46e39361c5
git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9607 8e941d3f-bd1b-0410-a28a-d453659cc2b4
95 lines
2.4 KiB
ObjectPascal
95 lines
2.4 KiB
ObjectPascal
unit main;
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{$mode objfpc}{$H+}
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interface
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uses
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Classes, ComCtrls, ExtCtrls, StdCtrls, SysUtils, Forms, Controls, Graphics,
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Dialogs, mvMapViewer, mvTypes, mvGeoMath;
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type
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{ TForm1 }
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TForm1 = class(TForm)
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Label1: TLabel;
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MapView1: TMapView;
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Panel1: TPanel;
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rgCenter: TRadioGroup;
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StatusBar1: TStatusBar;
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procedure FormCreate(Sender: TObject);
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procedure MapView1Change(Sender: TObject);
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procedure rgCenterClick(Sender: TObject);
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private
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FInitialArea: TRealArea;
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FMinZoom: Integer;
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procedure MapCenterMoving(Sender: TObject; var NewCenter: TRealPoint; var Allow: Boolean);
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procedure MapZoomChanging(Sender: TObject; NewZoom: Integer; var Allow: Boolean);
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public
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end;
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var
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Form1: TForm1;
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implementation
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{$R *.lfm}
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procedure TForm1.FormCreate(Sender: TObject);
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begin
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MapView1.Active := true;
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rgCenterClick(nil);
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MapView1Change(nil);
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end;
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procedure TForm1.MapView1Change(Sender: TObject);
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begin
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Statusbar1.Panels[0].Text := 'Latitude ' + LatToStr(MapView1.Center.Lat, true);
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Statusbar1.Panels[1].Text := 'Longitude ' + LonToStr(MapView1.Center.Lon, true);
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Statusbar1.Panels[2].Text := 'Zoom ' + IntToStr(MapView1.Zoom);
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end;
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procedure TForm1.rgCenterClick(Sender: TObject);
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const
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INFO = '%s cannot be moved out of the window.'#13'Only zoom levels > %d allowed.';
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begin
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MapView1.OnZoomChanging := nil;
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MapView1.OnCenterMoving := nil;
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case rgCenter.ItemIndex of
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0: begin // London
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MapView1.MapCenter.Longitude := -DMSToDeg(0, 7, 54.6);
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MapView1.MapCenter.Latitude := DMSToDeg(51, 30, 31.2);
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FMinZoom := 8;
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Label1.Caption := Format(INFO, ['London', FMinZoom]);
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end;
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1: begin // somewhere in Siberia near dateline
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MapView1.MapCenter.Longitude := 178;
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MapView1.MapCenter.Latitude := 64.7;
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FMinZoom := 6;
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Label1.Caption := Format(INFO, ['Center', FMinZoom]);
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end;
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end;
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MapView1.Zoom := FMinZoom;
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FInitialArea := MapView1.GetVisibleArea;
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MapView1.OnZoomChanging := @MapZoomChanging;
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MapView1.OnCenterMoving := @MapCenterMoving;
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end;
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procedure TForm1.MapCenterMoving(Sender: TObject; var NewCenter: TRealPoint;
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var Allow: Boolean);
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begin
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if not FInitialArea.ContainsPoint(NewCenter) then
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FInitialArea.MakeAreaPoint(NewCenter);
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end;
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procedure TForm1.MapZoomChanging(Sender: TObject; NewZoom: Integer; var Allow: Boolean);
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begin
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Allow := NewZoom >= FMinZoom;
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end;
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end.
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