# arrow.rb
#
# This demonstration script creates a canvas widget that displays a
# large line with an arrowhead whose shape can be edited interactively.
#
# arrowhead widget demo (called by 'widget')
#

# arrowSetup --
# This method regenerates all the text and graphics in the canvas
# window.  It's called when the canvas is initially created, and also
# whenever any of the parameters of the arrow head are changed
# interactively.
#
# Arguments:
# c -           Name of the canvas widget.

def arrowSetup(c)
  v = $demo_arrowInfo

  # Remember the current box, if there is one.
  tags = c.gettags('current')
  if tags != []
    cur = tags.find{|t| t.kind_of?(String) && t =~ /^box[1-3]$/ }
  else
    cur = nil
  end

  # Create the arrow and outline.
  c.delete('all')
  TkcLine.new(c, v.x1, v.y, v.x2, v.y,
              { 'width'=>10 * v.width,
                'arrowshape'=>[10*v.a, 10*v.b, 10*v.c],
                'arrow'=>'last'
              }.update(v.bigLineStyle) )
  xtip = v.x2 - 10*v.b
  deltaY = 10*v.c + 5*v.width
  TkcLine.new(c, v.x2, v.y, xtip, v.y + deltaY,
              v.x2 - 10*v.a, v.y, xtip, v.y - deltaY, v.x2, v.y,
              'width'=>2, 'capstyle'=>'round', 'joinstyle'=>'round')

  # Create the boxes for reshaping the line and arrowhead.
  TkcRectangle.new(c, v.x2-10*v.a-5, v.y-5, v.x2-10*v.a+5, v.y+5,
                   {'tags'=>['box1', $arrowTag_box]}.update(v.boxStyle) )
  TkcRectangle.new(c, xtip-5, v.y-deltaY-5, xtip+5, v.y-deltaY+5,
                   {'tags'=>['box2', $arrowTag_box]}.update(v.boxStyle) )
  TkcRectangle.new(c, v.x1-5, v.y-5*v.width-5, v.x1+5, v.y-5*v.width+5,
                   {'tags'=>['box3', $arrowTag_box]}.update(v.boxStyle) )
  c.itemconfigure cur, v.activeStyle if cur

  # Create three arrows in actual size with the same parameters
  TkcLine.new(c, v.x2+50, 0, v.x2+50, 1000, 'width'=>2)
  tmp = v.x2+100
  TkcLine.new(c, tmp, v.y-125, tmp, v.y-75, 'width'=>v.width,
              'arrow'=>'both', 'arrowshape'=>[v.a, v.b, v.c])
  TkcLine.new(c, tmp-25, v.y, tmp+25, v.y, 'width'=>v.width,
              'arrow'=>'both', 'arrowshape'=>[v.a, v.b, v.c])
  TkcLine.new(c, tmp-25, v.y+75, tmp+25, v.y+125, 'width'=>v.width,
              'arrow'=>'both', 'arrowshape'=>[v.a, v.b, v.c])

  # Create a bunch of other arrows and text items showing the
  # current dimensions.
  tmp = v.x2+10
  TkcLine.new(c, tmp, v.y-5*v.width, tmp, v.y-deltaY,
              'arrow'=>'both', 'arrowshape'=>v.smallTips)
  TkcText.new(c, v.x2+15, v.y-deltaY+5*v.c, 'text'=>v.c, 'anchor'=>'w')
  tmp = v.x1-10
  TkcLine.new(c, tmp, v.y-5*v.width, tmp, v.y+5*v.width,
              'arrow'=>'both', 'arrowshape'=>v.smallTips)
  TkcText.new(c, v.x1-15, v.y, 'text'=>v.width, 'anchor'=>'e')
  tmp = v.y+5*v.width+10*v.c+10
  TkcLine.new(c, v.x2-10*v.a, tmp, v.x2, tmp,
              'arrow'=>'both', 'arrowshape'=>v.smallTips)
  TkcText.new(c, v.x2-5*v.a, tmp+5, 'text'=>v.a, 'anchor'=>'n')
  tmp = tmp+25
  TkcLine.new(c, v.x2-10*v.b, tmp, v.x2, tmp,
              'arrow'=>'both', 'arrowshape'=>v.smallTips)
  TkcText.new(c, v.x2-5*v.b, tmp+5, 'text'=>v.b, 'anchor'=>'n')

