Merge branch 'dev' of https://github.com/littlevgl/lvgl into dev

.github/workflows/merge-to-dev.yml

@@ -0,0 +1,17 @@
+name: Merge master branch to dev
+on:
+  push:
+    branches:
+      - 'master'
+jobs:
+  merge-branch:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: Merge to dev branch
+        uses: devmasx/merge-branch@v1.1.0
+        with:
+          type: now
+          target_branch: 'dev'
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

examples/arduino/ESP32_TFT_eSPI/ESP32_TFT_eSPI.ino

@@ -0,0 +1,119 @@
+#include <lvgl.h>
+#include <TFT_eSPI.h>
+
+TFT_eSPI tft = TFT_eSPI(); /* TFT instance */
+static lv_disp_buf_t disp_buf;
+static lv_color_t buf[LV_HOR_RES_MAX * 10];
+
+#if USE_LV_LOG != 0
+/* Serial debugging */
+void my_print(lv_log_level_t level, const char * file, uint32_t line, const char * dsc)
+{
+
+    Serial.printf("%s@%d->%s\r\n", file, line, dsc);
+    Serial.flush();
+}
+#endif
+
+/* Display flushing */
+void my_disp_flush(lv_disp_drv_t *disp, const lv_area_t *area, lv_color_t *color_p)
+{
+    uint32_t w = (area->x2 - area->x1 + 1);
+    uint32_t h = (area->y2 - area->y1 + 1);
+
+    tft.startWrite();
+    tft.setAddrWindow(area->x1, area->y1, w, h);
+    tft.pushColors(&color_p->full, w * h, true);
+    tft.endWrite();
+
+    lv_disp_flush_ready(disp);
+}
+
+/*Read the touchpad*/
+bool my_touchpad_read(lv_indev_drv_t * indev_driver, lv_indev_data_t * data)
+{
+    uint16_t touchX, touchY;
+
+    bool touched = tft.getTouch(&touchX, &touchY, 600);
+
+    if(!touched)
+    {
+      data->state = LV_INDEV_STATE_REL;
+      return false;
+    }
+    else
+    {
+      data->state = LV_INDEV_STATE_PR;
+    }
+
+    if(touchX>screenWidth || touchY > screenHeight)
+    {
+      Serial.println("Y or y outside of expected parameters..");
+      Serial.print("y:");
+      Serial.print(touchX);
+      Serial.print(" x:");
+      Serial.print(touchY);
+    }
+    else
+    {
+      /*Set the coordinates*/
+      data->point.x = touchX;
+      data->point.y = touchY;
+  
+      Serial.print("Data x");
+      Serial.println(touchX);
+      
+      Serial.print("Data y");
+      Serial.println(touchY);
+
+    }
+
+    return false; /*Return `false` because we are not buffering and no more data to read*/
+}
+
+void setup()
+{
+    Serial.begin(115200); /* prepare for possible serial debug */
+
+    lv_init();
+
+#if USE_LV_LOG != 0
+    lv_log_register_print_cb(my_print); /* register print function for debugging */
+#endif
+
+    tft.begin(); /* TFT init */
+    tft.setRotation(1); /* Landscape orientation */
+
+    uint16_t calData[5] = { 275, 3620, 264, 3532, 1 };
+    tft.setTouch(calData);
+  
+    lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX * 10);
+
+    /*Initialize the display*/
+    lv_disp_drv_t disp_drv;
+    lv_disp_drv_init(&disp_drv);
+    disp_drv.hor_res = 320;
+    disp_drv.ver_res = 240;
+    disp_drv.flush_cb = my_disp_flush;
+    disp_drv.buffer = &disp_buf;
+    lv_disp_drv_register(&disp_drv);
+
+    /*Initialize the (dummy) input device driver*/
+    lv_indev_drv_t indev_drv;
+    lv_indev_drv_init(&indev_drv);
+    indev_drv.type = LV_INDEV_TYPE_POINTER;
+    indev_drv.read_cb = my_touchpad_read;
+    lv_indev_drv_register(&indev_drv);
+
+		/* Try an example from the lv_examples repository
+		 * https://github.com/lvgl/lv_examples*/
+		lv_ex_btn_1();
+}
+
+
+void loop()
+{
+
+    lv_task_handler(); /* let the GUI do its work */
+    delay(5);
+}

