57 lines
991 B
Go
57 lines
991 B
Go
 
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// SPDX-License-Identifier: Unlicense OR MIT
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package text
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import (
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"fmt"
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"gioui.org/io/system"
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"golang.org/x/image/math/fixed"
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)
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type Alignment uint8
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const (
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Start Alignment = iota
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End
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Middle
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)
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func (a Alignment) String() string {
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switch a {
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case Start:
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return "Start"
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case End:
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return "End"
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case Middle:
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return "Middle"
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default:
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panic("invalid Alignment")
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}
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}
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// Align returns the x offset that should be applied to text with width so that it
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// appears correctly aligned within a space of size maxWidth and with the primary
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// text direction dir.
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func (a Alignment) Align(dir system.TextDirection, width fixed.Int26_6, maxWidth int) fixed.Int26_6 {
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mw := fixed.I(maxWidth)
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if dir.Progression() == system.TowardOrigin {
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switch a {
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case Start:
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a = End
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case End:
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a = Start
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}
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}
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switch a {
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case Middle:
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return (mw - width) / 2
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case End:
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return (mw - width)
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case Start:
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return 0
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default:
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panic(fmt.Errorf("unknown alignment %v", a))
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}
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}
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