update

csrc/mui.c

@@ -282,12 +282,15 @@ static size_t mui_fds_get_cmd_size(mui_t *ui, fds_t *s)
 }
 
 
-
+/*
+  mui_Init() will setup the menu system but will not activate or display anything.
+  Use mui_GotoForm() after this command, then use mui_Draw() to draw the menu on a display.
+*/
 void mui_Init(mui_t *ui, void *graphics_data, fds_t *fds, muif_t *muif_tlist, size_t muif_tcnt)
 {
   memset(ui, 0, sizeof(mui_t));
   ui->root_fds = fds;
-  ui->current_form_fds = fds;
+  //ui->current_form_fds = NULL;   // not required, because there was a memset before
   ui->muif_tlist = muif_tlist;
   ui->muif_tcnt = muif_tcnt;
   ui->graphics_data = graphics_data;
@@ -424,7 +427,7 @@ void mui_inner_loop_over_form(mui_t *ui, uint8_t (*task)(mui_t *ui))
 
 void mui_loop_over_form(mui_t *ui, uint8_t (*task)(mui_t *ui))
 {
-  if ( ui->current_form_fds == NULL )
+  if ( mui_IsFormActive(ui) == 0 )
     return;
   
   ui->fds = ui->current_form_fds;
@@ -635,15 +638,21 @@ void mui_GetSelectableFieldTextOption(mui_t *ui, uint8_t form_id, uint8_t cursor
 }
 
 /* 
-  input: current_form_fds 
   if called from a field function, then the current field variables are destroyed, so that call should be the last call in the field callback.
+  mui_EnterForm is similar to mui_GotoForm and differes only in the second argument (which is the form id instead of the fds pointer)
 */
-void mui_EnterForm(mui_t *ui, uint8_t initial_cursor_position)
+void mui_EnterForm(mui_t *ui, fds_t *fds, uint8_t initial_cursor_position)
 {
+  /* exit any previous form, will not do anything if there is no current form */
+  mui_LeaveForm(ui);
+  
   /* clean focus fields */
   ui->touch_focus_fds = NULL;
   ui->cursor_focus_fds = NULL;
   
+  /* assign the form, which should be entered */
+  ui->current_form_fds = fds;
+  
   /* inform all fields that we start a new form */
   mui_loop_over_form(ui, mui_task_form_start);
   
@@ -666,6 +675,9 @@ void mui_EnterForm(mui_t *ui, uint8_t initial_cursor_position)
 */
 void mui_LeaveForm(mui_t *ui)
 {
+  if ( mui_IsFormActive(ui) == 0 )
+    return;
+  
   mui_send_cursor_msg(ui, MUIF_MSG_CURSOR_LEAVE);
   ui->cursor_focus_fds = NULL;
   
@@ -683,17 +695,16 @@ uint8_t mui_GotoForm(mui_t *ui, uint8_t form_id, uint8_t initial_cursor_position
   fds_t *fds = mui_find_form(ui, form_id);
   if ( fds == NULL )
     return 0;
-  mui_LeaveForm(ui);
-  ui->current_form_fds = fds;
-  mui_EnterForm(ui, initial_cursor_position);
+  /* EnterForm will also leave any previous form */
+  mui_EnterForm(ui, fds, initial_cursor_position);
   return 1;
 }
 
 void mui_SaveForm(mui_t *ui)
 {
-  if ( ui->current_form_fds == NULL )
+  if ( mui_IsFormActive(ui) == 0 )
     return;
-
+  
   ui->last_form_id = mui_get_fds_char(ui->current_form_fds+1);
   ui->last_form_cursor_focus_position = mui_GetCurrentCursorFocusPosition(ui);
 }

csrc/mui.h

@@ -501,7 +501,7 @@ void mui_Init(mui_t *ui, void *graphics_data, fds_t *fds, muif_t *muif_tlist, si
 uint8_t mui_GetCurrentCursorFocusPosition(mui_t *ui);
 void mui_Draw(mui_t *ui);
 void mui_GetSelectableFieldTextOption(mui_t *ui, uint8_t form_id, uint8_t cursor_position, uint8_t nth_token);
-void mui_EnterForm(mui_t *ui, uint8_t initial_cursor_position);
+void mui_EnterForm(mui_t *ui, fds_t *fds, uint8_t initial_cursor_position);
 void mui_LeaveForm(mui_t *ui);
 uint8_t mui_GotoForm(mui_t *ui, uint8_t form_id, uint8_t initial_cursor_position);
 void mui_SaveForm(mui_t *ui);
@@ -510,6 +510,7 @@ void mui_NextField(mui_t *ui);
 void mui_PrevField(mui_t *ui);
 void mui_SendSelect(mui_t *ui);
 
+#define mui_IsFormActive(ui) ((ui)->current_form_fds != NULL) 
 
 #ifdef __cplusplus
 }

sys/arduino/u8g2_page_buffer/MUIDemo/MUIDemo.ino

@@ -520,7 +520,7 @@ void setup(void) {
   //u8g2.begin(/*Select=*/ 7, /*Right/Next=*/ A1, /*Left/Prev=*/ A2, /*Up=*/ A0, /*Down=*/ A3, /*Home/Cancel=*/ 8); // Arduboy 10 (Production)
   
   mui_Init(&ui, u8g2.getU8g2(), fds_data, muif_list, sizeof(muif_list)/sizeof(muif_t));
-  mui_EnterForm(&ui, 0);
+  mui_GotoForm(&ui, /* form_id= */ 1, /* initial_cursor_position= */ 0);
   
 }
 
@@ -528,31 +528,41 @@ uint8_t is_redraw = 1;
 
 void loop(void) {
 
-  /* draw the menu */
+  /* check whether the menu is active */
+  if ( mui_IsFormActive(&ui) )
+  {
 
-  if ( is_redraw ) {
-    u8g2.firstPage();
-    do {
-        mui_Draw(&ui);
-    } while( u8g2.nextPage() );
-    is_redraw = 0;
+    /* if so, then draw the menu */
+
+    if ( is_redraw ) {
+      u8g2.firstPage();
+      do {
+          mui_Draw(&ui);
+      } while( u8g2.nextPage() );
+      is_redraw = 0;
+    }
+    
+    /* handle events */
+    
+    switch(u8g2.getMenuEvent()) {
+      case U8X8_MSG_GPIO_MENU_SELECT:
+        mui_SendSelect(&ui);
+        is_redraw = 1;
+        break;
+      case U8X8_MSG_GPIO_MENU_NEXT:
+        mui_NextField(&ui);
+        is_redraw = 1;
+        break;
+      case U8X8_MSG_GPIO_MENU_PREV:
+        mui_PrevField(&ui);
+        is_redraw = 1;
+        break;
+    }
+    
   }
-  
-  /* handle events */
-  
-  switch(u8g2.getMenuEvent()) {
-    case U8X8_MSG_GPIO_MENU_SELECT:
-      mui_SendSelect(&ui);
-      is_redraw = 1;
-      break;
-    case U8X8_MSG_GPIO_MENU_NEXT:
-      mui_NextField(&ui);
-      is_redraw = 1;
-      break;
-    case U8X8_MSG_GPIO_MENU_PREV:
-      mui_PrevField(&ui);
-      is_redraw = 1;
-      break;
+  else
+  {
+    /* do something else, maybe clear the screen */
   }
 
 }