examples/arduino/ESP32_TFT_eSPI/README.md

@@ -0,0 +1,44 @@
+# Example for lv_arduino using a slider
+
+This example has the screen set to 320x480 (ILI9488), change this by altering the following lines in the main ino file:
+
+```C
+int screenWidth = 480;
+int screenHeight = 320;
+```
+
+## Backlight
+
+Change pin 32 to your preferred backlight pin using a PNP transistor (2N3906) or remove the following code and connect directly to +ve:
+
+```C
+  ledcSetup(10, 5000/*freq*/, 10 /*resolution*/);
+  ledcAttachPin(32, 10);
+  analogReadResolution(10);
+  ledcWrite(10,768);
+```
+
+## Theme selection
+
+Change the following to change the theme:
+
+```C
+  lv_theme_t * th = lv_theme_night_init(210, NULL);     //Set a HUE value and a Font for the Night Theme
+  lv_theme_set_current(th);
+```
+
+## Calibration
+
+This is using the bodmer tft_espi driver for touch. To correctly set the calibration load the calibration sketch and replace the following with your values:
+
+```C
+uint16_t calData[5] = { 275, 3620, 264, 3532, 1 };
+```
+
+## Screen rotation
+
+Check the following if you need to alter your screen rotation:
+
+```C
+  tft.setRotation(3);
+```

examples/arduino/README.md

@@ -0,0 +1,37 @@
+# LVGL Arduino examples
+
+LVGL can be installed via Arduino IDE Library Manager or as an .ZIP library.
+It will install [lv_exmaples](https://github.com/lvgl/lv_examples) which contains a lot of examples and demos to try LVGL.
+
+## Example
+
+There are simple examples which use the [TFT_eSPI](https://github.com/Bodmer/TFT_eSPI) library as a TFT driver to simplify testing. 
+To get all this to work you have to setup TFT_eSPI to work with your TFT display type via editing the `User_Setup.h` file in TFT_eSPI library folder, or by selecting your own configurtion in the `User_Setup_Select.h` file in TFT_eSPI library folder.
+
+LVGL library has its own configuration file called `lv_conf.h`. When LVGL is installed to followings needs to be done to configure it:
+1. Go to directory of the installed Arduno libraries
+2. Go to `lvgl` and copy `lv_conf_template.h` as `lvgl.h` next to the `lvgl` folder.
+3. Open `lv_conf.h` and change the first `#if 0` to `#if 1`
+4. Set the resolution of your display in `LV_HOR_RES_MAX` and `LV_VER_RES_MAX`
+5. Set the color depth of you display in `LV_COLOR_DEPTH`
+6. Set `LV_TICK_CUSTOM 1`
+
+## Debugging
+
+In case of trouble there are debug informations inside LVGL. In the `ESP32_TFT_eSPI` example there is `my_print` method, which allow to send this debug informations to the serial interface. To enable this feature you have to edit `lv_conf.h` file and enable logging in section `log settings`:
+
+```c
+/*Log settings*/
+#define USE_LV_LOG      1   /*Enable/disable the log module*/
+#if LV_USE_LOG
+/* How important log should be added:
+ * LV_LOG_LEVEL_TRACE       A lot of logs to give detailed information
+ * LV_LOG_LEVEL_INFO        Log important events
+ * LV_LOG_LEVEL_WARN        Log if something unwanted happened but didn't cause a problem
+ * LV_LOG_LEVEL_ERROR       Only critical issue, when the system may fail
+ * LV_LOG_LEVEL_NONE        Do not log anything
+ */
+#  define LV_LOG_LEVEL    LV_LOG_LEVEL_WARN
+```
+
+After enabling log module and setting LV_LOG_LEVEL accordingly the output log is sent to the `Serial` port @ 115200 Bd.

