MemoLib — Plan9Basic Documentation

MemoLib — Multi-Line Text Control Library

Complete functionality for creating and managing multi-line text edit controls in Plan9Basic. Ideal for text areas, notes, log viewers, code editors, and any multi-line text input. Features include line-by-line access, word wrap, scrollbars, selection, clipboard, and scroll control. 139 functions.

Category	Count	Description
Error Handling	4	memo_error, memo_errormsg$, memo_strerror$, memo_clearerror
Creation & Destruction	4	memo# (3 overloads), memo_free
Text Content	4	text (get/set), textlength, clear#
Lines	8	linecount, line (get/set), addline#, insertline#, deleteline#, lines (get/set)
Word Wrap & Scrollbars	4	wordwrap, showscrollbars (get/set)
Read-Only	2	readonly (get/set)
Font Properties	14	fontfamily, fontsize, fontcolor, bold, italic, underline, strikeout (get/set)
Text Alignment	2	textalign (get/set)
Selection	7	selstart, sellength, seltext$, selectall#, clearselection#
Caret Control	6	caretpositionline, caretpositionpos (get/set), gotoend#, gotobegin#
Clipboard	4	copy#, cut#, paste#, deleteselection#
Scroll Control	3	scrolltop (get/set), scrolltoend#
Position & Size	14	x, y, width, height (get/set), bounds#, move#, size#
Alignment & Margins	12	align (get/set), margin#, margins#, marginleft/top/right/bottom (get/set)
Visibility & State	6	visible, enabled, opacity (get/set)
Focus	5	isfocused, setfocus#, resetfocus#, taborder (get/set)
Tag & Parent	6	tag (get/set), parent# (get/set), bringtofront#, sendtoback#
Events	38	17 event types × set/get + clearcallbacks#

Cross-Platform Support

Platform	Status	Notes
Windows	✅ Full Support	Win32/Win64
Linux	✅ Full Support	GTK-based
Android	✅ Full Support	Mobile-optimized

Error Handling

Function	Signature	Description
`memo_error()`	`memo_error@`	Last error code (0 = no error)
`memo_errormsg$()`	`memo_errormsg$@`	Last error message as string
`memo_strerror$(code)`	`memo_strerror$@n`	Description for a given error code
`memo_clearerror()`	`memo_clearerror@`	Clear the error state

Numeric Values Reference

Plan9Basic does not have built-in constants. You can define your own named values for readability:

╯ plan9basic─◻✕
' Control alignment
let ALIGN_NONE = 0
let ALIGN_TOP = 1
let ALIGN_CLIENT = 9

' Text alignment
let TEXT_CENTER = 0
let TEXT_LEFT = 1
let TEXT_RIGHT = 2

Control Alignment `memo_align#`

Value	Description
0	None (absolute positioning)
1	Top
2	Left
3	Right
4	Bottom
9	Client (fill parent)

Text Alignment `memo_textalign#`

Value	Description
0	Center
1	Leading (Left for LTR languages)
2	Trailing (Right for LTR languages)

Creation & Destruction

Function	Signature	Description
`memo#(parent#)`	`memo#@#`	Create memo with default size
`memo#(parent#, x, y, w, h)`	`memo#@#nnnn`	Create with position and size
`memo#(parent#, x, y, w, h, text$)`	`memo#@#nnnn$`	Create with position, size, and initial text
`memo_free(mem#)`	`memo_free@#`	Destroy memo and release resources

╯ plan9basic─◻✕
' Simple creation
let mem# = memo#(frm#)

' With position and size
let mem# = memo#(frm#, 20, 20, 460, 300)

' With initial text
let mem# = memo#(frm#, 20, 20, 460, 300, "Initial text...")

' Cleanup
memo_free(mem#)

Text Content

Function	Signature	Description
`memo_text$(mem#)`	`memo_text$@#`	Get all text as a single string
`memo_text#(mem#, text$)`	`memo_text#@#$`	Set all text (replaces existing content)
`memo_textlength(mem#)`	`memo_textlength@#`	Get text length in characters
`memo_clear#(mem#)`	`memo_clear#@#`	Clear all text

╯ plan9basic─◻✕
memo_text#(mem#, "Hello World")
println "Length: " + str$(memo_textlength(mem#))

let allText$ = memo_text$(mem#)
memo_clear#(mem#)

Lines

MemoLib provides line-by-line access to the text content. Line indices are 0-based.