  if $tk_version =~ /^4.*/
    TkcText.new(c, v.x1, 310, 'text'=>"'width'=>#{v.width}", 'anchor'=>'w',
                'font'=>'-*-Helvetica-Medium-R-Normal--*-180-*-*-*-*-*-*')
    TkcText.new(c, v.x1, 330,
                'text'=>"'arrowshape'=>[#{v.a}, #{v.b}, #{v.c}]",'anchor'=>'w',
                'font'=>'-*-Helvetica-Medium-R-Normal--*-180-*-*-*-*-*-*')
  else
    TkcText.new(c, v.x1, 310, 'text'=>"'width'=>#{v.width}", 'anchor'=>'w',
                'font'=>'Helvetica 18')
    TkcText.new(c, v.x1, 330,
                'text'=>"'arrowshape'=>[#{v.a}, #{v.b}, #{v.c}]",
                'anchor'=>'w', 'font'=>'Helvetica 18')
  end

  v.count += 1
end

# toplevel widget
if defined?($arrow_demo) && $arrow_demo
  $arrow_demo.destroy
  $arrow_demo = nil
end

# demo toplevel widget
$arrow_demo = TkToplevel.new {|w|
  title("Arrowhead Editor Demonstration")
  iconname("arrow")
  positionWindow(w)
}

base_frame = TkFrame.new($arrow_demo).pack(:fill=>:both, :expand=>true)

# label
TkLabel.new(base_frame, 'font'=>$font, 'wraplength'=>'5i', 'justify'=>'left',
            'text'=>"This widget allows you to experiment with different widths and arrowhead shapes for lines in canvases.  To change the line width or the shape of the arrowhead, drag any of the three boxes attached to the oversized arrow.  The arrows on the right give examples at normal scale.  The text at the bottom shows the configuration options as you'd enter them for a canvas line item."){
  pack('side'=>'top')
}

# frame
$arrow_buttons = TkFrame.new(base_frame) {|frame|
  TkButton.new(frame) {
    text 'Dismiss'
    command proc{
      tmppath = $arrow_demo
      $arrow_demo = nil
      tmppath.destroy
    }
  }.pack('side'=>'left', 'expand'=>'yes')

  TkButton.new(frame) {
    text 'Show Code'
    command proc{showCode 'arrow'}
  }.pack('side'=>'left', 'expand'=>'yes')
}
$arrow_buttons.pack('side'=>'bottom', 'fill'=>'x', 'pady'=>'2m')

# canvas
$arrow_canvas = TkCanvas.new(base_frame, 'width'=>500, 'height'=>350,
                             'relief'=>'sunken', 'borderwidth'=>2)
$arrow_canvas.pack('expand'=>'yes', 'fill'=>'both')

