[RFC] framework of Ruby/Tk + VNC

Discussion in 'Ruby' started by Hidetoshi NAGAI, Oct 7, 2005.

  1. Hi,

    4 months ago, I wrote about the framework of Ruby/Tk + VNC
    ([ruby-talk:145031]).
    And now, I've exhibited a new demo to try its concept.

    The previous demo has the client script embedded in the main script.
    But the main script of this demo can load the external file as the
    client script which can work as a standalone Ruby/Tk script.
    It means that steps from developpng on local to opening to the net
    are seamless.

    You can also try its interactivity.
    One of the client script is an animation demo quoted from "Ruby/Tk
    Widget Demo".

    Please access 131.206.154.81:5933 by VNC viewer,
    or http://131.206.154.81/ by web browser.
    In both case, your firewall must pass through the packets to
    IP addr: 131.206.154.81 and port: 5933.

    # When by a web browser, a dialog to require password is shown.
    # Please ignore it and press the "OK" button with empty password.

    Any comments (or wish to participate in the development ;-))
    are welcome.

    Hidetoshi NAGAI ()

    ---------------------------------------------------------------
    The following is the sample script.
    The main script expects that the main and the 2 client scripts are
    placed on the same directory.

    =======< wrap-test-main2.rb >=========================================
    #!/usr/bin/env ruby

    require 'multi-tk'
    require 'tk/canvas'

    class Window_Frame < TkcWindow
    def _title_bind
    @titlebar.bind('ButtonPress-1',
    proc{|rx, ry|
    @rx = rx; @ry = ry; @sx, @sy = self.coords
    @base.raise
    }, '%X', '%Y')

    @titlebar.bind('B1-Motion',
    proc{|rx, ry|
    wx = @wall.winfo_rootx; wy = @wall.winfo_rooty
    if rx > wx && rx < wx + @wall.width &&
    ry > wy && ry < wy + @wall.height
    self.coords = [@sx + (rx - @rx), @sy + (ry - @ry)]
    end
    }, '%X', '%Y')
    end

    def initialize(wall, title, *args)
    @wall = wall
    @base = TkFrame.new(@wall, :borderwidth=>3, :relief=>:ridge)
    @titlebar = TkLabel.new(@base, :text=>" #{title} ", :relief=>:raised,
    :foreground=>'white',
    :background=>'midnight blue').pack:)fill=>:x)
    @container = TkFrame.new(@base, :container=>true).pack:)fill=>:both,
    :expand=>true)
    @container.bind('Destroy'){self.destroy}

    super(wall, *args)
    self.window = @base
    _title_bind
    end

    def winid
    @container.winfo_id
    end
    end

    def new_toplevel(wall, ip, top)
    w = Window_Frame.new(wall, "toplevel(#{top})", 200, 150, :anchor=>:nw)
    MultiTkIp.invoke_hidden(ip, 'toplevel', top, '-use', w.winid)
    end

    class TOPLEVEL_ARG < Exception
    def self.new(path, *args)
    obj = super(path)
    obj.instance_variable_set('@args', args)
    obj
    end
    alias value message
    attr_reader :args
    end

    def replace_toplevel_cmd(wall, slave_ip)
    th = Thread.new(wall, slave_ip){|w, ip|
    begin
    Thread.stop
    rescue TOPLEVEL_ARG => arg
    begin
    new_toplevel(w, ip, arg.value, *(arg.args))
    rescue Exception => e
    p e
    end
    retry
    end
    }

    cmd = TkComm._get_eval_string(proc{|t, *args|
    th.raise(TOPLEVEL_ARG.new(t, *args))
    until slave_ip.eval_proc{TkWinfo.exist?(t)}
    Thread.pass
    Tk.update
    end
    })

    MultiTkIp.hide_cmd(slave_ip, 'toplevel') unless slave_ip.safe?
    slave_ip._eval("proc toplevel {path args} {eval \"#{cmd} $path $args\"}")
    slave_ip._eval("proc wm {args} {}")
    end


    ##############################################

    timeout = 60

    wall = TkCanvas.new:)background=>'skyblue').pack
    #wall = TkCanvas.new:)width=>500, :height=>400, :background=>'skyblue').pack
    #wall = TkCanvas.new:)width=>800, :height=>600, :background=>'skyblue').pack

    wall.xscrollbar(h_scroll = TkScrollbar.new:)width=>10))
    wall.yscrollbar(v_scroll = TkScrollbar.new:)width=>10))

