g.wrapString fix issues wrapping long words in UTF8 strings over mult…

…iple lines

fix espruino/BangleApps#3037

ChangeLog

@@ -3,6 +3,7 @@
             Emulator: force stack alignment of 'data' variable when accessing ArrayBuffers (fix #2463)
             Swapped GCC version from 8.2.1 to 13.2.1 (fix #2455)
             nRF52: Write flash in 2k blocks (not 4k) as SD 6.1.1 can crash (probably good for earlier SD too)
+            g.wrapString fix issues wrapping long words in UTF8 strings over multiple lines
 
      2v21 : nRF52: free up 800b more flash by removing vector table padding
             Throw Exception when a Promise tries to resolve with another Promise (#2450)

libs/graphics/jswrap_graphics.c

@@ -2410,7 +2410,6 @@ JsVar *jswrap_graphics_wrapString(JsVar *parent, JsVar *str, int maxWidth) {
           // add the space/etc before (but not a space at the start of a newline)
           jsvAppendCharacter(currentLine, wordBreakCharacter);
           lineWidth += spaceWidth;
-          wordBreakCharacter = 0;
         }
         jsvAppendStringVar(currentLine, str, (size_t)wordStartIdx, (size_t)(currentPos-(wordStartIdx+1)));
         lineWidth += wordWidth;
@@ -2424,19 +2423,30 @@ JsVar *jswrap_graphics_wrapString(JsVar *parent, JsVar *str, int maxWidth) {
         while (wordWidth > maxWidth) {
           int width = 0;
           currentLine = jsvNewFromEmptyString();
-          while (wordStartIdx < currentPos) {
-            char wordCh = (char)jsvGetCharInString(str, (size_t)wordStartIdx);
+          JsvStringIterator wordIt;
+          jsvStringIteratorNew(&wordIt, str, wordStartIdx); // not UTF8 as wordStartIdx isn't UTF8 indexed
+          while (jsvStringIteratorGetIndex(&wordIt) < currentPos) {
+            int wordCh = jsvStringIteratorGetUTF8CharAndNext(&wordIt);
             int w = _jswrap_graphics_getCharWidth(&info, wordCh);
             if (width+w < maxWidth || !width) { // add while it fits OR it's the first character
               // !width stops us locking up if char width>split width
-              wordStartIdx++;
               wordWidth -= w;
               lineWidth -= w;
               width += w;
-              jsvAppendCharacter(currentLine, wordCh); // FIXME: UTF8?
+              wordStartIdx = jsvStringIteratorGetIndex(&wordIt);
+#ifdef ESPR_UNICODE_SUPPORT
+              jsvAppendUTF8Character(currentLine, wordCh);
+#else
+              jsvAppendCharacter(currentLine, wordCh);
+#endif
             } else
               break;
           }
+          jsvStringIteratorFree(&wordIt);
+#ifdef ESPR_UNICODE_SUPPORT
+          if (jsvIsUTF8String(str))
+            currentLine = jsvNewUTF8StringAndUnLock(currentLine);
+#endif
           jsvArrayPush(lines, currentLine);
           jsvUnLock(currentLine);
         }
@@ -2449,6 +2459,7 @@ JsVar *jswrap_graphics_wrapString(JsVar *parent, JsVar *str, int maxWidth) {
 #endif
         if (wasNewLine) wordBreakCharacter = ' ';
       }
+      wordBreakCharacter = 0;
       if (canSplitAfter && !canBreakOnCh) currentPos--; // include the current ch in the next word
       if (canBreakOnCh && ch>0)
         wordBreakCharacter = (char)ch;

src/jsvar.h

@@ -523,6 +523,14 @@ void jsvAppendStringBuf(JsVar *var, const char *str, size_t length); ///< Append
 void jsvAppendPrintf(JsVar *var, const char *fmt, ...); ///< Append the formatted string to a variable (see vcbprintf)
 JsVar *jsvVarPrintf( const char *fmt, ...); ///< Create a var from the formatted string
 static ALWAYS_INLINE void jsvAppendCharacter(JsVar *var, char ch) { jsvAppendStringBuf(var, &ch, 1); }; ///< Append the given character to this string
+#ifdef ESPR_UNICODE_SUPPORT
+///< Append the given UTF8 character to this string
+static ALWAYS_INLINE void jsvAppendUTF8Character(JsVar *var, int ch) {
+  char utf8buf[4];
+  int utf8len = jsUTF8Encode(ch, utf8buf);
+  jsvAppendStringBuf(var, utf8buf, utf8len);
+}
+#endif
 #define JSVAPPENDSTRINGVAR_MAXLENGTH (0x7FFFFFFF)
 void jsvAppendStringVar(JsVar *var, const JsVar *str, size_t stridx, size_t maxLength); ///< Append str to var. Both must be strings. stridx = start char or str, maxLength = max number of characters (can be JSVAPPENDSTRINGVAR_MAXLENGTH)
 void jsvAppendStringVarComplete(JsVar *var, const JsVar *str); ///< Append all of str to var. Both must be strings.

tests/test_graphics_wrapString.js

@@ -112,13 +112,15 @@ g.clear().setFont("4x6");
 lines = g.wrapString("F\u00F6n K\u00FCr B\u00E4r", 200);
 SHOULD_BE(lines, ["F\u00F6n K\u00FCr B\u00E4r"]);
 
+// UTF8 https://github.com/espruino/BangleApps/issues/3037
+g.clear().setFont("6x8");
+lines = g.wrapString("Talmannen Kevin McCarthy avs\u00E4tts \u2014 partikamrater avgjorde\nF\u00F6rsta g\u00F6rsta i USA:s historia \u2022 Republikanen förlorar posten i represent\u2022anthuset test",100)
+SHOULD_BE(lines, ["Talmannen Kevin","McCarthy avs\u00E4tts","\u2014partikamrater","avgjorde","F\u00F6rsta g\u00F6rsta i","USA:s historia \u2022","Republikanen","f\u00F6rlorar posten","i","represent\u2022anthuse","t test"]);
+
 // Using wrapstring from Storage
 require("Storage").write("x","Compacting...\nTakes approx\n1 minute")
 lines = g.wrapString(require("Storage").read("x"), 176)
 require("Storage").erase("x")
 SHOULD_BE(lines, ["Compacting...","Takes approx","1 minute"]);
 
-
-
-
 result = ok;