LazMapViewer: Add support for MouseWheel event.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9536 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/source/addons/plugins/mvplugins.pas

@@ -127,15 +127,20 @@ type
   end;
 
 type
-  TMvPluginNotifyEvent = procedure (Sender : TObject; AMapView: TMapView; var Handled: Boolean) of Object;
+  TMvPluginNotifyEvent = procedure (Sender : TObject; AMapView: TMapView;
+    var Handled: Boolean) of Object;
+
   TMvPluginMouseEvent = procedure (Sender : TObject; AMapView: TMapView; Button: TMouseButton;
-                                   Shift: TShiftState;
+    Shift: TShiftState; X, Y: Integer; var Handled: Boolean) of Object;
-                                   X, Y: Integer; var Handled: Boolean) of Object;
+
   TMvPluginMouseMoveEvent = procedure (Sender : TObject; AMapView: TMapView; AShift: TShiftState;
     X,Y: Integer; var Handled: Boolean) of Object;
+
+  TMvPluginMouseWheelEvent = procedure (Sender: TObject; AMapView: TMapView; AShift: TShiftState;
+    AWheelDelta: Integer; AMousePos: TPoint; var Handled: Boolean) of object;
+
   TMvPluginGPSItemsModifiedEvent = procedure (Sender: TObject; AMapView: TMapView;
-                                       ChangedList: TGPSObjectList;
+    ChangedList: TGPSObjectList; ActualObjs: TGPSObjList; Adding: Boolean;
-                                       ActualObjs: TGPSObjList; Adding: Boolean;
     var Handled: Boolean) of Object;
 
   { TUserDefinedPlugin }
@@ -146,18 +151,21 @@ type
     FAfterPaintEvent : TMvPluginNotifyEvent;
     FBeforeDrawObjectsEvent : TMvPluginNotifyEvent;
     FCenterMoveEvent : TMvPluginNotifyEvent;
+    FGPSItemsModifiedEvent : TMvPluginGPSItemsModifiedEvent;
     FMouseDownEvent : TMvPluginMouseEvent;
     FMouseEnterEvent : TMvPluginNotifyEvent;
     FMouseLeaveEvent : TMvPluginNotifyEvent;
     FMouseMoveEvent : TMvPluginMouseMoveEvent;
     FMouseUpEvent : TMvPluginMouseEvent;
+    FMouseWheelEvent : TMvPluginMouseWheelEvent;
     FZoomChangeEvent : TMvPluginNotifyEvent;
-    FGPSItemsModifiedEvent : TMvPluginGPSItemsModifiedEvent;
   protected
     procedure AfterDrawObjects(AMapView: TMapView; var Handled: Boolean); override;
     procedure AfterPaint(AMapView: TMapView; var Handled: Boolean); override;
     procedure BeforeDrawObjects(AMapView: TMapView; var Handled: Boolean); override;
     procedure CenterMove(AMapView: TMapView; var Handled: Boolean); override;
+    procedure GPSItemsModified(AMapView: TMapView; ChangedList: TGPSObjectList;
+      ActualObjs: TGPSObjList; Adding: Boolean; var Handled: Boolean); override;
     procedure MouseDown(AMapView: TMapView; Button: TMouseButton; Shift: TShiftState;
       X, Y: Integer; var Handled: Boolean); override;
     procedure MouseEnter(AMapView: TMapView; var Handled: Boolean); override;
@@ -166,23 +174,23 @@ type
       var Handled: Boolean); override;
     procedure MouseUp(AMapView: TMapView; Button: TMouseButton; Shift: TShiftState;
       X, Y: Integer; var Handled: Boolean); override;
+    procedure MouseWheel(AMapView: TMapView; AShift: TShiftState;
+      AWheelDelta: Integer; AMousePos: TPoint; var Handled: Boolean); override;
     procedure ZoomChange(AMapView: TMapView; var Handled: Boolean); override;
-    procedure GPSItemsModified(AMapView: TMapView; ChangedList: TGPSObjectList;
-                               ActualObjs: TGPSObjList; Adding: Boolean;
-                               var Handled : Boolean);override;
   public
   published
     property OnAfterDrawObjects : TMvPluginNotifyEvent read FAfterDrawObjectsEvent write FAfterDrawObjectsEvent;
     property OnAfterPaint : TMvPluginNotifyEvent read FAfterPaintEvent write FAfterPaintEvent;
     property OnBeforeDrawObjects : TMvPluginNotifyEvent read FBeforeDrawObjectsEvent write FBeforeDrawObjectsEvent;
     property OnCenterMove : TMvPluginNotifyEvent read FCenterMoveEvent write FCenterMoveEvent;
+    property OnGPSItemsModified : TMvPluginGPSItemsModifiedEvent read FGPSItemsModifiedEvent write FGPSItemsModifiedEvent;
     property OnMouseDown : TMvPluginMouseEvent read FMouseDownEvent write FMouseDownEvent;
     property OnMouseEnter : TMvPluginNotifyEvent read FMouseEnterEvent write FMouseEnterEvent;
     property OnMouseLeave : TMvPluginNotifyEvent read FMouseLeaveEvent write FMouseLeaveEvent;
     property OnMouseMove : TMvPluginMouseMoveEvent read FMouseMoveEvent write FMouseMoveEvent;
     property OnMouseUp : TMvPluginMouseEvent read FMouseUpEvent write FMouseUpEvent;
+    property OnMouseWheel : TMvPluginMouseWheelEvent read FMouseWheelEvent write FMouseWheelEvent;
     property OnZoomChange : TMvPluginNotifyEvent read FZoomChangeEvent write FZoomChangeEvent;
-    property OnGPSItemsModified : TMvPluginGPSItemsModifiedEvent read FGPSItemsModifiedEvent write FGPSItemsModifiedEvent;
 
