forked from joejulian/gio
Elias Naur
d572aa23ac
The pixel-aligned Rect is more efficient and easier to use in the common case of layout clipping. Signed-off-by: Elias Naur <mail@eliasnaur.com>
43 lines
1022 B
Go
43 lines
1022 B
Go
// SPDX-License-Identifier: Unlicense OR MIT
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package widget
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import (
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"image"
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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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// Image is a widget that displays an image.
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type Image struct {
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// Src is the image to display.
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Src paint.ImageOp
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// Scale is the ratio of image pixels to
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// dps. If Scale is zero Image falls back to
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// a scale that match a standard 72 DPI.
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Scale float32
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}
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func (im Image) Layout(gtx layout.Context) layout.Dimensions {
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scale := im.Scale
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if scale == 0 {
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scale = 160.0 / 72.0
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}
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size := im.Src.Rect.Size()
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wf, hf := float32(size.X), float32(size.Y)
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w, h := gtx.Px(unit.Dp(wf*scale)), gtx.Px(unit.Dp(hf*scale))
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cs := gtx.Constraints
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d := cs.Constrain(image.Pt(w, h))
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stack := op.Push(gtx.Ops)
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clip.Rect(image.Rectangle{Max: d}).Add(gtx.Ops)
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im.Src.Add(gtx.Ops)
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paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: float32(w), Y: float32(h)}}}.Add(gtx.Ops)
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stack.Pop()
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return layout.Dimensions{Size: d}
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}
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