Add exponent layout.

Change-Id: Iffce8dcdd4ecf10a8ed4170494b59fa6c524b9cb

poincare/Makefile

@@ -1,6 +1,6 @@
 SFLAGS += -Ipoincare/include
 objs += $(addprefix poincare/src/, addition.o context.o expression.o float.o integer.o fraction.o expression_lexer.o expression_parser.o power.o product.o symbol.o)
-objs += $(addprefix poincare/src/layout/, expression_layout.o fraction_layout.o horizontal_layout.o string_layout.o)
+objs += $(addprefix poincare/src/layout/, expression_layout.o fraction_layout.o horizontal_layout.o exponent_layout.o string_layout.o)
 tests += $(addprefix poincare/test/, integer.cpp)
 
 # Even though flex and bison will generate both implementation and headers at

poincare/src/layout/exponent_layout.cpp

@@ -0,0 +1,55 @@
+#include <string.h>
+#include <assert.h>
+#include "exponent_layout.h"
+
+// TODO(fraimundo): Find a better name.
+#define EXPONENT_HEIGHT 5
+
+ExponentLayout::ExponentLayout(ExpressionLayout * parent, Expression * base, Expression * exponent) :
+ExpressionLayout(parent) {
+  m_base_layout = base->createLayout(this);
+  m_exponent_layout = exponent->createLayout(this);
+}
+
+ExponentLayout::~ExponentLayout() {
+  delete m_exponent_layout;
+  delete m_base_layout;
+}
+
+// There is nothing to draw for a power, only the position of the children matters
+void ExponentLayout::render(KDPoint point) { }
+
+KDSize ExponentLayout::computeSize() {
+  KDSize s;
+  KDSize exponent_size, base_size;
+  exponent_size = m_exponent_layout->size();
+  base_size = m_base_layout->size();
+  s.height = base_size.height + exponent_size.height - EXPONENT_HEIGHT;
+  s.width = base_size.width + exponent_size.width;
+  return s;
+}
+
+ExpressionLayout * ExponentLayout::child(uint16_t index) {
+  switch (index) {
+    case 0:
+      return m_base_layout;
+    case 1:
+      return m_exponent_layout;
+    default:
+      return nullptr;
+  }
+}
+
+KDPoint ExponentLayout::positionOfChild(ExpressionLayout * child) {
+  KDPoint p;
+  if (child == m_base_layout) {
+    p.x = 0;
+    p.y = m_exponent_layout->size().height - EXPONENT_HEIGHT;
+  } else if (child == m_exponent_layout) {
+    p.x = m_base_layout->size().width;
+    p.y = 0;
+  } else {
+    assert(false); // Should not happen
+  }
+  return p;
+}

poincare/src/layout/exponent_layout.h

@@ -0,0 +1,21 @@
+#ifndef POINCARE_EXPONENT_LAYOUT_H
+#define POINCARE_EXPONENT_LAYOUT_H
+
+#include <poincare/expression.h>
+#include <poincare/expression_layout.h>
+
+class ExponentLayout : public ExpressionLayout {
+  public:
+    ExponentLayout(ExpressionLayout * parent, Expression * base, Expression * exponent);
+    ~ExponentLayout();
+  protected:
+    void render(KDPoint point) override;
+    KDSize computeSize() override;
+    ExpressionLayout * child(uint16_t index) override;
+    KDPoint positionOfChild(ExpressionLayout * child) override;
+  private:
+    ExpressionLayout * m_base_layout;
+    ExpressionLayout * m_exponent_layout;
+};
+
+#endif

poincare/src/power.cpp

@@ -1,5 +1,5 @@
 #include <poincare/power.h>
-#include "layout/horizontal_layout.h"
+#include "layout/exponent_layout.h"
 
 Power::Power(Expression * base, Expression * exponent) :
   m_base(base),
@@ -17,5 +17,5 @@ float Power::approximate(Context& context) {
 }
 
 ExpressionLayout * Power::createLayout(ExpressionLayout * parent) {
-  return new HorizontalLayout(parent, m_base, '^', m_exponent);
+  return new ExponentLayout(parent, m_base, m_exponent);
 }