[apps/statistics] Create a histogram view inheriting from cruve view

Change-Id: I7e6d027e50ec040e1fe6ee6354d9275dc3a025d9

apps/statistics/Makefile

@@ -5,6 +5,7 @@ app_objs += $(addprefix apps/statistics/,\
   data.o\
   data_controller.o\
   histogram_controller.o\
+  histogram_view.o\
 )
 
 app_images += apps/statistics/stat_icon.png

apps/statistics/histogram_view.cpp

@@ -0,0 +1,36 @@
+#include "histogram_view.h"
+#include <assert.h>
+
+namespace Statistics {
+
+HistogramView::HistogramView(Data * data) :
+  CurveView(data),
+  m_data(data)
+{
+}
+
+void HistogramView::reload() {
+  markRectAsDirty(bounds());
+  computeLabels(Axis::Horizontal);
+}
+
+void HistogramView::drawRect(KDContext * ctx, KDRect rect) const {
+  ctx->fillRect(rect, KDColorWhite);
+  drawAxes(Axis::Horizontal, ctx, rect);
+  drawAxes(Axis::Vertical, ctx, rect);
+  drawLabels(Axis::Horizontal, true, ctx, rect);
+  drawHistogram(nullptr, KDColorBlack, ctx, rect);
+}
+
+char * HistogramView::label(Axis axis, int index) const {
+  if (axis == Axis::Vertical) {
+    return nullptr;
+  }
+  return (char *)m_labels[index];
+}
+
+float HistogramView::evaluateCurveAtAbscissa(void * curve, float t) const {
+  return m_data->sizeAtValue(t);
+}
+
+}

apps/statistics/histogram_view.h

@@ -0,0 +1,26 @@
+#ifndef STATISTICS_HISTOGRAM_VIEW_H
+#define STATISTICS_HISTOGRAM_VIEW_H
+
+#include <escher.h>
+#include "data.h"
+#include "../constant.h"
+#include "../curve_view.h"
+
+namespace Statistics {
+
+class HistogramView : public CurveView {
+public:
+  HistogramView(Data * m_data);
+  void reload();
+  void drawRect(KDContext * ctx, KDRect rect) const override;
+private:
+  char * label(Axis axis, int index) const override;
+  float evaluateCurveAtAbscissa(void * curve, float t) const override;
+  Data * m_data;
+  char m_labels[k_maxNumberOfXLabels][Constant::FloatBufferSizeInScientificMode];
+};
+
+}
+
+
+#endif