[reader] Foundation of latex handling

apps/reader/Makefile

@@ -7,6 +7,7 @@ app_sreader_src = $(addprefix apps/reader/,\
   utility.cpp \
   read_book_controller \
   word_wrap_view.cpp \
+  tex_parser.cpp \
 )
 
 apps_src += $(app_sreader_src)

apps/reader/tex_parser.cpp

@@ -0,0 +1,124 @@
+#include "tex_parser.h"
+#include <ion/unicode/utf8_decoder.h>
+
+namespace Reader {
+
+TexParser::TexParser(const char * text, const char * endOfText) : 
+  m_text(text), 
+  m_endOfText(endOfText),
+  m_hasError(false)
+{
+    
+}
+
+Layout TexParser::getLayout() {
+  HorizontalLayout layout = HorizontalLayout::Builder();
+  const char * start = m_text;
+  
+  while (m_text < m_endOfText) {
+    if (*m_text == '\\') {
+      if (start != m_text) {
+        layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+      }
+      m_text ++;
+      layout.addOrMergeChildAtIndex(popCommand(), layout.numberOfChildren(), false);
+      start = m_text;
+    }
+    else if (*m_text == " ") {
+      if (start != m_text) {
+        layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+      }
+      m_text ++;
+      start = m_text;
+    }
+    else if (*m_text == "^") {
+      if (start != m_text) {
+        layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+      }
+      m_text ++;
+      layout.addOrMergeChildAtIndex(popCommand(), layout.numberOfChildren(), false);
+      start = m_text;
+    }
+    else {
+      m_text ++;
+    }
+  }
+
+  if (start != m_text) {
+    layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+  }
+
+  if (m_hasError) {
+    return CodePointLayout::Builder(CodePoint(0xFFD));
+  }
+
+  return layout;
+}
+
+Layout TexParser::popBlock() {
+  while (*m_text == ' ') {
+    m_text ++;
+  }
+
+  if (*m_text == '{') {
+    m_text ++;
+    return popText('}');
+  }
+
+  if (*m_text == '\\') {
+    m_text ++;
+    return popCommand();
+  }
+
+  if (m_text >= m_endOfText) {
+    m_hasError = true;
+  }
+
+  UTF8Decoder decoder(m_text);
+  m_text ++;
+  return CodePointLayout::Builder(decoder.nextCodePoint());
+}
+
+Layout TexParser::popText(char stop) {
+  if (*m_text == '\\') {
+    m_text ++;
+    return popCommand();
+  }
+
+  HorizontalLayout layout = HorizontalLayout::Builder();
+  const char * start = m_text;
+  
+  while (m_text < m_endOfText) {
+    if (*m_text == '\\') {
+      layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+      m_text ++;
+      layout.addOrMergeChildAtIndex(popCommand(), layout.numberOfChildren(), false);
+      start = m_text;
+    }
+
+    m_text ++;
+  }
+
+  if (start != m_text) {
+    layout.addOrMergeChildAtIndex(LayoutHelper::String(start, m_text - start), layout.numberOfChildren(), false);
+  }
+  return layout;
+}
+
+Layout TexParser::popCommand() {
+  if (strncmp(k_fracCommand, m_text, strlen(k_fracCommand)) == 0) {
+    m_text += strlen(k_fracCommand);
+    if (*m_text == ' ' || *m_text == '{') {
+      return popFracCommand();
+    } 
+  }
+  return popFracCommand();
+}
+
+Layout TexParser::popFracCommand() {
+  Layout firstBlock = popBlock();
+  Layout secondBlock = popBlock();
+  return FractionLayout::Builder(firstBlock, secondBlock);
+}
+
+}

