auto merge of #932 : june0cho/servo/text_deco, r=metajack

Implement 'overline' and 'line-through' in 'text-decoration' property. Add a test case.

src/components/gfx/display_list.rs

@@ -26,6 +26,8 @@ use servo_net::image::base::Image;
 use servo_util::range::Range;
 use extra::arc::Arc;
 
+use newcss::values::{CSSTextDecorationUnderline, CSSTextDecorationOverline, CSSTextDecorationLineThrough};
+
 /// A list of rendering operations to be performed.
 pub struct DisplayList<E> {
     list: ~[DisplayItem<E>]
@@ -135,14 +137,31 @@ impl<E> DisplayItem<E> {
                                             baseline_origin,
                                             text.color);
 
-                if new_run.underline {
+                let width = text.base.bounds.size.width;
-                    // TODO(eatkinson): Use the font metrics to properly position the underline
+                let underline_size = font.metrics.underline_size;
-                    // bar.
+                let underline_offset = font.metrics.underline_offset;
-                    let width = text.base.bounds.size.width;
+                let strikeout_size = font.metrics.strikeout_size;
-                    let underline_size = font.metrics.underline_size;
+                let strikeout_offset = font.metrics.strikeout_offset;
-                    let underline_bounds = Rect(Point2D(baseline_origin.x, baseline_origin.y),
+
-                                                Size2D(width, underline_size));
+                match new_run.decoration {
-                    render_context.draw_solid_color(&underline_bounds, text.color);
+                    CSSTextDecorationUnderline => {
+                        let underline_y = baseline_origin.y - underline_offset;
+                        let underline_bounds = Rect(Point2D(baseline_origin.x, underline_y),
+                                                    Size2D(width, underline_size));
+                        render_context.draw_solid_color(&underline_bounds, text.color);
+                    },
+                    CSSTextDecorationOverline => {
+                        let overline_bounds = Rect(Point2D(baseline_origin.x, origin.y),
+                                                   Size2D(width, underline_size));
+                        render_context.draw_solid_color(&overline_bounds, text.color);
+                    },
+                    CSSTextDecorationLineThrough => {
+                        let strikeout_y = baseline_origin.y - strikeout_offset;
+                        let strikeout_bounds = Rect(Point2D(baseline_origin.x, strikeout_y),
+                                                    Size2D(width, strikeout_size));
+                        render_context.draw_solid_color(&strikeout_bounds, text.color);
+                    },
+                    _ => ()
                 }
             }
 

src/components/gfx/font.rs

@@ -28,6 +28,8 @@ use servo_util::time;
 use servo_util::time::profile;
 use servo_util::time::ProfilerChan;
 
+use newcss::values::CSSTextDecoration;
+
 // FontHandle encapsulates access to the platform's font API,
 // e.g. quartz, FreeType. It provides access to metrics and tables
 // needed by the text shaper as well as access to the underlying font
@@ -80,6 +82,8 @@ pub trait FontTableMethods {
 pub struct FontMetrics {
     underline_size:   Au,
     underline_offset: Au,
+    strikeout_size:   Au,
+    strikeout_offset: Au,
     leading:          Au,
     x_height:         Au,
     em_size:          Au,
@@ -191,11 +195,11 @@ impl FontGroup {
         self.fonts = ~[];
     }
 
-    pub fn create_textrun(&self, text: ~str, underline: bool) -> TextRun {
+    pub fn create_textrun(&self, text: ~str, decoration: CSSTextDecoration) -> TextRun {
         assert!(self.fonts.len() > 0);
 
         // TODO(Issue #177): Actually fall back through the FontGroup when a font is unsuitable.
-        return TextRun::new(self.fonts[0], text, underline);
+        return TextRun::new(self.fonts[0], text, decoration);
     }
 }
 

src/components/gfx/platform/android/font.rs

@@ -219,6 +219,7 @@ impl FontHandleMethods for FontHandle {
         }
     }
 
+    #[fixed_stack_segment]
     fn get_metrics(&self) -> FontMetrics {
         /* TODO(Issue #76): complete me */
         let face = self.get_face_rec();
@@ -230,11 +231,26 @@ impl FontHandleMethods for FontHandle {
         let descent = self.font_units_to_au(face.descender as float);
         let max_advance = self.font_units_to_au(face.max_advance_width as float);
 
