fix(screens/index): correctly handle Unicode strings

This fix is likely to apply elsewhere, but we'll tackle those issues
when we find them, so that we do not accidentaly introduce new bugs.

Resolves #83

CHANGELOG.md

@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org)
 * Correctly look for `--author` option, not `--authors`.
 * Screens/details: "Serie" -> "Series"
 * Screens/details: Correctly print empty fields.
+* Screens/index: Correctly print Unicode strings. #83
 
 ## [v0.8.0] - 2019-05-26
 

src/tui/curses_wrap.hpp

@@ -83,7 +83,18 @@ namespace bookwyrm::tui::curses {
                         colour clr = colour::none)
     {
         wattron(win, clr | attrs);
-        int retval = mvwaddnstr(win, y, x, str.c_str(), n);
+
+        /*
+         * Special handling for eventual Unicode strings.
+         * We want to print n characters, not n bytes.
+         *
+         * XXX: inefficient, must std::wstring be used?
+         */
+        std::vector<wchar_t> wstr;
+        wstr.resize(std::max<int>(str.size(), n));
+        std::mbstowcs(wstr.data(), str.c_str(), n);
+        int retval = mvwaddnwstr(win, y, x, wstr.data(), n);
+
         wattroff(win, clr | attrs);
         return retval;
     }

src/tui/screens/base.cpp

@@ -61,9 +61,10 @@ namespace bookwyrm::tui::screen {
     {
         space = std::min<size_t>(space, get_width() - x);
         curses::mvprintn(window_, x, y, str, space, attrs, clr);
+        const auto len = std::mbstowcs(nullptr, str.c_str(), str.size());
 
         int truncd = 0;
-        if (str.length() > space) {
+        if (len > space) {
             /* The whole string did not fit; indicate this to the user. */
 
             /* From the substing written in the space, find the number of whitespaces from the end of the string to the first
@@ -73,8 +74,8 @@ namespace bookwyrm::tui::screen {
             while (std::isspace(*(--ch)))
                 ++whitespace;
 
-            truncd = str.length() - space + whitespace;
-            curses::mvprint(window_, x + str.length() - truncd - 1, y, "~", attrs, clr);
+            truncd = len - space + whitespace;
+            curses::mvprint(window_, x + len - truncd - 1, y, "~", attrs, clr);
         }
 
         return truncd;

src/tui/screens/index.cpp

@@ -203,7 +203,8 @@ namespace bookwyrm::tui::screen {
              * padding on the right side of it (e.g. up to and including the first char
              * in the next column, hence the magic offset).
              */
-            const auto start = col.startx + str.length() - trunc_len, end = col.startx + col.width + 2;
+            const auto start = col.startx + std::mbstowcs(nullptr, str.c_str(), str.size()) - trunc_len,
+                       end = col.startx + col.width + 2;
             for (auto x = start; x <= end; x++)
                 print(x, y, " ", attrs);
         }