Example of using the LittlevGL with the MbedOS (bare metal) on the Disco-F746NG board and also the GPU STM32 chrom-art accelerator is used

Dependencies:   BSP_DISCO_F746NG

Revision:
0:10c4b83c458d
Child:
1:627f26953c53
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Dec 02 19:28:26 2019 +0000
@@ -0,0 +1,78 @@
+//#pragma -O0
+#include "mbed.h"
+#include "lvgl/lvgl.h"
+#include "lv_port_disp.h"
+#include "lv_port_indev.h"
+#include "demo.h" //Comment/uncomment will switch between LittlevGL demo and Hello word example
+
+#define LVGL_TICK 5                             //Time tick value for lvgl in ms (1-10msa)
+#define TICKER_TIME 0.001 * LVGL_TICK           //modified to miliseconds
+#define WAIT_TIME 1000 * LVGL_TICK              //modified to microseconds
+
+Ticker ticker;                                  //Ticker for lvgl                    
+
+//Callback function for lvgl timing.
+void lv_ticker_func(){
+    
+    lv_tick_inc(LVGL_TICK); 
+    //Call lv_tick_inc(x) every x milliseconds in a Timer or Task (x should be between 1 and 10). 
+    //It is required for the internal timing of LittlevGL.
+    lv_task_handler(); 
+    //Call lv_task_handler() periodically every few milliseconds. 
+    //It will redraw the screen if required, handle input devices etc.
+}
+
+//lvgl button object event handler
+void event_handler(lv_obj_t * obj, lv_event_t event){ 
+    if(event == LV_EVENT_CLICKED) {
+        printf("Clicked\n");
+    }
+    else if(event == LV_EVENT_VALUE_CHANGED) {
+        printf("Toggled\n");
+    }
+} 
+
+int main()
+{
+    printf("LittlevGL GUI-"); 
+    lv_init();                                  //Initialize the LittlevGL
+    lv_port_disp_init();                        //Initialize diplay 
+    lv_port_indev_init();                       //Initialize touchpad
+    ticker.attach(callback(&lv_ticker_func),TICKER_TIME); //Attach callback to ticker
+    
+#ifndef DEMO_H
+    printf("Hello word\n");
+    lv_obj_t * label_h = lv_label_create(lv_scr_act(), NULL);
+    static lv_style_t st;
+    lv_style_copy( &st, &lv_style_plain );
+    st.text.font = &lv_font_roboto_28;
+    lv_obj_set_style( label_h, &st );
+    lv_obj_set_size(label_h, 50, 30);
+    lv_label_set_recolor(label_h, true);
+    lv_label_set_text(label_h, "#ff0000 Hello word#");
+    lv_obj_align(label_h, NULL, LV_ALIGN_IN_TOP_MID, 0, 0);
+    
+    lv_obj_t * label;
+    lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_set_event_cb(btn1, event_handler);
+    lv_obj_align(btn1, NULL, LV_ALIGN_CENTER, 0, -40);
+    label = lv_label_create(btn1, NULL);
+    lv_label_set_text(label, "Button");
+    lv_obj_t *btn2 = lv_btn_create(lv_scr_act(), NULL);
+    lv_obj_set_event_cb(btn2, event_handler);
+    lv_obj_align(btn2, NULL, LV_ALIGN_CENTER, 0, 40);
+    lv_btn_set_toggle(btn2, true);
+    lv_btn_toggle(btn2);
+    lv_btn_set_fit2(btn2, LV_FIT_NONE, LV_FIT_TIGHT);
+    label = lv_label_create(btn2, NULL);
+    lv_label_set_text(label, "Toggled");
+#else   
+    printf("Demo\n");
+    demo_create(); // Demo from lv_examples
+#endif   
+
+    while(1) {
+        //something   
+        //wait_us(WAIT_TIME);
+    }
+}