Hilbish/readline/update.go

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4.8 KiB
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package readline
import (
"strings"
"golang.org/x/text/width"
)
// updateHelpers is a key part of the whole refresh process:
// it should coordinate reprinting the input line, any Infos and completions
// and manage to get back to the current (computed) cursor coordinates
func (rl *Instance) updateHelpers() {
// Load all Infos & completions before anything.
// Thus overwrites anything having been dirtily added/forced/modified, like rl.SetInfoText()
rl.getInfoText()
rl.getHintText()
if rl.modeTabCompletion && !rl.completionOpen {
rl.getTabCompletion()
} else {
if rl.completionOpen { rl.completionOpen = false }
}
// We clear everything
rl.clearHelpers()
// We are at the prompt line (with the latter
// not printed yet), then reprint everything
rl.renderHelpers()
}
const tabWidth = 4
func getWidth(x []rune) int {
var w int
for _, j := range x {
k := width.LookupRune(j).Kind()
if j == '\t' {
w += tabWidth
} else if k == width.EastAsianWide || k == width.EastAsianFullwidth {
w += 2
} else {
w++
}
}
return w
}
// Update reference should be called only once in a "loop" (not Readline(), but key control loop)
func (rl *Instance) updateReferences() {
// We always need to work with clean data,
// since we will have incrementers all around
rl.posX = 0
rl.fullX = 0
rl.posY = 0
rl.fullY = 0
var curLine []rune
if len(rl.currentComp) > 0 {
curLine = rl.lineComp
} else {
curLine = rl.line
}
fullLine := getWidth(curLine)
cPosLine := getWidth(curLine[:rl.pos])
// We need the X offset of the whole line
toEndLine := rl.promptLen + fullLine
fullOffset := toEndLine / GetTermWidth()
rl.fullY = fullOffset + strings.Count(string(curLine), "\n")
fullRest := toEndLine % GetTermWidth()
rl.fullX = fullRest
if fullRest == 0 && fullOffset > 0 {
print("\n")
}
// Use rl.pos value to get the offset to go TO/FROM the CURRENT POSITION
lineToCursorPos := rl.promptLen + cPosLine
offsetToCursor := lineToCursorPos / GetTermWidth()
cPosRest := lineToCursorPos % GetTermWidth()
// If we are at the end of line
if fullLine == rl.pos {
rl.posY = fullOffset
if fullRest == 0 {
rl.posX = 0
} else if fullRest > 0 {
rl.posX = fullRest
}
} else if rl.pos < fullLine {
// If we are somewhere in the middle of the line
rl.posY = offsetToCursor
if cPosRest == 0 {
} else if cPosRest > 0 {
rl.posX = cPosRest
}
}
}
func (rl *Instance) resetHelpers() {
rl.modeAutoFind = false
// Now reset all below-input helpers
rl.resetInfoText()
rl.resetTabCompletion()
}
// clearHelpers - Clears everything: prompt, input, Infos & comps,
// and comes back at the prompt.
func (rl *Instance) clearHelpers() {
// Now go down to the last line of input
moveCursorDown(rl.fullY - rl.posY)
moveCursorBackwards(rl.posX)
moveCursorForwards(rl.fullX)
// Clear everything below
print(seqClearScreenBelow)
// Go back to current cursor position
moveCursorBackwards(GetTermWidth())
moveCursorUp(rl.fullY - rl.posY)
moveCursorForwards(rl.posX)
}
// renderHelpers - pritns all components (prompt, line, Infos & comps)
// and replaces the cursor to its current position. This function never
// computes or refreshes any value, except from inside the echo function.
func (rl *Instance) renderHelpers() {
// when the instance is in this state we want it to be "below" the user's
// input for it to be aligned properly
if !rl.compConfirmWait {
rl.writeHintText()
}
rl.echo()
if rl.modeTabCompletion {
// in tab complete mode we want it to update
// when something has been selected
// (dynamic!!)
rl.getHintText()
rl.writeHintText()
} else if !rl.compConfirmWait {
// for the same reason above of wanting it below user input, do nothing here
} else {
rl.writeHintText()
}
rl.echoRightPrompt()
// Go at beginning of first line after input remainder
moveCursorDown(rl.fullY - rl.posY)
moveCursorBackwards(GetTermWidth())
// Print Infos, check for any confirmation Info current.
// (do not overwrite the confirmation question Info)
if !rl.compConfirmWait {
if len(rl.infoText) > 0 {
print("\n")
}
rl.writeInfoText()
moveCursorBackwards(GetTermWidth())
// Print completions and go back to beginning of this line
print("\n")
rl.writeTabCompletion()
moveCursorBackwards(GetTermWidth())
moveCursorUp(rl.tcUsedY)
}
// If we are still waiting for the user to confirm too long completions
// Immediately refresh the Infos
if rl.compConfirmWait {
print("\n")
rl.writeInfoText()
rl.getInfoText()
moveCursorBackwards(GetTermWidth())
}
// Anyway, compensate for Info printout
if len(rl.infoText) > 0 {
moveCursorUp(rl.infoY)
} else if !rl.compConfirmWait {
moveCursorUp(1)
} else if rl.compConfirmWait {
moveCursorUp(1)
}
// Go back to current cursor position
moveCursorUp(rl.fullY - rl.posY)
moveCursorForwards(rl.posX)
}