added gwin enabled parameter and implemented button enable/disable functions

include/gwin/button.h

@@ -63,7 +63,7 @@ typedef enum GButtonState_e {
 	GBTN_UP, GBTN_DOWN
 } GButtonState;
 
-typedef void (*GButtonDrawFunction)(GHandle gh, bool_t isdown, const char *txt, const GButtonDrawStyle *pstyle, void *param);
+typedef void (*GButtonDrawFunction)(GHandle gh, bool_t enabled, bool_t isdown, const char *txt, const GButtonDrawStyle *pstyle, void *param);
 
 // A button window
 typedef struct GButtonObject_t {
@@ -145,6 +145,16 @@ void gwinSetButtonText(GHandle gh, const char *txt, bool_t useAlloc);
  */
 void gwinButtonDraw(GHandle gh);
 
+/**
+ * @brief	Enable or disable a button
+ *
+ * @param[in] gh		The window handle (must be a button window)
+ * @param[in] enabled	Enable or disable the button
+ *
+ * @api
+ */
+void gwinButtonSetEnabled(GHandle gh, bool_t enabled);
+
 /**
  * @brief   Set the callback routine to perform a custom button drawing.
  *
@@ -156,6 +166,27 @@ void gwinButtonDraw(GHandle gh);
  */
 void gwinSetButtonCustom(GHandle gh, GButtonDrawFunction fn, void *param);
 
+/**
+ * @brief Enable a button
+ *
+ * @api
+ */
+#define gwinEnableButton(gh)		gwinButtonSetEnabled( ((GButtonObject *)(gh)), TRUE)
+
+/**
+ * @brief Disable a button
+ *
+ * @api
+ */
+#define gwinDisableButton(gh)		gwinButtonSetEnabled( ((GButtonObject *)(gh)), FALSE)
+
+/**
+ * @brief Get the state of a button
+ *
+ * @param[in] gh	The window handle (must be a button window)
+ *
+ * @api
+ */
 #define gwinGetButtonState(gh)		(((GButtonObject *)(gh))->state)
 
 /**

include/gwin/gwin.h

@@ -45,6 +45,7 @@ typedef struct GWindowObject_t {
 	coord_t		x, y;				// Screen relative position
 	coord_t		width, height;		// Dimensions of this window
 	color_t		color, bgcolor;		// Current drawing colors
+	bool_t		enabled;			// Enabled/Disabled state
 #if GDISP_NEED_TEXT
 	font_t		font;				// Current font
 #endif

src/gwin/button.c

@@ -55,6 +55,10 @@ static void gwinButtonCallback(void *param, GEvent *pe) {
 	#define pxe		((GEventToggle *)pe)
 	#define pbe		((GEventGWinButton *)pe)
 
+	// check if button is disabled
+	if (gh->enabled == false)
+		return;
+
 	switch (pe->type) {
 	#if GFX_USE_GINPUT && GINPUT_NEED_MOUSE
 		case GEVENT_MOUSE:
@@ -135,6 +139,7 @@ static void gwinButtonCallback(void *param, GEvent *pe) {
 GHandle gwinCreateButton(GButtonObject *gb, coord_t x, coord_t y, coord_t width, coord_t height, font_t font, GButtonType type) {
 	if (!(gb = (GButtonObject *)_gwinInit((GWindowObject *)gb, x, y, width, height, sizeof(GButtonObject))))
 		return 0;
+
 	gb->gwin.type = GW_BUTTON;
 	gb->fn = 0;
 	gb->param = 0;
@@ -145,6 +150,10 @@ GHandle gwinCreateButton(GButtonObject *gb, coord_t x, coord_t y, coord_t width,
 	gb->txt = "";
 	geventListenerInit(&gb->listener);
 	geventRegisterCallback(&gb->listener, gwinButtonCallback, gb);
+
+	// buttons are enabled by default
+	gb->gwin.enabled = true;
+
 	return (GHandle)gb;
 }
 
@@ -225,6 +234,7 @@ void gwinButtonDraw(GHandle gh) {
 	#endif
 
 	gbw->fn(gh,
+			gbw->gwin.enabled,
 			gbw->state == GBTN_DOWN,
 			gh->font && gbw->txt ? gbw->txt : "",
 			gbw->state == GBTN_DOWN ? &gbw->dn : &gbw->up,
@@ -245,6 +255,13 @@ void gwinSetButtonCustom(GHandle gh, GButtonDrawFunction fn, void *param) {
 	#undef gbw
 }
 
+void gwinButtonSetEnabled(GHandle gh, bool_t enabled) {
+	if (gh->type != GW_BUTTON)
+		return;
+
+	gh->enabled = enabled;
+}
+
 void gwinButtonDraw_3D(GHandle gh, bool_t isdown, const char *txt, const GButtonDrawStyle *pstyle, void *param) {
 	(void) isdown;
 	(void) param;