apps/reader/tex_parser.h

@@ -0,0 +1,31 @@
+#ifndef __TEX_PARSER_H__
+#define __TEX_PARSER_H__
+
+#include <poincare_layouts.h>
+#include <poincare/layout_helper.h>
+#include <string.h>
+
+using namespace Poincare;
+
+namespace Reader
+{
+/// @brief Class used in the WordWrapTextView class to parse a Tex expression
+class TexParser {
+public:
+  TexParser(const char * text, const char * endOfText);
+  Layout getLayout();
+private:
+  Layout popBlock();
+  Layout popText(char stop);
+  Layout popCommand();
+  Layout popFracCommand();
+  const char * m_text;
+  const char * m_endOfText;
+  bool m_hasError;
+
+  static constexpr char const * k_fracCommand = "frac";
+};
+  
+}
+
+#endif

apps/reader/utility.cpp

@@ -117,7 +117,7 @@ const char * EndOfPrintableWord(const char * word, const char * end) {
   UTF8Decoder decoder(word);
   CodePoint codePoint = decoder.nextCodePoint();
   const char * result = word;
-  while (codePoint != '\n' && codePoint != ' ' && codePoint != '%') {
+  while (codePoint != '\n' && codePoint != ' ' && codePoint != '%' && codePoint != '$') {
     result = decoder.stringPosition();
     if (result >= end) {
       break;
@@ -127,4 +127,21 @@ const char * EndOfPrintableWord(const char * word, const char * end) {
   return result;
 }
 
+const char * StartOfPrintableWord(const char * word, const char * start) {
+  if (word == start) {
+    return word;
+  }
+  UTF8Decoder decoder(word);
+  CodePoint codePoint = decoder.previousCodePoint();
+  const char * result = word;
+  while (codePoint != '\n' && codePoint != ' ' && codePoint != '%' && codePoint != '$') {
+    result = decoder.stringPosition();
+    if (result >= start) {
+      break;
+    }
+    codePoint = decoder.previousCodePoint();
+  }
+  return result;
+}
+
 }

apps/reader/utility.h

@@ -12,6 +12,7 @@ bool stringEndsWith(const char* str, const char* end);
 int filesWithExtension(const char* extension, External::Archive::File* files, int filesSize);
 void stringNCopy(char* dest, int max, const char* src, int len);
 const char * EndOfPrintableWord(const char * word, const char * end);
+const char * StartOfPrintableWord(const char * word, const char * start);
   
 }
 #endif

apps/reader/word_wrap_view.cpp

@@ -1,6 +1,7 @@
 
 #include "word_wrap_view.h"
 #include "utility.h"
+#include "tex_parser.h"
 #include <poincare/expression.h>
 #include "../shared/poincare_helpers.h"
 #include <poincare/undefined.h>
@@ -38,16 +39,17 @@ void WordWrapTextView::previousPage() {
   const int charWidth = m_font->glyphSize().width();
   const int charHeight = m_font->glyphSize().height();
 
+  const char * endOfFile = text() + m_length;
   const char * endOfWord = text() + m_pageOffset - 1;
-  const char * startOfWord = UTF8Helper::BeginningOfWord(text(), endOfWord);
+  const char * startOfWord = StartOfPrintableWord(endOfWord, text());
 
   KDSize textSize = KDSizeZero;
 
   KDPoint textEndPosition(m_frame.width() - k_margin, m_frame.height() - k_margin);
 
   while(startOfWord>=text()) {
-    startOfWord = UTF8Helper::BeginningOfWord(text(), endOfWord);
-    endOfWord = UTF8Helper::EndOfWord(startOfWord);
+    startOfWord = StartOfPrintableWord(endOfWord, text());
+    endOfWord = EndOfPrintableWord(startOfWord, endOfFile);
 
