65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
// Package layout arranges screens, windows and panes on dots.
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package layout
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import (
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"fmt"
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"github.com/egoist/mygo/ui"
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"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
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)
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// orDef is v, or def for zero; negative panics.
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func orDef(name string, v, def int) int {
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if v < 0 {
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panic(fmt.Sprintf("layout: %s %d is negative", name, v))
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}
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if v == 0 {
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return def
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}
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return v
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}
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// box frames the canvas unless it is too small.
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func box(g pixel.Canvas, style pixel.FrameStyle, fill pixel.Slot) {
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if g.W >= 3 && g.H >= 3 {
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g.Frame(0, 0, g.W, g.H, style, fill)
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}
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}
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// rule draws n dots on an axis in on/off runs.
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func rule(g pixel.Canvas, x, y, n int, vertical bool, on, off int, s pixel.Slot) {
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for i := 0; i < n; i += on + off {
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run := min(on, n-i)
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if vertical {
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g.VLine(x, y+i, run, s)
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} else {
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g.HLine(x+i, y, run, s)
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}
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}
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}
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type dragKey struct{}
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// drag is enabled e's pointer travel this frame, in dots.
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func drag(k pixel.Kit, e *ui.Element) (dx, dy int, ok bool) {
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rest := ui.Local(e, dragKey{}, func() [2]float32 { return [2]float32{} })
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fx, fy, ok := e.Dragged()
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if !ok || e.IsDisabled() {
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*rest = [2]float32{}
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return 0, 0, false
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}
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x, y := rest[0]+fx/k.Dot(), rest[1]+fy/k.Dot()
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dx, dy = int(x), int(y)
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*rest = [2]float32{x - float32(dx), y - float32(dy)}
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return dx, dy, true
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}
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// label is o's label, or the built-in copy for key.
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func label(k pixel.Kit, s, key string) string {
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if s != "" {
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return s
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}
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return k.Msg(key)
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}
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