Tk Source Code

This is sent to a text widget when the selection in the widget is
changed.
.TP
\fB<<ThemeChanged>>\fR
This is sent to all widgets when the ttk theme changed. The ttk
widgets listen to this event and redisplay themselves when it fires.
The legacy widgets ignore this event.
.TP
\fB<<TkWorldChanged>>\fR
.
This event is sent to all widgets when a font is changed, for example,
by the use of [font configure].  The user_data field (%d) will have the
value "FontChanged".  For other system wide changes, this event will
be sent to all widgets, and the user_data field will indicate the
cause of the change.  NOTE: all tk and ttk widgets already handle this
event internally.
.TP
\fB<<TraverseIn>>\fR
This is sent to a widget when the focus enters the widget because of a
user-driven
.QW "tab to widget"
action.
.TP

static void
RecomputeWidgets(
    TkWindow *winPtr)		/* Window to which command is sent. */
{
    Tk_ClassWorldChangedProc *proc =
	    Tk_GetClassProc(winPtr->classProcsPtr, worldChangedProc);
    TkWindow *tkwinPtr;
    
    if (proc != NULL) {
	proc(winPtr->instanceData);
    }

    /*
     * Notify all the descendants of this window that the world has changed.
     *
     * This could be done recursively or iteratively. The recursive version is
     * easier to implement and understand, and typically, windows with a -font
     * option will be leaf nodes in the widget heirarchy (buttons, labels,
     * etc.), so the recursion depth will be shallow.
     *
     * However, the additional overhead of the recursive calls may become a
     * performance problem if typical usage alters such that -font'ed widgets
     * appear high in the hierarchy, causing deep recursion. This could happen
     * with text widgets, or more likely with the labelframe
     * widget. With these widgets it is possible, even likely, that a
     * -font'ed widget (text or labelframe) will not be a leaf node, but
     * will instead have many descendants. If this is ever found to cause a
     * performance problem, it may be worth investigating an iterative version
     * of the code below.
     */

    for (tkwinPtr=winPtr->childList ; tkwinPtr!=NULL ; tkwinPtr=tkwinPtr->nextPtr) {
	RecomputeWidgets(tkwinPtr);
    }
    
    /* 
     * Broadcast font change virtually for mega-widget layout managers.
     * Do this after the font change has been propagated to core widgets. 
    */
    TkSendVirtualEvent((Tk_Window)winPtr, "TkWorldChanged",
		       Tcl_NewStringObj("FontChanged",-1));
}

/*
 *---------------------------------------------------------------------------
 *
 * TkCreateNamedFont --
 *

    event.general.xany.type = VirtualEvent;
    event.general.xany.serial = NextRequest(Tk_Display(target));
    event.general.xany.send_event = False;
    event.general.xany.window = Tk_WindowId(target);
    event.general.xany.display = Tk_Display(target);
    event.virt.name = Tk_GetUid(eventName);
    event.virt.user_data = detail;
    if (detail) Tcl_IncrRefCount(detail); // Event code will DecrRefCount

    Tk_QueueWindowEvent(&event.general, TCL_QUEUE_TAIL);
}

/* Tcl 8.6 has a different definition of Tcl_UniChar than other Tcl versions for TCL_UTF_MAX > 3 */
#if TCL_UTF_MAX <= (3 + (TCL_MAJOR_VERSION == 8 && TCL_MINOR_VERSION == 6))
/*

    load {} Tk one
    load {} Tk two
    one eval menu .menubar
    two eval menu .menubar
    interp delete one
    interp delete two
} -result {}

test font-47.2 {Bug 3049518 - Canvas} -body {
    if {"MyFont" ni [font names]} {
	font create MyFont -family "Liberation Sans" -size 13
    }
    set text Hello!
    destroy .t.c
    set c [canvas .t.c]
    set textid [$c create text 20 20 -font MyFont -text $text -anchor nw]
    set twidth [font measure MyFont $text]
    set theight [font metrics MyFont -linespace]
    set circid [$c create polygon \
		    15                    15 \
		    [expr {15 + $twidth}] 15 \
		    [expr {15 + $twidth}] [expr {15 + $theight}] \
		    15                    [expr {15 + $theight}] \
		    -width 1 -joinstyle round -smooth true -fill {} -outline blue]
    pack $c -fill both -expand 1 -side top
    tkwait visibility $c
    
