all: rename the gioui.org/ui module to gioui.org

The "ui" is redundant and stutters.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

widget/image.go

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+// Package widget implements common widgets.
+package widget
+
+import (
+	"image"
+
+	"gioui.org/ui"
+	"gioui.org/f32"
+	"gioui.org/layout"
+	"gioui.org/paint"
+)
+
+// Image is a widget that displays an image.
+type Image struct {
+	// Src is the image to display.
+	Src image.Image
+	// Rect is the source rectangle.
+	Rect image.Rectangle
+	// Scale is the ratio of image pixels to
+	// device pixels. If zero, a scale that
+	// makes the image appear at approximately
+	// 72 DPI is used.
+	Scale float32
+}
+
+func (im Image) Layout(gtx *layout.Context) {
+	size := im.Src.Bounds()
+	wf, hf := float32(size.Dx()), float32(size.Dy())
+	var w, h int
+	if im.Scale == 0 {
+		const dpPrPx = 160 / 72
+		w, h = gtx.Px(ui.Dp(wf*dpPrPx)), gtx.Px(ui.Dp(hf*dpPrPx))
+	} else {
+		w, h = int(wf*im.Scale+.5), int(hf*im.Scale+.5)
+	}
+	cs := gtx.Constraints
+	d := image.Point{X: cs.Width.Constrain(w), Y: cs.Height.Constrain(h)}
+	aspect := float32(w) / float32(h)
+	dw, dh := float32(d.X), float32(d.Y)
+	dAspect := dw / dh
+	if aspect < dAspect {
+		d.X = int(dh*aspect + 0.5)
+	} else {
+		d.Y = int(dw/aspect + 0.5)
+	}
+	dr := f32.Rectangle{
+		Max: f32.Point{X: float32(d.X), Y: float32(d.Y)},
+	}
+	paint.ImageOp{Src: im.Src, Rect: im.Rect}.Add(gtx.Ops)
+	paint.PaintOp{Rect: dr}.Add(gtx.Ops)
+	gtx.Dimensions = layout.Dimensions{Size: d, Baseline: d.Y}
+}