com.yworks.yfiles.server.tiles.servlet
Class TileServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.yworks.yfiles.server.tiles.servlet.BaseServlet
              com.yworks.yfiles.server.tiles.servlet.TileServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class TileServlet
extends BaseServlet

This servlet serves information for displaying and interacting with a graph.

A graph tile is an image of a part of the graph. The image of a tile is a quadratic PNG. Its magnification with respect to the world coordinates of the graph is controlled by the zoom factor. For a fixed graph and a fixed zoom factor, all tiles form a grid covering the plane containing the graph. One of those tiles is specified by its column and row.

For interacting with a graph, information on the bounds of the graph elements can be requested, which enables client side hit tests.

See Also:

Serialized Form

Constructor Summary

TileServlet()

Method Summary

protected void	handleGetRequest(HttpServletRequest request, HttpServletResponse response) answers "GET" requests of kind "getWorldBounds", "getElementBounds" and "getImage".
protected void	handlePostRequest(HttpServletRequest request, HttpServletResponse response) calls handleGetRequest(HttpServletRequest, HttpServletResponse).

Methods inherited from class com.yworks.yfiles.server.tiles.servlet.BaseServlet

cachedGraphs, cacheGraph, doGet, doPost, getEdgeDescription, getEdgeURL, getForId, getGraph, getGraphBounds, getId, getId, getId, getId, getNodeDescription, getNodeURL, getWriter, hasDescriptions, hasURLs, init, initialize, newGraph, setEdgeDescription, setEdgeURL, setNodeDescription, setNodeURL, uncacheGraph, writeWorldBounds

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TileServlet

public TileServlet()

Method Detail

handleGetRequest

protected void handleGetRequest(HttpServletRequest request,
                                HttpServletResponse response)
                         throws ServletException,
                                IOException

answers "GET" requests of kind "getWorldBounds", "getElementBounds" and "getImage".

"getWorldBounds" returns the world bounds as an enclosing rectangle for a given graph in JSON format.

"getElementBounds" returns hit test information for a given graph in JSON format.

"getImage" returns a PNG image for a part of the graph.

All kinds of requests have a mandatory parameter "path" describing the graph for the request. "getWorldBounds" has no further parameters.

"getImage" uses the mandatory parameters "zoom", "row", "col" and "size".

• "zoom" is a double specifying the magnification factor of view units with respect to world units
• "size" is the width and height of the image of a tile in view units
• "col" specifies the x coordinate range of a tile, a tile at column c starts at c*size view units and extends over size view units
• "row" specifies the y coordinate range of a tile, a tile at row r starts at r*size view units and extends over size view units

"getElementBounds" uses the mandatory parameters "x", "y", "width", "height" and "types".

• "x" and "y" are doubles specifying the upper left corner of the rectangular area for which to obtain element bounds in world units
• "width" and "height" are doubles specifying the width and height of the rectangular area for which to obtain element bounds in world units
• "types" is an integer specifying the kinds of elements for which to get information. Nodes are specified by 1, edges by 2, node labels by 4 and edge labels by 8. Combinations are specified by ORing these values together.

Overrides:

handleGetRequest in class BaseServlet

Parameters:

request - the current request

response - the answer to the client

Throws:

ServletException

IOException

handlePostRequest

protected void handlePostRequest(HttpServletRequest request,
                                 HttpServletResponse response)
                          throws ServletException,
                                 IOException

calls handleGetRequest(HttpServletRequest, HttpServletResponse).

Overrides:

handlePostRequest in class BaseServlet

Parameters:

request - the current request

response - response the answer to the client

Throws:

ServletException

IOException