    # Lamda test functions
    set circle_text {{w user_data text circ} {
	if {[winfo class $w] ne "Canvas"} {
	    puts "Wrong widget type: $w"
	    return
	}
	if {$user_data ne "FontChanged"} {
	    return
	}
	lappend ::results called-$w
	lassign [$w bbox $text] x0 y0 x1 y1
	set offset 5
	set coord [lmap expr {
			      $x0-5 $y0-5   $x1+5 $y0-5
			      $x1+5 $y1+5   $x0-5 $y1+5
			  } {expr $expr}]
	if {[catch {$w coord $circ $coord} err]} {
	    puts Error:$err
	}
    }}
    set waitfor {{tag {time 333}} {after $time incr ::wait4; vwait ::wait4}}
    set enclosed {{can id} {$can find enclosed {*}[$can bbox $id]}}

    set results {}
    apply $circle_text $c FontChanged $textid $circid
    bind $c <<TkWorldChanged>> [list apply $circle_text %W %d $textid $circid]
    apply $waitfor 1

    # Begin test:
    set results {}
    lappend results [apply $enclosed $c $circid]
    font configure MyFont -size 26
    apply $waitfor 2
    lappend results [apply $enclosed $c $circid]
    font configure MyFont -size 9
    apply $waitfor 3
    lappend results [apply $enclosed $c $circid]
    apply $waitfor 4
    font configure MyFont -size 12
    apply $waitfor 5
    lappend results [apply $enclosed $c $circid]
} -cleanup {
    destroy $c
    unset -nocomplain ::results
} -result {{1 2} called-.t.c {1 2} called-.t.c {1 2} called-.t.c {1 2}}

test font-47.3 {Bug 3049518 - Label} -body {
    if {"MyFont" ni [font names]} {
	font create MyFont -family "Liberation Sans" -size 13
    }
    set text "Label Test"
    destroy .t.l

    set make-img {{size} {
	set img [image create photo -width $size -height $size]
	$img blank
	set max [expr {$size - 1}]
	for {set x 0} {$x < $size} {incr x} {
	    $img put red -to $x $x
	    $img put black -to 0 $x
	    $img put black -to $x 0
	    $img put black -to $max $x
	    $img put black -to $x $max
	}
	return $img
    }}
    
    set testWorldChanged {{w user_data} {
	global make-img
	if {$user_data ne "FontChanged"} {
	    return
	}
	if {![winfo exists $w] || [winfo class $w] ne "Label"} {
	    return
	}
	if {[$w cget -image] ne ""} {
	    image delete [$w cget -image]
	}
	set size [font metrics [$w cget -font] -linespace]
	set img [apply ${make-img} $size]
	$w configure -image $img
    }}

    set waitfor {{tag {time 500}} {
	after $time incr ::wait4
	vwait ::wait4
    }}

    set check {{w} {
	global results
	set f [$w cget -font]
	set i [$w cget -image]
	set fs [font metrics $f -linespace]
	set ish [image height $i]
	set isw [image width $i]
	lappend results [list [expr {$fs == $ish ? 1 : [list $fs $ish]}] [expr {$fs == $isw ? 1 : [list $fs $isw]}]]
    }}

    set size [font metrics MyFont -linespace]
    set img [apply ${make-img} $size]
    set l [label .t.l -compound left -image $img -text $text -font MyFont]
    pack $l -side top -fill both -expand 1
    bind $l <<TkWorldChanged>> [list apply $testWorldChanged %W %d]
    set ::results {}

    apply $waitfor 0
    apply $check $l
    font configure MyFont -size 26
    apply $waitfor 1
    apply $check $l
    font configure MyFont -size 9
    apply $waitfor 2
    apply $check $l
    font configure MyFont -size 13
    apply $waitfor 3
    apply $check $l
    set results
} -cleanup {
    destroy $l
    unset -nocomplain ::results
} -result {{1 1} {1 1} {1 1} {1 1}}

# cleanup
cleanupTests
return