lazMapViewer: Initial commit to CCR (based on Maciej Kaczkowski (https://github.com/maciejkaczkowski/mapviewer) and ti-dic's (https://sourceforge.net/p/roadbook/code/ci/master/tree/mapviewer/) MapViewer components. Removed dependence on RGB_Graphics. Rename TMapViewer to TMapView and TMVGLGeonames to TMvGeoNames to avoid naming conflicts with original packages.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6307 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/source/mvdragobj.pas

@@ -0,0 +1,202 @@
+{
+  (c) 2014 ti_dic
+
+  This library is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Library General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or (at your
+  option) any later version.
+
+  This program is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
+  for more details.
+
+  You should have received a copy of the GNU Library General Public License
+  along with this library; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+}
+unit mvdragobj;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+Type
+  TDragObj = Class;
+
+  TDragEvent = Procedure (Sender : TDragObj) of Object;
+
+  { TDragObj }
+
+  TDragObj = Class
+  private
+    FMouseDown : boolean;
+    FLnkObj: TObject;
+    FDragsrc,FStartSrc : TObject;
+    FOfsX: integer;
+    FOfsY: integer;
+    InDrag : Boolean;
+    FStartX,FStartY : integer;
+    FMouseX,FMouseY : integer;
+    FEndX,FEndY : integer;
+    FOnDrag: TDragEvent;
+    FOnEndDrag: TDragEvent;
+
+    procedure SetDest(X,Y : Integer);
+    procedure SetLnkObj(AValue: TObject);
+    procedure SetOnDrag(AValue: TDragEvent);
+    procedure SetOnEndDrag(AValue: TDragEvent);
+
+    Procedure DostartDrag(X,Y : Integer);
+    Procedure DoDrag(X,Y : integer);
+    Procedure DoEndDrag(X,Y : integer);
+    Function HasMoved(X,Y : integer) : Boolean;
+    Procedure AbortDrag;
+
+    public
+      Procedure MouseDown(aDragSrc : TObject;X,Y : integer);
+      Procedure MouseUp(X,Y : integer);
+      Procedure MouseMove(X,Y : integer);
+
+      property OnDrag : TDragEvent read FOnDrag write SetOnDrag;
+      property OnEndDrag : TDragEvent read FOnEndDrag write SetOnEndDrag;
+
+
+
+      property OfsX : integer read FOfsX;
+      property OfsY : integer read FOfsY;
+      property StartX : integer read FStartX;
+      property StartY : integer read FStartY;
+      property MouseX : Integer read FMouseX;
+      property MouseY : integer read FMouseY;
+      property EndX : integer read FEndX;
+      property EndY : integer read FEndY;
+      Property LnkObj : TObject Read FLnkObj write SetLnkObj;
+      property DragSrc : TObject Read FStartSrc;
+  end;
+
+implementation
+
+{ TDragObj }
+
+procedure TDragObj.SetDest(X, Y: Integer);
+begin
+  FEndX:=X;
+  FEndY:=Y;
+  FOfsX:=FEndX-FstartX;
+  FOfsY:=FEndY-FstartY;
+end;
+
+procedure TDragObj.SetLnkObj(AValue: TObject);
+begin
+  if FLnkObj=AValue then Exit;
+  FreeAndNil(FLnkObj);
+  FLnkObj:=AValue;
+end;
+
+procedure TDragObj.SetOnDrag(AValue: TDragEvent);
+begin
+  if FOnDrag=AValue then Exit;
+  FOnDrag:=AValue;
+end;
+
+procedure TDragObj.SetOnEndDrag(AValue: TDragEvent);
+begin
+  if FOnEndDrag=AValue then Exit;
+  FOnEndDrag:=AValue;
+end;
+
+procedure TDragObj.DostartDrag(X, Y: Integer);
+begin
+   InDrag:=True;
+   FStartSrc := FDragSrc;
+   DoDrag(X,Y);
+end;
+
+procedure TDragObj.DoDrag(X, Y: integer);
+begin
+  if (X<>FEndX) or (Y<>FEndY) then
+  Begin
+    SetDest(X,Y);
+    if Assigned(FOnDrag) then
+      FOnDrag(Self);
+  end;
+end;
+
+procedure TDragObj.DoEndDrag(X, Y: integer);
+begin
+  DoDrag(X,Y);
+  if Assigned(FOnEndDrag) then
+    FOnEndDrag(self);
+  FreeAndNil(FLnkObj);
+  FStartSrc := nil;
+  InDrag:=False;
+end;
+
+function TDragObj.HasMoved(X, Y: integer): Boolean;
+begin
+  Result:=(X<>FStartX) or (Y<>FStartY);
+end;
+
+procedure TDragObj.AbortDrag;
+begin
+  if InDrag then
+  Begin
+    DoDrag(FstartX,FStartY);
+    InDrag:=False;
+    FMouseDown:=False;
+    FDragSrc :=nil;
+    FStartSrc := nil;
+    FreeAndNil(FLnkObj);
+  end;
+end;
+
+procedure TDragObj.MouseDown(aDragSrc : TObject;X, Y: integer);
+begin
+  if not(FMouseDown) then
+  Begin
+       FDragSrc := aDragSrc;
+       FMouseDown := True;
+       FStartX := X;
+       FStartY := Y;
+       FEndX := X;
+       FEndY := Y;
+  End
+  Else
+      AbortDrag;
+end;
+
+
+procedure TDragObj.MouseMove(X, Y: integer);
+begin
+  FMouseX := X;
+  FMouseY := Y;
+  if FMouseDown then
+  Begin
+    if InDrag then
+       DoDrag(X,Y)
+    else
+    Begin
+       if HasMoved(X,Y) then
+         DoStartDrag(X,Y);
+    end;
+  end;
+end;
+
+
+procedure TDragObj.MouseUp(X, Y: integer);
+begin
+  if FMouseDown then
+  Begin
+    FMouseDown:=False;
+    if InDrag then
+       DoEndDrag(X,Y);
+    FDragSrc := nil;
+  end;
+end;
+
+end.
+