TReadMapFile

Hierarchy

TCollectionItem->TPersistent->TObject

Unit

uReadMap

Description

TReadMap a parent of class TNLayer. The class is used as the bottom level of program functions realization on work with data MapInfo.

  • Functions on reading geographical coordinates and their initialization for further use.
  • Functions of drawing objects.
  • Functions of drawing labels on the map.
  • Functions of searching objects in coordinate X, Y.
  • Functions of saving and data reading from Tstream.
  • Functions for work with the table data.

Properties

bInit:Boolean Defines are initialized geographical data
Head :pMapHeader Cartographic parameters layer, from map header
LConv:TConverter Object for convert coordinates
SelList:TList Uses for method of object selection
SelMinLength:Frmt Constant unit for selection
InitDatFile:Boolean Defines if the file DAT open
InitTabFile:Boolean Defines if the file TAB open
TabFile:TTabFile Object for working with file TAB
DatFile:TDatFile Object for working with file DAT
FrontColor:TColor Background color
property MapDataSource:TComponent It is used for relation with another user defined labels

Methods

constructor Create(Collection: TCollection) Constructor
destructor Destroy Destructor
procedure DrawMap(CVS:TCanvas; Conv:TConverter; DrawMode:integer; DrawLabel:Boolean) Draws this layer in the TCanvas object
procedure DrawLabelsInMap(CVS:TCanvas; Conv:TConverter; GLblRange:TList; NFont:TFont; FieldName:String) Draws the layer labels on the TCanvas object
Function SelPointXY(CVS:TCanvas; slX,slY:integer; Conv:TConverter):boolean Finds geographical objects in the set coordinates of the screen slX, xlY
Procedure ReadCoordBlock(zSeg, zSize:integer; buf:pointer) Reads the file of coordinate set displacement of segment inside the file and the sizes in variable of buffer Buf
Function SaveToStream(Stream: TStream):Boolean Saves a layer in the Stream
Function LoadFromStream(Stream: TStream): Boolean Loads the given map data into a layer from Stream

Events