# cscroll.tcl -- # # This demonstration script creates a simple canvas that can be # scrolled in two dimensions. if {![info exists widgetDemo]} { error "This script should be run from the \"widget\" demo." } package require Tk set w .cscroll catch {destroy $w} toplevel $w wm title $w "Scrollable Canvas Demonstration" wm iconname $w "cscroll" positionWindow $w set c $w.c label $w.msg -font $font -wraplength 4i -justify left -text "This window displays a canvas widget that can be scrolled either using the scrollbars or by dragging with button 2 in the canvas. If you click button 1 on one of the rectangles, its indices will be printed on stdout." pack $w.msg -side top ## See Code / Dismiss buttons set btns [addSeeDismiss $w.buttons $w] pack $btns -side bottom -fill x frame $w.grid scrollbar $w.hscroll -orient horiz -command "$c xview" scrollbar $w.vscroll -command "$c yview" canvas $c -relief sunken -borderwidth 2 -scrollregion {-11c -11c 50c 20c} \ -xscrollcommand "$w.hscroll set" \ -yscrollcommand "$w.vscroll set" pack $w.grid -expand yes -fill both -padx 1 -pady 1 grid rowconfig $w.grid 0 -weight 1 -minsize 0 grid columnconfig $w.grid 0 -weight 1 -minsize 0 grid $c -padx 1 -in $w.grid -pady 1 \ -row 0 -column 0 -rowspan 1 -columnspan 1 -sticky news grid $w.vscroll -in $w.grid -padx 1 -pady 1 \ -row 0 -column 1 -rowspan 1 -columnspan 1 -sticky news grid $w.hscroll -in $w.grid -padx 1 -pady 1 \ -row 1 -column 0 -rowspan 1 -columnspan 1 -sticky news set bg [lindex [$c config -bg] 4] for {set i 0} {$i < 20} {incr i} { set x [expr {-10 + 3*$i}] for {set j 0; set y -10} {$j < 10} {incr j; incr y 3} { $c create rect ${x}c ${y}c [expr {$x+2}]c [expr {$y+2}]c \ -fill $bg -tags rect $c create text [expr {$x+1}]c [expr {$y+1}]c -text "$i,$j" \ -anchor center -tags text } } $c bind all "scrollEnter $c" $c bind all "scrollLeave $c" $c bind all "scrollButton $c" if {([tk windowingsystem] eq "aqua") && ![package vsatisfies [package provide Tk] 8.7-]} { bind $c "$c scan mark %x %y" bind $c "$c scan dragto %x %y" bind $c { %W yview scroll [expr {-%D}] units } bind $c { %W yview scroll [expr {-10*%D}] units } bind $c { %W xview scroll [expr {-%D}] units } bind $c { %W xview scroll [expr {-10*%D}] units } } else { bind $c "$c scan mark %x %y" bind $c "$c scan dragto %x %y" # We must make sure that positive and negative movements are rounded # equally to integers, avoiding the problem that # (int)1/-30 = -1, # but # (int)-1/-30 = 0 # The following code ensure equal +/- behaviour. bind $c { if {%D >= 0} { %W yview scroll [expr {%D/-30}] units } else { %W yview scroll [expr {(%D-29)/-30}] units } } bind $c { if {%D >= 0} { %W yview scroll [expr {%D/-3}] units } else { %W yview scroll [expr {(%D-2)/-3}] units } } bind $c { if {%D >= 0} { %W xview scroll [expr {%D/-30}] units } else { %W xview scroll [expr {(%D-29)/-30}] units } } bind $c { if {%D >= 0} { %W xview scroll [expr {%D/-3}] units } else { %W xview scroll [expr {(%D-2)/-3}] units } } } if {[tk windowingsystem] eq "x11" && ![package vsatisfies [package provide Tk] 8.7-]} { # Support for mousewheels on Linux/Unix commonly comes through mapping # the wheel to the extended buttons. If you have a mousewheel, find # Linux configuration info at: # http://linuxreviews.org/howtos/xfree/mouse/ bind $c { if {!$tk_strictMotif} { %W yview scroll -5 units } } bind $c { if {!$tk_strictMotif} { %W xview scroll -5 units } } bind $c { if {!$tk_strictMotif} { %W yview scroll 5 units } } bind $c { if {!$tk_strictMotif} { %W xview scroll 5 units } } } proc scrollEnter canvas { global oldFill set id [$canvas find withtag current] if {[lsearch [$canvas gettags current] text] >= 0} { set id [expr {$id-1}] } set oldFill [lindex [$canvas itemconfig $id -fill] 4] if {[winfo depth $canvas] > 1} { if {[tk windowingsystem] eq "aqua"} { $canvas itemconfigure $id -fill systemSelectedTextBackgroundColor } else { $canvas itemconfigure $id -fill LightSeaGreen } } } proc scrollLeave canvas { global oldFill set id [$canvas find withtag current] if {[lsearch [$canvas gettags current] text] >= 0} { set id [expr {$id-1}] } $canvas itemconfigure $id -fill $oldFill } proc scrollButton canvas { set id [$canvas find withtag current] if {[lsearch [$canvas gettags current] text] < 0} { set id [expr {$id+1}] } puts stdout "You buttoned at [lindex [$canvas itemconf $id -text] 4]" }