Allow calculating a nicer normal line-height

crengine/include/lvstyles.h

@@ -93,9 +93,10 @@ enum css_style_rec_important_bit {
     imp_bit_box_sizing,
     imp_bit_caption_side,
     imp_bit_content,
-    imp_bit_cr_hint
+    imp_bit_cr_hint,
+    imp_bit_cr_normal_line_height
 };
-#define NB_IMP_BITS 70 // The number of lines in the enum above: KEEP IT UPDATED.
+#define NB_IMP_BITS 71 // The number of lines in the enum above: KEEP IT UPDATED.
 
 #define NB_IMP_SLOTS    ((NB_IMP_BITS-1)>>5)+1
 // In lvstyles.cpp, we have hardcoded important[0] ... importance[2]
@@ -185,6 +186,7 @@ struct css_style_rec_tag {
     css_caption_side_t     caption_side;
     lString32              content;
     css_length_t           cr_hint;
+    css_length_t           cr_normal_line_height;
     // The following should only be used when applying stylesheets while in lvend.cpp setNodeStyle(),
     // and cleaned up there, before the style is cached and shared. They are not serialized.
     lInt8                flags; // bitmap of STYLE_REC_FLAG_*
@@ -243,6 +245,7 @@ struct css_style_rec_tag {
     , box_sizing(css_bs_content_box)
     , caption_side(css_cs_inherit)
     , cr_hint(css_val_inherited, 0)
+    , cr_normal_line_height(css_val_inherited, 0)
     , flags(0)
     , pseudo_elem_before_style(NULL)
     , pseudo_elem_after_style(NULL)

crengine/src/lvrend.cpp

@@ -3129,7 +3129,14 @@ lString32 renderListItemMarker( ldomNode * enode, int & marker_width, int * fina
         if (line_h < 0) { // -1, not specified by caller: find it out from the node
             if ( style->line_height.type == css_val_unspecified &&
                         style->line_height.value == css_generic_normal ) {
-                line_h = font->getHeight(); // line-height: normal
+                int em = font->getSize();
+                if ( style->cr_normal_line_height.type == css_val_unspecified &&
+                            style->cr_normal_line_height.value == css_generic_normal ) {
+                    line_h = font->getHeight(); // line-height: normal
+                }
+                else {
+                    line_h = lengthToPx(enode, style->cr_normal_line_height, em, em, true);
+                }
             }
             else {
                 int em = font->getSize();
@@ -3400,7 +3407,13 @@ void renderFinalBlock( ldomNode * enode, LFormattedText * txform, RenderRectAcce
             // Only "normal" uses enode->getFont()->getHeight()
             if ( style->line_height.type == css_val_unspecified &&
                         style->line_height.value == css_generic_normal ) {
-                line_h = enode->getFont()->getHeight(); // line-height: normal
+                if ( style->cr_normal_line_height.type == css_val_unspecified &&
+                            style->cr_normal_line_height.value == css_generic_normal ) {
+                    line_h = enode->getFont()->getHeight(); // line-height: normal
+                }
+                else {
+                    line_h = lengthToPx(enode, style->cr_normal_line_height, em, em, true);
+                }
             }
             else {
                 // In all other cases (%, em, unitless/unspecified), we can just scale 'em',
@@ -4584,6 +4597,8 @@ void copystyle( css_style_ref_t source, css_style_ref_t dest )
     dest->content = source->content ;
     dest->cr_hint.type = source->cr_hint.type ;
     dest->cr_hint.value = source->cr_hint.value ;
+    dest->cr_normal_line_height.type = source->cr_normal_line_height.type ;
+    dest->cr_normal_line_height.value = source->cr_normal_line_height.value ;
 }
 
