View file File name : ruler.tcl Content :# ruler.tcl -- # # This demonstration script creates a canvas widget that displays a ruler # with tab stops that can be set, moved, and deleted. if {![info exists widgetDemo]} { error "This script should be run from the \"widget\" demo." } package require Tk # rulerMkTab -- # This procedure creates a new triangular polygon in a canvas to # represent a tab stop. # # Arguments: # c - The canvas window. # x, y - Coordinates at which to create the tab stop. proc rulerMkTab {c x y} { upvar #0 demo_rulerInfo v $c create polygon $x $y [expr {$x+$v(size)}] [expr {$y+$v(size)}] \ [expr {$x-$v(size)}] [expr {$y+$v(size)}] } set w .ruler catch {destroy $w} toplevel $w wm title $w "Ruler Demonstration" wm iconname $w "ruler" positionWindow $w set c $w.c label $w.msg -font $font -wraplength 5i -justify left -text "This canvas widget shows a mock-up of a ruler. You can create tab stops by dragging them out of the well to the right of the ruler. You can also drag existing tab stops. If you drag a tab stop far enough up or down so that it turns dim, it will be deleted when you release the mouse button." pack $w.msg -side top ## See Code / Dismiss buttons set btns [addSeeDismiss $w.buttons $w] pack $btns -side bottom -fill x canvas $c -width 14.8c -height 2.5c pack $w.c -side top -fill x set demo_rulerInfo(grid) .25c set demo_rulerInfo(left) [winfo fpixels $c 1c] set demo_rulerInfo(right) [winfo fpixels $c 13c] set demo_rulerInfo(top) [winfo fpixels $c 1c] set demo_rulerInfo(bottom) [winfo fpixels $c 1.5c] set demo_rulerInfo(size) [winfo fpixels $c .2c] set demo_rulerInfo(normalStyle) "-fill black" # Main widget program sets variable tk_demoDirectory if {[winfo depth $c] > 1} { set demo_rulerInfo(activeStyle) "-fill red -stipple {}" set demo_rulerInfo(deleteStyle) [list -fill red \ -stipple @[file join $tk_demoDirectory images gray25.xbm]] } else { set demo_rulerInfo(activeStyle) "-fill black -stipple {}" set demo_rulerInfo(deleteStyle) [list -fill black \ -stipple @[file join $tk_demoDirectory images gray25.xbm]] } $c create line 1c 0.5c 1c 1c 13c 1c 13c 0.5c -width 1 for {set i 0} {$i < 12} {incr i} { set x [expr {$i+1}] $c create line ${x}c 1c ${x}c 0.6c -width 1 $c create line $x.25c 1c $x.25c 0.8c -width 1 $c create line $x.5c 1c $x.5c 0.7c -width 1 $c create line $x.75c 1c $x.75c 0.8c -width 1 $c create text $x.15c .75c -text $i -anchor sw } $c addtag well withtag [$c create rect 13.2c 1c 13.8c 0.5c \ -outline black -fill [lindex [$c config -bg] 4]] $c addtag well withtag [rulerMkTab $c [winfo pixels $c 13.5c] \ [winfo pixels $c .65c]] $c bind well <1> "rulerNewTab $c %x %y" $c bind tab <1> "rulerSelectTab $c %x %y" bind $c <B1-Motion> "rulerMoveTab $c %x %y" bind $c <Any-ButtonRelease-1> "rulerReleaseTab $c" # rulerNewTab -- # Does all the work of creating a tab stop, including creating the # triangle object and adding tags to it to give it tab behavior. # # Arguments: # c - The canvas window. # x, y - The coordinates of the tab stop. proc rulerNewTab {c x y} { upvar #0 demo_rulerInfo v $c addtag active withtag [rulerMkTab $c $x $y] $c addtag tab withtag active set v(x) $x set v(y) $y rulerMoveTab $c $x $y } # rulerSelectTab -- # This procedure is invoked when mouse button 1 is pressed over # a tab. It remembers information about the tab so that it can # be dragged interactively. # # Arguments: # c - The canvas widget. # x, y - The coordinates of the mouse (identifies the point by # which the tab was picked up for dragging). proc rulerSelectTab {c x y} { upvar #0 demo_rulerInfo v set v(x) [$c canvasx $x $v(grid)] set v(y) [expr {$v(top)+2}] $c addtag active withtag current eval "$c itemconf active $v(activeStyle)" $c raise active } # rulerMoveTab -- # This procedure is invoked during mouse motion events to drag a tab. # It adjusts the position of the tab, and changes its appearance if # it is about to be dragged out of the ruler. # # Arguments: # c - The canvas widget. # x, y - The coordinates of the mouse. proc rulerMoveTab {c x y} { upvar #0 demo_rulerInfo v if {[$c find withtag active] == ""} { return } set cx [$c canvasx $x $v(grid)] set cy [$c canvasy $y] if {$cx < $v(left)} { set cx $v(left) } if {$cx > $v(right)} { set cx $v(right) } if {($cy >= $v(top)) && ($cy <= $v(bottom))} { set cy [expr {$v(top)+2}] eval "$c itemconf active $v(activeStyle)" } else { set cy [expr {$cy-$v(size)-2}] eval "$c itemconf active $v(deleteStyle)" } $c move active [expr {$cx-$v(x)}] [expr {$cy-$v(y)}] set v(x) $cx set v(y) $cy } # rulerReleaseTab -- # This procedure is invoked during button release events that end # a tab drag operation. It deselects the tab and deletes the tab if # it was dragged out of the ruler. # # Arguments: # c - The canvas widget. # x, y - The coordinates of the mouse. proc rulerReleaseTab c { upvar #0 demo_rulerInfo v if {[$c find withtag active] == {}} { return } if {$v(y) != $v(top)+2} { $c delete active } else { eval "$c itemconf active $v(normalStyle)" $c dtag active } }