Add vtkContextArea.

Similar to vtkChartXY, but supports on vtkContextItems, not just
vtkPlots.

Charts/Core/CMakeLists.txt

@@ -16,6 +16,7 @@ set(Module_SRCS
   vtkColorTransferFunctionItem.cxx
   vtkCompositeControlPointsItem.cxx
   vtkCompositeTransferFunctionItem.cxx
+  vtkContextArea.cxx
   vtkContextPolygon.cxx
   vtkControlPointsItem.cxx
   vtkLookupTableItem.cxx

Charts/Core/vtkContextArea.h

+/*=========================================================================
+
+  Program:   Visualization Toolkit
+  Module:    vtkContextArea.h
+
+  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
+  All rights reserved.
+  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
+
+     This software is distributed WITHOUT ANY WARRANTY; without even
+     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+     PURPOSE.  See the above copyright notice for more information.
+
+=========================================================================*/
+
+// .NAME vtkContextArea - Clipped, transformed area with axes for context items.
+//
+// .SECTION Description
+// vtkContextArea provides an clipped drawing area surrounded by four axes.
+// The drawing area is transformed to map the 2D area described by
+// DrawAreaBounds into pixel coordinates. DrawAreaBounds is also used to
+// configure the axes. Item to be rendered in the draw area should be added
+// to the context item returned by GetDrawAreaItem().
+//
+// The size and shape of the draw area is configured by the following member
+// variables:
+// - Geometry: The rect (pixel coordinates) defining the location of the context
+//   area in the scene. This includes the draw area and axis ticks/labels.
+// - FillViewport: If true (default), Geometry is set to span the size returned
+//   by vtkContextDevice2D::GetViewportSize().
+// - DrawAreaResizeBehavior: Controls how the draw area should be shaped.
+//   Available options: Expand (default), FixedAspect, FixedRect, FixedMargins.
+// - FixedAspect: Aspect ratio to enforce for FixedAspect resize behavior.
+// - FixedRect: Rect used to enforce for FixedRect resize behavior.
+// - FixedMargins: Margins to enforce for FixedMargins resize behavior.
+
+#ifndef __vtkContextArea_h
+#define __vtkContextArea_h
+
+#include "vtkAbstractContextItem.h"
+
+#include "vtkAxis.h" // For enums
+#include "vtkChartsCoreModule.h" // For export macro
+#include "vtkRect.h" // For vtkRect/vtkVector/vtkTuple
+#include "vtkNew.h" // For vtkNew
+
+class vtkContextClip;
+class vtkContextTransform;
+class vtkPlotGrid;
+
+class VTKCHARTSCORE_EXPORT vtkContextArea: public vtkAbstractContextItem
+{
+public:
+  typedef vtkTuple<int, 4> Margins;
+  vtkTypeMacro(vtkContextArea, vtkAbstractContextItem)
+  virtual void PrintSelf(ostream &os, vtkIndent indent);
+
+  static vtkContextArea *New();
+
+  // Description:
+  // Get the vtkAxis associated with the specified location.
+  vtkAxis* GetAxis(vtkAxis::Location location);
+
+  // Description:
+  // Returns the vtkAbstractContextItem that will draw in the clipped,
+  // transformed space. This is the item to add children for.
+  vtkAbstractContextItem* GetDrawAreaItem();
+
+  // Description:
+  // Paint event for the item, called whenever the item needs to be drawn.
+  virtual bool Paint(vtkContext2D *painter);
+
+  // Description:
+  // The rect defining the pixel location and size of the entire vtkContextArea,
+  // including axis labels, title, etc. Note that this will be updated to the
+  // window geometry if FillWindow is true.
+  vtkGetMacro(Geometry, vtkRecti)
+  vtkSetMacro(Geometry, vtkRecti)
+
+  // Description:
+  // The data bounds of the clipped and transformed area inside of the axes.
+  // This is used to configure the axes labels and setup the transform.
+  vtkGetMacro(DrawAreaBounds, vtkRectd)
+  vtkSetMacro(DrawAreaBounds, vtkRectd)
+
+  enum DrawAreaResizeBehaviorType {
+    DARB_Expand,
+    DARB_FixedAspect,
+    DARB_FixedRect,
+    DARB_FixedMargins
+  };
+
+  // Description:
+  // Set the resize behavior for the draw area:
+  // - @a Expand: The default behavior. The draw area will automatically resize
+  //   to take up as much of @a Geometry as possible. Margin sizes are
+  //   minimized based on the space required for axis labels/tick marks.
+  // - FixedAspect: Same as Expand, but a fixed aspected ratio is enforced.
+  //   See SetFixedAspect.
+  // - FixedRect: Draw area is always constrained to a fixed rectangle.
+  //   See SetFixedRect.
+  // - FixMargins: The draw area expands to fill @a Geometry, but margins
+  //   (axis labels, etc) are fixed, rather than dynamically sized.
+  //   See SetFixedMargins.
+  vtkGetMacro(DrawAreaResizeBehavior, DrawAreaResizeBehaviorType)
+  vtkSetMacro(DrawAreaResizeBehavior, DrawAreaResizeBehaviorType)
+
+  // Description:
+  // The fixed aspect ratio, if DrawAreaResizeBehavior is FixedAspect.
+  // Defined as width/height. Default is 1.
