+void _gwinInit(void) {
+	#if GWIN_NEED_WINDOWMANAGER
+		gfxQueueASyncInit(&_GWINList);
+		cwm = &GNullWindowManager;
+		cwm->vmt->Init();
+	#endif
+}
 
 // Internal routine for use by GWIN components only
-// Initialise a window creating it dynamicly if required.
-GHandle _gwinInit(GWindowObject *pgw, coord_t x, coord_t y, coord_t width, coord_t height, size_t size, const gwinVMT *vmt) {
-	coord_t	w, h;
-
-	// Check the window size against the screen size
-	w = gdispGetWidth();
-	h = gdispGetHeight();
-	if (x < 0) { width += x; x = 0; }
-	if (y < 0) { height += y; y = 0; }
-	if (x >= w || y >= h) return 0;
-	if (x+width > w) width = w - x;
-	if (y+height > h) height = h - y;
-	
+// Initialise a window creating it dynamically if required.
+GHandle _gwindowInit(GWindowObject *pgw, coord_t x, coord_t y, coord_t width, coord_t height, size_t size, const gwinVMT *vmt, uint16_t flags) {
 	// Allocate the structure if necessary
 	if (!pgw) {
 		if (!(pgw = (GWindowObject *)gfxAlloc(size)))
 			return 0;
-		pgw->flags = GWIN_FLG_DYNAMIC;
+		pgw->flags = flags|GWIN_FLG_DYNAMIC;
 	} else
-		pgw->flags = 0;
+		pgw->flags = flags;
 	
 	// Initialise all basic fields
 	pgw->vmt = vmt;
-	pgw->x = x;
-	pgw->y = y;
-	pgw->width = width;
-	pgw->height = height;
 	pgw->color = defaultFgColor;
 	pgw->bgcolor = defaultBgColor;
 	#if GDISP_NEED_TEXT
 		pgw->font = defaultFont;
 	#endif
+
+	#if GWIN_NEED_WINDOWMANAGER
+		if (!cwm->vmt->Add(pgw, x, y, width, height)) {
+			if ((pgw->flags & GWIN_FLG_DYNAMIC))
+				gfxFree(pgw);
+			return 0;
+		}
+	#else
+		_gwm_redim(pgw, x, y, width, height);
+		if ((pgw->flags & GWIN_FLG_VISIBLE))
+			_gwm_vis(pgw);
+	#endif
+
 	return (GHandle)pgw;
 }
 
+/*-----------------------------------------------
+ * Routines that affect all windows
+ *-----------------------------------------------*/
+
+#if GWIN_NEED_WINDOWMANAGER
+	void gwinSetWindowManager(struct GWindowManager *gwm) {
+		if (!gwm)
+			gwm = &GNullWindowManager;
+		if (cwm != gwm) {
+			cwm->vmt->DeInit();
+			cwm = gwm;
+			cwm->vmt->Init();
+		}
+	}
+#endif
+
+void gwinSetDefaultColor(color_t clr) {
+	defaultFgColor = clr;
+}
+
+void gwinSetDefaultBgColor(color_t bgclr) {
+	defaultBgColor = bgclr;
+}
+
+#if GDISP_NEED_TEXT
+	void gwinSetDefaultFont(font_t font) {
+		defaultFont = font;
+	}
+#endif
+
+/*-----------------------------------------------
+ * The GWindow Routines
+ *-----------------------------------------------*/
+
 GHandle gwinCreateWindow(GWindowObject *pgw, coord_t x, coord_t y, coord_t width, coord_t height) {
-	return _gwinInit(pgw, x, y, width, height, sizeof(GWindowObject), &basegwinVMT);
+	return _gwindowInit(pgw, x, y, width, height, sizeof(GWindowObject), &basegwinVMT, GWIN_FLG_VISIBLE);
 }
 
 void gwinDestroy(GHandle gh) {
+	// Remove from the window manager
+	#if GWIN_NEED_WINDOWMANAGER
+		cwm->vmt->Delete(gh);
+	#endif
+
+	// Class destroy routine
 	if (gh->vmt->Destroy)
 		gh->vmt->Destroy(gh);
 
 	// Clean up the structure
-	if (gh->flags & GWIN_FLG_DYNAMIC) {
-		gh->flags = 0;							// To be sure, to be sure
+	if (gh->flags & GWIN_FLG_DYNAMIC)
 		gfxFree((void *)gh);
-	}
+
+	gh->flags = 0;							// To be sure, to be sure
 }
 
 const char *gwinGetClassName(GHandle gh) {
 	return gh->vmt->classname;
 }
 
-void gwinSetDefaultColor(color_t clr) {
-	defaultFgColor = clr;
+void gwinSetVisible(GHandle gh, bool_t visible) {
+	if (visible) {
+		if (!(gh->flags & GWIN_FLG_VISIBLE)) {
+			gh->flags |= GWIN_FLG_VISIBLE;
+			#if GWIN_NEED_WINDOWMANAGER
+				cwm->vmt->Visible(gh);
+			#else
+				_gwm_vis(gh);
+			#endif
+		}
+	} else {
+		if ((gh->flags & GWIN_FLG_VISIBLE)) {
+			gh->flags &= ~GWIN_FLG_VISIBLE;
+			#if GWIN_NEED_WINDOWMANAGER
+				cwm->vmt->Visible(gh);
+			#endif
+		}
+	}
 }
 
