public override void Draw(ICanvas canvas, ICanvasScreenConvertable canvasProxy)
{
base.Draw(canvas, canvasProxy);
//检查两个关键位置是否为空;
if (MousePositionTracker.LastMouseDownPosition == null || MousePositionTracker.CurrentHoverPosition == null)
{
return;
}
//绘制当前随鼠标位置移动的编辑线段;
//绘制本次尚未完成的线段的起始点小正方形;
var lastMouseDownScreenPosition = canvasProxy.ToScreen(MousePositionTracker.LastMouseDownPosition);
var sideLength = HighLightRectLength;
var startEditRect = NativeGeometryExtensions.GetNativeSuroundingScreenRect(lastMouseDownScreenPosition, sideLength, sideLength);
canvas.NativeDrawRectangle(startEditRect, HighLightRectColorBrush, LinePen);
//在外部加入了动态输入,此时显示线段编辑状态多余;
//DrawEditingLineState(canvas, canvasProxy);
}
/// <summary>
/// 绘制选择状态;
/// </summary>
/// <param name="canvas"></param>
private void DrawSelectedState(ICanvas canvas, ICanvasScreenConvertable canvasProxy)
{
if (!IsSelected)
{
return;
}
if (Ellipse2D == null)
{
return;
}
if (Ellipse2D.Center == null)
{
return;
}
var centerScreenPoint = canvasProxy.ToScreen(Ellipse2D.Center);
var screenRadiusX = canvasProxy.ToScreen(Ellipse2D.RadiusX);
var screenRadiusY = canvasProxy.ToScreen(Ellipse2D.RadiusY);
var rectLength = TolerantedScreenLength;
//依次绘制左、下、右、上、圆心的矩形;
var points = new Vector2D[] {
new Vector2D(centerScreenPoint.X - screenRadiusX, centerScreenPoint.Y),
new Vector2D(centerScreenPoint.X, centerScreenPoint.Y - screenRadiusY),
new Vector2D(centerScreenPoint.X + screenRadiusX, centerScreenPoint.Y),
new Vector2D(centerScreenPoint.X, centerScreenPoint.Y + screenRadiusY),
new Vector2D(centerScreenPoint.X, centerScreenPoint.Y),
};
foreach (var point in points)
{
var rect = NativeGeometryExtensions.GetNativeSuroundingScreenRect(point, rectLength, rectLength);
canvas.NativeDrawRectangle(rect, HighLightEllipseColorBrush, HighLightLinePen);
}
}