From 0d5bec125e3d6d824faa5a555dc432eb711f8d8b Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Tue, 18 Mar 2025 17:44:21 +0000
Subject: [PATCH] LazMapViewer: Add MarkerDragPlugin.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9687 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 .../source/addons/plugins/mvplugins.pas       | 88 +++++++++++++++++--
 1 file changed, 81 insertions(+), 7 deletions(-)

diff --git a/components/lazmapviewer/source/addons/plugins/mvplugins.pas b/components/lazmapviewer/source/addons/plugins/mvplugins.pas
index 86277d7f3..81e1c663d 100644
--- a/components/lazmapviewer/source/addons/plugins/mvplugins.pas
+++ b/components/lazmapviewer/source/addons/plugins/mvplugins.pas
@@ -144,15 +144,20 @@ type
   TMarkerClickPlugin = class(TMvMarkerPlugin)
   private
     FCursor: TCursor;
-    FSavedCursor: TCursor;
     FShift: TShiftState;
     FOnCanClick: TMarkerCanClickEvent;
     FOnMarkerClick: TMarkerClickEvent;
   protected
+    FMouseDown: Boolean;
+    FMousePoint: TPoint;
+    FOrigGpsPoint: TGPSPoint;
+    FSavedCursor: TCursor;
     procedure MouseDown(AMapView: TMapView; {%H-}Button: TMouseButton;
       AShift: TShiftState; X,Y: Integer; var Handled: Boolean); override;
     procedure MouseMove(AMapView: TMapView; {%H-}AShift: TShiftState;
       X,Y: Integer; var Handled: Boolean); override;
+    procedure MouseUp(AMapView: TMapView; {%H-}Button: TMouseButton;
+      AShift: TShiftState; X,Y: Integer; var Handled: Boolean); override;
     procedure SetMapView(AValue: TMapView); override;
   public
     constructor Create(AOwner: TComponent); override;
@@ -164,6 +169,25 @@ type
   end;
 
 
+  { TMarkerDragPlugin }
+
+  TMarkerDragPlugin = class(TMarkerClickPlugin)
+  private
+    FDragCursor: TCursor;
+  protected
+    procedure MouseDown(AMapView: TMapView; {%H-}Button: TMouseButton;
+      AShift: TShiftState; X,Y: Integer; var Handled: Boolean); override;
+    procedure MouseMove(AMapView: TMapView; {%H-}AShift: TShiftState;
+      X,Y: Integer; var Handled: Boolean); override;
+    procedure MouseUp(AMapView: TMapView; {%H-}Button: TMouseButton;
+      AShift: TShiftState; X,Y: Integer; var Handled: Boolean); override;
+  public
+    constructor Create(AOwner: TComponent); override;
+  published
+    property DragCursor: TCursor read FDragCursor write FDragCursor default crSizeAll;
+  end;
+
+
   { TMarkerHintPlugin }
 
   TMarkerCreateHintWindowEvent = procedure(AMapView: TMapView;
@@ -951,23 +975,25 @@ end;
 procedure TMarkerClickPlugin.MouseDown(AMapView: TMapView; Button: TMouseButton;
   AShift: TShiftState; X, Y: Integer; var Handled: Boolean);
 var
-  gpsPoint: TGPSPoint;
   canClick: Boolean;
 begin
   if Handled then
     exit;
 
-  gpsPoint := FindNearestMarker(AMapView, X, Y);
-  if Assigned(gpsPoint) and Assigned(FOnMarkerClick) and (AShift = FShift) then
+  FOrigGPSPoint := FindNearestMarker(AMapView, X, Y);
+  if Assigned(FOrigGPSPoint) and (AShift = FShift) then
   begin
     if Assigned(FOnCanClick) then
     begin
       canClick := true;
-      FOnCanClick(AMapView, gpsPoint, canClick);
+      FOnCanClick(AMapView, FOrigGPSPoint, canClick);
       if not canClick then
         exit;
     end;
-    FOnMarkerClick(AMapView, gpsPoint);
+    if Assigned(FOnMarkerClick) then
+      FOnMarkerClick(AMapView, FOrigGPSPoint);
+    FMouseDown := true;
+    FMousePoint := Point(X, Y);
     Handled := true;
   end;
 end;
@@ -991,6 +1017,12 @@ begin
   AMapView.Cursor := IfThen(canClick, FCursor, FSavedCursor);
 end;
 
+procedure TMarkerClickPlugin.MouseUp(AMapView: TMapView; Button: TMouseButton;
+  AShift: TShiftState; X, Y: Integer; var Handled: Boolean);
+begin
+  FMouseDown := false;
+end;
+
 { Store the original MapView cursor. Is used when the mouse is not over a
   clickable point. If no MapView is assigned to the plugin it is assumed that
   the MapView has the default cursor. }
@@ -1004,6 +1036,47 @@ begin
 end;
 
 
+{ TMarkerDragPlugin }
+
+constructor TMarkerDragPlugin.Create(AOwner: TComponent);
+begin
+  inherited;
+  FDragCursor := crSizeAll;
+end;
+
+procedure TMarkerDragPlugin.MouseDown(AMapView: TMapView; {%H-}Button: TMouseButton;
+  AShift: TShiftState; X,Y: Integer; var Handled: Boolean);
+begin
+  inherited;
+  if FMouseDown then
+    Handled := true;
+end;
+
+procedure TMarkerDragPlugin.MouseMove(AMapView: TMapView;
+  {%H-}AShift: TShiftState; X,Y: Integer; var Handled: Boolean);
+var
+  P: TRealPoint;
+begin
+  inherited;
+
+  if FMouseDown then
+  begin
+    AMapView.Cursor := FDragCursor;
+    P := AMapView.ScreenToLatLon(Point(X, Y));
+    FOrigGPSPoint.MoveTo(P.Lon, P.Lat);
+    Update;
+    Handled := true;
+  end;
+end;
+
+procedure TMarkerDragPlugin.MouseUp(AMapView: TMapView; {%H-}Button: TMouseButton;
+  AShift: TShiftState; X,Y: Integer; var Handled: Boolean);
+begin
+  inherited;
+  AMapView.Cursor := FSavedCursor;
+end;
+
+
 { TMarkerHintPlugin }
 
 constructor TMarkerHintPlugin.Create(AOwner: TComponent);
@@ -1386,8 +1459,9 @@ initialization
   RegisterPluginClass(TTileInfoPlugin, 'Tile info');
   RegisterPluginClass(TLegalNoticePlugin, 'Legal notice');
   RegisterPluginClass(TLinkedMapsPlugin, 'Linked maps');
-  RegisterPluginClass(TMarkerClickPlugin, 'Marker click');
   RegisterPluginClass(TMarkerHintPlugin, 'Marker hint');
+  RegisterPluginClass(TMarkerClickPlugin, 'Marker click');
+  RegisterPluginClass(TMarkerDragPlugin, 'Marker drag');
   RegisterPluginClass(TDraggableMarkerPlugin, 'Draggable marker');
   RegisterPluginClass(TUserDefinedPlugin, 'User-defined');