SlideTransitionEffectLib — Plan9Basic Documentation

Overview

SlideTransitionEffectLib slides the source image in a specified direction, wrapping the FireMonkey TSlideTransitionEffect component. This creates a classic sliding/pushing animation commonly used in presentations and UI transitions.

Property	Details
Library	`SlideTransitionEffectLib`
Prefix	`slidetrans_`
Wraps	`TSlideTransitionEffect`
Functions	16
Type	Transition effect

Category	Count	Description
Creation / Destruction	2	Create and free effect
Progress	2	Get/set transition progress
Slide Amount	4	Get/set X and Y slide distances
Effect Control	4	Enabled and trigger get/set
Error Handling	4	Error codes and messages

⚠ Pixel Coordinates: Unlike most effects, SlideAmount uses pixel values, not normalized 0–1 ranges. To slide an image completely off-screen, set the amount to the image's width or height.

Cross-Platform Support

Platform	Support
Windows	✅ Full support
Linux	✅ Full support
Android	✅ Full support

Creation & Destruction

slidetrans#(parent#)

Creates a new slide transition effect attached to the specified visual control.

Parameter	Type	Description
`parent#`	Pointer	Target visual control
Returns	Pointer	Effect handle, or 0 on failure

slidetrans_free(effect#)

Destroys the effect and releases associated resources.

Error Handling

Function	Signature	Description
`slidetrans_error()`	`slidetrans_error@`	Returns last error code (0 = none)
`slidetrans_errormsg$()`	`slidetrans_errormsg$@`	Returns last error message
`slidetrans_strerror$(code)`	`slidetrans_strerror$@n`	Converts error code to text
`slidetrans_clearerror()`	`slidetrans_clearerror@`	Clears the error state

Progress

Function	Signature	Description
`slidetrans_progress#(effect#, value)`	`slidetrans_progress#@#n`	Set progress (0.0–1.0)
`slidetrans_progress(effect#)`	`slidetrans_progress@#`	Get current progress

At progress 0, the image is at its original position. At progress 1, the image has slid the full amount specified by SlideAmountX/Y.

Slide Amount

Controls the slide direction and distance in pixels. Positive X slides right, negative slides left. Positive Y slides down, negative slides up.

Function	Signature	Description
`slidetrans_amountx#(effect#, value)`	`slidetrans_amountx#@#n`	Set horizontal slide (pixels)
`slidetrans_amountx(effect#)`	`slidetrans_amountx@#`	Get X amount
`slidetrans_amounty#(effect#, value)`	`slidetrans_amounty#@#n`	Set vertical slide (pixels)
`slidetrans_amounty(effect#)`	`slidetrans_amounty@#`	Get Y amount

Direction	AmountX	AmountY
Slide right	`+imgW`	`0`
Slide left	`-imgW`	`0`
Slide down	`0`	`+imgH`
Slide up	`0`	`-imgH`
Diagonal	`+imgW`	`+imgH`

💡 Tip: To slide the image completely off-screen, set the amount to the image's width (for horizontal) or height (for vertical). This effect works on the source image only — no target image is required.

Effect Control

Function	Signature	Description
`slidetrans_enabled#(effect#, value)`	`slidetrans_enabled#@#n`	Enable (1) or disable (0)
`slidetrans_enabled(effect#)`	`slidetrans_enabled@#`	Gets enabled state
`slidetrans_trigger#(effect#, trigger$)`	`slidetrans_trigger#@#$`	Sets trigger string
`slidetrans_trigger$(effect#)`	`slidetrans_trigger$@#`	Gets trigger string

Complete Examples

Example 1: Animated Slide Right

╯ animated-slide.bas─◻✕
let frm# = Pointer#(0)
let img# = Pointer#(0)
let trans# = Pointer#(0)
let tmr# = Pointer#(0)
let btn# = Pointer#(0)
let progress = 0
let imgW = 200

frm# = form#("Animated Slide", 400, 350)

img# = image#(frm#)
image_bounds#(img#, 100, 30, imgW, 150)
image_load#(img#, "https://picsum.photos/200/150")

