chore(conf) update lv_conf_template.h with demos

lv_conf_template.h

@@ -618,6 +618,35 @@
 /*Enable the examples to be built with the library*/
 #define LV_BUILD_EXAMPLES 1
 
+/*===================
+ * DEMO USAGE
+ ====================*/
+
+/*Show some widget*/
+#define LV_USE_DEMO_WIDGETS        1
+#if LV_USE_DEMO_WIDGETS
+#define LV_DEMO_WIDGETS_SLIDESHOW  0
+#endif
+
+/*Demonstrate the usage of encoder and keyboard*/
+#define LV_USE_DEMO_KEYPAD_AND_ENCODER     1
+
+/*Benchmark your system*/
+#define LV_USE_DEMO_BENCHMARK   1
+
+/*Stress test for LVGL*/
+#define LV_USE_DEMO_STRESS      1
+
+/*Music player demo*/
+#define LV_USE_DEMO_MUSIC       1
+#if LV_USE_DEMO_MUSIC
+# define LV_DEMO_MUSIC_SQUARE       0
+# define LV_DEMO_MUSIC_LANDSCAPE    0
+# define LV_DEMO_MUSIC_ROUND        0
+# define LV_DEMO_MUSIC_LARGE        0
+# define LV_DEMO_MUSIC_AUTO_PLAY    0
+#endif
+
 /*--END OF LV_CONF_H--*/
 
 #endif /*LV_CONF_H*/

src/core/lv_obj_style.c

@@ -422,7 +422,7 @@ void lv_obj_fade_in(lv_obj_t * obj, uint32_t time, uint32_t delay)
     lv_anim_t a;
     lv_anim_init(&a);
     lv_anim_set_var(&a, obj);
-    lv_anim_set_values(&a, lv_obj_get_style_opa(obj, 0), LV_OPA_COVER);
+    lv_anim_set_values(&a, 0, LV_OPA_COVER);
     lv_anim_set_exec_cb(&a, fade_anim_cb);
     lv_anim_set_ready_cb(&a, fade_in_anim_ready);
     lv_anim_set_time(&a, time);

src/lv_conf_internal.h

@@ -1981,6 +1981,121 @@
     #endif
 #endif
 
+/*===================
+ * DEMO USAGE
+ ====================*/
+
+/*Show some widget*/
+#ifndef LV_USE_DEMO_WIDGETS
+    #ifdef _LV_KCONFIG_PRESENT
+        #ifdef CONFIG_LV_USE_DEMO_WIDGETS
+            #define LV_USE_DEMO_WIDGETS CONFIG_LV_USE_DEMO_WIDGETS
+        #else
+            #define LV_USE_DEMO_WIDGETS 0
+        #endif
+    #else
+        #define LV_USE_DEMO_WIDGETS        1
+    #endif
+#endif
+#if LV_USE_DEMO_WIDGETS
+#ifndef LV_DEMO_WIDGETS_SLIDESHOW
+    #ifdef CONFIG_LV_DEMO_WIDGETS_SLIDESHOW
+        #define LV_DEMO_WIDGETS_SLIDESHOW CONFIG_LV_DEMO_WIDGETS_SLIDESHOW
+    #else
+        #define LV_DEMO_WIDGETS_SLIDESHOW  0
+    #endif
+#endif
+#endif
+
+/*Demonstrate the usage of encoder and keyboard*/
+#ifndef LV_USE_DEMO_KEYPAD_AND_ENCODER
+    #ifdef _LV_KCONFIG_PRESENT
+        #ifdef CONFIG_LV_USE_DEMO_KEYPAD_AND_ENCODER
+            #define LV_USE_DEMO_KEYPAD_AND_ENCODER CONFIG_LV_USE_DEMO_KEYPAD_AND_ENCODER
+        #else
+            #define LV_USE_DEMO_KEYPAD_AND_ENCODER 0
+        #endif
+    #else
+        #define LV_USE_DEMO_KEYPAD_AND_ENCODER     1
+    #endif
+#endif
+
+/*Benchmark your system*/
+#ifndef LV_USE_DEMO_BENCHMARK
+    #ifdef _LV_KCONFIG_PRESENT
+        #ifdef CONFIG_LV_USE_DEMO_BENCHMARK
+            #define LV_USE_DEMO_BENCHMARK CONFIG_LV_USE_DEMO_BENCHMARK
+        #else
+            #define LV_USE_DEMO_BENCHMARK 0
+        #endif
+    #else
+        #define LV_USE_DEMO_BENCHMARK   1
+    #endif
+#endif
+
+/*Stress test for LVGL*/
+#ifndef LV_USE_DEMO_STRESS
+    #ifdef _LV_KCONFIG_PRESENT
+        #ifdef CONFIG_LV_USE_DEMO_STRESS
+            #define LV_USE_DEMO_STRESS CONFIG_LV_USE_DEMO_STRESS
+        #else
+            #define LV_USE_DEMO_STRESS 0
+        #endif
+    #else
+        #define LV_USE_DEMO_STRESS      1
+    #endif
+#endif
+
+/*Music player demo*/
+#ifndef LV_USE_DEMO_MUSIC
+    #ifdef _LV_KCONFIG_PRESENT
+        #ifdef CONFIG_LV_USE_DEMO_MUSIC
+            #define LV_USE_DEMO_MUSIC CONFIG_LV_USE_DEMO_MUSIC
+        #else
+            #define LV_USE_DEMO_MUSIC 0
+        #endif
+    #else
+        #define LV_USE_DEMO_MUSIC       1
+    #endif
+#endif
+#if LV_USE_DEMO_MUSIC
+#ifndef LV_DEMO_MUSIC_SQUARE
+    #ifdef CONFIG_LV_DEMO_MUSIC_SQUARE
+        #define LV_DEMO_MUSIC_SQUARE CONFIG_LV_DEMO_MUSIC_SQUARE
+    #else
+        #define LV_DEMO_MUSIC_SQUARE       0
+    #endif
+#endif
+#ifndef LV_DEMO_MUSIC_LANDSCAPE
+    #ifdef CONFIG_LV_DEMO_MUSIC_LANDSCAPE
+        #define LV_DEMO_MUSIC_LANDSCAPE CONFIG_LV_DEMO_MUSIC_LANDSCAPE
+    #else
+        #define LV_DEMO_MUSIC_LANDSCAPE    0
+    #endif
+#endif
+#ifndef LV_DEMO_MUSIC_ROUND
+    #ifdef CONFIG_LV_DEMO_MUSIC_ROUND
+        #define LV_DEMO_MUSIC_ROUND CONFIG_LV_DEMO_MUSIC_ROUND
+    #else
+        #define LV_DEMO_MUSIC_ROUND        0
+    #endif
+#endif
+#ifndef LV_DEMO_MUSIC_LARGE
+    #ifdef CONFIG_LV_DEMO_MUSIC_LARGE
+        #define LV_DEMO_MUSIC_LARGE CONFIG_LV_DEMO_MUSIC_LARGE
+    #else
+        #define LV_DEMO_MUSIC_LARGE        0
+    #endif
+#endif
+#ifndef LV_DEMO_MUSIC_AUTO_PLAY
+    #ifdef CONFIG_LV_DEMO_MUSIC_AUTO_PLAY
+        #define LV_DEMO_MUSIC_AUTO_PLAY CONFIG_LV_DEMO_MUSIC_AUTO_PLAY
+    #else
+        #define LV_DEMO_MUSIC_AUTO_PLAY    0
+    #endif
+#endif
+#endif
+
 
 
 /*----------------------------------