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https://git.sr.ht/~eliasnaur/gio
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Egon Elbre
21ef492cc9
color.RGBA has two problems with regards to using it. First the color values need to be premultiplied, whereas most APIs have non-premultiplied values. This is mainly to preserve color components with low alpha values. Second there are two ways to premultiply with sRGB. One is to premultiply after sRGB conversion, the other is before. This makes using the API more confusing. Using color.NRGBA in sRGB makes it align with CSS.e Signed-off-by: Egon Elbre <egonelbre@gmail.com>
41 lines
804 B
Go
41 lines
804 B
Go
// SPDX-License-Identifier: Unlicense OR MIT
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package widget
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import (
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"image/color"
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"gioui.org/f32"
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"gioui.org/layout"
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"gioui.org/op"
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"gioui.org/op/clip"
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"gioui.org/op/paint"
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"gioui.org/unit"
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)
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// Border lays out a widget and draws a border inside it.
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type Border struct {
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Color color.NRGBA
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CornerRadius unit.Value
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Width unit.Value
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}
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func (b Border) Layout(gtx layout.Context, w layout.Widget) layout.Dimensions {
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dims := w(gtx)
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sz := dims.Size
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rr := float32(gtx.Px(b.CornerRadius))
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st := op.Push(gtx.Ops)
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width := gtx.Px(b.Width)
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clip.Border{
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Rect: f32.Rectangle{
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Max: layout.FPt(sz),
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},
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NE: rr, NW: rr, SE: rr, SW: rr,
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Width: float32(width),
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}.Add(gtx.Ops)
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paint.ColorOp{Color: b.Color}.Add(gtx.Ops)
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paint.PaintOp{}.Add(gtx.Ops)
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st.Pop()
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return dims
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}
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