InnerGlowEffectLib — Plan9Basic Documentation

InnerGlowEffectLib — Inner Glow Effect

Creates a glow inside control boundaries. Unlike GlowEffectLib which radiates outwards, inner glow shines inward from the edges, creating an embossed or inset look. Wraps FireMonkey’s TInnerGlowEffect. 16 functions.

Category	Count	Description
Error Handling	4	innerglow_error, errormsg$, strerror$, clearerror
Creation & Destruction	2	innerglow# (create), innerglow_free (destroy)
Properties	6	softness (2), color (2), opacity (2)
Effect Control	4	enabled, trigger (get/set)

ⓘ Color functions: InnerGlow has 2 colour functions: innerglow_color# sets by string name/hex, innerglow_color$ gets as string. Unlike GlowEffectLib, there is no numeric colour getter.

Inner vs Outer Glow

Feature	InnerGlowEffectLib	GlowEffectLib (Outer)
Direction	Inward — glows inside edges	Outward — radiates beyond edges
Visual	Inner border glow / embossed frame	Luminous halo / aura
Best for	Panels, cards, inset effects, frames	Neon buttons, selection, hover
Default colour	Gold	Yellow
Functions	16	17
Colour functions	2 (set string, get string)	3 (set string, get string, get number)

Default Values

Property	Range	Default	Description
Color	Named / hex	Gold	Glow colour
Softness	0.0–9.0	4.0	Glow spread into interior
Opacity	0.0–1.0	0.9	Glow intensity

Cross-Platform Support

Platform	Status
Windows	✅ Full Support
Linux	✅ Full Support
Android	✅ Full Support

Error Handling

Function	Signature	Description
`innerglow_error()`	`innerglow_error@`	Returns last error code (0 = no error)
`innerglow_errormsg$()`	`innerglow_errormsg$@`	Returns last error message
`innerglow_strerror$(code)`	`innerglow_strerror$@n`	Converts error code to text
`innerglow_clearerror()`	`innerglow_clearerror@`	Clears error state

Error Codes

Code	Constant	Meaning
0	ERR_NONE	No error
1	ERR_NIL_EFFECT	Effect pointer is nil
2	ERR_INVALID_EFFECT	Not a valid TInnerGlowEffect
3	ERR_INVALID_VALUE	Property value out of range
4	ERR_NIL_PARENT	Parent control is nil
5	ERR_INVALID_PARENT	Not a valid TFmxObject
6	ERR_INVALID_COLOR	Unrecognised colour name/hex

Creation & Destruction

Function	Signature	Description
`innerglow#(parent#)`	`innerglow#@#`	Creates inner glow on parent. Returns effect pointer. Defaults: softness 4.0, colour Gold, opacity 0.9
`innerglow_free(effect#)`	`innerglow_free@#`	Destroys effect, removes from parent

Softness

Controls how far the inner glow spreads from the edges towards the centre. Range 0.0–9.0.

Function	Signature	Description
`innerglow_softness#(effect#, value)`	`innerglow_softness#@#n`	Sets softness (0.0–9.0)
`innerglow_softness(effect#)`	`innerglow_softness@#`	Gets current softness

Range	Effect	Use Case
0.0–2.0	Thin inner border glow	Subtle frame, selection outline
2.0–5.0	Normal inner glow spread	Embossed panels, card frames
5.0–9.0	Deep glow reaching centre	Dramatic inset, vignette-like

Color

Accepts named colours or hex strings. Two functions: set (by string) and get (as string).

Function	Signature	Description
`innerglow_color#(effect#, color$)`	`innerglow_color#@#$`	Sets colour (name or hex)
`innerglow_color$(effect#)`	`innerglow_color$@#`	Gets colour as string

Supported named colours: Black, White, Red, Green, Blue, Yellow, Cyan, Magenta, Gray, Grey, Silver, Maroon, Olive, Navy, Purple, Teal, Orange, Pink, Brown, Lime, Aqua, Fuchsia, Transparent, Null

Hex format: #RRGGBB or #AARRGGBB

Opacity

Function	Signature	Description
`innerglow_opacity#(effect#, value)`	`innerglow_opacity#@#n`	Sets opacity (0.0–1.0)
`innerglow_opacity(effect#)`	`innerglow_opacity@#`	Gets current opacity

Effect Control

Function	Signature	Description
`innerglow_enabled#(effect#, value)`	`innerglow_enabled#@#n`	Enables (1) or disables (0)
`innerglow_enabled(effect#)`	`innerglow_enabled@#`	Gets enabled state
`innerglow_trigger#(effect#, trigger$)`	`innerglow_trigger#@#$`	Sets trigger string
`innerglow_trigger$(effect#)`	`innerglow_trigger$@#`	Gets trigger string