-void gwinSetDefaultBgColor(color_t bgclr) {
-	defaultBgColor = bgclr;
+bool_t gwinGetVisible(GHandle gh) {
+	return (gh->flags & GWIN_FLG_VISIBLE) ? TRUE : FALSE;
 }
 
-#if GDISP_NEED_TEXT
-	void gwinSetDefaultFont(font_t font) {
-		defaultFont = font;
-	}
+void gwinMove(GHandle gh, coord_t x, coord_t y) {
+	#if GWIN_NEED_WINDOWMANAGER
+		cwm->vmt->Redim(gh, x, y, gh->width, gh->height);
+	#else
+		_gwm_redim(gh, x, y, gh->width, gh->height);
+	#endif
+}
+
+void gwinResize(GHandle gh, coord_t width, coord_t height) {
+	#if GWIN_NEED_WINDOWMANAGER
+		cwm->vmt->Redim(gh, gh->x, gh->y, width, height);
+	#else
+		_gwm_redim(gh, gh->x, gh->y, width, height);
+	#endif
+}
 
+void gwinSetMinMax(GHandle gh, GWindowMinMax minmax) {
+	#if GWIN_NEED_WINDOWMANAGER
+		cwm->vmt->MinMax(gh, minmax);
+	#else
+		(void) gh;
+		(void) minmax;
+	#endif
+}
+
+void gwinRaise(GHandle gh) {
+	#if GWIN_NEED_WINDOWMANAGER
+		cwm->vmt->Raise(gh);
+	#else
+		if ((gh->flags & GWIN_FLG_VISIBLE)) {
+			if (gh->vmt->Redraw) {
+				#if GDISP_NEED_CLIP
+					gdispSetClip(gh->x, gh->y, gh->width, gh->height);
+				#endif
+				gh->vmt->Redraw(gh);
+			}
+		}
+	#endif
+}
+
+GWindowMinMax gwinGetMinMax(GHandle gh) {
+	if (gh->flags & GWIN_FLG_MINIMIZED)
+		return GWIN_MINIMIZE;
+	if (gh->flags & GWIN_FLG_MAXIMIZED)
+		return GWIN_MAXIMIZE;
+	return GWIN_NORMAL;
+}
+
+#if GDISP_NEED_TEXT
 	void gwinSetFont(GHandle gh, font_t font) {
 		gh->font = font;
 	}
 #endif
 
 void gwinClear(GHandle gh) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -104,6 +261,9 @@ void gwinClear(GHandle gh) {
 }
 
 void gwinDrawPixel(GHandle gh, coord_t x, coord_t y) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -111,6 +271,9 @@ void gwinDrawPixel(GHandle gh, coord_t x, coord_t y) {
 }
 
 void gwinDrawLine(GHandle gh, coord_t x0, coord_t y0, coord_t x1, coord_t y1) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -118,6 +281,9 @@ void gwinDrawLine(GHandle gh, coord_t x0, coord_t y0, coord_t x1, coord_t y1) {
 }
 
 void gwinDrawBox(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -125,6 +291,9 @@ void gwinDrawBox(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy) {
 }
 
 void gwinFillArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -132,6 +301,9 @@ void gwinFillArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy) {
 }
 
