The drawscreen draws on the screen. It can be sourced or used stand-alone.
(I tried to find the screen drawing in the wiki, by words screen drawing. Got a lot of pages, seemingly no one fit the query.)
When sourced, it's run this way:
source drawscreen.tcl ::drawscreen::run wins events ?fill? ?width?
where:
When stand-alone, it's run this way:
tclsh drawscreen.tcl ?events? ?fill? ?width?
where:
Alt+X keys are used to start drawing. Then the left mouse button is used to drag-and-drop the mouse pointer. To end with the drawing, the right / double click is used.
In Windows, there is a short lag between Alt+X and the bell signalizing the drawing is available.
#! /usr/bin/env tclsh ########################################################### # Name: drawscreen.tcl # Author: Alex Plotnikov ([email protected]) # Date: 02/11/2023 # Brief: Handles drawing on the screen. # License: MIT. ########################################################### package require Tk package require treectrl # ________________________ Data of drawscreen _________________________ # namespace eval ::drawscreen { namespace eval my { variable draw array set draw { width 6 fill #ff0000 distance 10 dobell yes started no X 0 Y 0 img {} } } } # ________________________ Private procedures _________________________ # proc ::drawscreen::my::Bind {w events} { # Binds drawing events on a window to Drawing proc. # w - the window's path # events - list of events to start drawing # The windows may be created and destroyed, # this procedure checks periodically if they are available. variable draw set scrp "::drawscreen::my::Drawing $w" if {[winfo exists $w]} { foreach ev $events { if {[string first $scrp [bind $w $ev]]==-1} { if {![string match <*> $ev]} {set ev <$ev>} bind $w $ev "$scrp ; break" } } } after 200 [list ::drawscreen::my::Bind $w $events] } #_______________________ proc ::drawscreen::my::Binds {wins events {fill ""} {width ""}} { # Sets the bindings to start drawing. # wins - the list of parent window pathes # events - events to start drawing # fill - color of draw brush # width - width of draw brush variable draw if {$fill ne {}} {set draw(fill) $fill} if {$width ne {}} {set draw(width) $width} if {$events eq {}} {set events {<Alt-x> <Alt-X>}} foreach w $wins { after 10 [list ::drawscreen::my::Bind $w $events] } } #_______________________ proc ::drawscreen::my::Drawing {rootwin} { # Initializes drawing: creates a canvas holding the screen's content. # rootwin - a parent window's path variable draw set win [string trimright $rootwin .].drawscreen if {[winfo exists $win]} return ;# esp. for Windows' lag catch {set draw(oldfocus) [focus]} focus $rootwin set draw(win) $win set draw(cnv) $win.canvas set w [winfo screenwidth .] set h [winfo screenheight .] toplevel $win wm geometry $win 1x1+0+0 wm attributes $win -alpha 0.0 -topmost 1 wm overrideredirect $win 1 wm withdraw $win set draw(img) [image create photo -width $w -height $h] canvas $draw(cnv) -width $w -height $h -relief flat -bd 0 -highlightthickness 0 $draw(cnv) create image 0 0 -image $draw(img) -anchor nw pack $draw(cnv) -expand 1 -fill both -ipady 0 -padx 0 -pady 0 -side top ::drawscreen::my::Loupe $w $h bind $draw(cnv) <ButtonPress-1> "::drawscreen::my::DrawStart %X %Y" bind $draw(cnv) <Motion> "::drawscreen::my::Draw %X %Y" bind $draw(cnv) <ButtonRelease-1> "::drawscreen::my::DrawFinish" bind $draw(cnv) <Double-Button-1> ::drawscreen::my::DrawEnd bind $draw(cnv) <ButtonPress-3> ::drawscreen::my::DrawEnd # with "after" we avoid Tk shimmering after 10 [list after idle [list after 10 [list after idle [list after 10 " \ wm deiconify $win; \ wm attributes $win -alpha 1.0; \ wm geometry $win ${w}x${h}+0+0"]]]] Bell } #_______________________ proc ::drawscreen::my::DrawStart {X Y} { # Starts a current drawing. # X - x-coordinate of mouse pointer # Y - y-coordinate of mouse pointer variable draw set draw(X) $X set draw(Y) $Y set draw(started) yes } #_______________________ proc ::drawscreen::my::Draw {X Y} { # Does a current drawing. # X - x-coordinate of mouse pointer # Y - y-coordinate of mouse pointer variable draw if {$draw(started)} { if {abs($X-$draw(X))>$draw(distance) || abs($Y-$draw(Y))>$draw(distance)} { $draw(cnv) create line $X $Y $draw(X) $draw(Y) -fill $draw(fill) -width $draw(width) set draw(X) $X set draw(Y) $Y } } } #_______________________ proc ::drawscreen::my::DrawFinish {} { # Finishes a current drawing. variable draw set draw(started) no } #_______________________ proc ::drawscreen::my::DrawEnd {} { # Destroys drawing stuff. variable draw set draw(started) no image delete $draw(img) destroy $draw(win) catch {focus $draw(oldfocus)} Bell } #_______________________ proc ::drawscreen::my::Loupe {w h} { # Captures a screen image and pushes it into the canvas. # w - width of image # h - height of image variable draw set loupe_ctr_x [expr {$w / 2}] set loupe_ctr_y [expr {$h / 2}] loupe $draw(img) $loupe_ctr_x $loupe_ctr_y $w $h 1 } #_______________________ proc ::drawscreen::my::Bell {} { # Sounds. variable draw if {$draw(dobell)} bell } # ________________________ Interface procedures _________________________ # proc ::drawscreen::run {args} { # Runs my::Binds and catches errors. Logs errors to a log file. # args - arguments of my::Binds if {[catch {my::Binds {*}$args} err]} { Bell catch { set ch [open ~/TMP/drawscreen.log a] puts $ch $err close $ch } } } # _________________________________ main _________________________________ # if {[info exist ::argv0] && [file normalize $::argv0] eq [file normalize [info script]]} { lassign $::argv hotk fill width if {$hotk eq {}} {set hotk {Alt-x Alt-X}} set hk [string map [list < {} > {} { } {, }] $hotk] label .labinfo -text \ "Press $hk, then\ndrag-n-drop... or\nright/double click." pack .labinfo -padx 50 -pady 50 bind . <Escape> exit ::drawscreen::run . $hotk $fill $width } # _________________________________ EOF _________________________________ #