unit UnitEagleEye;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, OleCtrls, MapXLib_TLB, ExtCtrls;

type
  TFrmEagleEye = class(TForm)
    PanelEagleEye: TPanel;
    MapEagleEye: TMapXObject;
    procedure MapEagleEyeMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MapEagleEyeMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MapEagleEyeMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
  private
    FOperMap: TMapXObject;
    FGeoFileName: string;
    { Private declarations }
  public
    { Public declarations }
    procedure SetMapViewChanged;
    procedure InitLayers(const ReBuild:Boolean);
    procedure ReBuildLayers;
    property OperMap:TMapXObject read FOperMap write FOperMap;
    property GeoFileName:string read FGeoFileName write FGeoFileName;
  end;

var
  FrmEagleEye: TFrmEagleEye;

implementation

uses
  UnitShellAPIs;

{$R *.dfm}

var
// 鷹眼實現的參數
  EagleEye_Layer: MapXLib_TLB.Layer;   // 鷹眼圖上臨時圖層
  EagleEye_Fea: MapXLib_TLB.Feature;   // 鷹眼圖上反映 Map1 窗口位置的Feature
  Have_EagleEye: Boolean=False;        // 記錄是否已經加載鷹眼
  EagleEye_CanMove: Boolean=False;     // 記錄在鷹眼上移動Map1的標識

// 地圖顯示變化處理
procedure TFrmEagleEye.SetMapViewChanged;
var
  tempFea: MapXLib_TLB.Feature; //聲明Feature變量
  tempStyle: MapXLib_TLB.Style; //聲明Style變量
begin
  if (MapEagleEye.Layers.Count=0)or(EagleEye_Layer=nil) then Exit;
  if EagleEye_Layer.AllFeatures.Count=0 then
  begin
    //  設置矩形邊框樣式
    tempStyle := MapXLib_TLB.CoStyle.Create;
    tempStyle.RegionPattern := miPatternNoFill; //設置Style的矩形內部填充樣式
    tempStyle.RegionBorderColor := RGB(255, 0, 0); //設置Style的矩形邊框顏色
    tempStyle.RegionBorderWidth := 2; //設置Style的矩形邊框寬度
    //在圖層創建大小為Map1的邊界的Rectangle對象
    tempFea := FrmEagleEye.MapEagleEye.FeatureFactory.CreateRegion(FOperMap.Bounds, tempStyle);
    EagleEye_Fea := EagleEye_Layer.AddFeature(tempFea, EmptyParam); //添加矩形邊框
  end
  else begin  //否則，根據Map1的視野變化改變矩形邊框的大小和位置
    EagleEye_Fea.Parts.Item[1].RemoveAll; //除去已有的矩形邊框的頂點
    //添加大小和位置已變化的矩形邊框的四個頂點
    EagleEye_Fea.Parts.Item[1].AddXY(FOperMap.Bounds.XMin, FOperMap.Bounds.YMin, 1);
    EagleEye_Fea.Parts.Item[1].AddXY(FOperMap.Bounds.XMax, FOperMap.Bounds.YMin, 1);
    EagleEye_Fea.Parts.Item[1].AddXY(FOperMap.Bounds.XMax, FOperMap.Bounds.YMax, 1);
    EagleEye_Fea.Parts.Item[1].AddXY(FOperMap.Bounds.XMin, FOperMap.Bounds.YMax, 1);
  end;
  EagleEye_Fea.Update(EagleEye_Fea, EmptyParam);
end;

procedure TFrmEagleEye.MapEagleEyeMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  MapEagleEye.Cursor := crHandPoint;
  EagleEye_CanMove := True;
end;

procedure TFrmEagleEye.MapEagleEyeMouseUp(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  MapEagleEye.Cursor := crDefault;
  EagleEye_CanMove := False;  
end;

procedure TFrmEagleEye.MapEagleEyeMouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Integer);
var
  Map_X, Map_Y: Double;
  X_X, Y_Y: Single;
begin
  if EagleEye_CanMove then
  begin
  //把屏幕坐標轉換為地圖坐標
    X_X := X;  Y_Y := Y;
    MapEagleEye.ConvertCoord(X_X, Y_Y, Map_X, Map_Y, miScreenToMap);
  //設置主圖的中心x坐標和y坐標
    FOperMap.CenterX := Map_X;
    FOperMap.CenterY := Map_Y;
  end;
end;

procedure TFrmEagleEye.InitLayers(const ReBuild:Boolean);
begin
  EagleEye_Layer:=nil;
  if (ReBuild or (not FileExists(GeoFileName)))and(FOperMap.Layers.Count>0) then
    MyGIS.GMapTools.m_Map.SaveMapAsGeoset(GeoFileName);
  if (FOperMap.Layers.Count>0)and(FileExists(GeoFileName)) then
    MapEagleEye.GeoSet:=GeoFileName
  else
    MapEagleEye.Layers.RemoveAll;
  EagleEye_Layer := MapEagleEye.Layers.CreateLayer('EagleEye', EmptyParam, 1, EmptyParam, EmptyParam);
end;

procedure TFrmEagleEye.ReBuildLayers;
begin
  FOperMap.SaveMapAsGeoset('', GeoFileName);
  MapEagleEye.GeoSet:=GeoFileName;
end;

end.