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ImageAttrHandler.h
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1 //# ImageAttrHandler.h: Abstract base class for an image attributes handler
2 //# Copyright (C) 2012
3 //# Associated Universities, Inc. Washington DC, USA.
4 //#
5 //# This library is free software; you can redistribute it and/or modify it
6 //# under the terms of the GNU Library General Public License as published by
7 //# the Free Software Foundation; either version 2 of the License, or (at your
8 //# option) any later version.
9 //#
10 //# This library is distributed in the hope that it will be useful, but WITHOUT
11 //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 //# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13 //# License for more details.
14 //#
15 //# You should have received a copy of the GNU Library General Public License
16 //# along with this library; if not, write to the Free Software Foundation,
17 //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18 //#
19 //# Correspondence concerning AIPS++ should be addressed as follows:
20 //# Internet email: aips2-request@nrao.edu.
21 //# Postal address: AIPS++ Project Office
22 //# National Radio Astronomy Observatory
23 //# 520 Edgemont Road
24 //# Charlottesville, VA 22903-2475 USA
25 //#
26 //# $Id$
27 
28 #ifndef IMAGES_IMAGEATTRHANDLER_H
29 #define IMAGES_IMAGEATTRHANDLER_H
30 
31 
32 //# Includes
33 #include <casacore/casa/aips.h>
37 
38 namespace casacore {
39 
40 // <summary>
41 // Abstract base class for an image attributes handler.
42 // </summary>
43 
44 // <use visibility=export>
45 
46 // <reviewed reviewer="" date="" tests="tPagedmage.cc" demos="dPagedImage.cc">
47 // </reviewed>
48 
49 // <prerequisite>
50 // <li> <linkto class=ImageInterface>ImageInterface</linkto>
51 // </prerequisite>
52 
53 // <etymology>
54 // This class makes it possible to store extra attributes with an image to
55 // describe atrbitrary meta information.
56 // </etymology>
57 
58 // <synopsis>
59 // For LOFAR it was needed to store extra meta information and to be able to
60 // convert it from casacore table format to HDF5 format and vice-versa.
61 // Furthermore, it must be possible to access the information in a way that
62 // arbitrary info can be stored and retrieved.
63 //
64 // An ImageAttrHandler object handles those attributes in an image. Specific
65 // handler classes exist for images stored in casacore and in HDF5 format.
66 // The attributes are divided into group which are handled by ImageAttrGroup.
67 // A group (e.g. LOFAR_SOURCES) maps to a subtable in casacore format and a
68 // group in HDF5 format.
69 // </synopsis>
70 
71 // <example>
72 // This example shows how to get attributes from an image.
73 // <srcblock>
74 // // Open the image (done as read/write when having write access).
75 // PagedImage<Float> myimage ("image.name");
76 // // Get access to the attibute handler.
77 // ImageAttrHandler& attrHandler = myimage.attrHandler();
78 // // Get the names of all attribute groups.
79 // Vector<String> groupNames = attrHandler.groupNames();
80 // // Create a new group and define an attribute defining Freq in Hz.
81 // ImageAttrGroup& newGroup = attrHandler.createGroup ("NEW_GROUP");
82 // newGroup.putAttr ("Freq", ValueHolder(Vector<Double>(1, 1e7)),
83 // Vector<String>(1,"Hz"));
84 // </srcblock>
85 // </example>
86 //
87 // <motivation>
88 // LOFAR needed functionality to store arbitrary attributes.
89 // </motivation>
90 
92 {
93 public:
94  // Default constructor.
96  {}
97 
98  virtual ~ImageAttrHandler();
99 
100  // Flush the attibrutes if needed.
101  // The default implementation does nothing.
102  virtual void flush();
103 
104  // Test if the given attribute group is present.
105  // The default implementation returns False.
106  virtual Bool hasGroup (const String& name);
107 
108  // Get all attribute group names.
109  // The default implementation returns an empty vector.
110  virtual Vector<String> groupNames() const;
111 
112  // Get access to a group.
113  // The default implementation throws an exception.
114  virtual ImageAttrGroup& openGroup (const String& groupName);
115 
116  // Create an attribute group with the given name.
117  // The default implementation throws an exception.
118  virtual ImageAttrGroup& createGroup (const String& groupName);
119 
120  // Close the group with the given name.
121  // The default implementation does nothing.
122  virtual void closeGroup (const String& groupName);
123 };
124 
125 } //# NAMESPACE CASACORE - END
126 
127 #endif
A 1-D Specialization of the Array class.
virtual void flush()
Flush the attibrutes if needed.
ImageAttrHandler()
Default constructor.
Abstract base class for an image attributes group.
ABSTRACT CLASSES Abstract class for colors Any implementation of color should be able to provide a hexadecimal form of the if a human readable name(i.e."black").In many places throughout the plotter
Abstract base class for an image attributes handler.
virtual Bool hasGroup(const String &name)
Test if the given attribute group is present.
virtual ImageAttrGroup & openGroup(const String &groupName)
Get access to a group.
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42
virtual ImageAttrGroup & createGroup(const String &groupName)
Create an attribute group with the given name.
String: the storage and methods of handling collections of characters.
Definition: String.h:223
virtual void closeGroup(const String &groupName)
Close the group with the given name.
virtual Vector< String > groupNames() const
Get all attribute group names.
#define casacore
&lt;X11/Intrinsic.h&gt; #defines true, false, casacore::Bool, and String.
Definition: X11Intrinsic.h:42