Properties · Methods · Demos · Examples

Declaration

TIEPolylineLayer = class(TIELayer);

Description

TImageEnView supports multiple layers, allowing the creation of a single image from multiple source images (which can be resized, rotated, moved, etc).
TIEPolylineLayer is a descendent of TIELayer that displays a line formed from multiple points. It can also be closed to display a polygon.



You can easily add curved lines to polyline layers:



You can create polyline layers with code using LayersAdd or by user action by setting MouseInteractLayers:
 * Auto-closing of the polyline layer is controlled by LayersAutoClosePolylines

Review the Layer Documentation for a full description of layer support.

Demos

Examples

// Draw a triangle polygon
With TIEPolylineLayer( ImageEnView1.CurrentLayer ) do
begin
  ClearAllPoints();
  AddPoint( 500, 0 );
  AddPoint( 1000, 1000 );
  AddPoint( 0, 1000 );
  PolylineClosed := True;
end;
ImageEnView1.Update();

// Which is the same as..
var
  shapePoints: array of TPoint;
begin
  SetLength( shapePoints, 3 );
  shapePoints[0] := Point( 500, 0 );
  shapePoints[1] := Point( 1000, 1000 );
  shapePoints[2] := Point( 0, 1000 );
  TIEPolylineLayer( ImageEnView1.CurrentLayer ).SetPoints( shapePoints, True );
  ImageEnView1.Update();
end;

// Which is the same as...
TIEPolylineLayer( ImageEnView1.CurrentLayer ).SetPoints( [ Point(500, 0), Point(1000, 1000), Point(0, 1000) ], True );
ImageEnView1.Update();

// Which is the same as...
TIEPolylineLayer( ImageEnView1.CurrentLayer ).SetPoints( iesTriangle, True );
ImageEnView1.Update();




// If PolylineClosed is not enabled, we get a polyline, instead of a polygon
TIEPolylineLayer( ImageEnView1.CurrentLayer ).PolylineClosed := False;
ImageEnView1.Update();




// Allow users to create and edit a polygon
ImageEnView1.LayersAutoClosePolylines := iecmAlways;
ImageEnView1.MouseInteractLayers := [ mlClickCreatePolylineLayers, mlEditLayerPoints ];

// Allow users to freehand draw a polyline
ImageEnView1.MouseInteractLayers := [ mlDrawCreatePolylineLayers, mlEditLayerPoints ];

// Allow users to create and edit a polyline
ImageEnView1.LayersAutoClosePolylines := iecmManual;
ImageEnView1.MouseInteractLayers := [ mlClickCreatePolylineLayers, mlEditLayerPoints ];




Hold Alt to convert a line to a curve...



// Add a 5-pointed star polyline layer
var
  pp: array[0..10] of TPoint;
  polyLayer: TIEPolylineLayer;
begin
  pp[0]  := Point(175, 50);
  pp[1]  := Point(205, 145);
  pp[2]  := Point(300, 145);
  pp[3]  := Point(225, 205);
  pp[4]  := Point(253, 300);
  pp[5]  := Point(175, 243);
  pp[6]  := Point(98 , 300);
  pp[7]  := Point(128, 205);
  pp[8]  := Point(50 , 145);
  pp[9]  := Point(148, 145);
  pp[10] := Point(175, 50);

  ImageEnView1.LayersAdd( ielkPolyline );
  polyLayer := TIEPolylineLayer( ImageEnView1.CurrentLayer );
  polyLayer.LineColor := clOrangeRed;
  polyLayer.LineWidth := 3;
  polyLayer.FillColor := clYellow;
  polyLayer.SetPoints( pp, True, iepbBitmap );

  ImageEnView1.Update();
end;



// Draw a pink balloon
ImageEnView1.LayersAdd( ielkPolyline, 100, 100, 600, 800 );
With TIEPolylineLayer( ImageEnView1.CurrentLayer ) do
begin
  AddPoint( 500, 500 );
  AddCurvePoints( 0.95, Point( 500, 0 ));
  AddCurvePoints( 0.95, Point( 500, 500 ));
  AddPoint($FFFEE, $FFFEE);     // End shape and close polyline
  AddPoint( 500, 500 );
  AddPoint( 520, 517 );
  AddPoint( 480, 517 );
  AddPoint($FFFEE, $FFFEE);     // End shape and close polyline
  AddPoint( 500, 517 );
  AddCurvePoints( 3, Point( 500, 690 ));
  AddCurvePoints( -3, Point( 510, 850 ));
  AddCurvePoints( 3, Point( 500, 1000 ));
  AddPoint($FFFFF, $FFFFF);     // End polyline (optional at end)

  LineWidth := 2;
  FillColor := $00921CF0;
  PolylineClosed := False;
end;
ImageEnView1.Update();

Methods and Properties

General

Polygon Points

Style

Size and Position
 Unique to TIEPolylineLayer

See Also

◼Layer Editing Overview
◼LayersAdd
◼LayersInsert
◼MouseInteractLayers
◼AdvancedDrawPolyline

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