lv_conf_template.h

@@ -268,8 +268,8 @@ typedef void * lv_img_decoder_user_data_t;
  * It removes the need to manually update the tick with `lv_tick_inc`) */
 #define LV_TICK_CUSTOM     0
 #if LV_TICK_CUSTOM == 1
-#define LV_TICK_CUSTOM_INCLUDE  "something.h"       /*Header for the sys time function*/
-#define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current systime in ms*/
+#define LV_TICK_CUSTOM_INCLUDE  "Arduino.h"         /*Header for the system time function*/
+#define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current system time in ms*/
 #endif   /*LV_TICK_CUSTOM*/
 
 typedef void * lv_disp_drv_user_data_t;             /*Type of user data in the display driver*/

src/lv_conf_internal.h

@@ -394,10 +394,10 @@ e.g. "stm32f769xx.h" or "stm32f429xx.h" */
 #endif
 #if LV_TICK_CUSTOM == 1
 #ifndef LV_TICK_CUSTOM_INCLUDE
-#define LV_TICK_CUSTOM_INCLUDE  "something.h"       /*Header for the sys time function*/
+#define LV_TICK_CUSTOM_INCLUDE  "Arduino.h"       /*Header for the sys time function*/
 #endif
 #ifndef LV_TICK_CUSTOM_SYS_TIME_EXPR
-#define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current systime in ms*/
+#define LV_TICK_CUSTOM_SYS_TIME_EXPR (millis())     /*Expression evaluating to current sys time in ms*/
 #endif
 #endif   /*LV_TICK_CUSTOM*/
 

src/lv_gpu/lv_gpu_stm32_dma2d.c

@@ -27,9 +27,9 @@
 #endif
 
 #if LV_COLOR_DEPTH == 16
-    #define DMA2D_COLOR_FORMAT DMA2D_RGB565
+    #define LV_DMA2D_COLOR_FORMAT LV_DMA2D_RGB565
 #elif LV_COLOR_DEPTH == 32
-    #define DMA2D_COLOR_FORMAT DMA2D_ARGB8888
+    #define LV_DMA2D_COLOR_FORMAT LV_DMA2D_ARGB8888
 #else
     /*Can't use GPU with other formats*/
 #endif
@@ -68,7 +68,7 @@ void lv_gpu_stm32_dma2d_init(void)
     volatile uint32_t temp = RCC->AHB1ENR;
 
     /* set output colour mode */
-    DMA2D->OPFCCR = DMA2D_COLOR_FORMAT;
+    DMA2D->OPFCCR = LV_DMA2D_COLOR_FORMAT;
 }
 
 /**
@@ -160,7 +160,7 @@ void lv_gpu_stm32_dma2d_copy(lv_color_t * buf, lv_coord_t buf_w, const lv_color_
 
     DMA2D->CR = 0;
     /* copy output colour mode, this register controls both input and output colour format */
-    DMA2D->FGPFCCR = DMA2D_COLOR_FORMAT;
+    DMA2D->FGPFCCR = LV_DMA2D_COLOR_FORMAT;
     DMA2D->FGMAR = (uint32_t)map;
     DMA2D->FGOR = map_w - copy_w;
     DMA2D->OMAR = (uint32_t)buf;
@@ -189,11 +189,11 @@ void lv_gpu_stm32_dma2d_blend(lv_color_t * buf, lv_coord_t buf_w, const lv_color
     invalidate_cache();
     DMA2D->CR = 0x20000;
 
-    DMA2D->BGPFCCR = DMA2D_COLOR_FORMAT;
+    DMA2D->BGPFCCR = LV_DMA2D_COLOR_FORMAT;
     DMA2D->BGMAR = (uint32_t)buf;
     DMA2D->BGOR = buf_w - copy_w;
 
