zntg/ui/button.go

package ui

import (
	"opslag.de/schobers/geom"
	"opslag.de/schobers/zntg/allg5"
)

type Button struct {
	ControlBase
	Text                string
	HorizontalAlignment allg5.HorizontalAlignment
}

func NewButton(text string, click MouseClickFn) *Button {
	return &Button{ControlBase: ControlBase{OnClick: click}, Text: text}
}

func NewButtonAlign(text string, click MouseClickFn, align allg5.HorizontalAlignment) *Button {
	return &Button{ControlBase: ControlBase{OnClick: click}, Text: text, HorizontalAlignment: align}
}

func (b *Button) DesiredSize(ctx Context) geom.PointF {
	var fonts = ctx.Fonts()
	var fnt = fonts.Get("default")
	var w = fnt.TextWidth(b.Text)
	var fntH = fnt.Height()
	return geom.PtF(float64(w+fntH), float64(2*fntH))
}

func (b *Button) Render(ctx Context) {
	var fonts = ctx.Fonts()

	var min = b.Bounds.Min.To32()
	var max = b.Bounds.Max.To32()

	var fnt = fonts.Get("default")
	var fntH = fnt.Height()

	var back = ctx.Palette().Primary()
	if b.IsOver && !b.IsPressed {
		back = ctx.Palette().PrimaryHighlight()
	}
	allg5.DrawFilledRectangle(min.X, min.Y, max.X, max.Y, back)
	switch b.HorizontalAlignment {
	case allg5.AlignLeft:
		fnt.Draw(min.X+.5*fntH, min.Y+.5*fntH, ctx.Palette().Lightest(), allg5.AlignLeft, b.Text)
	case allg5.AlignCenter:
		fnt.Draw(.5*(min.X+max.X), min.Y+.5*fntH, ctx.Palette().Lightest(), allg5.AlignCenter, b.Text)
	case allg5.AlignRight:
		fnt.Draw(min.X-.5*fntH, min.Y+.5*fntH, ctx.Palette().Lightest(), allg5.AlignRight, b.Text)
	}

	b.ControlBase.Render(ctx)
}