Method cursorUp

texteditor/nav.go:400–444

cursorUp moves the cursor up line(s)

(steps int)

// cursorUp moves the cursor up line(s)
func (ed *Editor) cursorUp(steps int) {
	ed.validateCursor()
	org := ed.CursorPos
	pos := ed.CursorPos
	for i := 0; i < steps; i++ {
		gotwrap := false
		if wln := ed.wrappedLines(pos.Ln); wln > 1 {
			si, ri, _ := ed.wrappedLineNumber(pos)
			if si > 0 {
				ri = ed.cursorColumn
				nwc, _ := ed.renders[pos.Ln].SpanPosToRuneIndex(si-1, ri)
				if nwc == pos.Ch {
					ed.cursorColumn = 0
					ri = 0
					nwc, _ = ed.renders[pos.Ln].SpanPosToRuneIndex(si-1, ri)
				}
				pos.Ch = nwc
				gotwrap = true
			}
		}
		if !gotwrap {
			pos.Ln--
			if pos.Ln < 0 {
				pos.Ln = 0
				break
			}
			if wln := ed.wrappedLines(pos.Ln); wln > 1 { // just entered end of wrapped line
				si := wln - 1
				ri := ed.cursorColumn
				nwc, _ := ed.renders[pos.Ln].SpanPosToRuneIndex(si, ri)
				pos.Ch = nwc
			} else {
				mxlen := min(ed.Buffer.LineLen(pos.Ln), ed.cursorColumn)
				if ed.cursorColumn < mxlen {
					pos.Ch = ed.cursorColumn
				} else {
					pos.Ch = mxlen
				}
			}
		}
	}
	ed.SetCursorShow(pos)
	ed.cursorSelect(org)
	ed.NeedsRender()
}

// cursorPageUp moves the cursor up page(s), where a page is defined
// dynamically as just moving the cursor off the screen