feat(font): add imgfont - can be used to add emojis to label/span (#3160)

* feature(font): draw img in label/span

* add to tests

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>

examples/others/imgfont/index.rst

@@ -0,0 +1,6 @@
+Use emojis in a text.
+"""""""""""""""""""""""""""""""""""""""""""""""
+
+.. lv_example:: others/imgfont/lv_example_imgfont_1
+  :language: c
+

examples/others/imgfont/lv_example_imgfont.h

@@ -0,0 +1,38 @@
+/**
+ * @file lv_example_imgfont.h
+ *
+ */
+
+#ifndef LV_EXAMPLE_IMGFONT_H
+#define LV_EXAMPLE_IMGFONT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+void lv_example_imgfont_1(void);
+
+/**********************
+ *      MACROS
+ **********************/
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif /*LV_EXAMPLE_IMGFONT_H*/

examples/others/imgfont/lv_example_imgfont_1.c

@@ -0,0 +1,54 @@
+#include "../../lv_examples.h"
+#include <stdio.h>
+
+#if LV_BUILD_EXAMPLES
+#if LV_USE_IMGFONT
+
+LV_IMG_DECLARE(emoji_F617)
+static bool get_imgfont_path(const lv_font_t * font, void * img_src,
+                             uint16_t len, uint32_t unicode, uint32_t unicode_next)
+{
+    LV_UNUSED(font);
+    LV_UNUSED(unicode_next);
+    LV_ASSERT_NULL(img_src);
+
+    if(unicode == 0xF617) {
+        memcpy(img_src, &emoji_F617, sizeof(lv_img_dsc_t));
+    }
+    else {
+        char * path = (char *)img_src;
+        snprintf(path, len, "%s/%04X.%s", "A:lvgl/examples/assets/emoji", unicode, "png");
+        path[len - 1] = '\0';
+    }
+
+    return true;
+}
+
+/**
+ * draw img in label or span obj
+ */
+void lv_example_imgfont_1(void)
+{
+    lv_font_t * imgfont = lv_imgfont_create(80, get_imgfont_path);
+    if(imgfont == NULL) {
+        LV_LOG_ERROR("imgfont init error");
+    }
+
+    imgfont->fallback = LV_FONT_DEFAULT;
+
+    lv_obj_t * label1 = lv_label_create(lv_scr_act());
+    lv_label_set_text(label1, "12\uF600\uF617AB");
+    lv_obj_set_style_text_font(label1, imgfont, LV_PART_MAIN);
+    lv_obj_center(label1);
+}
+#else
+
+void lv_example_imgfont_1(void)
+{
+    lv_obj_t * label = lv_label_create(lv_scr_act());
+    lv_label_set_text(label, "imgfont is not installed");
+    lv_obj_center(label);
+}
+
+#endif
+#endif

examples/others/lv_example_others.h

@@ -17,6 +17,7 @@ extern "C" {
 #include "monkey/lv_example_monkey.h"
 #include "gridnav/lv_example_gridnav.h"
 #include "fragment/lv_example_fragment.h"
+#include "imgfont/lv_example_imgfont.h"
 
 /*********************
  *      DEFINES