Add functions to get data bounds and number of plotted bars.

Those functions will be used for a PV improvement.

Change-Id: Idb4f4fdd2558d6cb7b7c936697e923fd7ea3ff3a

Charts/Core/vtkPlotBar.cxx

@@ -1113,3 +1113,36 @@ vtkStdString vtkPlotBar::GetTooltipLabel(const vtkVector2d &plotPos,
     }
   return tooltipLabel;
 }
+
+//-----------------------------------------------------------------------------
+int vtkPlotBar::GetBarsCount()
+{
+  vtkTable *table = this->Data->GetInput();
+  if (!table)
+    {
+    vtkWarningMacro(<< "GetBarsCount called with no input table set.");
+    return 0;
+    }
+  vtkDataArray* x = this->Data->GetInputArrayToProcess(0, table);
+  return x ? x->GetNumberOfTuples() : 0;
+}
+
+//-----------------------------------------------------------------------------
+void vtkPlotBar::GetDataBounds(double bounds[2])
+{
+  assert(bounds);
+  // Get the x and y arrays (index 0 and 1 respectively)
+  vtkTable *table = this->Data->GetInput();
+  if (!table)
+    {
+    vtkWarningMacro(<< "GetDataBounds called with no input table set.");
+    bounds[0] = VTK_DOUBLE_MAX;
+    bounds[1] = VTK_DOUBLE_MIN;
+    return;
+    }
+  vtkDataArray* x = this->Data->GetInputArrayToProcess(0, table);
+  if (x)
+    {
+    x->GetRange(bounds);
+    }
+}

Charts/Core/vtkPlotBar.h

@@ -192,6 +192,14 @@ public:
                                     vtkVector2f* location,
                                     vtkIdType* segmentIndex);
 
+  // Description:
+  // Get amount of plotted bars.
+  int GetBarsCount();
+
+  // Description:
+  // Get the data bounds for this mapper as (Xmin,Xmax).
+  void GetDataBounds(double bounds[2]);
+
 protected:
   vtkPlotBar();
   ~vtkPlotBar();