Function	Signature	Description
`memo_linecount(mem#)`	`memo_linecount@#`	Get total number of lines
`memo_line$(mem#, index)`	`memo_line$@#n`	Get text of a specific line (0-based)
`memo_line#(mem#, index, text$)`	`memo_line#@#n$`	Set text of a specific line
`memo_addline#(mem#, text$)`	`memo_addline#@#$`	Append a new line at the end
`memo_insertline#(mem#, index, text$)`	`memo_insertline#@#n$`	Insert a new line at the given index
`memo_deleteline#(mem#, index)`	`memo_deleteline#@#n`	Delete the line at the given index
`memo_lines$(mem#)`	`memo_lines$@#`	Get all lines as a single string (preserving line structure)
`memo_lines#(mem#, text$)`	`memo_lines#@#$`	Set all lines from a single string

╯ plan9basic─◻✕
' Build content line by line
memo_addline#(mem#, "First line")
memo_addline#(mem#, "Second line")
memo_addline#(mem#, "Third line")

' Read a specific line
println "Line 0: " + memo_line$(mem#, 0)

' Modify a line
memo_line#(mem#, 1, "Modified second line")

' Insert at position
memo_insertline#(mem#, 1, "Inserted between first and second")

' Delete a line
memo_deleteline#(mem#, 2)

println "Total lines: " + str$(memo_linecount(mem#))

Word Wrap & Scrollbars

Function	Signature	Description
`memo_wordwrap(mem#)`	`memo_wordwrap@#`	Get word wrap state (0/1)
`memo_wordwrap#(mem#, n)`	`memo_wordwrap#@#n`	Enable/disable word wrap
`memo_showscrollbars(mem#)`	`memo_showscrollbars@#`	Get scrollbar visibility (0/1)
`memo_showscrollbars#(mem#, n)`	`memo_showscrollbars#@#n`	Show/hide scrollbars

╯ plan9basic─◻✕
' Text editor style: no wrap, with scrollbars
memo_wordwrap#(mem#, 0)
memo_showscrollbars#(mem#, 1)

' Notes style: wrap text, hide scrollbars
memo_wordwrap#(mem#, 1)
memo_showscrollbars#(mem#, 0)

ⓘ Note: When word wrap is enabled, lines wrap at the memo width and no horizontal scrollbar is shown. Disable word wrap for code editors where line width matters.

Read-Only

Function	Signature	Description
`memo_readonly(mem#)`	`memo_readonly@#`	Get read-only state (0/1)
`memo_readonly#(mem#, n)`	`memo_readonly#@#n`	Enable/disable read-only mode

╯ plan9basic─◻✕
' Log viewer: read-only, programmatic content only
memo_readonly#(mem#, 1)
memo_addline#(mem#, "[INFO] Application started")

ⓘ Note: Read-only prevents user editing, but you can still modify the text programmatically via memo_text#, memo_addline#, etc.

Font Properties

Function	Signature	Description
`memo_fontfamily$(mem#)`	`memo_fontfamily$@#`	Get font family name
`memo_fontfamily#(mem#, family$)`	`memo_fontfamily#@#$`	Set font family
`memo_fontsize(mem#)`	`memo_fontsize@#`	Get font size
`memo_fontsize#(mem#, size)`	`memo_fontsize#@#n`	Set font size
`memo_fontcolor$(mem#)`	`memo_fontcolor$@#`	Get font color
`memo_fontcolor#(mem#, color$)`	`memo_fontcolor#@#$`	Set font color
`memo_bold(mem#)`	`memo_bold@#`	Get bold state (0/1)
`memo_bold#(mem#, n)`	`memo_bold#@#n`	Set bold (0/1)
`memo_italic(mem#)`	`memo_italic@#`	Get italic state (0/1)
`memo_italic#(mem#, n)`	`memo_italic#@#n`	Set italic (0/1)
`memo_underline(mem#)`	`memo_underline@#`	Get underline state (0/1)
`memo_underline#(mem#, n)`	`memo_underline#@#n`	Set underline (0/1)
`memo_strikeout(mem#)`	`memo_strikeout@#`	Get strikeout state (0/1)
`memo_strikeout#(mem#, n)`	`memo_strikeout#@#n`	Set strikeout (0/1)

