Margin top in <margin> tag

CHANGES.txt

@@ -23,7 +23,7 @@ Template features:
  * Added <font:...> tag to change the font inside a text field.
  * Added <margin:...> tag to change the margins of a block of text.
  * Added <align:...> tag to change the horizontal alignment of a block of text.
- * Added <li> tag for list bullet points.
+ * Added <li> tag for list bullet points. (Experimental!)
  * Colors can now be written using hex notation, #rrggbb / #rrggbbaa, and short hex notation (#rgb / #rgba)
 
 Scripting:

doc/type/tagged_string.txt

@@ -19,7 +19,7 @@ This is written as the character with code 1 in files.
 | @<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.
 | @<align:???>@			The block inside the tag is aligned with the given horizontal [[type:alignment]]
-| @<margin:??:??>@			The block inside the tag has additional left and right (optional) margins of the specified size in pixels.
+| @<margin:??:??>@			The block inside the tag has additional left, right (optional), and top (optional) margins of the specified size in pixels.
 | @<li>@			The text inside the tag is treated as a list marker, meaning that if the line wraps it will be indented to match the content of the @<li>@ tag.
 | @<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]].

src/render/text/element.cpp

@@ -27,6 +27,10 @@ Color param_colors[] =
   };
 const size_t param_colors_count = sizeof(param_colors) / sizeof(param_colors[0]);
 
+struct Margins {
+  double left, right, top;
+};
+
 // Helper class for TextElements::fromString, to allow persistent formating state accross recusive calls
 struct TextElementsFromString {
   // What formatting is enabled?
@@ -37,7 +41,7 @@ struct TextElementsFromString {
   vector<Color> colors;
   vector<double> sizes;
   vector<String> fonts;
-  vector<pair<double,double>> margins;
+  vector<Margins> margins;
   vector<Alignment> aligns;
 
   const TextStyle& style;
@@ -169,16 +173,20 @@ private:
           size_t colon = text.find_first_of(_(">:"), tag_start);
           if (colon < pos - 1 && text.GetChar(colon) == _(':')) {
             size_t colon2 = text.find_first_of(_(">:"), colon + 1);
-            double margin_left = 0., margin_right = 0.;
-            text.substr(colon + 1, colon2 - colon - 2).ToDouble(&margin_left);
-            text.substr(colon2 + 1, pos - colon2 - 2).ToDouble(&margin_right);
+            size_t colon3 = colon2 < pos-1 ? text.find_first_of(_(">:"), colon2 + 1) : colon2;
+            Margins m = {0.,0.,0.};
+            text.substr(colon + 1, colon2 - colon - 2).ToDouble(&m.left);
+            text.substr(colon2 + 1, colon3 - colon2 - 2).ToDouble(&m.right);
+            text.substr(colon3 + 1, pos - colon3 - 2).ToDouble(&m.top);
             if (!margins.empty()) {
-              margin_left += margins.back().first;
-              margin_right += margins.back().second;
+              m.left  += margins.back().left;
+              m.right += margins.back().right;
+              m.top   += margins.back().top;
             }
-            margins.emplace_back(margin_left, margin_right);
-            paragraphs.back().margin_left = margin_left;
-            paragraphs.back().margin_right = margin_right;
+            margins.emplace_back(m);
+            paragraphs.back().margin_left = m.left;
+            paragraphs.back().margin_right = m.right;
+            paragraphs.back().margin_top = m.top;
           }
         } else if (is_substr(text, tag_start, _("</margin"))) {
           if (!margins.empty()) margins.pop_back();
@@ -267,8 +275,9 @@ private:
         paragraphs.back().start = i + 1;
         paragraphs.back().margin_end_char = i + 1;
         if (!margins.empty()) {
-          paragraphs.back().margin_left  = margins.back().first;
-          paragraphs.back().margin_right = margins.back().second;
+          paragraphs.back().margin_left  = margins.back().left;
+          paragraphs.back().margin_right = margins.back().right;
+          paragraphs.back().margin_top   = margins.back().top;
         }
         if (!aligns.empty()) {
           paragraphs.back().alignment = aligns.back();

src/render/text/element.hpp

@@ -149,7 +149,7 @@ class TextParagraph {
 public:
   optional<Alignment> alignment;
   double margin_left = 0., margin_right = 0.;
-  //double margin_top = 0., margin_bottom = 0.; // TODO: more margin options?
+  double margin_top = 0.; //, margin_bottom = 0.; // TODO: more margin options?
   size_t start = String::npos, end = String::npos;
   size_t margin_end_char = 0; // end position of characters that are added to the margin (i.e. bullet points)
 };

src/render/text/viewer.cpp

@@ -691,6 +691,7 @@ bool TextViewer::prepareLinesAtScale(RotatedDC& dc, const vector<CharInfo>& char
         assert(elements.paragraphs[i_para].start == i + 1);
         line.margin_left = elements.paragraphs[i_para].margin_left;
         line.margin_right = elements.paragraphs[i_para].margin_right;
+        line.top += elements.paragraphs[i_para].margin_top;
         line.alignment = elements.paragraphs[i_para].alignment;
       }
       line.break_after = LineBreak::NO;