From 84600a78db83bd02b781e8cc2d5c108720f98cd6 Mon Sep 17 00:00:00 2001
From: alsaleem00 <alsaleem@tge.com.sa>
Date: Thu, 11 Feb 2021 20:53:00 +0300
Subject: [PATCH] fix(text) improve Arabic contextual analysis (#2062)

Adds hyphen processing and proper handling of lam-alef sequence
---
 CHANGELOG.md            |  1 +
 src/lv_misc/lv_txt_ap.c | 53 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0510485bb..5c1148fda 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Bugfixes
 - fix(indev) clear the indev's `act_obj` in `lv_indev_reset`
 - fix(text) fix out of bounds read in `_lv_txt_get_width`
+- fix(text) improve Arabic contextual analysis by adding hyphen processing and proper handling of lam-alef sequence
 - fix(delete) delete animation after the children are deleted
 
 ## v7.10.0
diff --git a/src/lv_misc/lv_txt_ap.c b/src/lv_misc/lv_txt_ap.c
index 6bd7124ac..168edebd4 100644
--- a/src/lv_misc/lv_txt_ap.c
+++ b/src/lv_misc/lv_txt_ap.c
@@ -25,6 +25,7 @@
  **********************/
 #if LV_USE_ARABIC_PERSIAN_CHARS == 1
 static uint32_t lv_ap_get_char_index(uint16_t c);
+static uint32_t lv_txt_lam_alef(uint32_t ch_curr, uint32_t ch_next);
 
 /**********************
  *  STATIC VARIABLES
@@ -58,6 +59,7 @@ const ap_chars_map_t ap_chars_map[] = {
     {22, 0xFEC6, 1, 2, -1,  {1, 1}},   // ظ
     {23, 0xFECA, 1, 2, -1,  {1, 1}},   // ع
     {24, 0xFECE, 1, 2, -1,  {1, 1}},   // غ
+    {30, 0x0640, 0, 0, 0,  {1, 1}},   // - (mad, hyphen)
     {31, 0xFED2, 1, 2, -1,  {1, 1}},   // ف
     {32, 0xFED6, 1, 2, -1,  {1, 1}},   // ق
     {135, 0xFB8F, 1, 2, -1,  {1, 1}},  // ک
@@ -130,11 +132,13 @@ void _lv_txt_ap_proc(const char * txt, char * txt_out)
     uint32_t txt_length = 0;
     uint32_t index_current, idx_next, idx_previous, i, j;
     uint32_t * ch_enc;
+    uint32_t * ch_fin;
     char * txt_out_temp;
 
     txt_length = _lv_txt_get_encoded_length(txt);
 
     ch_enc = (uint32_t *)lv_mem_alloc(sizeof(uint32_t) * (txt_length + 1));
+    ch_fin = (uint32_t *)lv_mem_alloc(sizeof(uint32_t) * (txt_length + 1));
 
     i = 0;
     j = 0;
@@ -144,12 +148,15 @@ void _lv_txt_ap_proc(const char * txt, char * txt_out)
     ch_enc[j] = 0;
 
     i = 0;
+    j = 0;
     idx_previous = LV_UNDEF_ARABIC_PERSIAN_CHARS;
     while(i < txt_length) {
         index_current = lv_ap_get_char_index(ch_enc[i]);
         idx_next = lv_ap_get_char_index(ch_enc[i + 1]);
 
         if(index_current == LV_UNDEF_ARABIC_PERSIAN_CHARS) {
+            ch_fin[j] = ch_enc[i];
+            j++;
             i++;
             idx_previous = LV_UNDEF_ARABIC_PERSIAN_CHARS;
             continue;
@@ -160,18 +167,37 @@ void _lv_txt_ap_proc(const char * txt, char * txt_out)
         uint8_t conjunction_to_next = ((i == txt_length - 1) ||
                                        idx_next == LV_UNDEF_ARABIC_PERSIAN_CHARS) ? 0 : ap_chars_map[idx_next].ap_chars_conjunction.conj_to_previous;
 
+        uint32_t lam_alef = lv_txt_lam_alef(index_current, idx_next);
+        if ( lam_alef ) {
+            if (conjunction_to_previuse) {
+                lam_alef ++;
+            }
+            ch_fin[j] = lam_alef;
+            idx_previous = LV_UNDEF_ARABIC_PERSIAN_CHARS;
+            i += 2;
+            j++;
+            continue;
+        }
+
         if(conjunction_to_previuse && conjunction_to_next)
-            ch_enc[i] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_middle_form_offset;
+            ch_fin[j] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_middle_form_offset;
         else if(!conjunction_to_previuse && conjunction_to_next)
-            ch_enc[i] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_begining_form_offset;
+            ch_fin[j] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_begining_form_offset;
         else if(conjunction_to_previuse && !conjunction_to_next)
-            ch_enc[i] = ap_chars_map[index_current].char_end_form;
+            ch_fin[j] = ap_chars_map[index_current].char_end_form;
         else
-            ch_enc[i] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_isolated_form_offset;
+            ch_fin[j] = ap_chars_map[index_current].char_end_form + ap_chars_map[index_current].char_isolated_form_offset;
         idx_previous = index_current;
         i++;
+        j++;
     }
-
+    ch_fin[j] = 0;
+    for (i=0; i<txt_length; i++)
+        ch_enc[i] = 0;
+    for (i=0; i<j; i++)
+        ch_enc[i] = ch_fin[i];
+    lv_mem_free(ch_fin);
+    
     txt_out_temp = txt_out;
     i = 0;
 
@@ -219,4 +245,21 @@ static uint32_t lv_ap_get_char_index(uint16_t c)
     return LV_UNDEF_ARABIC_PERSIAN_CHARS;
 }
 
+static uint32_t lv_txt_lam_alef(uint32_t ch_curr, uint32_t ch_next)
+{
+    uint32_t ch_code = 0;
+    if (ap_chars_map[ch_curr].char_offset != 34) {
+        return 0;
+    }
+    if (ch_next == LV_UNDEF_ARABIC_PERSIAN_CHARS) {
+        return 0;
+    }
+    ch_code = ap_chars_map[ch_next].char_offset + LV_AP_ALPHABET_BASE_CODE;
+    if (ch_code == 0x0622) { return 0xFEF5; } // (lam-alef) mad
+    if (ch_code == 0x0623) { return 0xFEF7; } // (lam-alef) top hamza
+    if (ch_code == 0x0625) { return 0xFEF9; } // (lam-alef) bot hamza
+    if (ch_code == 0x0627) { return 0xFEFB; } // (lam-alef) alef
+    return 0;
+}
+
 #endif