forms - 榆树 - 形式检查

Question

下面的函数包括使用collage, 仅用于将形状/表单转换为元素。

makeSlider : Element -> Form -> Element
makeSlider sliderShape sliderBarForm =
  let                                                                                                 
    sliderBar =
      --convert sliderBarForm from type Form to Element
      collage 1000 1000 [(move (0,0) sliderBarForm)]
  in 
    layers [sliderShape, sliderBar]

有没有办法提取表单的维度，比如Graphics.Element.sizeOf，这样makeSlider函数就不需要知道 的显式维度sliderBarForm？

或者是否toElement存在一个函数，使得

collage 1000 1000 [(move (0,0) sliderBarForm)]

可以替换为

toElement (move (0,0) sliderBarForm)?

Answer 1

我认为您不能轻易获得表格的尺寸。我想这是因为一个表单可以是很多不同种类的东西（形状、路径等）。当我以后需要知道尺寸时，我会在创建表单时跟踪它们。

type alias MyForm =
  {   form : Form
    , width : Int
    , height : Int
  }

makeRectForm: Float -> Float -> MyForm
makeRectForm  w h = {form: (filled grey (rect w h)), width: (round w), height: (round h)}

然后在您的情况下，您可以将 aMyForm与collage.

makeSlider : Element -> MyForm -> Element
makeSlider sliderShape sliderBarMyForm =
  let                                                                                                 
    sliderBar =
      --convert sliderBarForm from type Form to Element
      collage sliderBarMyForm.width sliderBarMyForm.height [(move (0,0) sliderBarMyForm)]
  in 
    layers [sliderShape, sliderBar]