Add preliminary support for letter-spacing and word-spacing

Change-Id: If3f64cf0c18ff0aa087091626532bcd983f6b54c

src/paragraph.cc

@@ -149,7 +149,7 @@ void Paragraph::Layout(double width,
 
   // Reset member variables so Layout still works when called more than once
   max_intrinsic_width_ = 0.0f;
-  lines_ = 1;
+  lines_ = 0;
 
   minikin::Layout layout;
   SkScalar x = x_offset;
@@ -170,8 +170,7 @@ void Paragraph::Layout(double width,
 
     size_t layout_start = run.start;
 
-    while (layout_start < run.end &&
-           GetLineCount() <= paragraph_style_.max_lines) {
+    while (layout_start < run.end && lines_ < paragraph_style_.max_lines) {
       const size_t next_break = (break_index > breaks_count - 1)
                                     ? std::numeric_limits<size_t>::max()
                                     : breaks[break_index];
@@ -194,14 +193,15 @@ void Paragraph::Layout(double width,
           const size_t glyph_index = blob_start + blob_index;
           buffer.glyphs[blob_index] = layout.getGlyphId(glyph_index);
           const size_t pos_index = 2 * blob_index;
-          letter_spacing_offset += run.style.letter_spacing;
           buffer.pos[pos_index] = layout.getX(glyph_index) +
                                   letter_spacing_offset + word_spacing_offset;
+          letter_spacing_offset += run.style.letter_spacing;
           buffer.pos[pos_index + 1] = layout.getY(glyph_index);
         }
         blob_start += blob_length;
 
-        // Subtract letter offset to avoid big gap at end of run.
+        // Subtract letter offset to avoid big gap at end of run. This my be
+        // removed depending on the specificatins for letter spacing.
         letter_spacing_offset -= run.style.letter_spacing;
 
         word_spacing_offset += run.style.word_spacing;
@@ -210,6 +210,10 @@ void Paragraph::Layout(double width,
             layout.getX(blob_start - 1) + letter_spacing_offset;
       }
 
+      // Subtract word offset to avoid big gap at end of run. This my be
+      // removed depending on the specificatins for word spacing.
+      word_spacing_offset -= run.style.word_spacing;
+
       // TODO(abarth): We could keep the same SkTextBlobBuilder as long as the
       // color stayed the same.
       records_.push_back(
@@ -224,8 +228,6 @@ void Paragraph::Layout(double width,
         y_ += run.style.font_size * run.style.height;
         break_index += 1;
         lines_++;
-        if (lines_ > paragraph_style_.max_lines)
-          lines_--;
       } else {
         x += layout.getAdvance();
       }
@@ -259,8 +261,7 @@ double Paragraph::GetMinIntrinsicWidth() const {
 }
 
 double Paragraph::GetHeight() const {
-  return paragraph_style_.font_size * paragraph_style_.line_height *
-         paragraph_style_.max_lines;
+  return y_;
 }
 
 void Paragraph::SetParagraphStyle(const ParagraphStyle& style) {
@@ -277,7 +278,6 @@ void Paragraph::Paint(SkCanvas* canvas, double x, double y) {
 }
 
 int Paragraph::GetLineCount() const {
-  // FTL_LOG(INFO) << "Lines: " << lines_;
   return lines_;
 }
 

tests/txt/paragraph_unittests.cc

@@ -92,25 +92,25 @@ TEST_F(RenderTest, SimpleRedParagraph) {
 }
 
 TEST_F(RenderTest, RainbowParagraph) {
-  const char* text1 = "RedRoboto ";
+  const char* text1 = "Red Roboto";
   auto icu_text1 = icu::UnicodeString::fromUTF8(text1);
   std::u16string u16_text1(icu_text1.getBuffer(),
                            icu_text1.getBuffer() + icu_text1.length());
-  const char* text2 = "Big Green Default ";
+  const char* text2 = "Big Green Default";
   auto icu_text2 = icu::UnicodeString::fromUTF8(text2);
   std::u16string u16_text2(icu_text2.getBuffer(),
                            icu_text2.getBuffer() + icu_text2.length());
-  const char* text3 = "DefcolorHomemadeApple ";
+  const char* text3 = "Defcolor Homemade Apple";
   auto icu_text3 = icu::UnicodeString::fromUTF8(text3);
   std::u16string u16_text3(icu_text3.getBuffer(),
                            icu_text3.getBuffer() + icu_text3.length());
-  const char* text4 = "SmallBlueRoboto ";
+  const char* text4 = "Small Blue Roboto";
   auto icu_text4 = icu::UnicodeString::fromUTF8(text4);
   std::u16string u16_text4(icu_text4.getBuffer(),
                            icu_text4.getBuffer() + icu_text4.length());
   const char* text5 =
-      "Continue Last Style With lots of words to check if it overlaps properly "
-      "or not";
+      "Continue Last Style With lots of words to check if it overlaps "
+      "properly or not";
   auto icu_text5 = icu::UnicodeString::fromUTF8(text5);
   std::u16string u16_text5(icu_text5.getBuffer(),
                            icu_text5.getBuffer() + icu_text5.length());
@@ -281,13 +281,13 @@ TEST_F(RenderTest, LinebreakParagraph) {
                           icu_text.getBuffer() + icu_text.length());
 
   txt::ParagraphStyle paragraph_style;
-  paragraph_style.max_lines = 1000;
+  paragraph_style.max_lines = 14;
   txt::ParagraphBuilder builder(paragraph_style);
 
   txt::TextStyle text_style;
   text_style.font_size = 26;
   // Letter spacing not yet implemented
-  text_style.letter_spacing = 10;
+  text_style.letter_spacing = 0;
   text_style.color = SK_ColorBLACK;
   text_style.height = 1.15;
   builder.PushStyle(text_style);
@@ -297,9 +297,9 @@ TEST_F(RenderTest, LinebreakParagraph) {
   builder.Pop();
 
   auto paragraph = builder.Build();
-  paragraph->Layout(GetTestCanvasWidth(), txt::GetFontDir());
+  paragraph->Layout(GetTestCanvasWidth() - 100, txt::GetFontDir());
 
-  paragraph->Paint(GetCanvas(), 5.0, 30.0);
+  paragraph->Paint(GetCanvas(), 0, 30.0);
 
   ASSERT_EQ(paragraph->text_.size(), std::string{text}.length());
   for (size_t i = 0; i < u16_text.length(); i++) {