Add <font:$family> tag, closes #24

CHANGES.txt

@@ -17,6 +17,9 @@ Bug fixes:
  * length function now gives correct results for maps
  * substr("foo",begin:3) now returns "" instead of true
 
+Template features:
+ * Added <font:...> tag to change the font inside a text field.
+
 Scripting:
  * Added type_name function
  * nil != "", so missing values are no longer equal to the empty string
@@ -26,7 +29,7 @@ Scripting:
 
 Internal:
  * Switch build system to to CMake
- * Update code to work with wxWidgets 3.0/3.1 and C++ 17
+ * Update code to work with wxWidgets 3.1 and C++ 17
  * Lots of code cleanup
 
 ------------------------------------------------------------------------------

doc/type/tagged_string.txt

@@ -17,6 +17,7 @@ This is written as the character with code 1 in files.
 | @<sym>@		The text inside the tag is rendered as symbols, if a [[prop:style:symbol font]] is set for the text box.
 | @<color:???>@		The text inside the tag is rendered with the given [[type:color]].
 | @<size:???>@		The text inside the tag is rendered with the given font size in points, for example @"<size:12>text</size>"@ makes the text 12 points. The text is scaled down proportionally when it does not fit in a text box and the @scale down to@ attribute allows it.
+| @<font:???>@		The text inside the tag is rendered with the given font family.
 | @<line>@		Line breaks inside this tag use the [[prop:style:line height line]], and they show a horizontal line.
 | @<soft-line>@		Line breaks inside this tag use the [[prop:style:soft line height]].
 | @<atom>@		An atomic piece of text. The cursor can never be inside it; it is selected as a whole.

src/data/font.cpp

@@ -50,7 +50,7 @@ void Font::initDependencies(Context& ctx, const Dependency& dep) const {
   shadow_color.initDependencies(ctx, dep);
 }
 
-FontP Font::make(int add_flags, Color* other_color, double* other_size) const {
+FontP Font::make(int add_flags, String const* other_family, Color const* other_color, double const* other_size) const {
   FontP f(new Font(*this));
   f->flags |= add_flags;
   if (add_flags & FONT_CODE_STRING) {
@@ -73,6 +73,9 @@ FontP Font::make(int add_flags, Color* other_color, double* other_size) const {
   if (other_size) {
     f->size = *other_size;
   }
+  if (other_family && !other_family->empty()) {
+    f->name = *other_family;
+  }
   return f;
 }
 

src/data/font.hpp

@@ -59,8 +59,8 @@ public:
     return shadow_displacement.width != 0 || shadow_displacement.height != 0;
   }
   
-  /// Add style to a font, and optionally change the color and size
+  /// Add style to a font, and optionally change the font family, color and size
-  FontP make(int add_flags, Color* other_color, double* other_size) const;
+  FontP make(int add_flags, String const* other_family, Color const* other_color, double const* other_size) const;
   
   /// Convert this font to a wxFont
   wxFont toWxFont(double scale) const;

src/render/text/element.cpp

@@ -78,6 +78,7 @@ struct TextElementsFromString {
   int param_id;
   vector<Color> colors;
   vector<double> sizes;
+  vector<String> fonts;
   /// put angle brackets around the text?
   bool bracket;
   
@@ -138,6 +139,14 @@ struct TextElementsFromString {
         } else if (is_substr(text, tag_start, _("</color"))) {
           if (!colors.empty()) colors.pop_back();
         }
+        else if (is_substr(text, tag_start, _( "<font"))) {
+          size_t colon = text.find_first_of(_(">:"), tag_start);
+          if (colon < pos - 1 && text.GetChar(colon) == _(':')) {
+            fonts.push_back(text.substr(colon+1, pos-colon-2));
+          }
+        } else if (is_substr(text, tag_start, _("</font"))) {
+          if (!fonts.empty()) fonts.pop_back();
+        }
         else if (is_substr(text, tag_start, _( "<size"))) {
           size_t colon = text.find_first_of(_(">:"), tag_start);
           if (colon < pos - 1 && text.GetChar(colon) == _(':')) {
@@ -251,6 +260,7 @@ private:
       (code        > 0 ? FONT_CODE        : FONT_NORMAL) |
       (code_kw     > 0 ? FONT_CODE_KW     : FONT_NORMAL) |
       (code_string > 0 ? FONT_CODE_STRING : FONT_NORMAL),
+      fonts.empty() ? nullptr : &fonts.back(),
       param > 0 || param_ref > 0
         ? &param_colors[(param_id++) % param_colors_count]
       : !colors.empty()

src/util/tagged_string.cpp

@@ -613,7 +613,7 @@ void check_tagged(const String& str, bool check_balance) {
       }
       for (size_t j = i + 1 ; j + 1 < end ; ++j) {
         Char c = str.GetChar(j);
-        if (c == _(' ') || c == _('<')) {
+        if (c == ESCAPED_LANGLE || c == _('<')) {
           queue_message(MESSAGE_WARNING, _("Invalid character in tag"));
         }
       }