    TkGrid.rowconfigure(Tk.root, 0, 'weight'=>1, 'minsize'=>0)
    TkGrid.columnconfigure(Tk.root, 0, 'weight'=>1, 'minsize'=>0)

    wall.grid:)row=>0, :column=>0, :sticky=>'news')
    h_scroll.grid:)row=>1, :column=>0, 'sticky'=>'ew')
    v_scroll.grid:)row=>0, :column=>1, 'sticky'=>'ns')

    TkcText.new(wall, 150, 50, :fill=>'navyblue', :font=>'courier -14',
    :text=>"Ruby/Tk+VNC :: concept example")

    TkcText.new(wall, 150, 300,
    :text=>"This example will exit in #{timeout} seconds.")
    TkcText.new(wall, 350, 340,
    :text=>"This is Master IP's canvas widget.\n\t($SAFE==#{$SAFE})")

    Tk.update
    Tk.root.geometry('500x380')

    Tk.after(timeout * 1000){exit}
    ev_thread = Thread.new{Tk.mainloop}

    #=========================================================#

    demos = [
    ['wrap-test-target.rb', 'Simple Demo: create a new toplevel'],
    ['pendulum.rb', 'Test of interactivity (Animation demo)'],
    ]

    v = TkVariable.new('')

    sel_frame = TkFrame.new(wall, :relief=>:flat, :borderwidth=>3)

    TkLabel.new(sel_frame,
    :text=>'Please select the demo which you want to try.',
    :foreground=>'red').pack:)padx=>10, :pady=>5)

    demos.each{|file, label|
    TkButton.new(sel_frame, :text=>label, #:anchor=>:w,
    :command=>proc{
    v.value = file
    sel_frame.destroy
    }).pack:)fill=>:x)
    }

    TkcWindow.new(wall, 40, 100, :anchor=>:nw, :window=>sel_frame)

    Tk.update
    sel_frame.wait
    #p v.value
    exit if v.value.empty?

    dirname = File.dirname(File.expand_path(__FILE__))
    #target_file = ARGV.shift.dup
    #target_file = File.expand_path(ARGV.shift.dup)
    target_file = File.join(dirname, v.value)

    #=========================================================#

    wall.scrollregion = [0, 0, 1024, 768]

    TkcText.new(wall, 370, 170, :text=><<EOT)
    The root window of the safeTk IP is
    embedded in Master IP's frame widget.

    You can move the root window by
    'Button-1 + Motion' on the titlebar.
    Master IP works like as a window manager.

    No window manager on the VNC server.
    Running one Ruby/Tk process only.
    EOT
    #'

    w = Window_Frame.new(wall, 'slave root', 50, 70, :anchor=>:nw)
    w.instance_variable_get:)@container).bind_append('Destroy'){Tk.exit}

    #ip = MultiTkIp.new_trusted_slave:)use=>w.winid)
    #ip = MultiTkIp.new_trusted_slave(3, :use=>w.winid)
    #ip = MultiTkIp.new_trusted_slave(4, :use=>w.winid)
    #ip = MultiTkIp.new_safeTk(0, :use=>w.winid)
    #ip = MultiTkIp.new_safeTk(3, :use=>w.winid)
    ip = MultiTkIp.new_safeTk:)use=>w.winid)

    replace_toplevel_cmd(wall, ip)

    #p ['on main', __FILE__]

    #=========================================================#
    target_file.untaint

    #ldr = proc{|f| $SAFE=ip.safe_level; load f,false}
    xp = proc{|val| p val}

    alias __require__ require
    @req = proc{|f|
    # p ['@req', f]
    __require__(f)}

    def require(f)
    @req.call(f)
    end

    #xp.call '-------------------'
    ip.bg_eval_proc{
    # xp.call self

    begin
    # xp.call target_file
    #ldr.call target_file
    load target_file, true
    rescue => e
    xp.call e if $DEBUG
    end
    }
    #xp.call '-------------------'

    =begin
    Tk.after(5000){
    w.instance_variable_get:)@container).configure:)width=>450, :height=>250)
    }
    Tk.after(10000){
    w.instance_variable_get:)@container).configure:)width=>500, :height=>600)
    }
    =end

    #p 'join'
    ev_thread.join
    ======================================================================