-    DMA2D->FGPFCCR = (uint32_t)DMA2D_COLOR_FORMAT
+    DMA2D->FGPFCCR = (uint32_t)LV_DMA2D_COLOR_FORMAT
     /* alpha mode 2, replace with foreground * alpha value */
     | (2 << DMA2D_FGPFCCR_AM_Pos)
     /* alpha value */

src/lv_gpu/lv_gpu_stm32_dma2d.h

@@ -20,11 +20,11 @@ extern "C" {
  *      DEFINES
  *********************/
 
-#define DMA2D_ARGB8888 0
-#define DMA2D_RGB888 1
-#define DMA2D_RGB565 2
-#define DMA2D_ARGB1555 3
-#define DMA2D_ARGB4444 4
+#define LV_DMA2D_ARGB8888 0
+#define LV_DMA2D_RGB888 1
+#define LV_DMA2D_RGB565 2
+#define LV_DMA2D_ARGB1555 3
+#define LV_DMA2D_ARGB4444 4
 
 /**********************
  *      TYPEDEFS

src/lv_hal/lv_hal_tick.c

@@ -29,7 +29,7 @@
  *  STATIC VARIABLES
  **********************/
 static uint32_t sys_time = 0;
-static volatile uint32_t tick_irq_flag;
+static volatile uint8_t tick_irq_flag;
 
 /**********************
  *      MACROS

src/lv_themes/lv_theme.c

@@ -106,6 +106,17 @@ void lv_theme_set_base(lv_theme_t * new, lv_theme_t * base)
     new->base = base;
 }
 
+/**
+ * Set a callback for a theme.
+ * The callback is used to add styles to different objects
+ * @param theme pointer to theme which callback should be set
+ * @param cb pointer to the callback
+ */
+void lv_theme_set_apply_cb(lv_theme_t * theme, lv_theme_apply_cb_t apply_cb)
+{
+    theme->apply_cb = apply_cb;
+}
+
 /**
  * Get the small font of the theme
  * @return pointer to the font

src/lv_themes/lv_theme.h

@@ -206,6 +206,14 @@ void lv_theme_copy(lv_theme_t * theme, const lv_theme_t * copy);
  */
 void lv_theme_set_base(lv_theme_t * new, lv_theme_t * base);
 
+/**
+ * Set an apply callback for a theme.
+ * The apply callback is used to add styles to different objects
+ * @param theme pointer to theme which callback should be set
+ * @param apply_cb pointer to the callback
+ */
+void lv_theme_set_apply_cb(lv_theme_t * theme, lv_theme_apply_cb_t apply_cb);
+
 /**
  * Get the small font of the theme
  * @return pointer to the font

src/lv_themes/lv_theme_material.c

@@ -792,6 +792,39 @@ static void roller_init(void)
 static void tabview_init(void)
 {
 #if LV_USE_TABVIEW != 0
+#endif
+}
+
+static void tileview_init(void)
+{
+#if LV_USE_TILEVIEW != 0
+#endif
+}
+
+static void table_init(void)
+{
+#if LV_USE_TABLE != 0
+    style_init_reset(&styles->table_cell);
+    lv_style_set_border_color(&styles->table_cell, LV_STATE_DEFAULT, COLOR_BG_BORDER);
+    lv_style_set_border_width(&styles->table_cell, LV_STATE_DEFAULT, 1);
+    lv_style_set_border_side(&styles->table_cell, LV_STATE_DEFAULT, LV_BORDER_SIDE_TOP | LV_BORDER_SIDE_BOTTOM);
+    lv_style_set_pad_left(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
+    lv_style_set_pad_right(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
+    lv_style_set_pad_top(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
+    lv_style_set_pad_bottom(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
+
+#endif
+}
+
+static void win_init(void)
+{
+#if LV_USE_WIN != 0
+#endif
+}
+
+static void tabview_win_shared_init(void)
+{
+#if LV_USE_TABVIEW || LV_USE_WIN
     style_init_reset(&styles->tabview_btns_bg);
     lv_style_set_bg_opa(&styles->tabview_btns_bg, LV_STATE_DEFAULT, LV_OPA_COVER);
     lv_style_set_bg_color(&styles->tabview_btns_bg, LV_STATE_DEFAULT, COLOR_BG);
@@ -831,34 +864,6 @@ static void tabview_init(void)
 #endif
 }
 