╯ plan9basic─◻✕
' Code editor font
memo_fontfamily#(mem#, "Consolas")
memo_fontsize#(mem#, 13)
memo_fontcolor#(mem#, "#333333")

' Notes font
memo_fontfamily#(mem#, "Arial")
memo_fontsize#(mem#, 14)

Text Alignment

Function	Signature	Description
`memo_textalign(mem#)`	`memo_textalign@#`	Get text alignment (0=center, 1=left, 2=right)
`memo_textalign#(mem#, n)`	`memo_textalign#@#n`	Set text alignment

╯ plan9basic─◻✕
memo_textalign#(mem#, 1)  ' Left-aligned (default for most uses)

Selection

Function	Signature	Description
`memo_selstart(mem#)`	`memo_selstart@#`	Get selection start position (0-based)
`memo_selstart#(mem#, pos)`	`memo_selstart#@#n`	Set selection start position
`memo_sellength(mem#)`	`memo_sellength@#`	Get selection length
`memo_sellength#(mem#, len)`	`memo_sellength#@#n`	Set selection length
`memo_seltext$(mem#)`	`memo_seltext$@#`	Get the currently selected text
`memo_selectall#(mem#)`	`memo_selectall#@#`	Select all text
`memo_clearselection#(mem#)`	`memo_clearselection#@#`	Clear the current selection

╯ plan9basic─◻✕
' Select all and read
memo_selectall#(mem#)
println "Selected: " + memo_seltext$(mem#)

' Programmatic selection
memo_selstart#(mem#, 0)
memo_sellength#(mem#, 10)  ' Select first 10 characters

Caret Control

The memo has a two-dimensional caret: a line number and a character position within the entire text.

Function	Signature	Description
`memo_caretpositionline(mem#)`	`memo_caretpositionline@#`	Get caret line number (0-based)
`memo_caretpositionline#(mem#, line)`	`memo_caretpositionline#@#n`	Set caret to a specific line
`memo_caretpositionpos(mem#)`	`memo_caretpositionpos@#`	Get caret character position in full text
`memo_caretpositionpos#(mem#, pos)`	`memo_caretpositionpos#@#n`	Set caret character position
`memo_gotoend#(mem#)`	`memo_gotoend#@#`	Move caret to the end of text
`memo_gotobegin#(mem#)`	`memo_gotobegin#@#`	Move caret to the beginning of text

╯ plan9basic─◻✕
' Display current line in a status label
let line = memo_caretpositionline(mem#)
label_text#(lblStatus#, "Line: " + str$(line + 1))

' Jump to line 10
memo_caretpositionline#(mem#, 10)

' Jump to end
memo_gotoend#(mem#)

Clipboard

Function	Signature	Description
`memo_copy#(mem#)`	`memo_copy#@#`	Copy selected text to clipboard
`memo_cut#(mem#)`	`memo_cut#@#`	Cut selected text to clipboard
`memo_paste#(mem#)`	`memo_paste#@#`	Paste from clipboard at caret position
`memo_deleteselection#(mem#)`	`memo_deleteselection#@#`	Delete the selected text without copying

╯ plan9basic─◻✕
' Edit menu operations
memo_selectall#(mem#)
memo_copy#(mem#)

' Or cut
memo_cut#(mem#)

' Paste
memo_paste#(mem#)

Scroll Control

Function	Signature	Description
`memo_scrolltop(mem#)`	`memo_scrolltop@#`	Get vertical scroll position (pixels from top)
`memo_scrolltop#(mem#, n)`	`memo_scrolltop#@#n`	Set vertical scroll position
`memo_scrolltoend#(mem#)`	`memo_scrolltoend#@#`	Scroll to the end of text (show last lines)

╯ plan9basic─◻✕
' Auto-scroll log after adding entries
memo_addline#(mem#, "[INFO] New event logged")
memo_scrolltoend#(mem#)

' Read scroll position
println "Scroll: " + str$(memo_scrolltop(mem#)) + "px"

ⓘ Note: memo_scrolltoend# is essential for log viewers — call it after memo_addline# to keep the latest entry visible.