     if (*startOfWord == '%') {
       if (updateTextColorBackward(startOfWord)) {
@@ -55,20 +57,28 @@ void WordWrapTextView::previousPage() {
         continue;
       }
     }
-    if (*startOfWord == '$' && *(endOfWord-1) == '$') {
-      const int wordMaxLength = 128;
-      char word[wordMaxLength];
-      stringNCopy(word, wordMaxLength, startOfWord + 1, endOfWord-startOfWord-2);
-      Poincare::Expression expr = Poincare::Expression::Parse(word, nullptr);
-      if (expr.isUninitialized()) {
-        expr = Poincare::Undefined::Builder();
+
+    if (*endOfWord == '$') {
+      startOfWord = endOfWord - 1;
+      while (*startOfWord != '$') {
+        if (startOfWord < text()) {
+          break; // File isn't rightly formated
+        }
+        startOfWord --;
       }
-      Poincare::Layout layout = Shared::PoincareHelpers::CreateLayout(expr);
-      textSize = layout.layoutSize();
-      
+      startOfWord --;
+
+      TexParser parser = TexParser(startOfWord + 1, endOfWord - 2);
+      Poincare::Layout layout = parser.getLayout();
+      textSize = layout.layoutSize(); 
     }
     else {
-      textSize = m_font->stringSizeUntil(startOfWord, endOfWord);
+      if (*startOfWord == '\\' || *(startOfWord + 1) == '$') {
+      textSize = m_font->stringSizeUntil(startOfWord + 1, endOfWord);
+      }
+      else {
+        textSize = m_font->stringSizeUntil(startOfWord, endOfWord);
+      }
     }
     KDPoint textStartPosition = KDPoint(textEndPosition.x()-textSize.width(), textEndPosition.y());
 
@@ -109,7 +119,7 @@ void WordWrapTextView::previousPage() {
     m_pageOffset = 0;
   }
   else {
-    m_pageOffset = UTF8Helper::EndOfWord(startOfWord) - text() + 1;
+    m_pageOffset = EndOfPrintableWord(startOfWord, endOfFile) - text() + 1;
   }
   markRectAsDirty(bounds());
 }
@@ -119,7 +129,12 @@ void WordWrapTextView::drawRect(KDContext * ctx, KDRect rect) const {
 
   const char * endOfFile = text() + m_length;
   const char * startOfWord = text() + m_pageOffset;
-  const char * endOfWord = EndOfPrintableWord(startOfWord, endOfFile);
+  const char * endOfWord;
+  
+  if (*startOfWord != '$') {
+    endOfWord = EndOfPrintableWord(startOfWord, endOfFile);
+  } // Else we don't need to update endOfWord
+
   KDPoint textPosition(k_margin, k_margin);
 
   const int wordMaxLength = 128;
@@ -152,18 +167,26 @@ void WordWrapTextView::drawRect(KDContext * ctx, KDRect rect) const {
         continue;
       }
     }
-    
-    if (*startOfWord == '$' && *(endOfWord-1) == '$') { // Look for expression
-      stringNCopy(word, wordMaxLength, startOfWord + 1, endOfWord-startOfWord-2);
-      Poincare::Expression expr = Poincare::Expression::Parse(word, nullptr);
-      if (expr.isUninitialized()) {
-        expr = Poincare::Undefined::Builder();
+
+    if (*startOfWord == '$') { // Look for expression
+      endOfWord = startOfWord + 1;
+      while (*endOfWord != '$') {
+        if (endOfWord > endOfFile) {
+          break; // If we are here, it's bad...
+        }
+        endOfWord ++;
       }
-      layout = Shared::PoincareHelpers::CreateLayout(expr);
+      endOfWord ++;
+
+      TexParser parser = TexParser(startOfWord + 1, endOfWord - 1);
+      layout = parser.getLayout();
       textSize = layout.layoutSize();
       toDraw = ToDraw::Expression;
     }
     else {
+      if (*startOfWord == '\\' || *(startOfWord + 1) == '$') {
+        startOfWord ++;
+      }
       textSize = m_font->stringSizeUntil(startOfWord, endOfWord);
       stringNCopy(word, wordMaxLength, startOfWord, endOfWord-startOfWord);
       toDraw = ToDraw::Text;
@@ -222,7 +245,10 @@ void WordWrapTextView::drawRect(KDContext * ctx, KDRect rect) const {
     }
 
     textPosition = nextTextPosition;
-    endOfWord = EndOfPrintableWord(startOfWord+1, endOfFile);
+
+    if (*startOfWord != '$') {
+      endOfWord = EndOfPrintableWord(startOfWord+1, endOfFile);
+    } // Else we don't need to update endOfWord
   }
 
   m_nextPageOffset = startOfWord - text();