-static void tileview_init(void)
-{
-#if LV_USE_TILEVIEW != 0
-#endif
-}
-
-static void table_init(void)
-{
-#if LV_USE_TABLE != 0
-    style_init_reset(&styles->table_cell);
-    lv_style_set_border_color(&styles->table_cell, LV_STATE_DEFAULT, COLOR_BG_BORDER);
-    lv_style_set_border_width(&styles->table_cell, LV_STATE_DEFAULT, 1);
-    lv_style_set_border_side(&styles->table_cell, LV_STATE_DEFAULT, LV_BORDER_SIDE_TOP | LV_BORDER_SIDE_BOTTOM);
-    lv_style_set_pad_left(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
-    lv_style_set_pad_right(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
-    lv_style_set_pad_top(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
-    lv_style_set_pad_bottom(&styles->table_cell, LV_STATE_DEFAULT, PAD_DEF);
-
-#endif
-}
-
-static void win_init(void)
-{
-#if LV_USE_WIN != 0
-
-#endif
-}
-
 
 /**********************
  *   GLOBAL FUNCTIONS
@@ -927,6 +932,7 @@ lv_theme_t * lv_theme_material_init(lv_color_t color_primary, lv_color_t color_s
     tileview_init();
     table_init();
     win_init();
+    tabview_win_shared_init();
 
     theme.apply_xcb = NULL;
     theme.apply_cb = theme_apply;

src/lv_widgets/lv_btn.c

@@ -289,6 +289,7 @@ static lv_res_t lv_btn_signal(lv_obj_t * btn, lv_signal_t sign, void * param)
         }
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT || c == LV_KEY_UP) {
             if(lv_btn_get_checkable(btn)) {
@@ -309,6 +310,7 @@ static lv_res_t lv_btn_signal(lv_obj_t * btn, lv_signal_t sign, void * param)
                 if(res != LV_RES_OK) return res;
             }
         }
+#endif
     }
 
     return res;

src/lv_widgets/lv_btnmatrix.c

@@ -992,6 +992,7 @@ static lv_res_t lv_btnmatrix_signal(lv_obj_t * btnm, lv_signal_t sign, void * pa
         ext->btn_id_act = LV_BTNMATRIX_BTN_NONE;
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT) {
             if(ext->btn_id_focused == LV_BTNMATRIX_BTN_NONE)
@@ -1059,10 +1060,13 @@ static lv_res_t lv_btnmatrix_signal(lv_obj_t * btnm, lv_signal_t sign, void * pa
             ext->btn_id_act = ext->btn_id_focused;
             lv_obj_invalidate(btnm);
         }
+#endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
     return res;
 }

src/lv_widgets/lv_calendar.c

@@ -519,6 +519,7 @@ static lv_res_t lv_calendar_signal(lv_obj_t * calendar, lv_signal_t sign, void *
         lv_obj_invalidate(calendar);
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         uint8_t c               = *((uint8_t *)param);
         lv_calendar_ext_t * ext = lv_obj_get_ext_attr(calendar);
         if(c == LV_KEY_RIGHT || c == LV_KEY_UP) {
@@ -541,6 +542,7 @@ static lv_res_t lv_calendar_signal(lv_obj_t * calendar, lv_signal_t sign, void *
             }
             lv_obj_invalidate(calendar);
         }
+#endif
     }
 
     return res;

src/lv_widgets/lv_checkbox.c

@@ -193,11 +193,13 @@ static lv_res_t lv_checkbox_signal(lv_obj_t * cb, lv_signal_t sign, void * param
         lv_obj_set_state(ext->bullet, lv_obj_get_state(cb, LV_CHECKBOX_PART_BG));
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT || c == LV_KEY_DOWN || c == LV_KEY_LEFT || c == LV_KEY_UP) {
             /*Follow the backgrounds state with the bullet*/
             lv_obj_set_state(ext->bullet, lv_obj_get_state(cb, LV_CHECKBOX_PART_BG));
         }
+#endif
     }
 
     return res;

src/lv_widgets/lv_cpicker.c

@@ -701,6 +701,7 @@ static lv_res_t lv_cpicker_signal(lv_obj_t * cpicker, lv_signal_t sign, void * p
         lv_obj_invalidate(cpicker);
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         uint32_t c = *((uint32_t *)param); /*uint32_t because can be UTF-8*/
 