     // inherited
     property Enabled;
@@ -682,6 +690,13 @@ begin
     FMouseUpEvent(Self, AMapView, Button, Shift, X, Y, Handled);
 end;
 
+procedure TUserDefinedPlugin.MouseWheel(AMapView: TMapView; AShift: TShiftState;
+  AWheelDelta: Integer; AMousePos: TPoint; var Handled: Boolean);
+begin
+  if Assigned(FMouseWheelEvent) then
+    FMouseWheelEvent(Self, AMapView, AShift, AWheelDelta, AMousePos, Handled);
+end;
+
 procedure TUserDefinedPlugin.ZoomChange(AMapView: TMapView; var Handled: Boolean);
 begin
   if Assigned(FZoomChangeEvent) then

components/lazmapviewer/source/mvmapviewer.pas

@@ -456,6 +456,8 @@ type
       AMapEvent: TMouseMoveEvent): Boolean; virtual;
     function MouseUp(AMapView: TMapView; AButton: TMouseButton; AShift: TShiftState;
       X, Y: Integer; AMapEvent: TMouseEvent): Boolean; virtual;
+    function MouseWheel(AMapView: TMapView; AShift: TShiftState; AWheelDelta: Integer;
+      AMousePos: TPoint): Boolean; virtual;
     function ZoomChange(AMapView: TMapView; AMapEvent: TNotifyEvent): Boolean; virtual;
     function GPSItemsModified(AMapView: TMapView; ModifiedList: TGPSObjectList;
       ActualObjs: TGPSObjList; Adding: Boolean): Boolean; virtual;
@@ -712,6 +714,7 @@ type
       property OnMouseLeave;
       property OnMouseMove;
       property OnMouseUp;
+      property OnMouseWheel;
 
   end;
 
@@ -2523,11 +2526,22 @@ begin
   Engine.ZoomToCursor := AValue;
 end;
 
+{ Is called when the mouse wheel is rotated.
+  Default behaviour is to first call the user event handler in "inherited" and
+  then to pass the event on the the Engine for zooming.
+  If plugins are used, the plugin manager dispatches the event at first to all
+  the plugins; if one of the plugins reports the event to be handled the
+  plugin manager inhibits further processing of the event by the Engine, i.e.
+  prevents zooming. }
 function TMapView.DoMouseWheel(Shift: TShiftState; WheelDelta: Integer;
   MousePos: TPoint): Boolean;
+var
+  lHandled: Boolean;
 begin
+  lHandled := GetPluginManager.MouseWheel(self, Shift, WheelDelta, MousePos);
+
   Result := inherited DoMouseWheel(Shift, WheelDelta, MousePos);
-  if IsActive and (mvoMouseZooming in FOptions) then
+  if IsActive and (mvoMouseZooming in FOptions) and not lHandled then
   begin
     Engine.MouseWheel(self,Shift,WheelDelta,MousePos,Result);
     Invalidate;
@@ -4449,6 +4463,13 @@ begin
   DefaultMouseEvent(AMapView, AButton, AShift, X, Y, AMapEvent);
 end;
 