 // Only used by renderBlockElementLegacy()
@@ -7455,7 +7470,13 @@ void renderBlockElementEnhanced( FlowState * flow, ldomNode * enode, int x, int
             int line_h;
             if ( style->line_height.type == css_val_unspecified &&
                         style->line_height.value == css_generic_normal ) {
-                line_h = enode->getFont()->getHeight(); // line-height: normal
+                if ( style->cr_normal_line_height.type == css_val_unspecified &&
+                            style->cr_normal_line_height.value == css_generic_normal ) {
+                    line_h = enode->getFont()->getHeight(); // line-height: normal
+                }
+                else {
+                    line_h = lengthToPx(enode, style->cr_normal_line_height, em, em, true);
+                }
             }
             else {
                 // In all other cases (%, em, unitless/unspecified), we can just
@@ -11205,6 +11226,9 @@ void setNodeStyle( ldomNode * enode, css_style_ref_t parent_style, LVFontRef par
                 break;
         }
     }
+    if (pstyle->cr_normal_line_height.type == css_val_inherited) {
+        pstyle->cr_normal_line_height = parent_style->cr_normal_line_height; // inherit as-is
+    }
 
     // vertical_align: computed value: "for percentage and length values, the absolute length, otherwise the keyword as specified"
     // Not inherited by default (html5.css has TR,TD,TH explicitely set to "vertical-align: inherit",

crengine/src/lvstsheet.cpp

@@ -142,6 +142,7 @@ enum css_decl_code {
     cssd_cr_hint,
     cssd_cr_only_if,
     cssd_cr_apply_func,
+    cssd_cr_normal_line_height,
     cssd_stop
 };
 
@@ -252,6 +253,7 @@ static const char * css_decl_name[] = {
     "-cr-hint",
     "-cr-only-if",
     "-cr-apply-func",
+    "-cr-normal-line-height",
     NULL
 };
 
@@ -3916,6 +3918,7 @@ bool LVCssDeclaration::parse( const char * &decl, bool higher_importance, lxmlDo
                 // no named value found, don't break: continue checking if value is a number
             case cssd_line_height:
             case cssd_letter_spacing:
+            case cssd_cr_normal_line_height:
                 IF_g_PUSH_LENGTH_AND_break(1, true, css_val_unspecified, css_generic_normal);
             case cssd_font_size:
                 IF_g_PUSH_LENGTH_AND_break(1, true, css_val_rem, 256);
@@ -3964,11 +3967,11 @@ bool LVCssDeclaration::parse( const char * &decl, bool higher_importance, lxmlDo
                         accept_none = true;
                     // only line-height and letter-spacing accept keyword "normal"
                     bool accept_normal = false;
-                    if ( prop_code==cssd_line_height || prop_code==cssd_letter_spacing )
+                    if ( prop_code==cssd_line_height || prop_code==cssd_letter_spacing || prop_code==cssd_cr_normal_line_height)
                         accept_normal = true;
                     // only line-height accepts numbers with unspecified unit
                     bool accept_unspecified = false;
-                    if ( prop_code==cssd_line_height )
+                    if ( prop_code==cssd_line_height || prop_code==cssd_cr_normal_line_height )
                         accept_unspecified = true;
                     // only font-size is... font-size
                     bool is_font_size = false;
@@ -5085,6 +5088,10 @@ void LVCssDeclaration::apply( css_style_rec_t * style, const ldomNode * node ) c
             style->Apply( read_length(p), &style->line_height, imp_bit_line_height, is_important );
             style->flags |= STYLE_REC_FLAG_INHERITABLE_APPLIED;
             break;
+        case cssd_cr_normal_line_height:
+            style->Apply( read_length(p), &style->cr_normal_line_height, imp_bit_cr_normal_line_height, is_important );
+            style->flags |= STYLE_REC_FLAG_INHERITABLE_APPLIED;
+            break;
         case cssd_letter_spacing:
             style->Apply( read_length(p), &style->letter_spacing, imp_bit_letter_spacing, is_important );
             style->flags |= STYLE_REC_FLAG_INHERITABLE_APPLIED;