Position & Size

Function	Signature	Description
`memo_x(mem#)`	`memo_x@#`	Get X position
`memo_x#(mem#, x)`	`memo_x#@#n`	Set X position
`memo_y(mem#)`	`memo_y@#`	Get Y position
`memo_y#(mem#, y)`	`memo_y#@#n`	Set Y position
`memo_width(mem#)`	`memo_width@#`	Get width
`memo_width#(mem#, w)`	`memo_width#@#n`	Set width
`memo_height(mem#)`	`memo_height@#`	Get height
`memo_height#(mem#, h)`	`memo_height#@#n`	Set height
`memo_bounds#(mem#, x, y, w, h)`	`memo_bounds#@#nnnn`	Set position and size in one call
`memo_move#(mem#, x, y)`	`memo_move#@#nn`	Set position only
`memo_size#(mem#, w, h)`	`memo_size#@#nn`	Set size only

╯ plan9basic─◻✕
memo_bounds#(mem#, 10, 50, 480, 300)

' Or separately
memo_move#(mem#, 10, 50)
memo_size#(mem#, 480, 300)

Alignment & Margins

Function	Signature	Description
`memo_align(mem#)`	`memo_align@#`	Get control alignment mode
`memo_align#(mem#, n)`	`memo_align#@#n`	Set control alignment (0=none, 1=top, 2=left, 3=right, 4=bottom, 9=client)
`memo_margin#(mem#, n)`	`memo_margin#@#n`	Set uniform margin on all four sides
`memo_margins#(mem#, l, t, r, b)`	`memo_margins#@#nnnn`	Set individual margins (left, top, right, bottom)
`memo_marginleft(mem#)`	`memo_marginleft@#`	Get left margin
`memo_marginleft#(mem#, n)`	`memo_marginleft#@#n`	Set left margin
`memo_margintop(mem#)`	`memo_margintop@#`	Get top margin
`memo_margintop#(mem#, n)`	`memo_margintop#@#n`	Set top margin
`memo_marginright(mem#)`	`memo_marginright@#`	Get right margin
`memo_marginright#(mem#, n)`	`memo_marginright#@#n`	Set right margin
`memo_marginbottom(mem#)`	`memo_marginbottom@#`	Get bottom margin
`memo_marginbottom#(mem#, n)`	`memo_marginbottom#@#n`	Set bottom margin

╯ plan9basic─◻✕
' Fill the entire form below a toolbar
memo_align#(mem#, 9)       ' Client = fill remaining space
memo_margin#(mem#, 5)      ' 5px spacing

Visibility & State

Function	Signature	Description
`memo_visible(mem#)`	`memo_visible@#`	Get visibility (0/1)
`memo_visible#(mem#, n)`	`memo_visible#@#n`	Set visibility (0=hidden, 1=visible)
`memo_enabled(mem#)`	`memo_enabled@#`	Get enabled state (0/1)
`memo_enabled#(mem#, n)`	`memo_enabled#@#n`	Set enabled state (0=disabled/grayed, 1=enabled)
`memo_opacity(mem#)`	`memo_opacity@#`	Get opacity (0.0–1.0)
`memo_opacity#(mem#, value)`	`memo_opacity#@#n`	Set opacity (0.0=transparent, 1.0=opaque)

Focus

Function	Signature	Description
`memo_isfocused(mem#)`	`memo_isfocused@#`	Is this memo focused? (0/1)
`memo_setfocus#(mem#)`	`memo_setfocus#@#`	Give keyboard focus to this memo
`memo_resetfocus#(mem#)`	`memo_resetfocus#@#`	Release focus from this memo
`memo_taborder(mem#)`	`memo_taborder@#`	Get tab order index
`memo_taborder#(mem#, n)`	`memo_taborder#@#n`	Set tab order index

Tag & Parent

Function	Signature	Description
`memo_tag(mem#)`	`memo_tag@#`	Get user-defined integer tag
`memo_tag#(mem#, n)`	`memo_tag#@#n`	Set user-defined integer tag
`memo_parent#(mem#)`	`memo_parent#@#`	Get parent control pointer
`memo_parent#(mem#, parent#)`	`memo_parent#@##`	Move memo to a different parent
`memo_bringtofront#(mem#)`	`memo_bringtofront#@#`	Bring to front of Z-order
`memo_sendtoback#(mem#)`	`memo_sendtoback#@#`	Send to back of Z-order

Events

Each event has a setter (memo_onXXX#(mem#, func$)) and a getter (memo_onXXX$(mem#)). Use memo_clearcallbacks#(mem#) to disconnect all callbacks at once.