+        let mut strikeout_size = geometry::from_pt(0.0);
+        let mut strikeout_offset = geometry::from_pt(0.0);
+        let mut x_height = geometry::from_pt(0.0);
+        unsafe {
+            let os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2) as *TT_OS2;
+            let valid = os2.is_not_null() && (*os2).version != 0xffff;
+            if valid {
+               strikeout_size = self.font_units_to_au((*os2).yStrikeoutSize as float);
+               strikeout_offset = self.font_units_to_au((*os2).yStrikeoutPosition as float);
+               x_height = self.font_units_to_au((*os2).sxHeight as float);
+            }
+        }
+
         return FontMetrics {
             underline_size:   underline_size,
             underline_offset: underline_offset,
+            strikeout_size:   strikeout_size,
+            strikeout_offset: strikeout_offset,
             leading:          geometry::from_pt(0.0), //FIXME
-            x_height:         geometry::from_pt(0.0), //FIXME
+            x_height:         x_height,
             em_size:          em_size,
             ascent:           ascent,
             descent:          -descent, // linux font's seem to use the opposite sign from mac

src/components/gfx/platform/linux/font.rs

@@ -219,6 +219,7 @@ impl FontHandleMethods for FontHandle {
         }
     }
 
+    #[fixed_stack_segment]
     fn get_metrics(&self) -> FontMetrics {
         /* TODO(Issue #76): complete me */
         let face = self.get_face_rec();
@@ -230,11 +231,26 @@ impl FontHandleMethods for FontHandle {
         let descent = self.font_units_to_au(face.descender as float);
         let max_advance = self.font_units_to_au(face.max_advance_width as float);
 
+        let mut strikeout_size = geometry::from_pt(0.0);
+        let mut strikeout_offset = geometry::from_pt(0.0);
+        let mut x_height = geometry::from_pt(0.0);
+        unsafe {
+            let os2 = FT_Get_Sfnt_Table(face, ft_sfnt_os2) as *TT_OS2;
+            let valid = os2.is_not_null() && (*os2).version != 0xffff;
+            if valid {
+               strikeout_size = self.font_units_to_au((*os2).yStrikeoutSize as float);
+               strikeout_offset = self.font_units_to_au((*os2).yStrikeoutPosition as float);
+               x_height = self.font_units_to_au((*os2).sxHeight as float);
+            }
+        }
+
         return FontMetrics {
             underline_size:   underline_size,
             underline_offset: underline_offset,
+            strikeout_size:   strikeout_size,
+            strikeout_offset: strikeout_offset,
             leading:          geometry::from_pt(0.0), //FIXME
-            x_height:         geometry::from_pt(0.0), //FIXME
+            x_height:         x_height,
             em_size:          em_size,
             ascent:           ascent,
             descent:          -descent, // linux font's seem to use the opposite sign from mac

src/components/gfx/platform/macos/font.rs

@@ -13,6 +13,7 @@ use font::{FontTableTag, FontWeight100, FontWeight200, FontWeight300, FontWeight
 use font::{FontWeight500, FontWeight600, FontWeight700, FontWeight800, FontWeight900};
 use font::{FractionalPixel, SpecifiedFontStyle};
 use geometry::{Au, px_to_pt};
+use geometry;
 use platform::macos::font_context::FontContextHandle;
 use text::glyph::GlyphIndex;
 
@@ -171,6 +172,8 @@ impl FontHandleMethods for FontHandle {
             // see also: https://bugs.webkit.org/show_bug.cgi?id=16768
             // see also: https://bugreports.qt-project.org/browse/QTBUG-13364
             underline_offset: Au::from_pt(self.ctfont.underline_position() as float),
+            strikeout_size:   geometry::from_pt(0.0), // FIXME(Issue #942)
+            strikeout_offset: geometry::from_pt(0.0), // FIXME(Issue #942)
             leading:          Au::from_pt(self.ctfont.leading() as float),
             x_height:         Au::from_pt(self.ctfont.x_height() as float),
             em_size:          em_size,

src/components/gfx/text/text_run.rs

@@ -10,12 +10,13 @@ use text::glyph::GlyphStore;
 use font::{Font, FontDescriptor, RunMetrics};
 use servo_util::range::Range;
 use extra::arc::Arc;
+use newcss::values::CSSTextDecoration;
 
 /// A text run.
 pub struct TextRun {
     text: ~str,
     font: @mut Font,
-    underline: bool,
+    decoration: CSSTextDecoration,
     glyphs: ~[Arc<GlyphStore>],
 }
 
@@ -23,7 +24,7 @@ pub struct TextRun {
 pub struct SendableTextRun {
     text: ~str,
     font: FontDescriptor,
-    underline: bool,
+    decoration: CSSTextDecoration,
     priv glyphs: ~[Arc<GlyphStore>],
 }
 
