[escher] Add textArea line number limit

Change-Id: Ia0d9a9136282efc87c0996c141c0852ed75892f9

apps/code/editor_view.cpp

@@ -67,11 +67,19 @@ void EditorView::GutterView::drawRect(KDContext * ctx, KDRect rect) const {
   KDCoordinate firstLine = m_offset / glyphSize.height();
   KDCoordinate firstLinePixelOffset = m_offset - firstLine * glyphSize.height();
 
-  char lineNumber[4];
+  char lineNumber[k_lineNumberCharLength];
   int numberOfLines = bounds().height() / glyphSize.height() + 1;
   for (int i=0; i<numberOfLines; i++) {
-    Poincare::Integer line(i + firstLine + 1);
-    line.serialize(lineNumber, 4);
+    // Only the first two digits are displayed
+    int lineNumberValue = (i + firstLine + 1) % 100;
+    Poincare::Integer line(lineNumberValue);
+    if (firstLine < 10 || lineNumberValue >= 10) {
+      line.serialize(lineNumber, k_lineNumberCharLength);
+    } else {
+      // Add a leading "0"
+      lineNumber[0] = '0';
+      line.serialize(lineNumber + 1, k_lineNumberCharLength - 1);
+    }
     KDCoordinate leftPadding = (2 - strlen(lineNumber)) * glyphSize.width();
     ctx->drawString(
       lineNumber,

apps/code/editor_view.h

@@ -42,6 +42,7 @@ private:
     KDSize minimalSizeForOptimalDisplay() const override;
   private:
     static constexpr KDCoordinate k_margin = 2;
+    static constexpr int k_lineNumberCharLength = 3;
     const KDFont * m_font;
     KDCoordinate m_offset;
   };

escher/include/escher/text_area.h

@@ -94,6 +94,9 @@ protected:
     size_t textLength() const {
       return strlen(m_buffer);
     }
+    int textLineTotal() const {
+      return positionAtPointer(m_buffer+textLength()).line();
+    }
   private:
     char * m_buffer;
     size_t m_bufferSize;
@@ -133,6 +136,8 @@ protected:
 private:
   void selectUpDown(bool up, int step);
   TextAreaDelegate * m_delegate;
+  // Due to rect size limitation, the editor cannot display more than 1800 lines
+  constexpr static int k_maxLines = 999;
 };
 
 #endif

escher/src/text_area.cpp

@@ -63,6 +63,11 @@ bool TextArea::handleEventWithText(const char * text, bool indentation, bool for
     }
   }
 
+  // Check the text will not overflow the max number of lines
+  if (contentView()->getText()->textLineTotal() + UTF8Helper::CountOccurrences(text, '\n') >= k_maxLines) {
+    return false;
+  }
+
   // Insert the text
   if (!insertTextAtLocation(text, insertionPosition)) {
     return true;