         if(c == LV_KEY_RIGHT || c == LV_KEY_UP) {
@@ -745,6 +746,7 @@ static lv_res_t lv_cpicker_signal(lv_obj_t * cpicker, lv_signal_t sign, void * p
                 if(res != LV_RES_OK) return res;
             }
         }
+#endif
     }
     else if(sign == LV_SIGNAL_PRESSED) {
         ext->last_change_time = lv_tick_get();

src/lv_widgets/lv_dropdown.c

@@ -968,6 +968,7 @@ static lv_res_t lv_dropdown_signal(lv_obj_t * ddlist, lv_signal_t sign, void * p
         if(ext->page) lv_obj_refresh_style(ext->page, LV_STYLE_PROP_ALL);
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT || c == LV_KEY_DOWN) {
             if(ext->page == NULL) {
@@ -992,10 +993,13 @@ static lv_res_t lv_dropdown_signal(lv_obj_t * ddlist, lv_signal_t sign, void * p
             ext->sel_opt_id = ext->sel_opt_id_orig;
             lv_dropdown_close(ddlist);
         }
+#endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
 
     return res;

src/lv_widgets/lv_list.c

@@ -730,8 +730,10 @@ static lv_res_t lv_list_signal(lv_obj_t * list, lv_signal_t sign, void * param)
 #endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
     else if(sign == LV_SIGNAL_CONTROL) {
 

src/lv_widgets/lv_msgbox.c

@@ -412,6 +412,7 @@ static lv_res_t lv_msgbox_signal(lv_obj_t * mbox, lv_signal_t sign, void * param
 {
     lv_res_t res;
 
+#if LV_USE_GROUP
     /*Translate LV_KEY_UP/DOWN to LV_KEY_LEFT/RIGHT */
     char c_trans = 0;
     if(sign == LV_SIGNAL_CONTROL) {
@@ -421,6 +422,7 @@ static lv_res_t lv_msgbox_signal(lv_obj_t * mbox, lv_signal_t sign, void * param
 
         param = &c_trans;
     }
+#endif
 
     if(sign == LV_SIGNAL_GET_STYLE) {
         lv_get_style_info_t * info = param;
@@ -460,8 +462,11 @@ static lv_res_t lv_msgbox_signal(lv_obj_t * mbox, lv_signal_t sign, void * param
             if(btn_id != LV_BTNMATRIX_BTN_NONE) lv_event_send(mbox, LV_EVENT_VALUE_CHANGED, &btn_id);
         }
     }
-    else if(sign == LV_SIGNAL_FOCUS || sign == LV_SIGNAL_DEFOCUS || sign == LV_SIGNAL_CONTROL ||
-            sign == LV_SIGNAL_GET_EDITABLE) {
+    else if(
+#if LV_USE_GROUP
+        sign == LV_SIGNAL_CONTROL || sign == LV_SIGNAL_GET_EDITABLE ||
+#endif
+        sign == LV_SIGNAL_FOCUS || sign == LV_SIGNAL_DEFOCUS) {
         if(ext->btnm) {
             ext->btnm->signal_cb(ext->btnm, sign, param);
         }

src/lv_widgets/lv_page.c

@@ -859,6 +859,7 @@ static lv_res_t lv_page_signal(lv_obj_t * page, lv_signal_t sign, void * param)
         refr_ext_draw_pad(page);
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         uint32_t c = *((uint32_t *)param);
 
         if(c == LV_KEY_DOWN) {
@@ -883,10 +884,13 @@ static lv_res_t lv_page_signal(lv_obj_t * page, lv_signal_t sign, void * param)
             else
                 lv_page_scroll_hor(page, lv_obj_get_width(page) / 4);
         }
+#endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
 
     return res;

src/lv_widgets/lv_roller.c

@@ -574,13 +574,16 @@ static lv_res_t lv_roller_signal(lv_obj_t * roller, lv_signal_t sign, void * par
 