' Slide right by image width
trans# = slidetrans#(img#)
slidetrans_amountx#(trans#, imgW)
slidetrans_amounty#(trans#, 0)

tmr# = timer#()
timer_interval#(tmr#, 30)
timer_enabled#(tmr#, 0)
timer_ontimer#(tmr#, "Animate")

btn# = button#(frm#, "Slide Right!")
button_bounds#(btn#, 140, 210, 120, 30)
button_onclick#(btn#, "StartSlide")

form_show(frm#)

function StartSlide(sender#)
  progress = 0
  slidetrans_progress#(trans#, 0)
  timer_enabled#(tmr#, 1)
  button_enabled#(btn#, 0)
endfunction

function Animate(sender#)
  progress = progress + 0.03
  slidetrans_progress#(trans#, progress)
  
  if progress >= 1 then
    timer_enabled#(tmr#, 0)
    button_enabled#(btn#, 1)
  endif
endfunction

Example 2: Direction Buttons

╯ slide-directions.bas─◻✕
let frm# = Pointer#(0)
let img# = Pointer#(0)
let trans# = Pointer#(0)
let imgW = 200
let imgH = 150

frm# = form#("Slide Directions", 450, 400)

img# = image#(frm#)
image_bounds#(img#, 125, 30, imgW, imgH)
image_load#(img#, "https://picsum.photos/200/150")

trans# = slidetrans#(img#)
slidetrans_amountx#(trans#, imgW)
slidetrans_progress#(trans#, 0.5)

let btnL# = button#(frm#, "Left")
button_bounds#(btnL#, 50, 210, 80, 30)
button_onclick#(btnL#, "SlideLeft")

let btnR# = button#(frm#, "Right")
button_bounds#(btnR#, 140, 210, 80, 30)
button_onclick#(btnR#, "SlideRight")

let btnU# = button#(frm#, "Up")
button_bounds#(btnU#, 230, 210, 80, 30)
button_onclick#(btnU#, "SlideUp")

let btnD# = button#(frm#, "Down")
button_bounds#(btnD#, 320, 210, 80, 30)
button_onclick#(btnD#, "SlideDown")

form_show(frm#)

function SlideLeft(sender#)
  slidetrans_amountx#(trans#, 0 - imgW)
  slidetrans_amounty#(trans#, 0)
endfunction

function SlideRight(sender#)
  slidetrans_amountx#(trans#, imgW)
  slidetrans_amounty#(trans#, 0)
endfunction

function SlideUp(sender#)
  slidetrans_amountx#(trans#, 0)
  slidetrans_amounty#(trans#, 0 - imgH)
endfunction

function SlideDown(sender#)
  slidetrans_amountx#(trans#, 0)
  slidetrans_amounty#(trans#, imgH)
endfunction

Best Practices

Practice	Why
Use image width/height as slide amount	Slides the image exactly off-screen
No target image needed	This effect slides the source only — simpler than dual-image transitions
Combine X and Y for diagonal slides	Set both AmountX and AmountY for diagonal movement
Use negative values for reverse direction	`0 - imgW` slides left instead of right

Quick Reference

Function	Signature	Description
CREATION & DESTRUCTION
`slidetrans#(parent#)`	`slidetrans#@#`	Create effect
`slidetrans_free(effect#)`	`slidetrans_free@#`	Destroy effect
PROGRESS
`slidetrans_progress#(effect#, value)`	`slidetrans_progress#@#n`	Set progress (0–1)
`slidetrans_progress(effect#)`	`slidetrans_progress@#`	Get progress
SLIDE AMOUNT
`slidetrans_amountx#(effect#, value)`	`slidetrans_amountx#@#n`	Set X slide (pixels)
`slidetrans_amountx(effect#)`	`slidetrans_amountx@#`	Get X amount
`slidetrans_amounty#(effect#, value)`	`slidetrans_amounty#@#n`	Set Y slide (pixels)
`slidetrans_amounty(effect#)`	`slidetrans_amounty@#`	Get Y amount
EFFECT CONTROL
`slidetrans_enabled#(effect#, value)`	`slidetrans_enabled#@#n`	Enable/disable
`slidetrans_enabled(effect#)`	`slidetrans_enabled@#`	Get enabled state
`slidetrans_trigger#(effect#, trigger$)`	`slidetrans_trigger#@#$`	Set trigger
`slidetrans_trigger$(effect#)`	`slidetrans_trigger$@#`	Get trigger
ERROR HANDLING
`slidetrans_error()`	`slidetrans_error@`	Last error code
`slidetrans_errormsg$()`	`slidetrans_errormsg$@`	Last error message
`slidetrans_strerror$(code)`	`slidetrans_strerror$@n`	Code to text
`slidetrans_clearerror()`	`slidetrans_clearerror@`	Clear error state

Library	Description
`SwipeTransitionEffectLib`	Page swipe transition
`BlindTransitionEffectLib`	Blind/stripe transition
`FadeTransitionEffectLib`	Cross-fade transition