ParaView Plugins Implementation

ParaView_Plugins focuses on the use cases and how a developer would add a plugin. This page focuses on the actual implementation of plugins, the interfaces of which a developer of a plugin would be exposed to. This is a rough draft.

Server vs. Client Plugins

• Server plugins should not depend on Qt and should be loadable in an instance of pvserver.
• The client plugin implementation will use Qt's plugin code as much as possible.
• This doesn't prevent anyone from building one shared library with both server and client plugins in it.
• The Server and Client plugin design should be quite similar to ease development.

Server Plugins

These plugins can be used to include new VTK reader/writers/sources/filters.

vtkPVPlugin Interface

A plugin has one instance of vtkPVPlugin, which returns all interfaces the plugin implements.

class vtkPVPlugin
{
  public:
  vtkPVPlugin() {}
  ~vtkPVPlugin() {}
  virtual void GetInterfaces(vtkCollection* collection) = 0;
};
PARAVIEW_DECLARE_INTERFACE("com.Kitware.Paraview.InterfaceCollection")

Developers implement that interface as

class MyPVPlugin : public vtkObject, public vtkPVPlugin
{
  public:
  .. Standard VTK stuff ...

  void GetInterfaces(vtkCollection* collection)
  {
    ...
    add MyFancyReader to the collection
    ...
  }
};

A macro will be provided to instantiate it and provide ParaView with entry points.

PARAVIEW_EXPORT_PLUGIN(MyPVPlugin)

vtkSMInterface Interface

An interface could be provided for adding readers/filters/etc...

class vtkSMInterface
{
  public:
  virtual ~vtkSMInterface() {}
  // add filters/readers to interpreter
  virtual void Initialize(vtkClientServerInterpreter* interp) = 0;
  // retrieve XML for readers/filters
  virtual const char* XML() = 0;
};
PARAVIEW_DECLARE_INTERFACE("com.Kitware.Paraview.Interface")

A developer would implement that interface

class MyFancyReader : public vtkObject, public vtkSMInterface
{
  public:
  .. Standard VTK stuff ...

  void Initialize(vtkClientServerInterpreter* interp)
  {
    ...
    add MyFancyReader to the interpreter
    ...
  }
  const char* XML()
  {
    // actually use kwProcessXML to generate this
    return "<ServerManagerConfiguration>\n<ProxyGroup name = \"readers\"> ....."
  }
};

Client Plugins

• Client plugins will work about the same, except that the interface implementations will derive from QObject instead of vtkObject.
• Qt macros will be used instead (Q_EXPORT_PLUGIN2, Q_DECLARE_INTERFACE, etc...)

To implement a panel for a source proxy, one would implement this interface (which already exists in the code).

class PQCOMPONENTS_EXPORT pqObjectPanelInterface
{
 public:
  /// destructor
  virtual ~pqObjectPanelInterface() {}

  /// Returns true if this panel can be created for the given the proxy.
  virtual bool canCreatePanel(pqProxy* proxy) const = 0;
  /// Creates a panel for the given proxy
  virtual pqObjectPanel* createPanel(pqProxy* proxy, QWidget* p) = 0;

  virtual QString name() const = 0;
};

Q_DECLARE_INTERFACE(pqObjectPanelInterface, "com.kitware.paraview.objectpanel")