    =======< wrap-test-target.rb >========================================
    require 'tk'

    p ['on target', __FILE__] if $SAFE < 4

    TkLabel.new:)text=>"safeTk interpreter's root").pack:)padx=>10, :pady=>5)

    top = nil
    cnt = 0

    b1 = TkButton.new:)text=>'create Toplevel')

    b2 = TkButton.new:)text=>'add label to the toplevel', :state=>:disabled,
    :command=>proc{
    cnt += 1
    TkLabel.new(top,
    :text=>"Pressed(#{cnt})!! $SAFE=#{$SAFE}"
    ).pack
    })

    b1[:command] = proc{
    top = TkToplevel.new
    b1[:state] = :disabled
    b2[:state] = :active
    TkLabel.new(top,
    :text=>'New toplevel of slaveIP').pack:)padx=>20, :pady=>30)
    }

    label = TkLabel.new:)foreground=>'red', :text=>"\n")
    timer = TkTimer.new(500, 1, proc{label.text = "\n"})
    TkButton.new:)text=>'BUTTON',
    :command=>proc{
    timer.cancel
    label.text = "button is pressed!!\n($SAFE==#{$SAFE})"
    timer.start
    }).pack:)padx=>5, :pady=>5, :fill=>:x)
    label.pack

    Tk.pack(b1, b2, :fill=>:x, :padx=>5, :pady=>5)

    Tk.mainloop
    ======================================================================

    =======< pendulum.rb >================================================
    #!/usr/bin/env ruby
    #
    # based on Tcl/Tk8.5a2 widget demos
    #
    require 'tk'

    #TkRoot.new:)title=>'Pendulum Animation Demonstration',
    # :iconname=>"pendulum")

    # create label
    msg = TkLabel.new {
    font 'Helvetica -12'
    wraplength '4i'
    justify 'left'
    text 'This demonstration shows how Ruby/Tk can be used to carry out animations that are linked to simulations of physical systems. In the left canvas is a graphical representation of the physical system itself, a simple pendulum, and in the right canvas is a graph of the phase space of the system, which is a plot of the angle (relative to the vertical) against the angular velocity. The pendulum bob may be repositioned by clicking and dragging anywhere on the left canvas.'
    }
    msg.pack('side'=>'top')

    # animated wave
    class PendulumAnimationDemo
    def initialize(frame)
    TkFrame.new(frame) {|f|
    TkButton.new(f, :command=>proc{Tk.root.destroy},
    :text=>'Dismiss').pack:)side=>:left, :expand=>true)
    }.pack:)side=>:bottom, :fill=>:x, :pady=>'2m')

    # Create some structural widgets
    pane = TkPanedWindow.new(frame #, :width=>350, :height=>200
    ).pack:)fill=>:both, :expand=>true)
    @lf1 = TkLabelFrame.new(pane, :text=>'Pendulum Simulation')
    @lf2 = TkLabelFrame.new(pane, :text=>'Phase Space')

    # Create the canvas containing the graphical representation of the
    # simulated system.
    @c = TkCanvas.new(@lf1, :width=>320, :height=>200, :background=>'white',
    :borderwidth=>2, :relief=>:sunken)
    TkcText.new(@c, 5, 5, :anchor=>:nw,
    :text=>'Click to Adjust Bob Start Position')
    # Coordinates of these items don't matter; they will be set properly below
    @plate = TkcLine.new(@c, 0, 25, 320, 25, :width=>2, :fill=>'grey50')
    @rod = TkcLine.new(@c, 1, 1, 1, 1, :width=>3, :fill=>'black')
    @bob = TkcOval.new(@c, 1, 1, 2, 2,
    :width=>3, :fill=>'yellow', :eek:utline=>'black')
    TkcOval.new(@c, 155, 20, 165, 30, :fill=>'grey50', :eek:utline=>'')

    # pack
    @c.pack:)fill=>:both, :expand=>true)

    # Create the canvas containing the phase space graph; this consists of
    # a line that gets gradually paler as it ages, which is an extremely
    # effective visual trick.
    @k = TkCanvas.new(@lf2, :width=>320, :height=>200, :background=>'white',
    :borderwidth=>2, :relief=>:sunken)
    @y_axis = TkcLine.new(@k, 160, 200, 160, 0, :fill=>'grey75', :arrow=>:last)
    @x_axis = TkcLine.new(@k, 0, 100, 320, 100, :fill=>'grey75', :arrow=>:last)

    @graph = {}
    90.step(0, -10){|i|
    # Coordinates of these items don't matter;
    # they will be set properly below
    @graph = TkcLine.new(@k, 0, 0, 1, 1, :smooth=>true, :fill=>"grey#{i}")
    }

    # labels
    @label_theta = TkcText.new(@k, 0, 0, :anchor=>:ne,
    :text=>'q', :font=>'Symbol 8')
    @label_dtheta = TkcText.new(@k, 0, 0, :anchor=>:ne,
    :text=>'dq', :font=>'Symbol 8')

