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...

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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