lazmapviewer: Add event OnDrawGpsPoint for custom drawing of gps points.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6796 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/example/main.lfm

@@ -392,6 +392,7 @@ object MainForm: TMainForm
     UseThreads = True
     Zoom = 0
     OnZoomChange = MapViewZoomChange
+    OnDrawGpsPoint = MapViewDrawGpsPoint
     OnMouseMove = MapViewMouseMove
     OnMouseUp = MapViewMouseUp
   end

components/lazmapviewer/example/main.pas

@@ -7,7 +7,7 @@ interface
 uses
   Classes, SysUtils, Types, Forms, Controls, Graphics, Dialogs,
   ExtCtrls, StdCtrls, ComCtrls,
-  mvGeoNames, mvMapViewer, mvTypes;
+  mvGeoNames, mvMapViewer, mvTypes, mvGpsObj;
 
 type
 
@@ -54,6 +54,7 @@ type
     procedure FormShow(Sender: TObject);
     procedure GeoNamesNameFound(const AName: string; const ADescr: String;
       const ALoc: TRealPoint);
+    procedure MapViewDrawGpsPoint(Sender, ACanvas: TObject; APoint: TGpsPoint);
     procedure MapViewMouseMove(Sender: TObject; Shift: TShiftState; X,
       Y: Integer);
     procedure MapViewMouseUp(Sender: TObject; Button: TMouseButton;
@@ -80,7 +81,8 @@ implementation
 {$R *.lfm}
 
 uses
-  LCLType, IniFiles, Math, mvGpsObj, mvExtraData,
+  LCLType, IniFiles, Math, FPCanvas, FPImage, IntfGraphics,
+  mvExtraData,
   gpslistform;
 
 type
@@ -244,6 +246,47 @@ begin
   CbFoundLocations.Items.AddObject(AName, P);
 end;
 
+procedure TMainForm.MapViewDrawGpsPoint(Sender, ACanvas: TObject;
+  APoint: TGpsPoint);
+const
+  R = 5;
+var
+  P: TPoint;
+  cnv: TFPCustomCanvas;
+  txt: String;
+  w, h: Integer;
+  bmp: TBitmap;
+  img: TLazIntfImage;
+begin
+  // Screen coordinates of the GPS point
+  P := TMapView(Sender).LonLatToScreen(APoint.RealPoint);
+
+  // Draw the GPS point as a circle
+  cnv := TFPCustomCanvas(ACanvas);
+  cnv.Brush.FPColor := colRed;
+  cnv.Ellipse(P.X-R, P.Y-R, P.X+R, P.Y+R);
+
+  // Draw the "name" of the GPS point. Note: FPCustomCanvas, by default,
+  // does not support text output. Therefore we paint to a bitmap first and
+  // render this on the FPCustomCanvas.
+  txt := APoint.Name;
+  bmp := TBitmap.Create;
+  try
+    bmp.PixelFormat := pf32Bit;
+    w := bmp.Canvas.TextWidth(txt);
+    h := bmp.Canvas.TextHeight(txt);
+    bmp.SetSize(w, h);
+    bmp.Canvas.Brush.Color := clWhite;
+    bmp.Canvas.FillRect(0, 0, w, h);
+    bmp.Canvas.TextOut(0, 0, txt);
+    img := bmp.CreateIntfImage;
+    cnv.Draw(P.X - w div 2, P.Y - h - 2*R, img);
+    img.Free;
+  finally
+    bmp.Free;
+  end;
+end;
+
 procedure TMainForm.MapViewMouseMove(Sender: TObject; Shift: TShiftState;
   X, Y: Integer);
 const

components/lazmapviewer/source/mvmapviewer.pas

@@ -39,6 +39,8 @@ uses
 
 Type
 
+  TDrawGpsPointEvent = procedure (Sender, ACanvas: TObject; APoint: TGpsPoint) of object;
+
   { TMapView }
 
   TMapView = class(TCustomControl)
@@ -56,6 +58,7 @@ Type
       FGPSItems: TGPSObjectList;
       FInactiveColor: TColor;
       FPOIImage: TBitmap;
+      FOnDrawGpsPoint: TDrawGpsPointEvent;
       procedure CallAsyncInvalidate;
       procedure DoAsyncInvalidate(Data: PtrInt);
       procedure DrawObjects(const TileId: TTileId; aLeft, aTop, aRight,aBottom: integer);
@@ -131,6 +134,7 @@ Type
       property OnCenterMove: TNotifyEvent  read GetOnCenterMove write SetOnCenterMove;
       property OnZoomChange: TNotifyEvent  read GetOnZoomChange write SetOnZoomChange;
       property OnChange: TNotifyEvent Read GetOnChange write SetOnChange;
+      property OnDrawGpsPoint: TDrawGpsPointEvent read FOnDrawGpsPoint write FOnDrawGpsPoint;
       property OnMouseDown;
       property OnMouseEnter;
       property OnMouseLeave;
@@ -579,6 +583,16 @@ var
   PT : TPoint;
   PtColor : TColor;
 begin
+  if Assigned(FOnDrawGpsPoint) then begin
+    {$IFDEF USE_RGBGRAPHICS}
+    FOnDrawGpsPoint(Self, Buffer, aPOI)
+    {$ENDIF}
+    {$IFDEF USE_LAZINTFIMAGE}
+    FOnDrawGpsPoint(Self, BufferCanvas, aPOI);
+    {$ENDIF}
+    exit;
+  end;
+
   Pt:=Engine.LonLatToScreen(aPOI.RealPoint);
   PtColor:=clRed;
   if aPOI.ExtraData<>nil then
@@ -772,7 +786,7 @@ end;
 
 function TMapView.LonLatToScreen(aPt: TRealPoint): TPoint;
 begin
-  Result:=LonLatToScreen(aPt);
+  Result:=Engine.LonLatToScreen(aPt);
 end;
 
 procedure TMapView.GetMapProviders(lstProviders: TStrings);