    # pack
    @k.pack:)fill=>:both, :expand=>true)

    # Initialize some variables
    @points = []
    @theta = 45.0
    @dTheta = 0.0
    @length = 150

    # init display
    showPendulum

    # animation loop
    @timer = TkTimer.new(15){ repeat }

    # binding
    @c.bindtags_unshift(btag = TkBindTag.new)
    btag.bind('Destroy'){ @timer.stop }
    btag.bind('1', proc{|x, y| @timer.stop; showPendulum(x, y)}, '%x %y')
    btag.bind('B1-Motion', proc{|x, y| showPendulum(x, y)}, '%x %y')
    btag.bind('ButtonRelease-1',
    proc{|x, y| showPendulum(x, y); @timer.start }, '%x %y')

    btag.bind('Configure', proc{|w| @plate.coords(0, 25, w, 25)}, '%w')

    @k.bind('Configure', proc{|h, w|
    @psh = h/2;
    @psw = w/2
    @x_axis.coords(2, @psh, w-2, @psh)
    @y_axis.coords(@psw, h-2, @psw, 2)
    @label_theta.coords(@psw-4, 6)
    @label_dtheta.coords(w-6, @psh+4)
    }, '%h %w')

    # add to pane
    Tk.update
    pane.add(@lf1, @lf2) # must be called after setting 'Configure' binding

    # animation start
    @timer.start(500)
    end

    # This procedure makes the pendulum appear at the correct place on the
    # canvas. If the additional arguments x, y are passed instead of computing
    # the position of the pendulum from the length of the pendulum rod and its
    # angle, the length and angle are computed in reverse from the given
    # location (which is taken to be the centre of the pendulum bob.)
    def showPendulum(x=nil, y=nil)
    if x && y && (x != 160 || y != 25)
    @dTheta = 0.0
    x2 = x - 160
    y2 = y - 25
    @length = Math.hypot(x2, y2)
    @theta = Math.atan2(x2,y2)*180/Math::pI
    else
    angle = @theta*Math::pI/180
    x = 160 + @length*Math.sin(angle)
    y = 25 + @length*Math.cos(angle)
    end

    @rod.coords(160, 25, x, y)
    @bob.coords(x-15, y-15, x+15, y+15)
    end

    # Update the phase-space graph according to the current angle and the
    # rate at which the angle is changing (the first derivative with
    # respect to time.)
    def showPhase
    @points << @theta + @psw << -20*@dTheta + @psh
    if @points.length > 100
    @points = @points[-100..-1]
    end
    (0...100).step(10){|i|
    first = - i
    last = 11 - i
    last = -1 if last >= 0
    next if first > last
    lst = @points[first..last]
    @graph.coords(lst) if lst && lst.length >= 4
    }
    end

    # This procedure is the "business" part of the simulation that does
    # simple numerical integration of the formula for a simple rotational
    # pendulum.
    def recomputeAngle
    scaling = 3000.0/@length/@length

    # To estimate the integration accurately, we really need to
    # compute the end-point of our time-step. But to do *that*, we
    # need to estimate the integration accurately! So we try this
    # technique, which is inaccurate, but better than doing it in a
    # single step. What we really want is bound up in the
    # differential equation:
    # .. - sin theta
    # theta + theta = -----------
    # length
    # But my math skills are not good enough to solve this!

    # first estimate
    firstDDTheta = -Math.sin(@theta * Math::pI/180) * scaling
    midDTheta = @dTheta + firstDDTheta
    midTheta = @theta + (@dTheta + midDTheta)/2
    # second estimate
    midDDTheta = -Math.sin(midTheta * Math::pI/180) * scaling
    midDTheta = @dTheta + (firstDDTheta + midDDTheta)/2
    midTheta = @theta + (@dTheta + midDTheta)/2
    # Now we do a double-estimate approach for getting the final value
    # first estimate
    midDDTheta = -Math.sin(midTheta * Math::pI/180) * scaling
    lastDTheta = midDTheta + midDDTheta
    lastTheta = midTheta + (midDTheta+ lastDTheta)/2
    # second estimate
    lastDDTheta = -Math.sin(lastTheta * Math::pI/180) * scaling
    lastDTheta = midDTheta + (midDDTheta + lastDDTheta)/2
    lastTheta = midTheta + (midDTheta + lastDTheta)/2
    # Now put the values back in our globals
    @dTheta = lastDTheta
    @theta = lastTheta
    end

    # This method ties together the simulation engine and the graphical
    # display code that visualizes it.
    def repeat
    # Simulate
    recomputeAngle

    # Update the display
    showPendulum
    showPhase
    end
    end

    # Start the animation processing
    PendulumAnimationDemo.new(Tk.root)

    Tk.mainloop
    ======================================================================
     
    Hidetoshi NAGAI, Oct 7, 2005
    #1
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