LazMapViewer: In GridPlugin, draw grid lines before objects. Extend demo to add/delete points of interest (note: memory leak after deleting!)

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@9523 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/lazmapviewer/examples/plugin_demos/grid_demo/GridPlugin_Demo.lpi

@@ -65,6 +65,7 @@
     <Linking>
       <Debugging>
         <DebugInfoType Value="dsDwarf3"/>
+        <UseHeaptrc Value="True"/>
       </Debugging>
       <Options>
         <Win32>

components/lazmapviewer/examples/plugin_demos/grid_demo/main.pas

@@ -7,7 +7,7 @@ interface
 uses
   Classes, ComCtrls, DividerBevel, ExtCtrls, Spin, StdCtrls, SysUtils,
   Forms, Controls, Graphics, Dialogs, //LazLogger,
-  mvMapViewer, mvEngine, mvPluginCore, mvPlugins;
+  mvMapViewer, mvTypes, mvEngine, mvPluginCore, mvPlugins;
 
 type
   TForm1 = class(TForm)
@@ -24,6 +24,8 @@ type
     divLines: TDividerBevel;
     divLabels: TDividerBevel;
     GroupBox1: TGroupBox;
+    ImageList1: TImageList;
+    Label1: TLabel;
     lblLabelDistance: TLabel;
     lblIncrement: TLabel;
     lblOpacity: TLabel;
@@ -40,9 +42,12 @@ type
     procedure clbPenColorColorChanged(Sender: TObject);
     procedure cmbIncrementChange(Sender: TObject);
     procedure FormCreate(Sender: TObject);
+    procedure MapViewMouseUp(Sender: TObject; Button: TMouseButton; Shift:
+      TShiftState; X, Y: Integer);
     procedure seLabelDistanceChange(Sender: TObject);
     procedure tbOpacityChange(Sender: TObject);
   private
+    procedure AddPointOfInterest(X, Y: Integer);
 
   public
 
@@ -57,6 +62,7 @@ implementation
 
 procedure TForm1.FormCreate(Sender: TObject);
 begin
+  Randomize;
   MapView.Zoom := 5;
   with TGridPlugin.Create(PluginManager) do
   begin
@@ -67,9 +73,44 @@ begin
   end;
 end;
 
-procedure TForm1.seLabelDistanceChange(Sender: TObject);
+procedure TForm1.AddPointOfInterest(X, Y: Integer);
+const
+  DELTA = 4;
+var
+  layer: TMapLayer;
+  poi: TPointOfInterest;
+  RP: TRealPoint;
+  area: TRealArea;
+  list: TMapObjectList;
+  i: Integer;
 begin
-  (PluginManager.PluginList[0] as TGridPlugin).GridLabels.Distance := seLabelDistance.Value;
+  if MapView.Layers.Count = 0 then
+    layer := TMapLayer(MapView.Layers.Add)
+  else
+    layer := MapView.Layers[0];
+
+  RP := MapView.Engine.ScreenToLatLon(Point(X, Y));
+  area := MapView.Engine.ScreenRectToRealArea(Rect(X-DELTA, Y-DELTA, X+DELTA, Y+DELTA));
+
+  list := layer.PointsOfInterest.HitTest(area);
+  if (list = nil) then
+  begin
+    poi := TPointOfInterest(layer.PointsOfInterest.Add);
+    poi.Caption := 'Test ' + IntToStr(layer.PointsOfInterest.Count);
+    poi.ImageIndex := Random(ImageList1.Count);
+    poi.Longitude := RP.Lon;
+    poi.Latitude := RP.Lat;
+  end else
+  begin
+    for i := list.Count-1 downto 0 do
+    begin
+      if list[i] is TPointOfInterest then
+      begin
+        poi := TPointOfInterest(list[i]);
+        poi.Free;
+      end;
+    end;
+  end;
 end;
 
 procedure TForm1.cbCyclicChange(Sender: TObject);
@@ -77,32 +118,6 @@ begin
   MapView.Cyclic := cbCyclic.Checked;
 end;
 
-procedure TForm1.LabelPositionChange(Sender: TObject);
-begin
-  with (PluginManager.PluginList[0] as TGridPlugin).GridLabels do
-  begin
-    if cbLeft.Checked then
-      Position := Position + [glpLeft]
-    else
-      Position := Position - [glpLeft];
-
-    if cbTop.Checked then
-      Position := Position + [glpTop]
-    else
-      Position := Position - [glpTop];
-
-    if cbRight.Checked then
-      Position := Position + [glpRight]
-    else
-      Position := Position - [glpRight];
-
-    if cbBottom.Checked then
-      Position := Position + [glpBottom]
-    else
-      Position := Position - [glpBottom];
-  end;
-end;
-
 procedure TForm1.cbEnabledChange(Sender: TObject);
 begin
   (PluginManager.PluginList[0] as TGridPlugin).Enabled := cbEnabled.Checked;
@@ -156,6 +171,44 @@ begin
   end;
 end;
 
+procedure TForm1.LabelPositionChange(Sender: TObject);
+begin
+  with (PluginManager.PluginList[0] as TGridPlugin).GridLabels do
+  begin
+    if cbLeft.Checked then
+      Position := Position + [glpLeft]
+    else
+      Position := Position - [glpLeft];
+
+    if cbTop.Checked then
+      Position := Position + [glpTop]
+    else
+      Position := Position - [glpTop];
+
+    if cbRight.Checked then
+      Position := Position + [glpRight]
+    else
+      Position := Position - [glpRight];
+
+    if cbBottom.Checked then
+      Position := Position + [glpBottom]
+    else
+      Position := Position - [glpBottom];
+  end;
+end;
+
+procedure TForm1.MapViewMouseUp(Sender: TObject; Button: TMouseButton; Shift:
+  TShiftState; X, Y: Integer);
+begin
+  if Button = mbRight then
+    AddPointOfInterest(X, Y);
+end;
+
+procedure TForm1.seLabelDistanceChange(Sender: TObject);
+begin
+  (PluginManager.PluginList[0] as TGridPlugin).GridLabels.Distance := seLabelDistance.Value;
+end;
+
 procedure TForm1.tbOpacityChange(Sender: TObject);
 begin
   (PluginManager.PluginList[0] as TGridPlugin).Opacity := tbOpacity.Position / 100;

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

@@ -82,7 +82,7 @@ type
   private
     procedure Changed(Sender: TObject);
   protected
-    procedure AfterDrawObjects(AMapView: TMapView; var {%H-}Handled: Boolean); override;
+    procedure BeforeDrawObjects(AMapView: TMapView; var {%H-}Handled: Boolean); override;
     function CalcIncrement(AMapView: TMapView; Area: TRealArea): Double;
     function CalcVisibleArea(AMapView: TMapView): TRealArea;
     procedure DrawGridLine(ADrawingEngine: TMvCustomDrawingEngine;
@@ -387,7 +387,7 @@ begin
   inherited;
 end;
 
-procedure TGridPlugin.AfterDrawObjects(AMapView: TMapView; var Handled: Boolean);
+procedure TGridPlugin.BeforeDrawObjects(AMapView: TMapView; var Handled: Boolean);
 var
   area: TRealArea;
   coordType: TGridCoordType;