Plumb default_widget_handler and default_user_data for widgets read from JSON/File

src/main.c

@@ -50,11 +50,12 @@ void tft_demo(void)
   mgos_ili9341_jpg_image(CENTER, CENTER, 1, "mongoose-os.jpg", NULL, 0);
 //  mgos_ili9341_jpg_image(200, 150, 2, "flower.jpg", NULL, 0);
 
-  screen = screen_create_from_file("/screen_main.json");
+  screen = screen_create_from_file("/screen_main.json", widget_default_ev, NULL);
   if (!screen) {
     LOG(LL_ERROR, ("Could not load screen"));
     return;
   }
+
   w = widget_create("name", 0, 0, 198, 20);
   widget_set_handler(w, widget_name_ev, NULL);
   screen_widget_add(screen, w);

src/screen.c

@@ -17,7 +17,7 @@ struct screen_t *screen_create(char *name, uint16_t x, uint16_t y, uint16_t w, u
   return screen;
 }
 
-struct screen_t *screen_create_from_file(char *fn) {
+struct screen_t *screen_create_from_file(char *fn, widget_event_fn handler, void *user_data) {
   char *json;
   struct screen_t *screen = NULL;
 
@@ -27,12 +27,12 @@ struct screen_t *screen_create_from_file(char *fn) {
     return NULL;
   }
 
-  screen = screen_create_from_json(json);
+  screen = screen_create_from_json(json, handler, user_data);
   free (json);
   return screen;
 }
 
-struct screen_t *screen_create_from_json(char *json) {
+struct screen_t *screen_create_from_json(char *json, widget_event_fn handler, void *user_data) {
   void *h = NULL;
 //  struct json_token key;
   struct json_token val;
@@ -47,6 +47,9 @@ struct screen_t *screen_create_from_json(char *json) {
     screen=NULL; goto exit;
   }
   screen = screen_create(screen_name, screen_x, screen_y, screen_w, screen_h);
+  if (!screen)
+    return NULL;
+  screen_widget_set_handler(screen, handler, user_data);
   
 /*
   // Traverse Object
@@ -61,6 +64,7 @@ struct screen_t *screen_create_from_json(char *json) {
 //    printf("[%d]: [%.*s]\n", idx, val.len, val.ptr);
     if (val.len>0 && val.ptr) {
       widget = widget_create_from_json(val.ptr);
+      widget_set_handler(widget, screen->default_widget_handler, screen->default_user_data);
       if (!screen_widget_add(screen, widget)) {
         LOG(LL_ERROR, ("Could not add widget to screen"));
       }
@@ -99,6 +103,7 @@ struct widget_t *screen_widget_add_from_file(struct screen_t *s, char *fn) {
   w = widget_create_from_file(fn);
   if (!w)
     return NULL;
+  widget_set_handler(w, s->default_widget_handler, s->default_user_data);
   screen_widget_add(s, w);
   return w;
 }
@@ -145,3 +150,11 @@ struct widget_t *screen_widget_find_by_xy(struct screen_t *s, uint16_t x, uint16
   }
   return NULL;
 }
+
+void screen_widget_set_handler(struct screen_t *s, widget_event_fn handler, void *user_data) {
+  if (!s)
+    return;
+  s->default_widget_handler=handler;
+  s->default_user_data=user_data;
+  return;
+}

src/widget_default.c

@@ -0,0 +1,22 @@
+#include "mgos.h"
+#include "tft.h"
+#include "mongoose-touch.h"
+
+void widget_default_ev(int ev, struct widget_t *w, void *ev_data) {
+  if (!w)
+    return;
+
+  LOG(LL_INFO, ("Event %d received for widget '%s'", ev, w->name));
+
+  switch(ev) {
+    case EV_WIDGET_CREATE:
+    case EV_WIDGET_DRAW:
+    case EV_WIDGET_REDRAW:
+    case EV_WIDGET_TIMER:
+    case EV_WIDGET_TOUCH_UP:
+    case EV_WIDGET_TOUCH_DOWN:
+    case EV_WIDGET_DESTROY:
+    default: // EV_WIDGET_NONE
+      break;
+  }
+}