Since the MIF file can contain rendering information, the JViews Maps package provides
classes to use this rendering information directly. This includes a
ready-to-use IlvFeatureRenderer suitable to render
geometries found in the MIF file and a factory to create IlvMapLineRenderingStyle.
In addition to these rendering classes, the JViews Maps package also
provides a set of specific IlvGraphic objects to display the MID/MIF
geometries. These
IlvGraphic
objects are needed by the MID/MIF specifications but can also be
used outside a MID/MIF context.
The IlvMIFFeatureRenderer Class
This class is a subclass of the IlvDefaultFeatureRenderer that dispatches
on the appropriate renderer with the rendering styles found in
the MIF file. This is the IlvFeatureRenderer returned by the getDefaultFeatureRenderer method of the IlvMIFReader class. The rendering styles
found in the MIF file are attached to the IlvMapFeature as properties by the reader
and interpreted in the renderer.
The IlvMIFPenFactory Class
This class is a factory to create an
IlvMapLineRenderingStyle
by specifying a MID/MIF pattern identifier.
The IlvMIFCoordinateSystemFactory Class
This class is a factory to translate a
MID/MIF coordinate system into a Maps coordinate system.
Specialized Graphics
The IlvGraphic objects needed to render MID/MIF
geometries include the following classes:
- IlvDecoratedPath: A general path supporting decorations. A decoration is a drawing that follows the path of the graphic. These decorations can be clipped against the clip region of the
java.awt.Graphicsto provide high performance drawing. - IlvMapLabel: A label able to display multiline text. This label supports interline spacing.
- IlvFontMarkerA graphic object able to display a character of a given font as the marker point. This object is usually used with a symbol font that provides cartographic symbology.
Coordinate System Support
Along with objects and attribute
information, MIF files also contain information on the coordinate
system used to store the graphic objects of a defined file.
The possible coordinate systems in MID/MIF
are:
- Earth: a coordinate system where coordinates are expressed within a projected coordinate system. See List of Supported MID/MIF Projections for the list of supported projections.
- NonEarth: a coordinate system where coordinates are expressed in a specified unit. When such a file is encountered, the coordinate system is set to
null, and the getUnit method returns the unit defined in the file. - Layout: a coordinate system corresponding to coordinates on a sheet of paper. When such a file is encountered, the coordinate system is set to
null, and the getUnit method returns the unit defined in the file. - Table: a coordinate system corresponding to an open table in MapInfo. This coordinate system is not supported in the JViews Maps package.
- Window: a coordinate system corresponding to an open window in MapInfo. This coordinate system is not supported in the JViews Maps package.
The JViews Maps
package fully supports projected coordinates defined in a MID/MIF
file. The supported projections are listed in List of Supported MID/MIF Projections:
List of Supported MID/MIF Projections
MID/MIF
Projection Number |
Name |
Corresponding
Projection |
|---|---|---|
9 |
Albers
Equal-Area Conic |
IlvAlbersEqualAreaProjection |
5 |
Azimuthal
Equidistant |
IlvAzimuthalEquidistantProjection |
2 |
Cylindrical
Equal Area |
IlvCylindricalEqualAreaProjection |
14 |
Eckert
IV |
IlvEckert4Projection |
15 |
Eckert
VI |
IlvEckert6Projection |
17 |
Gall |
IlvMercatorProjection |
7 |
Hotine
Oblique Mercator |
IlvObliqueMercatorProjection |
4 |
Lambert
Azimuthal Equal Area |
IlvLambertAzimuthalEqualAreaProjection |
3 |
Lambert
Conformal Conic |
IlvLambertConformalConicProjection |
19 |
Lambert
Conformal Conic
(modified for Belgium 1972) |
IlvLambertConformalConicProjection |
1 |
Longitude/Latitude |
Not a projection. An
IlvGeographicCoordinateSystem
is used.
|
10 |
Mercator |
IlvMercatorProjection |
11 |
Miller
Cylindrical |
IlvMillerCylindrical Projection |
13 |
Mollweide |
IlvMollweideProjection |
27 |
Polyconic |
IlvPolyconicProjection |
12 |
Robinson |
IlvRobinsonProjection |
16 |
Sinusoidal |
IlvSinusoidalProjection |
20 |
Stereographic |
IlvStereographicProjection |
8 |
Transverse
Mercator |
IlvTransverseMercatorProjection |
JViews Maps supports
all ellipsoids and nearly all datums from MapInfo (see the
MID/MIF file format specification for the full list of ellipsoids
and datums).
Note
The MIF format specification allows user datum definition, with
either 3 or 7 parameters. As the JViews Maps package does
not support 7-parameter datum yet, definitions of 7- parameter
datum is decoded as 3-parameter datum, skipping the rotations
and scale part of datum definitions.