+  // Setting the aspect ratio will also set DrawAreaResizeBehavior to
+  // FixedAspect.
+  vtkGetMacro(FixedAspect, float)
+  virtual void SetFixedAspect(float aspect);
+
+  // Description:
+  // The fixed rect to use for the draw area, if DrawAreaResizeBehavior is
+  // FixedRect. Units are in pixels, default is 300x300+0+0.
+  // Setting the fixed rect will also set DrawAreaResizeBehavior to
+  // FixedRect.
+  vtkGetMacro(FixedRect, vtkRecti)
+  virtual void SetFixedRect(vtkRecti rect);
+  virtual void SetFixedRect(int x, int y, int width, int height);
+
+  // Description:
+  // The left, right, bottom, and top margins for the draw area, if
+  // DrawAreaResizeBehavior is FixedMargins. Units are in pixels, default is
+  // { 0, 0, 0, 0 }.
+  // Setting the fixed margins will also set DrawAreaResizeBehavior to
+  // FixedMargins.
+  virtual const Margins& GetFixedMargins() { return this->FixedMargins; }
+  virtual void GetFixedMarginsArray(int margins[4]);
+  virtual const int* GetFixedMarginsArray();
+  virtual void SetFixedMargins(Margins margins);
+  virtual void SetFixedMargins(int margins[4]);
+  virtual void SetFixedMargins(int left, int right, int bottom, int top);
+
+  // Description:
+  // If true, Geometry is set to (0, 0, vpSize[0], vpSize[1]) at the start
+  // of each Paint call. vpSize is vtkContextDevice2D::GetViewportSize. Default
+  // is true.
+  vtkGetMacro(FillViewport, bool)
+  vtkSetMacro(FillViewport, bool)
+  vtkBooleanMacro(FillViewport, bool)
+
+  // Description:
+  // Turn on/off grid visibility.
+  virtual void SetShowGrid(bool show);
+  virtual bool GetShowGrid();
+  virtual void ShowGridOn() { this->SetShowGrid(true); }
+  virtual void ShowGridOff() { this->SetShowGrid(false); }
+
+protected:
+  vtkContextArea();
+  ~vtkContextArea();
+
+  // Description:
+  // Sync the Axes locations with Geometry, and update the DrawAreaGeometry
+  // to account for Axes size (margins). Must be called while the painter
+  // is active.
+  void LayoutAxes(vtkContext2D *painter);
+
+  // Description:
+  // Return the draw area's geometry.
+  vtkRecti ComputeDrawAreaGeometry(vtkContext2D *painter);
+
+  // Description:
+  // Working implementations for ComputeDrawAreaGeometry.
+  vtkRecti ComputeExpandedDrawAreaGeometry(vtkContext2D *painter);
+  vtkRecti ComputeFixedAspectDrawAreaGeometry(vtkContext2D *painter);
+  vtkRecti ComputeFixedRectDrawAreaGeometry(vtkContext2D *painter);
+  vtkRecti ComputeFixedMarginsDrawAreaGeometry(vtkContext2D *painter);
+
+  // Description:
+  // Set the transform to map DrawAreaBounds to DrawAreaGeometry. Should be
+  // called after LayoutAxes to ensure that DrawAreaGeometry is up to date.
+  void UpdateDrawArea();
+
+  // Description:
+  // vtkAxis objects that surround the draw area, indexed by vtkAxis::Location.
+  vtkTuple<vtkAxis*, 4> Axes;
+
+  // Description:
+  // The vtkPlotGrid that renders a grid atop the data in the draw area.
+  vtkNew<vtkPlotGrid> Grid;
+
+  // Description:
+  // The context item that clips rendered data.
+  vtkNew<vtkContextClip> Clip;
+
+  // Description:
+  // The context item that clips rendered data.
+  vtkNew<vtkContextTransform> Transform;
+
+  // Description:
+  // The rect defining the pixel location and size of the entire vtkContextArea,
+  // including axis label, title, etc.
+  vtkRecti Geometry;
+
+  // Description:
+  // The data bounds of the clipped and transformed area inside of the axes.
+  // This is used to configure the axes labels and setup the transform.
+  vtkRectd DrawAreaBounds;
+
+  // Description:
+  // The rect defining the pixel location and size of the clipped and
+  // transformed area inside the axes. Relative to Geometry.
+  vtkRecti DrawAreaGeometry;
+
+  // Description:
+  // Controls how the draw area size is determined.
+  DrawAreaResizeBehaviorType DrawAreaResizeBehavior;
+
+  // Description:
+  // The fixed aspect ratio, if DrawAreaResizeBehavior is FixedAspect.
+  // Defined as width/height. Default is 1.
+  float FixedAspect;
+
+  // Description:
+  // The fixed rect to use for the draw area, if DrawAreaResizeBehavior is
+  // FixedRect. Units are in pixels, default is 300x300+0+0.
+  vtkRecti FixedRect;
+
+  // Description:
+  // The left, right, bottom, and top margins for the draw area, if
+  // DrawAreaResizeBehavior is FixedMargins. Units are in pixels, default is
+  // { 0, 0, 0, 0 }
+  Margins FixedMargins;
+
+  // Description:
+  // If true, Geometry is set to (0, 0, vpSize[0], vpSize[1]) at the start
+  // of each Paint call. vpSize is vtkContextDevice2D::GetViewportSize. Default
+  // is true.
+  bool FillViewport;
+
+private:
+  vtkContextArea(const vtkContextArea &); // Not implemented.
+  void operator=(const vtkContextArea &); // Not implemented.
+
+  // Smart pointers for axis lifetime management. See this->Axes.
+  vtkNew<vtkAxis> TopAxis;
+  vtkNew<vtkAxis> BottomAxis;
+  vtkNew<vtkAxis> LeftAxis;
+  vtkNew<vtkAxis> RightAxis;
+};
+
+#endif //__vtkContextArea_h