+// No user event here; it is handled by the MapView itself.
+function TMvCustomPluginManager.MouseWheel(AMapView: TMapView; AShift: TShiftState;
+  AWheelDelta: Integer; AMousePos: TPoint): Boolean;
+begin
+  Result := False;
+end;
+
 procedure TMvCustomPluginManager.RemoveMapView(AMapView: TMapView);
 begin
   //

components/lazmapviewer/source/mvplugincore.pas

@@ -39,9 +39,11 @@ type
     procedure SetPluginManager(AValue: TMvPluginManager);
   protected
     function GetIndex: Integer; override;
+    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
     procedure ReadState(Reader: TReader); override;
     procedure SetIndex(AValue: Integer); override;
     procedure SetParentComponent(AParent: TComponent); override;
+    procedure Update; virtual;
   protected
     procedure AfterDrawObjects(AMapView: TMapView; var Handled: Boolean); virtual;
     procedure AfterPaint(AMapView: TMapView; var Handled: Boolean); virtual;
@@ -57,10 +59,10 @@ type
       var Handled: Boolean); virtual;
     procedure MouseUp(AMapView: TMapView; Button: TMouseButton; Shift: TShiftState;
       X,Y: Integer; var Handled: Boolean); virtual;
-    procedure Notification(AComponent: TComponent; Operation: TOperation); override;
+    procedure MouseWheel(AMapView: TMapView; AShift: TShiftState;
+      AWheelDelta: Integer; AMousePos: TPoint; var Handled: Boolean); virtual;
     procedure ZoomChange(AMapView: TMapView; var Handled: Boolean); virtual;
   //  procedure ZoomChanging(AMapView: TMapView; NewZoom: Integer; var Allow, Handled: Boolean); virtual;
-    procedure Update; virtual;
   protected
     property MapView: TMapView read FMapView write SetMapView;
     property Enabled: Boolean read FEnabled write SetEnabled default true;
@@ -192,6 +194,8 @@ type
       AMapEvent: TMouseMoveEvent): Boolean; override;
     function MouseUp(AMapView: TMapView; AButton: TMouseButton; AShift: TShiftState;
       X, Y: Integer; AMapEvent: TMouseEvent): Boolean; override;
+    function MouseWheel(AMapView: TMapView; AShift: TShiftState; AWheelDelta: Integer;
+      AMousePos: TPoint): Boolean; override;
     function ZoomChange(AMapView: TMapView; AMapEvent: TNotifyEvent): Boolean; override;
 //    procedure ZoomChanging(AMapView: TMapView; NewZoom: Integer; var Allow: Boolean; AMapEvent); override;
 
@@ -345,6 +349,13 @@ begin
   Unused(Shift, X, Y);
 end;
 
+procedure TMvCustomPlugin.MouseWheel(AMapView: TMapView; AShift: TShiftState;
+  AWheelDelta: Integer; AMousePos: TPoint; var Handled: Boolean);
+begin
+  Unused(AMapView, Handled);
+  Unused(AShift, AWheelDelta, AMousePos);
+end;
+
 procedure TMvCustomPlugin.Notification(AComponent: TComponent; Operation: TOperation);
 begin
   inherited;
@@ -871,6 +882,22 @@ begin
   inherited MouseUp(AMapView, AButton, AShift, X, Y, AMapEvent);
 end;
 
+function TMvPluginManager.MouseWheel(AMapView: TMapView; AShift: TShiftState;
+  AWheelDelta: Integer; AMousePos: TPoint): Boolean;
+var
+  i: Integer;
+  plugin: TMvCustomPlugin;
+begin
+  Result := False;
+  for i := 0 to FPluginList.Count-1 do
+  begin
+    plugin := Item[i];
+    if HandlePlugin(plugin, AMapView) then
+      plugin.MouseWheel(AMapView, AShift, AWheelDelta, AMousePos, Result);
+  end;
+  // No user event here; it is handled by the Mapview itself
+end;
+
 procedure TMvPluginManager.Notification(AComponent: TComponent; Operation: TOperation);
 begin
   inherited;