#
unless Struct.const_defined?("ArrowInfo")
  $demo_arrowInfo = Struct.new("ArrowInfo", :a, :b, :c, :width, :motionProc,
                               :x1, :x2, :y, :smallTips, :count,
                               :bigLineStyle, :boxStyle, :activeStyle).new
end
$demo_arrowInfo.a = 8
$demo_arrowInfo.b = 10
$demo_arrowInfo.c = 3
$demo_arrowInfo.width = 2
$demo_arrowInfo.motionProc = proc{}
$demo_arrowInfo.x1 = 40
$demo_arrowInfo.x2 = 350
$demo_arrowInfo.y = 150
$demo_arrowInfo.smallTips = [5, 5, 2]
$demo_arrowInfo.count = 0
if TkWinfo.depth($arrow_canvas) > 1
  $demo_arrowInfo.bigLineStyle = {'fill'=>'SkyBlue1'}
  $demo_arrowInfo.boxStyle = {'fill'=>'', 'outline'=>'black', 'width'=>1}
  $demo_arrowInfo.activeStyle = {'fill'=>'red', 'outline'=>'black', 'width'=>1}
else
  $demo_arrowInfo.bigLineStyle = {'fill'=>'black',
    'stipple'=>'@'+[$demo_dir,'..','images','grey.25'].join(File::Separator)}
  $demo_arrowInfo.boxStyle = {'fill'=>'', 'outline'=>'black', 'width'=>1}
  $demo_arrowInfo.activeStyle = {'fill'=>'black','outline'=>'black','width'=>1}
end
$arrowTag_box = TkcTag.new($arrow_canvas)
arrowSetup $arrow_canvas
$arrowTag_box.bind('Enter', proc{$arrow_canvas.itemconfigure('current', $demo_arrowInfo.activeStyle)})
$arrowTag_box.bind('Leave', proc{$arrow_canvas.itemconfigure('current', $demo_arrowInfo.boxStyle)})
$arrowTag_box.bind('B1-Enter', proc{})
$arrowTag_box.bind('B1-Leave', proc{})
$arrow_canvas.itembind('box1', '1',
                       proc{$demo_arrowInfo.motionProc \
                         = proc{|x,y| arrowMove1 $arrow_canvas, x, y}})
$arrow_canvas.itembind('box2', '1',
                       proc{$demo_arrowInfo.motionProc \
                         = proc{|x,y| arrowMove2 $arrow_canvas, x, y}})
$arrow_canvas.itembind('box3', '1',
                       proc{$demo_arrowInfo.motionProc \
                         = proc{|x,y| arrowMove3 $arrow_canvas, x, y}})
$arrowTag_box.bind('B1-Motion',
                  proc{|x,y| $demo_arrowInfo.motionProc.call(x,y)}, "%x %y")
$arrow_canvas.bind('Any-ButtonRelease-1', proc{arrowSetup $arrow_canvas})

# arrowMove1 --
# This method is called for each mouse motion event on box1 (the
# one at the vertex of the arrow).  It updates the controlling parameters
# for the line and arrowhead.
#
# Arguments:
# c -           The name of the canvas window.
# x, y -        The coordinates of the mouse.

def arrowMove1(c,x,y)
  v = $demo_arrowInfo
  newA = (v.x2+5-c.canvasx(x).round)/10
  newA = 0 if newA < 0
  newA = 25 if newA > 25
  if newA != v.a
    c.move('box1', 10*(v.a-newA), 0)
    v.a = newA
  end
end

# arrowMove2 --
# This method is called for each mouse motion event on box2 (the
# one at the trailing tip of the arrowhead).  It updates the controlling
# parameters for the line and arrowhead.
#
# Arguments:
# c -           The name of the canvas window.
# x, y -        The coordinates of the mouse.

def arrowMove2(c,x,y)
  v = $demo_arrowInfo
  newB = (v.x2+5-c.canvasx(x).round)/10
  newB = 0 if newB < 0
  newB = 25 if newB > 25
  newC = (v.y+5-c.canvasy(y).round-5*v.width)/10
  newC = 0 if newC < 0
  newC = 20 if newC > 20
  if newB != v.b || newC != v.c
    c.move('box2', 10*(v.b-newB), 10*(v.c-newC))
    v.b = newB
    v.c = newC
  end
end

# arrowMove3 --
# This method is called for each mouse motion event on box3 (the
# one that controls the thickness of the line).  It updates the
# controlling parameters for the line and arrowhead.
#
# Arguments:
# c -           The name of the canvas window.
# x, y -        The coordinates of the mouse.

def arrowMove3(c,x,y)
  v = $demo_arrowInfo
  newWidth = (v.y+2-c.canvasy(y).round)/5
  newWidth = 0 if newWidth < 0
  newWidth = 20 if newWidth > 20
  if newWidth != v.width
    c.move('box3', 0, 5*(v.width-newWidth))
    v.width = newWidth
  end
end

