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>

src/extra/others/imgfont/lv_imgfont.c

@@ -0,0 +1,126 @@
+/**
+ * @file lv_imgfont.c
+ *
+ */
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "lv_imgfont.h"
+
+#if LV_USE_IMGFONT
+
+/*********************
+ *      DEFINES
+ *********************/
+#define LV_IMGFONT_PATH_MAX_LEN 64
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+typedef struct {
+    lv_font_t * font;
+    lv_get_imgfont_path_cb_t path_cb;
+    char path[LV_IMGFONT_PATH_MAX_LEN];
+} imgfont_dsc_t;
+
+/**********************
+ *  STATIC PROTOTYPES
+ **********************/
+static const uint8_t * imgfont_get_glyph_bitmap(const lv_font_t * font, uint32_t unicode);
+static bool imgfont_get_glyph_dsc(const lv_font_t * font, lv_font_glyph_dsc_t * dsc_out,
+                                  uint32_t unicode, uint32_t unicode_next);
+
+/**********************
+ *  STATIC VARIABLES
+ **********************/
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+/**********************
+ *      MACROS
+ **********************/
+
+/**********************
+ *   GLOBAL FUNCTIONS
+ **********************/
+lv_font_t * lv_imgfont_create(uint16_t height, lv_get_imgfont_path_cb_t path_cb)
+{
+    LV_ASSERT_MSG(LV_IMGFONT_PATH_MAX_LEN > sizeof(lv_img_dsc_t),
+                  "LV_IMGFONT_PATH_MAX_LEN must be greater than sizeof(lv_img_dsc_t)");
+
+    size_t size = sizeof(imgfont_dsc_t) + sizeof(lv_font_t);
+    imgfont_dsc_t * dsc = (imgfont_dsc_t *)lv_mem_alloc(size);
+    if(dsc == NULL) return NULL;
+    lv_memset_00(dsc, size);
+
+    dsc->font = (lv_font_t *)(((char *)dsc) + sizeof(imgfont_dsc_t));
+    dsc->path_cb = path_cb;
+
+    lv_font_t * font = dsc->font;
+    font->dsc = dsc;
+    font->get_glyph_dsc = imgfont_get_glyph_dsc;
+    font->get_glyph_bitmap = imgfont_get_glyph_bitmap;
+    font->subpx = LV_FONT_SUBPX_NONE;
+    font->line_height = height;
+    font->base_line = 0;
+    font->underline_position = 0;
+    font->underline_thickness = 0;
+
+    return dsc->font;
+}
+
+void lv_imgfont_destroy(lv_font_t * font)
+{
+    if(font == NULL) {
+        return;
+    }
+
+    imgfont_dsc_t * dsc = (imgfont_dsc_t *)font->dsc;
+    lv_mem_free(dsc);
+}
+
+/**********************
+ *   STATIC FUNCTIONS
+ **********************/
+
+static const uint8_t * imgfont_get_glyph_bitmap(const lv_font_t * font, uint32_t unicode)
+{
+    LV_UNUSED(unicode);
+    LV_ASSERT_NULL(font);
+    imgfont_dsc_t * dsc = (imgfont_dsc_t *)font->dsc;
+    return (uint8_t *)dsc->path;
+}
+
+static bool imgfont_get_glyph_dsc(const lv_font_t * font, lv_font_glyph_dsc_t * dsc_out,
+                                  uint32_t unicode, uint32_t unicode_next)
+{
+    LV_ASSERT_NULL(font);
+
+    imgfont_dsc_t * dsc = (imgfont_dsc_t *)font->dsc;
+    LV_ASSERT_NULL(dsc);
+    if(dsc->path_cb == NULL) return false;
+
+    if(!dsc->path_cb(dsc->font, dsc->path, LV_IMGFONT_PATH_MAX_LEN, unicode, unicode_next)) {
+        return false;
+    }
+
+    lv_img_header_t header;
+    if(lv_img_decoder_get_info(dsc->path, &header) != LV_RES_OK) {
+        return false;
+    }
+
+    dsc_out->is_placeholder = 0;
+    dsc_out->adv_w = header.w;
+    dsc_out->box_w = header.w;
+    dsc_out->box_h = header.h;
+    dsc_out->bpp = LV_IMGFONT_BPP;   /* is image identifier */
+    dsc_out->ofs_x = 0;
+    dsc_out->ofs_y = 0;
+
+    return true;
+}
+
+#endif /*LV_USE_IMGFONT*/

src/extra/others/imgfont/lv_imgfont.h

@@ -0,0 +1,60 @@
+/**
+ * @file lv_imgfont.h
+ *
+ */
+
+#ifndef LV_IMGFONT_H
+#define LV_IMGFONT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "../../../lvgl.h"
+
+#if LV_USE_IMGFONT
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/* gets the image path name of this character */
+typedef bool (*lv_get_imgfont_path_cb_t)(const lv_font_t * font, void * img_src,
+                                         uint16_t len, uint32_t unicode, uint32_t unicode_next);
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+/**
+ * Creates a image font with info parameter specified.
+ * @param height font size
+ * @param path_cb a function to get the image path name of character.
+ * @return pointer to the new imgfont or NULL if create error.
+ */
+lv_font_t * lv_imgfont_create(uint16_t height, lv_get_imgfont_path_cb_t path_cb);
+
+/**
+ * Destroy a image font that has been created.
+ * @param font pointer to image font handle.
+ */
+void lv_imgfont_destroy(lv_font_t * font);
+
+/**********************
+ *      MACROS
+ **********************/
+
+#endif /*LV_USE_IMGFONT*/
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif /* LV_IMGFONT_H */

src/extra/others/lv_others.h

@@ -17,6 +17,7 @@ extern "C" {
 #include "monkey/lv_monkey.h"
 #include "gridnav/lv_gridnav.h"
 #include "fragment/lv_fragment.h"
+#include "imgfont/lv_imgfont.h"
 
 /*********************
  *      DEFINES