Text Events

Event Setter	Getter	Callback Signature	When It Fires
`memo_onchange#(mem#, func$)`	`memo_onchange$(mem#)`	`function name(sender#)`	When editing is complete (focus lost)
`memo_onchangetracking#(mem#, func$)`	`memo_onchangetracking$(mem#)`	`function name(sender#)`	On every keystroke (real-time)

ⓘ Note: OnChange vs OnChangeTracking: Use memo_onchange# for final validation. Use memo_onchangetracking# for live statistics (line count, character count) but keep the callback lightweight.

Focus & Click Events

Event Setter	Getter	Callback Signature
`memo_onenter#(mem#, func$)`	`memo_onenter$(mem#)`	`function name(sender#)`
`memo_onexit#(mem#, func$)`	`memo_onexit$(mem#)`	`function name(sender#)`
`memo_onclick#(mem#, func$)`	`memo_onclick$(mem#)`	`function name(sender#)`
`memo_ondblclick#(mem#, func$)`	`memo_ondblclick$(mem#)`	`function name(sender#)`

Keyboard Events

Event Setter	Getter	Callback Signature
`memo_onkeydown#(mem#, func$)`	`memo_onkeydown$(mem#)`	`function name(sender#, key, keychar$, shift$)`
`memo_onkeyup#(mem#, func$)`	`memo_onkeyup$(mem#)`	`function name(sender#, key, keychar$, shift$)`

Mouse Events

Event Setter	Getter	Callback Signature
`memo_onmousedown#(mem#, func$)`	`memo_onmousedown$(mem#)`	`function name(sender#, button, x, y, shift$)`
`memo_onmouseup#(mem#, func$)`	`memo_onmouseup$(mem#)`	`function name(sender#, button, x, y, shift$)`
`memo_onmousemove#(mem#, func$)`	`memo_onmousemove$(mem#)`	`function name(sender#, x, y, shift$)`
`memo_onmouseenter#(mem#, func$)`	`memo_onmouseenter$(mem#)`	`function name(sender#)`
`memo_onmouseleave#(mem#, func$)`	`memo_onmouseleave$(mem#)`	`function name(sender#)`

Other Events

Event Setter	Getter	Callback Signature
`memo_onresize#(mem#, func$)`	`memo_onresize$(mem#)`	`function name(sender#)`
`memo_ondragenter#(mem#, func$)`	`memo_ondragenter$(mem#)`	`function name(sender#)`
`memo_ondragover#(mem#, func$)`	`memo_ondragover$(mem#)`	`function name(sender#)`
`memo_ondragdrop#(mem#, func$)`	`memo_ondragdrop$(mem#)`	`function name(sender#)`
`memo_ondragleave#(mem#, func$)`	`memo_ondragleave$(mem#)`	`function name(sender#)`
`memo_clearcallbacks#(mem#)`	—	Disconnect all event callbacks

Complete Examples

Simple Text Editor

╯ editor.bas─◻✕
function OnNew(sender#)
    memo_clear#(mem#)
    label_text#(lblStatus#, "New document")
endfunction

function OnCopy(sender#)
    memo_copy#(mem#)
    label_text#(lblStatus#, "Copied to clipboard")
endfunction

function OnPaste(sender#)
    memo_paste#(mem#)
    label_text#(lblStatus#, "Pasted from clipboard")
endfunction

function OnSelectAll(sender#)
    memo_selectall#(mem#)
    label_text#(lblStatus#, "All text selected")
endfunction

function OnTextChange(sender#) local lines, chars
    lines = memo_linecount(sender#)
    chars = memo_textlength(sender#)
    label_text#(lblStatus#, "Lines: " + str$(lines) + " | Chars: " + str$(chars))
endfunction

let frm# = form#("Text Editor", 500, 420)
form_position#(frm#, 4)

let mem# = memo#(frm#, 10, 50, 480, 310)
memo_wordwrap#(mem#, 1)
memo_fontsize#(mem#, 13)

let lblStatus# = label#(frm#, "Ready")
label_bounds#(lblStatus#, 10, 375, 480, 20)

let btnNew# = button#(frm#, "New", 10, 10, 70, 30)
let btnCopy# = button#(frm#, "Copy", 90, 10, 70, 30)
let btnPaste# = button#(frm#, "Paste", 170, 10, 70, 30)
let btnSelectAll# = button#(frm#, "Select All", 250, 10, 90, 30)

button_onclick#(btnNew#, "OnNew")
button_onclick#(btnCopy#, "OnCopy")
button_onclick#(btnPaste#, "OnPaste")
button_onclick#(btnSelectAll#, "OnSelectAll")
memo_onchangetracking#(mem#, "OnTextChange")

form_show(frm#)

while form_visible(frm#) = 1
    processmessages()
end while

Log Viewer (Read-Only)

