5 files changed, 49 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 724ff1c9..d999c9fa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,8 @@ dillo-2.2.1 [not released yet]
  - Fix segfault with form inputs and repush for stylesheets.
  - Handle white-space: pre-wrap.
    Patches: corvid
++- Implement line-height.
+   Patch: Johannes Hofmann, corvid
 
 -----------------------------------------------------------------------------
 
diff --git a/dw/style.cc b/dw/style.cc
index 8d3035d0..65c51f89 100644
--- a/dw/style.cc
+++ b/dw/style.cc
@@ -45,9 +45,7 @@ void StyleAttrs::initValues ()
    listStyleType = LIST_STYLE_TYPE_DISC;
    valign = VALIGN_BASELINE;
    backgroundColor = NULL;
-   width = LENGTH_AUTO;
-   height = LENGTH_AUTO;
-
+   width = height = lineHeight = LENGTH_AUTO;
    margin.setVal (0);
    borderWidth.setVal (0);
    padding.setVal (0);
@@ -119,6 +117,7 @@ bool StyleAttrs::equals (object::Object *other) {
        vBorderSpacing == otherAttrs->vBorderSpacing &&
        width == otherAttrs->width &&
        height == otherAttrs->height &&
+       lineHeight == otherAttrs->lineHeight &&
        margin.equals (&otherAttrs->margin) &&
        borderWidth.equals (&otherAttrs->borderWidth) &&
        padding.equals (&otherAttrs->padding) &&
@@ -152,6 +151,7 @@ int StyleAttrs::hashValue () {
       vBorderSpacing +
       width +
       height +
+      lineHeight +
       margin.hashValue () +
       borderWidth.hashValue () +
       padding.hashValue () +
@@ -238,6 +238,7 @@ void Style::copyAttrs (StyleAttrs *attrs)
    vBorderSpacing = attrs->vBorderSpacing;
    width = attrs->width;
    height = attrs->height;
+   lineHeight = attrs->lineHeight;
    margin = attrs->margin;
    borderWidth = attrs->borderWidth;
    padding = attrs->padding;
diff --git a/dw/style.hh b/dw/style.hh
index 50a2045a..af55bb87 100644
--- a/dw/style.hh
+++ b/dw/style.hh
@@ -427,7 +427,7 @@ public:
    char textAlignChar; /* In future, strings will be supported. */
 
    int hBorderSpacing, vBorderSpacing;
-   Length width, height;
+   Length width, height, lineHeight;
 
    Box margin, borderWidth, padding;
    struct { Color *top, *right, *bottom, *left; } borderColor;
diff --git a/dw/textblock.cc b/dw/textblock.cc
index 82b335ae..21c134a4 100644
--- a/dw/textblock.cc
+++ b/dw/textblock.cc
@@ -1565,13 +1565,38 @@ void Textblock::calcTextSize (const char *text, size_t len,
    size->ascent = style->font->ascent;
    size->descent = style->font->descent;
 
+   /*
+    * For 'normal' line height, just use ascent and descent from font.
+    * For absolute/percentage, line height is relative to font size, which
+    * is (irritatingly) smaller than ascent+descent.
+    */
+   if (style->lineHeight != core::style::LENGTH_AUTO) {
+      int height, leading;
+      float factor = style->font->size;
+
+      factor /= (style->font->ascent + style->font->descent);
+
+      size->ascent = size->ascent * factor + 0.5;
+      size->descent = size->descent * factor + 0.5;
+
+      if (core::style::isAbsLength (style->lineHeight))
+         height = core::style::absLengthVal(style->lineHeight);
+      else
+         height = core::style::perLengthVal(style->lineHeight) *
+                  style->font->size;
+      leading = height - style->font->size;
+
+      size->ascent += leading / 2;
+      size->descent += leading - (leading / 2);
+   }
+
    /* In case of a sub or super script we increase the word's height and
     * potentially the line's height.
     */
    if (style->valign == core::style::VALIGN_SUB)
-      size->descent += (size->ascent / 3);
+      size->descent += (style->font->ascent / 3);
    else if (style->valign == core::style::VALIGN_SUPER)
-      size->ascent += (size->ascent / 2);
+      size->ascent += (style->font->ascent / 2);
 }
 
 
diff --git a/src/styleengine.cc b/src/styleengine.cc
index f0f70bf6..6691ba41 100644
--- a/src/styleengine.cc
+++ b/src/styleengine.cc
@@ -188,6 +188,7 @@ void StyleEngine::apply (StyleAttrs *attrs, CssPropertyList *props) {
    FontAttrs fontAttrs = *attrs->font;
    Font *parentFont = stack->get (stack->size () - 2).style->font;
    char *c, *fontName;
+   int lineHeight;
 
    /* Determine font first so it can be used to resolve relative lenths. */
    for (int i = 0; i < props->size (); i++) {
@@ -398,6 +399,20 @@ void StyleEngine::apply (StyleAttrs *attrs, CssPropertyList *props) {
          case CSS_PROPERTY_DISPLAY:
             attrs->display = (DisplayType) p->value.intVal;
             break;
+         case CSS_PROPERTY_LINE_HEIGHT:
+            if (p->type == CSS_TYPE_ENUM) { //only valid enum value is "normal"
+               attrs->lineHeight = dw::core::style::LENGTH_AUTO;
+            } else if (p->type == CSS_TYPE_LENGTH_PERCENTAGE_NUMBER) {
+               if (CSS_LENGTH_TYPE (p->value.intVal) == CSS_LENGTH_TYPE_NONE) {
+                  attrs->lineHeight =
+                     createPerLength(CSS_LENGTH_VALUE(p->value.intVal));
+               } else {
+                  computeValue (&lineHeight, p->value.intVal, attrs->font,
+                                attrs->font->size);
+                  attrs->lineHeight = createAbsLength(lineHeight);
+               }
+            }
+            break;
          case CSS_PROPERTY_LIST_STYLE_POSITION:
             attrs->listStylePosition = (ListStylePosition) p->value.intVal;
             break;