 void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coord_t srcx, coord_t srcy, coord_t srccx, const pixel_t *buffer) {
+	if (!((gh->flags & GWIN_FLG_VISIBLE)))
+		return;
+
 	#if GDISP_NEED_CLIP
 		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
@@ -140,6 +312,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_CIRCLE
 	void gwinDrawCircle(GHandle gh, coord_t x, coord_t y, coord_t radius) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -147,6 +322,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillCircle(GHandle gh, coord_t x, coord_t y, coord_t radius) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -156,6 +334,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_ELLIPSE
 	void gwinDrawEllipse(GHandle gh, coord_t x, coord_t y, coord_t a, coord_t b) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -163,6 +344,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillEllipse(GHandle gh, coord_t x, coord_t y, coord_t a, coord_t b) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -172,6 +356,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_ARC
 	void gwinDrawArc(GHandle gh, coord_t x, coord_t y, coord_t radius, coord_t startangle, coord_t endangle) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -179,6 +366,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillArc(GHandle gh, coord_t x, coord_t y, coord_t radius, coord_t startangle, coord_t endangle) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -188,6 +378,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_PIXELREAD
 	color_t gwinGetPixelColor(GHandle gh, coord_t x, coord_t y) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -197,7 +390,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_TEXT
 	void gwinDrawChar(GHandle gh, coord_t x, coord_t y, char c) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -205,7 +400,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillChar(GHandle gh, coord_t x, coord_t y, char c) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -213,7 +410,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinDrawString(GHandle gh, coord_t x, coord_t y, const char *str) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -221,7 +420,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillString(GHandle gh, coord_t x, coord_t y, const char *str) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -229,7 +430,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinDrawStringBox(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, const char* str, justify_t justify) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -237,7 +440,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillStringBox(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, const char* str, justify_t justify) {
-		if (!gh->font) return;
+		if (!((gh->flags & GWIN_FLG_VISIBLE)) || !gh->font)
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -247,6 +452,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_CONVEX_POLYGON
 	void gwinDrawPoly(GHandle gh, coord_t tx, coord_t ty, const point *pntarray, unsigned cnt) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -254,6 +462,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 	}
 
 	void gwinFillConvexPoly(GHandle gh, coord_t tx, coord_t ty, const point *pntarray, unsigned cnt) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
@@ -263,6 +474,9 @@ void gwinBlitArea(GHandle gh, coord_t x, coord_t y, coord_t cx, coord_t cy, coor
 