╯ log_viewer.bas─◻✕
function OnAddLog(sender#) local ts$
    ts$ = formatdatetime$("yyyy-mm-dd hh:nn:ss", now())
    memo_addline#(mem#, "[" + ts$ + "] Log entry added")
    memo_scrolltoend#(mem#)
endfunction

function OnClear(sender#)
    memo_clear#(mem#)
endfunction

let frm# = form#("Log Viewer", 600, 400)
form_position#(frm#, 4)

let mem# = memo#(frm#, 10, 10, 580, 340)
memo_readonly#(mem#, 1)
memo_wordwrap#(mem#, 0)
memo_fontfamily#(mem#, "Courier New")
memo_fontsize#(mem#, 10)

let btnAdd# = button#(frm#, "Add Log Entry", 10, 360, 120, 30)
let btnClear# = button#(frm#, "Clear", 140, 360, 80, 30)
button_onclick#(btnAdd#, "OnAddLog")
button_onclick#(btnClear#, "OnClear")

form_show(frm#)

while form_visible(frm#) = 1
    processmessages()
end while

Code Editor with Line Tracking

╯ code_editor.bas─◻✕
function OnMemoClick(sender#) local line
    line = memo_caretpositionline(sender#)
    label_text#(lblLine#, "Line: " + str$(line + 1))
endfunction

let frm# = form#("Code Editor", 700, 500)
form_position#(frm#, 4)

let mem# = memo#(frm#, 10, 50, 680, 400)
memo_wordwrap#(mem#, 0)
memo_fontfamily#(mem#, "Consolas")
memo_fontsize#(mem#, 13)
memo_showscrollbars#(mem#, 1)

' Sample code
memo_addline#(mem#, "' Plan9Basic Sample")
memo_addline#(mem#, "let x = 10")
memo_addline#(mem#, "let y = 20")
memo_addline#(mem#, "")
memo_addline#(mem#, "function Add(a, b)")
memo_addline#(mem#, "    return a + b")
memo_addline#(mem#, "endfunction")
memo_addline#(mem#, "")
memo_addline#(mem#, "println Add(x, y)")

let lblLine# = label#(frm#, "Line: 1")
label_move#(lblLine#, 10, 460)
memo_onclick#(mem#, "OnMemoClick")

form_show(frm#)

while form_visible(frm#) = 1
    processmessages()
end while

Line Operations

╯ lines.bas─◻✕
function OnInsert(sender#)
    memo_insertline#(mem#, 1, "Inserted Line")
    label_text#(lblResult#, "Inserted new line at index 1")
endfunction

function OnDelete(sender#)
    if memo_linecount(mem#) > 0 then
        memo_deleteline#(mem#, 0)
        label_text#(lblResult#, "Deleted line at index 0")
    endif
endfunction

function OnGetLine(sender#) local txt$
    if memo_linecount(mem#) > 0 then
        txt$ = memo_line$(mem#, 0)
        label_text#(lblResult#, "Line 0: " + txt$)
    endif
endfunction

function OnSetLine(sender#)
    if memo_linecount(mem#) > 0 then
        memo_line#(mem#, 0, "Modified Line")
        label_text#(lblResult#, "Line 0 modified")
    endif
endfunction

let frm# = form#("Line Operations", 500, 400)
form_position#(frm#, 4)

let mem# = memo#(frm#, 10, 10, 350, 300)
memo_addline#(mem#, "Line 1")
memo_addline#(mem#, "Line 2")
memo_addline#(mem#, "Line 3")

let btnInsert# = button#(frm#, "Insert at 1", 370, 10, 120, 30)
let btnDelete# = button#(frm#, "Delete Line 0", 370, 50, 120, 30)
let btnGetLine# = button#(frm#, "Get Line 0", 370, 90, 120, 30)
let btnSetLine# = button#(frm#, "Set Line 0", 370, 130, 120, 30)

