Min and Max Intrinsic Widths look mostly correct now.

Change-Id: I0201c88bab4a46baf5164def8cccd51f4c5486c1

engine/src/flutter/src/paragraph.cc

@@ -401,11 +401,10 @@ void Paragraph::Layout(double width, bool force) {
         max_line_spacing = temp_line_spacing;
         // Record the alphabetic_baseline_:
         if (lines_ == 0) {
-          alphabetic_baseline_ = metrics.fCapHeight * run.style.height;
+          alphabetic_baseline_ = -metrics.fAscent * run.style.height;
           // TODO(garyq): Properly implement ideographic_baseline_.
           ideographic_baseline_ =
-              (metrics.fUnderlinePosition + metrics.fCapHeight) *
-              run.style.height;
+              (metrics.fUnderlinePosition - metrics.fAscent) * run.style.height;
         }
       }
       temp_line_spacing = metrics.fDescent * run.style.height;
@@ -455,6 +454,8 @@ void Paragraph::Layout(double width, bool force) {
       buffer_sizes.size() > 0) {
     JustifyLine(buffers, buffer_sizes, word_count, justify_spacing, -1);
   }
+  line_widths_ =
+      std::vector<double>(breaker_.getWidths(), breaker_.getWidths() + lines_);
   CalculateIntrinsicWidths();
 }
 
@@ -509,12 +510,25 @@ double Paragraph::GetIdeographicBaseline() const {
 }
 
 void Paragraph::CalculateIntrinsicWidths() {
-  for (size_t i = 0; i < word_widths_.size(); ++i) {
-    max_intrinsic_width_ += word_widths_[i];
+  // TODO(garyq): Investigate correctness of the following implementation of max
+  // intrinsic width. This is currently the sum of all the widths of each line
+  // after layout.
+  max_intrinsic_width_ = 0;
+  for (size_t i = 0; i < line_widths_.size(); ++i) {
+    max_intrinsic_width_ += line_widths_[i];
   }
 
-  // TODO(garyq): Implement the DP algorithm version instead of this stand in!
-  min_intrinsic_width_ = max_intrinsic_width_ / paragraph_style_.max_lines;
+  // TODO(garyq): Investigate correctness of the following implementation of max
+  // intrinsic width. This is currently the longest line in the text after
+  // layout.
+  min_intrinsic_width_ = 0;
+  for (size_t i = 0; i < line_widths_.size(); ++i) {
+    min_intrinsic_width_ = std::max(min_intrinsic_width_, line_widths_[i]);
+  }
+
+  // Ensure that min < max widths.
+  min_intrinsic_width_ = std::min(max_intrinsic_width_, min_intrinsic_width_);
+  max_intrinsic_width_ = std::max(max_intrinsic_width_, min_intrinsic_width_);
 }
 
 double Paragraph::GetMaxIntrinsicWidth() const {
@@ -534,6 +548,18 @@ double Paragraph::GetHeight() const {
   return line_heights_[line_heights_.size() - 2];
 }
 
+double Paragraph::GetLayoutWidth() const {
+  double w = 0;
+  for (size_t i = 0; i < line_widths_.size(); ++i) {
+    w = std::max(w, line_widths_[i]);
+  }
+  return w;
+}
+
+double Paragraph::GetMaxWidth() const {
+  return width_;
+}
+
 void Paragraph::SetParagraphStyle(const ParagraphStyle& style) {
   needs_layout_ = true;
   paragraph_style_ = style;

engine/src/flutter/src/paragraph.h

@@ -53,6 +53,12 @@ class Paragraph {
 
   double GetHeight() const;
 
+  // Returns the actual max width of the longest line after Layout().
+  double GetLayoutWidth() const;
+
+  // Returns the width provided in the Layout() method.
+  double GetMaxWidth() const;
+
   double GetAlphabeticBaseline() const;
 
   double GetIdeographicBaseline() const;
@@ -115,8 +121,8 @@ class Paragraph {
   SkScalar height_ = 0.0f;
   double width_ = 0.0f;
   size_t lines_ = 0;
-  double max_intrinsic_width_ = -1;
-  double min_intrinsic_width_ = -1;
+  double max_intrinsic_width_ = 0;
+  double min_intrinsic_width_ = 0;
   // TODO(garyq): Instead of using whitespace to delimit "words", use the
   // results of minikin breaker.
   std::vector<double> word_widths_;

engine/src/flutter/src/paragraph_style.h

@@ -17,6 +17,7 @@
 #ifndef LIB_TXT_SRC_PARAGRAPH_STYLE_H_
 #define LIB_TXT_SRC_PARAGRAPH_STYLE_H_
 
+#include <climits>
 #include <string>
 
 #include "lib/txt/src/font_style.h"
@@ -32,7 +33,7 @@ class ParagraphStyle {
   FontStyle font_style = FontStyle::normal;
   std::string font_family = "";
   double font_size = 14;
-  size_t max_lines = 1;
+  size_t max_lines = UINT_MAX;
   double line_height = 1.0;
   std::string ellipsis = "...";
   // TODO(garyq): Implement right to left.

engine/src/flutter/tests/txt/paragraph_unittests.cc

@@ -1025,7 +1025,7 @@ TEST_F(RenderTest, GetRectsForRangeParagraph) {
   // end of paragraph handling needs to be fixed in a later patch.
   EXPECT_FLOAT_EQ(rects[16].left(), 0);
   EXPECT_FLOAT_EQ(rects[16].top(), 234.375);
-  EXPECT_FLOAT_EQ(rects[16].right(), 133.875);
+  EXPECT_FLOAT_EQ(rects[16].right(), 140);
   EXPECT_FLOAT_EQ(rects[16].bottom(), 292.96875);
 
   ASSERT_TRUE(Snapshot());