 #if GDISP_NEED_IMAGE
 	gdispImageError gwinImageDraw(GHandle gh, gdispImage *img, coord_t x, coord_t y, coord_t cx, coord_t cy, coord_t sx, coord_t sy) {
+		if (!((gh->flags & GWIN_FLG_VISIBLE)))
+			return GDISP_IMAGE_ERR_OK;
+
 		#if GDISP_NEED_CLIP
 			gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 		#endif
diff --git a/src/gwin/gwin.mk b/src/gwin/gwin.mk
index 90a8e9b4..fb8fdfd1 100644
--- a/src/gwin/gwin.mk
+++ b/src/gwin/gwin.mk
@@ -1,5 +1,6 @@
 GFXSRC +=   $(GFXLIB)/src/gwin/gwin.c \
 			$(GFXLIB)/src/gwin/gwidget.c \
+			$(GFXLIB)/src/gwin/gwm.c \
 			$(GFXLIB)/src/gwin/console.c \
 			$(GFXLIB)/src/gwin/graph.c \
 			$(GFXLIB)/src/gwin/button.c \
diff --git a/src/gwin/gwm.c b/src/gwin/gwm.c
new file mode 100644
index 00000000..bc561345
--- /dev/null
+++ b/src/gwin/gwm.c
@@ -0,0 +1,144 @@
+/*
+ * This file is subject to the terms of the GFX License, v1.0. If a copy of
+ * the license was not distributed with this file, you can obtain one at:
+ *
+ *              http://chibios-gfx.com/license.html
+ */
+
+#include "gfx.h"
+
+// Used by the NULL window manager
+#define MIN_WIN_WIDTH	3
+#define MIN_WIN_HEIGHT	3
+
+/*-----------------------------------------------
+ * The default window manager (GNullWindowManager)
+ *-----------------------------------------------*/
+
+#if GFX_USE_GWIN && GWIN_NEED_WINDOWMANAGER
+
+#include "gwin/class_gwin.h"
+
+/*-----------------------------------------------
+ * Data
+ *-----------------------------------------------*/
+
+static void WM_Init(void);
+static void WM_DeInit(void);
+static bool_t WM_Add(GHandle gh, coord_t x, coord_t y, coord_t w, coord_t h);
+static void WM_Delete(GHandle gh);
+static void WM_Visible(GHandle gh);
+static void WM_Redim(GHandle gh, coord_t x, coord_t y, coord_t w, coord_t h);
+static void WM_Raise(GHandle gh);
+static void WM_MinMax(GHandle gh, GWindowMinMax minmax);
+
+static const gwmVMT GNullWindowManagerVMT = {
+	WM_Init,
+	WM_DeInit,
+	WM_Add,
+	WM_Delete,
+	WM_Visible,
+	WM_Redim,
+	WM_Raise,
+	WM_MinMax,
+};
+
+const GWindowManager	GNullWindowManager = {
+	&GNullWindowManagerVMT,
+};
+
+/*-----------------------------------------------
+ * Window Manager Routines
+ *-----------------------------------------------*/
+
+static void WM_Init(void) {
+	// We don't need to do anything here.
+	// A full window manager would move the windows around, add borders etc
+
+	// clear the screen
+	// cycle through the windows already defined displaying them
+	// or cut all the window areas out of the screen and clear the remainder
+}
+
+static void WM_DeInit(void) {
+	// We don't need to do anything here.
+	// A full window manager would remove any borders etc
+}
+
+static bool_t WM_Add(GHandle gh, coord_t x, coord_t y, coord_t w, coord_t h) {
+	// Put it on the queue
+	gfxQueueASyncPut(&_GWINList, &gh->wmq);
+
+	// Make sure the size is valid
+	WM_Redim(gh, x, y, w, h);
+
+	// Display it if it is visible
+	WM_Visible(gh);
+	return TRUE;
+}
+
+static void WM_Delete(GHandle gh) {
+	// A real window manager would make the window invisible
+	//	(and then clear the area underneath)
+
+	// Just remove it from the queue
+	gfxQueueASyncRemove(&_GWINList, &gh->wmq);
+}
+
+static void WM_Visible(GHandle gh) {
+	if ((gh->flags & GWIN_FLG_VISIBLE)) {
+		if (gh->vmt->Redraw) {
+			#if GDISP_NEED_CLIP
+				gdispSetClip(gh->x, gh->y, gh->width, gh->height);
+			#endif
+			gh->vmt->Redraw(gh);
+		} else
+			gwinClear(gh);
+		// A real window manager would also redraw the borders
+	}
+
+	// else
+	// A real window manager would make the window invisible
+	//	(and then clear the area underneath)
+
+}
+
+static void WM_Redim(GHandle gh, coord_t x, coord_t y, coord_t w, coord_t h) {
+	// This is the simplest way of doing it - just clip the the screen
+	// If it won't fit on the screen move it around until it does.
+	if (x < 0) { w += x; x = 0; }
+	if (y < 0) { h += y; y = 0; }
+	if (x > gdispGetWidth()-MIN_WIN_WIDTH)		x = gdispGetWidth()-MIN_WIN_WIDTH;
+	if (y > gdispGetHeight()-MIN_WIN_HEIGHT)	y = gdispGetHeight()-MIN_WIN_HEIGHT;
+	if (w < MIN_WIN_WIDTH) { w = MIN_WIN_WIDTH; }
+	if (h < MIN_WIN_HEIGHT) { h = MIN_WIN_HEIGHT; }
+	if (x+w > gdispGetWidth()) w = gdispGetWidth() - x;
+	if (y+h > gdispGetHeight()) h = gdispGetHeight() - y;
+	gh->x = x; gh->y = y;
+	gh->width = w; gh->height = h;
+}
+
+static void WM_MinMax(GHandle gh, GWindowMinMax minmax) {
+	(void)gh; (void) minmax;
+	// We don't support minimising, maximising or restoring
+}
+
+static void WM_Raise(GHandle gh) {
+	// Take it off the list and then put it back on top
+	// The order of the list then reflects the z-order.
+	gfxQueueASyncRemove(&_GWINList, &gh->wmq);
+	gfxQueueASyncPut(&_GWINList, &gh->wmq);
+
+	// Redraw the window
+	if ((gh->flags & GWIN_FLG_VISIBLE)) {
+		if (gh->vmt->Redraw) {
+			#if GDISP_NEED_CLIP
+				gdispSetClip(gh->x, gh->y, gh->width, gh->height);
+			#endif
+			gh->vmt->Redraw(gh);
+		}
+	}
+}
+
+#endif /* GFX_USE_GWIN && GWIN_NEED_WINDOWMANAGER */
+/** @} */
diff --git a/src/gwin/slider.c b/src/gwin/slider.c
index a0289d3d..1a1855a9 100644
--- a/src/gwin/slider.c
+++ b/src/gwin/slider.c
@@ -35,6 +35,7 @@ static const gwidgetVMT sliderVMT = {
 	{
 		"Slider",				// The classname
 		_gwidgetDestroy,		// The destroy routine
+		_gwidgetRedraw,			// The redraw routine
 		0,						// The after-clear routine
 	},
 	gwinSliderDraw_Std,		// The default drawing routine
@@ -101,7 +102,7 @@ static void MouseUp(GWidgetObject *gw, coord_t x, coord_t y) {
 		if (x < 0 || x >= gh->width || y < 0 || y >= gh->height) {
 			// No - restore the slider
 			ResetDisplayPos(gsw);
-			gwinDraw(gh);
+			_gwidgetRedraw(gh);
 			return;
 		}
 	#endif
@@ -124,7 +125,7 @@ static void MouseUp(GWidgetObject *gw, coord_t x, coord_t y) {
 	}
 
 	ResetDisplayPos(gsw);
-	gwinDraw(gh);
+	_gwidgetRedraw(gh);
 
 	// Generate the event
 	SendSliderEvent(gw);
@@ -154,7 +155,7 @@ static void MouseMove(GWidgetObject *gw, coord_t x, coord_t y) {
 	}
 
 	// Update the display
-	gwinDraw(&gw->g);
+	_gwidgetRedraw(&gw->g);
 	#undef gsw
 }