@@ -37,7 +38,7 @@ impl SendableTextRun {
         TextRun {
             text: self.text.clone(),
             font: font,
-            underline: self.underline,
+            decoration: self.decoration,
             glyphs: self.glyphs.clone(),
         }
     }
@@ -116,13 +117,13 @@ impl<'self> Iterator<Range> for LineIterator<'self> {
 }
 
 impl<'self> TextRun {
-    pub fn new(font: @mut Font, text: ~str, underline: bool) -> TextRun {
+    pub fn new(font: @mut Font, text: ~str, decoration: CSSTextDecoration) -> TextRun {
         let glyphs = TextRun::break_and_shape(font, text);
 
         let run = TextRun {
             text: text,
             font: font,
-            underline: underline,
+            decoration: decoration,
             glyphs: glyphs,
         };
         return run;
@@ -191,7 +192,7 @@ impl<'self> TextRun {
         SendableTextRun {
             text: self.text.clone(),
             font: self.font.get_descriptor(),
-            underline: self.underline,
+            decoration: self.decoration,
             glyphs: self.glyphs.clone(),
         }
     }

src/components/main/layout/text.rs

@@ -12,7 +12,6 @@ use layout::box::{RenderBox, RenderBoxBase, TextRenderBox};
 use layout::box::{TextRenderBoxClass, UnscannedTextRenderBoxClass};
 use layout::context::LayoutContext;
 use layout::flow::FlowContext;
-use newcss::values::{CSSTextDecoration, CSSTextDecorationUnderline};
 use servo_util::range::Range;
 
 
@@ -128,13 +127,6 @@ impl TextRunScanner {
         let inline = flow.inline();
         let in_boxes = &inline.boxes;
 
-        fn has_underline(decoration: CSSTextDecoration) -> bool{
-            match decoration {
-                CSSTextDecorationUnderline => true,
-                _ => false
-            }
-        }
-
         assert!(self.clump.length() > 0);
 
         debug!("TextRunScanner: flushing boxes in range=%?", self.clump);
@@ -158,7 +150,7 @@ impl TextRunScanner {
                 let old_box = in_boxes[self.clump.begin()];
                 let text = old_box.raw_text();
                 let font_style = old_box.font_style();
-                let underline = has_underline(old_box.text_decoration());
+                let decoration = old_box.text_decoration();
 
                 // TODO(#115): Use the actual CSS `white-space` property of the relevant style.
                 let compression = CompressWhitespaceNewline;
@@ -171,7 +163,7 @@ impl TextRunScanner {
                     // font group fonts. This is probably achieved by creating the font group above
                     // and then letting `FontGroup` decide which `Font` to stick into the text run.
                     let fontgroup = ctx.font_ctx.get_resolved_font_for_style(&font_style);
-                    let run = @fontgroup.create_textrun(transformed_text, underline);
+                    let run = @fontgroup.create_textrun(transformed_text, decoration);
 
                     debug!("TextRunScanner: pushing single text box in range: %? (%?)", self.clump, text);
                     let new_box = do old_box.with_base |old_box_base| {
@@ -220,13 +212,13 @@ impl TextRunScanner {
                 // and then letting `FontGroup` decide which `Font` to stick into the text run.
                 let font_style = in_boxes[self.clump.begin()].font_style();
                 let fontgroup = ctx.font_ctx.get_resolved_font_for_style(&font_style);
-                let underline = has_underline(in_boxes[self.clump.begin()].text_decoration());
+                let decoration = in_boxes[self.clump.begin()].text_decoration();
 
                 // TextRuns contain a cycle which is usually resolved by the teardown
                 // sequence. If no clump takes ownership, however, it will leak.
                 let clump = self.clump;
                 let run = if clump.length() != 0 && run_str.len() > 0 {
-                    Some(@TextRun::new(fontgroup.fonts[0], run_str, underline))
+                    Some(@TextRun::new(fontgroup.fonts[0], run_str, decoration))
                 } else {
                     None
                 };

src/test/html/text_deco_simple.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title></title>
+</head>
+<body>
+    <p style="text-decoration:none;"> none </p>
+    <p style="text-decoration:underline;"> text underline </p>
+    <p style="text-decoration:overline;"> text underline </p>
+    <p style="text-decoration:line-through;"> text underline </p>
+    <p>
+    <p style="font-size:40px; text-decoration:underline; font-family:Verdana;"> text underline pqrstg </p>
+    <p style="text-decoration:overline;"> text overline xxxxxxxxXXXXXXX</p>
+    <p style="font-size:50px; text-decoration:line-through;"> text line-through xxxxxxxxXXXXX</p>
+    <p style="text-decoration:blink;"> text blink </p>
+</body>
+</html>