Map Image Conversion Plug-In APIChanges in Map Image Conversion Plug-In API documentation
Changes in Map Image Conversion Plug-In API
PurposeThis API is intended for implementation by Map and Navigation provider applications, which support MapImage service. This API declares ECom interface, which exposes two functions for converting world coordinates to image coordinates and vice versa. This functionality is used by Map Image API implementation. This document is intended for developers of Map and Navigation provider applications, which are going to support MapImage service. API descriptionThis API is a method call Framework API. The implementation of this API is the second part of Map and Navigation Provider application's support for the MapImage service. Service itself implements map rendering and is part of the provider application server. Rendering engines can use various projections and the client needs a way to calculate world coordinates corresponding to a particular point on map image and vice versa. Such functionality is exposed by provider applications by implementing this API. The implementation of this API is loaded as ECom plug-in into the process of the client of Map Image API. API class structure
MapImageParams() method.
Related APIs
Using Map Image Conversion Plug-In APIIn order to complete support for MapImage service and implement coordinate conversion plug-in, the Map and Navigation Provider application has to:
Implementing coordinate converterCoordinate converter should create a class derived from
The image itself is not provided for calculations, but instead the all
input given to rendering engine is accessible via
The calculation should be solely based on that information (and knowledge of rendering engine). Implementation must not make any IPC calls to rendering engine process and should perform as if it does not exist at all. In other words, the converter should be usable, even if no image has been actually rendered. Image to world coordinate conversionThis conversion is represented by the
Below is an example of the implementation of that function.
Related APIs
World to image coordinate conversionThis conversion is represented by the
Below is the example of implementation of that function.
Related APIs
Related APIs
Creating ECom plug-inImplementation of
ExamplesLet's assume that SID of the server application (which implements MapImage service) this plug-in is supposed to be used with, is 0x10203A4B. Let's also assume that DLL UID of the ECom plug-in is 0x10203A4C and implementation UID is 0x10203A4D. Actual UIDs must be allocated by developer. Here is an example of MMP file for the plug-in: Below is an example of ECom registration file, mycoordconverterplugin.rss. Note that the
And finally, the example code of exporting factory function, mycoordconvertermain.cpp.
Related APIs
Related APIs
Error handlingImplementation must not panic. All error cases must be informed via the
return value of conversion methods. See documentation of the
Related APIs
Memory overheadImplementation must try not to use memory excessively, because it will
be loaded into the client's process. However, whenever there is not enough
memory to perform calculations, the appropriate method should inform it by
returning the
Related APIs
Related APIs
Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies). All rights reserved. License: EPL
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