[Richard Suchenwirth] 2007-01-23 - Waiting for a lengthy zipping, I hacked up this plaything that simulates credits of a movie, rolling over the [canvas] screen.
[WikiDbImage credits.jpg]
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[Jeff Smith] 2020-11-06 : Below is an online demo using [CloudTk]. This demo runs Rolling credits in an Alpine Linux Docker Container. It is a 27.4MB image which is made up of Alpine Linux + tclkit + Rolling-credits.kit + libx11 + libxft + fontconfig + ttf-linux-libertine. It is run under a user account in the Container. The Container is restrictive with permissions for "Other" removed for "execute" and "read" for certain directories.
<<inlinehtml>>
<iframe height="275" width="380" src="https://cloudtk-app.tcl-lang.org/cloudtk/VNC?session=new&Tk=Rolling-credits" allowfullscreen></iframe>
<<inlinehtml>>
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======
package require Tk
proc titleshow {w title} {
set -fill black
set -font {Helvetica 16}
set x [expr {[winfo width $w]/2}]
set y [winfo height $w]
foreach line [split $title \n] {
set line [string trim $line]
if [string match -* $line] {
eval [linsert $line 0 set]
} else {
$w create text $x $y -text $line -fill ${-fill} -font ${-font} \
-justify center -tag title
incr y 48
}
}
every 40 "if !\[titleshow'roll $w title -2\] return"
}
proc titleshow'roll {w tag dy} {
$w move $tag 0 $dy ;# (1)
foreach i [$w find withtag $tag] {
set y1 [lindex [$w bbox $i] end]
if {$y1<0} {$w delete $i}
}
llength [$w find withtag $tag]
}
proc every {ms body} {eval $body; after $ms [info level 0]}
# That's all the code, here's a testing demo. Lines starting with - set parameters, the others are displayed:
pack [canvas .c -bg black]
tkwait visibility .c
titleshow .c {
-fill white
-font {Helvetica 18 italic}
Richard Suchenwirth presents
-font {Helvetica 24 bold}
-fill yellow
THE IMPORTANCE
OF BEING UNEARNEST
-font {Helvetica 18}
-fill white
with
-font {Helvetica 24}
-fill yellow
MARILYN MONROE
GARY COOPER
PETER SELLERS
-font {Helvetica 18}
Camera Alphonse de Lumiere
Gaffer Joe Smith
-font {Helvetica 10}
(c) United Hackers, Inc. MMVII
}
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[JM] Richard, this is very nice!
do we have something in the wiki to scroll text in the same line?
like the news at the bottom of the TV screen? - [RS]: You mean, what is sometimes called a [Ticker]?
You could either modify the code above (the line marked (1) in ''titleshow'roll'' has 0 for horizontal movement,
put your desired value there); or, you can do it with a plain [label] like this. First, a proc that "cycles" a string variable, so that "abcd" becomes "bcda":
proc string'cycle _str {
upvar 1 $_str str
set str [string range $str 1 end][string index $str 0]
}
# Example for test and demo:
pack [label .l -textvar ticker -anchor w -width 50]
set ticker "For all those who like to read news while watching a movie, \
here is a little ticker that displays at the bottom +++ "
every 100 {string'cycle ::ticker}
[HE] and here is [every]
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[JM] thanks Richard, thanks [HE], but in fact, "every" proc is in this very same page.
btw, homework (based on [RS] hints) is done, and text runs smoother than the label solution.
I will publish tomorrow, giving the credit to Richard, of course (-: - [RS]: For smoother scrolling in the label, use a fixed-pitch font.
[HE] Found it. I tried only the second example. As I missed "every" I looked for the side where it reside. I know [RS] saves everything about tcl anywhere on the wiki :-)
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[nscerqueira]
in order to repeat the text scrolling just change the lines
in the titleshow proc
every 40 "if !\[titleshow'roll $w title -2\] return"
to
every 40 [list titleshow'roll $w $y title -2]n"
and in the the titleshow'roll proc
if {$y1<0} {$w delete $i}
to
if {$y1<0} {$w move $i 0 $y}
[schelte] gave most of the help to make this possible.
And don't forget to add the argument to the titleshow'roll proc , i.e.,
proc titleshow'roll {w y tag dy} {
<<categories>>Animation