let lblResult# = label#(frm#, "")
label_bounds#(lblResult#, 10, 320, 480, 60)
label_wordwrap#(lblResult#, 1)

button_onclick#(btnInsert#, "OnInsert")
button_onclick#(btnDelete#, "OnDelete")
button_onclick#(btnGetLine#, "OnGetLine")
button_onclick#(btnSetLine#, "OnSetLine")

form_show(frm#)

while form_visible(frm#) = 1
    processmessages()
end while

Notes with Live Statistics

╯ notes.bas─◻✕
function UpdateStats(sender#) local lines, chars
    lines = memo_linecount(sender#)
    chars = memo_textlength(sender#)
    label_text#(lblLines#, "Lines: " + str$(lines))
    label_text#(lblChars#, "Characters: " + str$(chars))
endfunction

let frm# = form#("Notes", 500, 380)
form_position#(frm#, 4)

let mem# = memo#(frm#, 10, 10, 480, 300)
memo_wordwrap#(mem#, 1)

let lblLines# = label#(frm#, "Lines: 1")
label_move#(lblLines#, 10, 320)
let lblChars# = label#(frm#, "Characters: 0")
label_move#(lblChars#, 10, 345)

memo_onchangetracking#(mem#, "UpdateStats")

form_show(frm#)

while form_visible(frm#) = 1
    processmessages()
end while

Best Practices

Practice	Why
Enable `memo_wordwrap#` for prose, disable for code	Wrapping suits notes and text; code needs horizontal scrolling
Use `memo_readonly#` for log viewers	Prevents user editing while allowing programmatic updates
Use monospace fonts for code editors	`Consolas`, `Courier New` ensure consistent character width
Use `memo_onchangetracking#` sparingly	Fires on every keystroke — keep callbacks lightweight
Call `memo_scrolltoend#` after `memo_addline#`	Keeps the latest content visible in log-style memos
Use `memo_line$` / `memo_line#` for structured data	Access content by line number instead of parsing the full text
Use `memo_lines$` / `memo_lines#` for bulk operations	Get or set all text while preserving line structure

Quick Reference

Function	Signature	Description
`memo_error / errormsg$ / strerror$ / clearerror`	`various`	Error handling (4)
`memo#(parent#[, x, y, w, h][, text$])`	`various`	Create memo (3 overloads)
`memo_free(mem#)`	`memo_free@#`	Destroy memo
`memo_text$ / text# / textlength / clear#`	`various`	Text content (4)
`memo_linecount / line$ / line# / addline# / insertline# / deleteline# / lines$ / lines#`	`various`	Line operations (8)
`memo_wordwrap / showscrollbars`	`various`	Wrap & scrollbars (4)
`memo_readonly`	`various`	Read-only (2)
`memo_fontfamily / fontsize / fontcolor / bold / italic / underline / strikeout`	`various`	Font properties (14)
`memo_textalign`	`memo_textalign@# / #@#n`	Text alignment (2)
`memo_selstart / sellength / seltext$ / selectall# / clearselection#`	`various`	Selection (7)
`memo_caretpositionline / caretpositionpos / gotoend# / gotobegin#`	`various`	Caret control (6)
`memo_copy# / cut# / paste# / deleteselection#`	`various`	Clipboard (4)
`memo_scrolltop / scrolltoend#`	`various`	Scroll control (3)
`memo_x/y/width/height (get/set) / bounds# / move# / size#`	`various`	Position & size (14)
`memo_align / margin# / margins# / margin[left/top/right/bottom]`	`various`	Alignment & margins (12)
`memo_visible / enabled / opacity`	`various`	Visibility & state (6)
`memo_isfocused / setfocus# / resetfocus# / taborder`	`various`	Focus (5)
`memo_tag / parent# / bringtofront# / sendtoback#`	`various`	Tag & parent (6)
`memo_onchange/onchangetracking/onenter/onexit/onclick/ondblclick/onkeydown/onkeyup/onmousedown/onmouseup/onmousemove/onmouseenter/onmouseleave/onresize/ondragenter/ondragover/ondragdrop/ondragleave`	`various`	Events set+get (37)
`memo_clearcallbacks#`	`memo_clearcallbacks#@#`	Disconnect all events

139 functions. Part of the Plan9Basic GUI library system.