Complete Examples

Basic Inner Glow

╯ innerglow-basic.bas─◻✕
let frm# = Pointer#(0)
let rect# = Pointer#(0)
let ig# = Pointer#(0)

frm# = form#("Inner Glow Demo", 400, 300)

rect# = rectangle#(frm#)
rectangle_bounds#(rect#, 100, 80, 200, 120)
rectangle_fill#(rect#, "White")

ig# = innerglow#(rect#)
innerglow_color#(ig#, "Gold")
innerglow_softness#(ig#, 4)
innerglow_opacity#(ig#, 0.8)

form_show(frm#)

Toggle Inner Glow

╯ innerglow-toggle.bas─◻✕
let frm# = Pointer#(0)
let rect# = Pointer#(0)
let ig# = Pointer#(0)

frm# = form#("Toggle Inner Glow", 400, 300)

rect# = rectangle#(frm#)
rectangle_bounds#(rect#, 100, 50, 200, 120)
rectangle_fill#(rect#, "SteelBlue")

ig# = innerglow#(rect#)
innerglow_color#(ig#, "Cyan")
innerglow_softness#(ig#, 5)

let btn# = button#(frm#, "Toggle Glow")
button_bounds#(btn#, 130, 200, 120, 35)
button_onclick#(btn#, "OnToggle")

form_show(frm#)

function OnToggle(sender#)
  if innerglow_enabled(ig#) = 1 then
    innerglow_enabled#(ig#, 0)
  else
    innerglow_enabled#(ig#, 1)
  endif
endfunction

Colour Selector

╯ innerglow-colors.bas─◻✕
let frm# = Pointer#(0)
let rect# = Pointer#(0)
let ig# = Pointer#(0)

frm# = form#("Glow Colors", 450, 280)

rect# = rectangle#(frm#)
rectangle_bounds#(rect#, 125, 40, 200, 100)
rectangle_fill#(rect#, "White")

ig# = innerglow#(rect#)
innerglow_color#(ig#, "Gold")
innerglow_softness#(ig#, 4)

let btn1# = button#(frm#, "Gold")
button_bounds#(btn1#, 50, 180, 80, 30)
button_onclick#(btn1#, "SetGold")

let btn2# = button#(frm#, "Cyan")
button_bounds#(btn2#, 140, 180, 80, 30)
button_onclick#(btn2#, "SetCyan")

let btn3# = button#(frm#, "Red")
button_bounds#(btn3#, 230, 180, 80, 30)
button_onclick#(btn3#, "SetRed")

let btn4# = button#(frm#, "Lime")
button_bounds#(btn4#, 320, 180, 80, 30)
button_onclick#(btn4#, "SetLime")

form_show(frm#)

function SetGold(sender#)
  innerglow_color#(ig#, "Gold")
endfunction
function SetCyan(sender#)
  innerglow_color#(ig#, "Cyan")
endfunction
function SetRed(sender#)
  innerglow_color#(ig#, "Red")
endfunction
function SetLime(sender#)
  innerglow_color#(ig#, "Lime")
endfunction

Best Practices

Practice	Why
Use on light backgrounds	Inner glow is most visible on white/light surfaces
Softness 3–5 for panel frames	Natural-looking embossed border effect
Softness 6+ for vignette	Deep glow reaching the centre creates a vignette look
Combine outer + inner glow	Both effects can be applied to the same control
Animate with FloatAnimationLib	Animate Softness or Opacity for pulsing inner glow
Gold on white for elegance	Classic premium/luxury panel look

Quick Reference

Function	Signature	Description
ERROR HANDLING
`innerglow_error()`	`innerglow_error@`	Last error code
`innerglow_errormsg$()`	`innerglow_errormsg$@`	Last error message
`innerglow_strerror$(code)`	`innerglow_strerror$@n`	Error code to text
`innerglow_clearerror()`	`innerglow_clearerror@`	Clear error state
CREATION & DESTRUCTION
`innerglow#(parent#)`	`innerglow#@#`	Create inner glow on control
`innerglow_free(effect#)`	`innerglow_free@#`	Destroy effect
SOFTNESS
`innerglow_softness#(e#, val)`	`innerglow_softness#@#n`	Set spread (0–9)
`innerglow_softness(e#)`	`innerglow_softness@#`	Get spread
COLOR
`innerglow_color#(e#, color$)`	`innerglow_color#@#$`	Set colour (name/hex)
`innerglow_color$(e#)`	`innerglow_color$@#`	Get colour as string
OPACITY
`innerglow_opacity#(e#, val)`	`innerglow_opacity#@#n`	Set opacity (0–1)
`innerglow_opacity(e#)`	`innerglow_opacity@#`	Get opacity
EFFECT CONTROL
`innerglow_enabled#(e#, val)`	`innerglow_enabled#@#n`	Enable (1) / disable (0)
`innerglow_enabled(e#)`	`innerglow_enabled@#`	Get enabled state
`innerglow_trigger#(e#, str$)`	`innerglow_trigger#@#$`	Set trigger string
`innerglow_trigger$(e#)`	`innerglow_trigger$@#`	Get trigger string

16 functions. Part of the Plan9Basic visual effects library system.