8 files changed, 17 insertions, 9 deletions
diff --git a/src/gdisp/image.c b/src/gdisp/image.c
index fec05147..efeb6ad1 100644
--- a/src/gdisp/image.c
+++ b/src/gdisp/image.c
@@ -184,6 +184,14 @@ void gdispImageClose(gdispImage *img) {
 		img->fns->close(img);
 	else
 		img->io.fns->close(&img->io);
+	img->type = GDISP_IMAGE_TYPE_UNKNOWN;
+	img->flags = 0;
+	img->fns = 0;
+	img->priv = 0;
+}
+
+bool_t gdispImageIsOpen(gdispImage *img) {
+	return img->type != GDISP_IMAGE_TYPE_UNKNOWN && img->fns != 0;
 }
 
 void gdispImageSetBgColor(gdispImage *img, color_t bgcolor) {
diff --git a/src/gwin/button.c b/src/gwin/button.c
index 4f823aa6..303d1078 100644
--- a/src/gwin/button.c
+++ b/src/gwin/button.c
@@ -151,7 +151,7 @@ static uint16_t ToggleGet(GWidgetObject *gw, uint16_t role) {
 	return ((GButtonObject *)gw)->toggle;
 }
 
-GHandle gwinCreateButton(GButtonObject *gw, GWidgetInit *pInit) {
+GHandle gwinCreateButton(GButtonObject *gw, const GWidgetInit *pInit) {
 	if (!(gw = (GButtonObject *)_gwidgetCreate(&gw->w, pInit, &buttonVMT)))
 		return 0;
 
diff --git a/src/gwin/checkbox.c b/src/gwin/checkbox.c
index b4628ae0..62f4c55b 100644
--- a/src/gwin/checkbox.c
+++ b/src/gwin/checkbox.c
@@ -113,7 +113,7 @@ static uint16_t ToggleGet(GWidgetObject *gw, uint16_t role) {
 	return ((GCheckboxObject *)gw)->toggle;
 }
 
-GHandle gwinCreateCheckbox(GCheckboxObject *gb, GWidgetInit *pInit) {
+GHandle gwinCreateCheckbox(GCheckboxObject *gb, const GWidgetInit *pInit) {
 	if (!(gb = (GCheckboxObject *)_gwidgetCreate(&gb->w, pInit, &checkboxVMT)))
 		return 0;
 
diff --git a/src/gwin/console.c b/src/gwin/console.c
index 39e534b4..105cc79d 100644
--- a/src/gwin/console.c
+++ b/src/gwin/console.c
@@ -66,7 +66,7 @@ static const gwinVMT consoleVMT = {
 		AfterClear,				// The after-clear routine
 };
 
-GHandle gwinCreateConsole(GConsoleObject *gc, GWindowInit *pInit) {
+GHandle gwinCreateConsole(GConsoleObject *gc, const GWindowInit *pInit) {
 	if (!(gc = (GConsoleObject *)_gwindowCreate(&gc->g, pInit, &consoleVMT, 0)))
 		return 0;
 	#if GFX_USE_OS_CHIBIOS && GWIN_CONSOLE_USE_BASESTREAM
diff --git a/src/gwin/graph.c b/src/gwin/graph.c
index 81ce1b5f..049f52e0 100644
--- a/src/gwin/graph.c
+++ b/src/gwin/graph.c
@@ -165,7 +165,7 @@ static void lineto(GGraphObject *gg, coord_t x0, coord_t y0, coord_t x1, coord_t
 	}
 }
 
-GHandle gwinCreateGraph(GGraphObject *gg, GWindowInit *pInit) {
+GHandle gwinCreateGraph(GGraphObject *gg, const GWindowInit *pInit) {
 	if (!(gg = (GGraphObject *)_gwindowCreate(&gg->g, pInit, &graphVMT, 0)))
 		return 0;
 	gg->xorigin = gg->yorigin = 0;
diff --git a/src/gwin/gwidget.c b/src/gwin/gwidget.c
index 2825bf4c..a2b82f1d 100644
--- a/src/gwin/gwidget.c
+++ b/src/gwin/gwidget.c
@@ -165,7 +165,7 @@ void _gwidgetInit(void) {
 	geventRegisterCallback(&gl, gwidgetEvent, 0);
 }
 
-GHandle _gwidgetCreate(GWidgetObject *pgw, GWidgetInit *pInit, const gwidgetVMT *vmt) {
+GHandle _gwidgetCreate(GWidgetObject *pgw, const GWidgetInit *pInit, const gwidgetVMT *vmt) {
 	if (!(pgw = (GWidgetObject *)_gwindowCreate(&pgw->g, &pInit->g, &vmt->g, GWIN_FLG_WIDGET|GWIN_FLG_ENABLED)))
 		return 0;
 
diff --git a/src/gwin/gwin.c b/src/gwin/gwin.c
index 110d35cc..c1122b3f 100644
--- a/src/gwin/gwin.c
+++ b/src/gwin/gwin.c
@@ -52,7 +52,7 @@ static color_t	defaultBgColor = Black;
 		} else
 			gwinClear(gh);
 	}
-	static void _gwm_redim(GHandle gh, GWindowInit *pInit) {
+	static void _gwm_redim(GHandle gh, const GWindowInit *pInit) {
 		gh->x = pInit->x; gh->y = pInit->y;
 		gh->width = pInit->width; gh->height = pInit->height;
 		if (gh->x < 0) { gh->width += gh->x; gh->x = 0; }
@@ -85,7 +85,7 @@ void _gwinInit(void) {
 
 // Internal routine for use by GWIN components only
 // Initialise a window creating it dynamically if required.
-GHandle _gwindowCreate(GWindowObject *pgw, GWindowInit *pInit, const gwinVMT *vmt, uint16_t flags) {
+GHandle _gwindowCreate(GWindowObject *pgw, const GWindowInit *pInit, const gwinVMT *vmt, uint16_t flags) {
 	// Allocate the structure if necessary
 	if (!pgw) {
 		if (!(pgw = (GWindowObject *)gfxAlloc(vmt->size)))
@@ -149,7 +149,7 @@ void gwinSetDefaultBgColor(color_t bgclr) {
  * The GWindow Routines
  *-----------------------------------------------*/
 
-GHandle gwinCreateWindow(GWindowObject *pgw, GWindowInit *pInit) {
+GHandle gwinCreateWindow(GWindowObject *pgw, const GWindowInit *pInit) {
 	if (!(pgw = _gwindowCreate(pgw, pInit, &basegwinVMT, 0)))
 		return 0;
 	gwinSetVisible(pgw, pInit->show);
diff --git a/src/gwin/slider.c b/src/gwin/slider.c
index 08dd6ca7..2dfa3a7c 100644
--- a/src/gwin/slider.c
+++ b/src/gwin/slider.c
@@ -233,7 +233,7 @@ static uint16_t DialGet(GWidgetObject *gw, uint16_t role) {
 	return ((GSliderObject *)gw)->dial;
 }
 
-GHandle gwinCreateSlider(GSliderObject *gs, GWidgetInit *pInit) {
+GHandle gwinCreateSlider(GSliderObject *gs, const GWidgetInit *pInit) {
 	if (!(gs = (GSliderObject *)_gwidgetCreate(&gs->w, pInit, &sliderVMT)))
 		return 0;
 	gs->t_dn = (uint16_t) -1;