     /* Include the ancient signal function */
     if(sign != LV_SIGNAL_CONTROL) { /*Don't let the page to scroll on keys*/
+#if LV_USE_GROUP
         res = ancestor_signal(roller, sign, param);
         if(res != LV_RES_OK) return res;
+#endif
     }
 
     if(sign == LV_SIGNAL_GET_TYPE) return lv_obj_handle_get_type_signal(param, LV_OBJX_NAME);
 
     lv_roller_ext_t * ext = lv_obj_get_ext_attr(roller);
+    LV_UNUSED(ext);
 
     if(sign == LV_SIGNAL_STYLE_CHG) {
         lv_obj_t * label = get_label(roller);
@@ -640,6 +643,7 @@ static lv_res_t lv_roller_signal(lv_obj_t * roller, lv_signal_t sign, void * par
 #endif
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT || c == LV_KEY_DOWN) {
             if(ext->sel_opt_id + 1 < ext->option_cnt) {
@@ -656,6 +660,7 @@ static lv_res_t lv_roller_signal(lv_obj_t * roller, lv_signal_t sign, void * par
                 ext->sel_opt_id_ori = ori_id;
             }
         }
+#endif
     }
     else if(sign == LV_SIGNAL_CLEANUP) {
         lv_obj_clean_style_list(roller, LV_ROLLER_PART_SELECTED);

src/lv_widgets/lv_slider.c

@@ -407,6 +407,7 @@ static lv_res_t lv_slider_signal(lv_obj_t * slider, lv_signal_t sign, void * par
 
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
 
         if(c == LV_KEY_RIGHT || c == LV_KEY_UP) {
@@ -419,13 +420,16 @@ static lv_res_t lv_slider_signal(lv_obj_t * slider, lv_signal_t sign, void * par
             res = lv_event_send(slider, LV_EVENT_VALUE_CHANGED, NULL);
             if(res != LV_RES_OK) return res;
         }
+#endif
     }
     else if(sign == LV_SIGNAL_CLEANUP) {
         lv_obj_clean_style_list(slider, LV_SLIDER_PART_KNOB);
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
 
     return res;

src/lv_widgets/lv_spinbox.c

@@ -390,8 +390,10 @@ static lv_res_t lv_spinbox_signal(lv_obj_t * spinbox, lv_signal_t sign, void * p
 
     /* Include the ancient signal function */
     if(sign != LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         res = ancestor_signal(spinbox, sign, param);
         if(res != LV_RES_OK) return res;
+#endif
     }
     if(sign == LV_SIGNAL_GET_TYPE) return lv_obj_handle_get_type_signal(param, LV_OBJX_NAME);
 
@@ -464,6 +466,7 @@ static lv_res_t lv_spinbox_signal(lv_obj_t * spinbox, lv_signal_t sign, void * p
         }
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         lv_indev_type_t indev_type = lv_indev_get_type(lv_indev_get_act());
 
         uint32_t c = *((uint32_t *)param); /*uint32_t because can be UTF-8*/
@@ -488,6 +491,7 @@ static lv_res_t lv_spinbox_signal(lv_obj_t * spinbox, lv_signal_t sign, void * p
         else {
             lv_textarea_add_char(spinbox, c);
         }
+#endif
     }
 
     return res;

src/lv_widgets/lv_switch.c

@@ -296,12 +296,14 @@ static lv_res_t lv_switch_signal(lv_obj_t * sw, lv_signal_t sign, void * param)
 
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         char c = *((char *)param);
         if(c == LV_KEY_RIGHT || c == LV_KEY_UP) lv_switch_on(sw, LV_ANIM_ON);
         else if(c == LV_KEY_LEFT || c == LV_KEY_DOWN) lv_switch_off(sw, LV_ANIM_ON);
 
         res   = lv_event_send(sw, LV_EVENT_VALUE_CHANGED, NULL);
         if(res != LV_RES_OK) return res;
+#endif
     }
     else if(sign == LV_SIGNAL_REFR_EXT_DRAW_PAD) {
         lv_style_int_t knob_left = lv_obj_get_style_pad_left(sw,   LV_SWITCH_PART_KNOB);
@@ -320,8 +322,10 @@ static lv_res_t lv_switch_signal(lv_obj_t * sw, lv_signal_t sign, void * param)
         sw->ext_draw_pad = LV_MATH_MAX(sw->ext_draw_pad, knob_size);
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = false; /*The ancestor slider is editable the switch is not*/
+#endif
     }
 
     return res;

src/lv_widgets/lv_tabview.c

@@ -645,12 +645,17 @@ static lv_res_t lv_tabview_signal(lv_obj_t * tabview, lv_signal_t sign, void * p
 #endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
 