crengine/src/lvstyles.cpp

@@ -44,7 +44,7 @@ lUInt32 calcHash(font_ref_t & f)
 lUInt32 calcHash(css_style_rec_t & rec)
 {
     if ( !rec.hash )
-        rec.hash = (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
+        rec.hash = ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
          + (lUInt32)rec.important[0]) * 31
          + (lUInt32)rec.important[1]) * 31
          + (lUInt32)rec.important[2]) * 31
@@ -117,6 +117,7 @@ lUInt32 calcHash(css_style_rec_t & rec)
          + (lUInt32)rec.box_sizing) * 31
          + (lUInt32)rec.caption_side) * 31
          + (lUInt32)rec.cr_hint.pack()) * 31
+         + (lUInt32)rec.cr_normal_line_height.pack()) * 31
          + (lUInt32)rec.font_name.getHash()
          + (lUInt32)rec.background_image.getHash()
          + (lUInt32)rec.content.getHash());
@@ -198,7 +199,8 @@ bool operator == (const css_style_rec_t & r1, const css_style_rec_t & r2)
            r1.box_sizing == r2.box_sizing&&
            r1.caption_side == r2.caption_side&&
            r1.content == r2.content&&
-           r1.cr_hint==r2.cr_hint;
+           r1.cr_hint==r2.cr_hint&&
+           r1.cr_normal_line_height==r2.cr_normal_line_height;
 }
 
 
@@ -401,6 +403,7 @@ bool css_style_rec_t::serialize( SerialBuf & buf )
     ST_PUT_ENUM(caption_side);
     buf << content;
     ST_PUT_LEN(cr_hint);
+    ST_PUT_LEN(cr_normal_line_height);
     lUInt32 hash = calcHash(*this);
     buf << hash;
     return !buf.error();
@@ -475,6 +478,7 @@ bool css_style_rec_t::deserialize( SerialBuf & buf )
     ST_GET_ENUM(css_caption_side_t, caption_side);
     buf>>content;
     ST_GET_LEN(cr_hint);
+    ST_GET_LEN(cr_normal_line_height);
     lUInt32 hash = 0;
     buf >> hash;
     // printf("imp: %llx oldhash: %lx ", important, hash);

crengine/src/lvtinydom.cpp

@@ -5143,6 +5143,7 @@ bool ldomDocument::setRenderProps( int width, int dy, bool /*showCover*/, int /*
     s->word_break = css_wb_normal;
     s->caption_side = css_cs_top;
     s->cr_hint = css_length_t(css_val_unspecified, CSS_CR_HINT_NONE);
+    s->cr_normal_line_height = css_length_t(css_val_unspecified, css_generic_normal); // derived from font metrics
 
     //lUInt32 defStyleHash = (((_ua_stylesheet.getHash() * 31) + calcHash(_def_style))*31 + calcHash(_def_font));
     //defStyleHash = defStyleHash * 31 + getDocFlags();
@@ -21301,6 +21302,8 @@ void runBasicTinyDomUnitTests()
         style1->line_height.value = css_generic_normal; // line-height: normal
         style1->cr_hint.type = css_val_unspecified;
         style1->cr_hint.value = CSS_CR_HINT_NONE;
+        style1->cr_normal_line_height.type = css_val_unspecified;
+        style1->cr_normal_line_height.value = css_generic_normal;
 
         css_style_ref_t style2;
         style2 = css_style_ref_t( new css_style_rec_t );
@@ -21334,6 +21337,8 @@ void runBasicTinyDomUnitTests()
         style2->line_height.value = css_generic_normal; // line-height: normal
         style2->cr_hint.type = css_val_unspecified;
         style2->cr_hint.value = CSS_CR_HINT_NONE;
+        style2->cr_normal_line_height.type = css_val_unspecified;
+        style2->cr_normal_line_height.value = css_generic_normal;
 
         css_style_ref_t style3;
         style3 = css_style_ref_t( new css_style_rec_t );
@@ -21367,6 +21372,8 @@ void runBasicTinyDomUnitTests()
         style3->line_height.value = css_generic_normal; // line-height: normal
         style3->cr_hint.type = css_val_unspecified;
         style3->cr_hint.value = CSS_CR_HINT_NONE;
+        style3->cr_normal_line_height.type = css_val_unspecified;
+        style3->cr_normal_line_height.value = css_generic_normal;
 
         el1->setStyle(style1);
         css_style_ref_t s1 = el1->getStyle();