theme/material: add the material theme

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

widget/image.go

@@ -1,54 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-// Package widget implements common widgets.
-package widget
-
-import (
-	"image"
-
-	"gioui.org/f32"
-	"gioui.org/layout"
-	"gioui.org/op/paint"
-	"gioui.org/unit"
-)
-
-// 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(unit.Dp(wf*dpPrPx)), gtx.Px(unit.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}
-}