-    if(sign == LV_SIGNAL_FOCUS || sign == LV_SIGNAL_DEFOCUS || sign == LV_SIGNAL_CONTROL || sign == LV_SIGNAL_PRESSED  ||
-       sign == LV_SIGNAL_RELEASED) {
+    if(sign == LV_SIGNAL_FOCUS || sign == LV_SIGNAL_DEFOCUS ||
+#if LV_USE_GROUP
+       sign == LV_SIGNAL_CONTROL ||
+#endif
+       sign == LV_SIGNAL_PRESSED || sign == LV_SIGNAL_RELEASED) {
 
         /* The button matrix is not in a group (the tab view is in it) but it should handle the
          * group signals. So propagate the related signals to the button matrix manually*/

src/lv_widgets/lv_textarea.c

@@ -221,7 +221,7 @@ lv_obj_t * lv_textarea_create(lv_obj_t * par, const lv_obj_t * copy)
 
 /**
  * Insert a character to the current cursor position.
- * To add a wide char, e.g. 'Á' use `lv_txt_encoded_conv_wc('Á')`
+ * To add a wide char, e.g. 'Á' use `_lv_txt_encoded_conv_wc('Á')`
  * @param ta pointer to a text area object
  * @param c a character (e.g. 'a')
  */
@@ -1466,6 +1466,7 @@ static lv_res_t lv_textarea_signal(lv_obj_t * ta, lv_signal_t sign, void * param
         }
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         uint32_t c = *((uint32_t *)param); /*uint32_t because can be UTF-8*/
         if(c == LV_KEY_RIGHT)
             lv_textarea_cursor_right(ta);
@@ -1486,10 +1487,13 @@ static lv_res_t lv_textarea_signal(lv_obj_t * ta, lv_signal_t sign, void * param
         else {
             lv_textarea_add_char(ta, c);
         }
+#endif
     }
     else if(sign == LV_SIGNAL_GET_EDITABLE) {
+#if LV_USE_GROUP
         bool * editable = (bool *)param;
         *editable       = true;
+#endif
     }
     else if(sign == LV_SIGNAL_PRESSED || sign == LV_SIGNAL_PRESSING || sign == LV_SIGNAL_PRESS_LOST ||
             sign == LV_SIGNAL_RELEASED) {

src/lv_widgets/lv_textarea.h

@@ -106,7 +106,7 @@ lv_obj_t * lv_textarea_create(lv_obj_t * par, const lv_obj_t * copy);
 
 /**
  * Insert a character to the current cursor position.
- * To add a wide char, e.g. 'Á' use `lv_txt_encoded_conv_wc('Á')`
+ * To add a wide char, e.g. 'Á' use `_lv_txt_encoded_conv_wc('Á')`
  * @param ta pointer to a text area object
  * @param c a character (e.g. 'a')
  */

src/lv_widgets/lv_win.c

@@ -645,8 +645,10 @@ static lv_res_t lv_win_signal(lv_obj_t * win, lv_signal_t sign, void * param)
         ext->title_txt  = NULL;
     }
     else if(sign == LV_SIGNAL_CONTROL) {
+#if LV_USE_GROUP
         /*Forward all the control signals to the page*/
         ext->page->signal_cb(ext->page, sign, param);
+#endif
     }
 
     return res;

src/lvgl.h

@@ -0,0 +1,39 @@
+/**
+ * @file lvgl.h
+ * This file exists only to be compatible with Arduino's library structure
+ */
+
+#ifndef LVGL_SRC_H
+#define LVGL_SRC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+
+#include "../lvgl.h"
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+/**********************
+ *      MACROS
+ **********************/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*LVGL_SRC_H*/