Writing sublets\015\012\015\012{{>toc}}\015\012\015\012h2. Hello world\015\012\015\012Starting a sublet from scratch is really easy, just create an empty sublet with sur: sur template hello\015\012\015\012This will create a folder hello with two files:\015\012\015\012|_. Filename |_. Description |\015\012| hello.rb | The sublet file with the minimal required code |\015\012| hello.spec | The specification file with basic information for sur about the sublet |\015\012\015\012h3. Say hello\015\012\015\012Per default, the new sublet will do nothing and we need to add something do the data field:\015\012\015\012

{{hide}}# Hello sublet file\015\012# Created with sur-0.2\015\012configure :hello do |s|\015\012  s.interval = 60\015\012end\015\012\015\012on :run do |s|\015\012  s.data = "Hello, world!"\015\012end

\015\012\015\012h3. Using variables\015\012\015\012Typically, a sublet just needs local and instance variables to store data across runs and/or to calculate intermediate values. Due to the DSL, instance variables that normally just need a to be prefixed with a just @ now need an owner to be tracked as instance variable. That can either be the first argument of every event block or self inside of a helper.\015\012\015\012

{{hide}}# Hello sublet file\015\012# Created with sur-0.2\015\012configure :hello do |s|\015\012  s.interval = 60\015\012  s.world    = "variable world"\015\012end\015\012\015\012on :run do |s|\015\012  s.data = "Hello, #{s.world}"\015\012end

\015\012\015\012h3. Move code to helper\015\012\015\012Sometimes it can be useful to move code into own functions to call it on several events. Instead of just copying the code let's move the code into a helper. A helper is just another block that can be used to add methods to the sublet itself.\015\012\015\012

{{hide}}# Hello sublet file\015\012# Created with sur-0.2\015\012configure :hello do |s|\015\012  s.interval = 60\015\012  s.world    = "variable world"\015\012end\015\012\015\012helper do |s|\015\012  def hello_time\015\012    case Time.now.strftime("%H").to_i\015\012      when  6..9  then "Good morning"\015\012      when 10..15 then "Good day"\015\012      when 16..18 then "Good evening"\015\012      when 19..5  then "Good night"\015\012    end\015\012  end\015\012end\015\012\015\012on :run do |s|\015\012  s.data = "%s, %s" % [ s.hello_time, s.world ]\015\012end

\015\012\015\012h3. Test your sublet\015\012\015\012sur comes with a tester for sublet to ease the whole thing: sur test hello/hello.rb\015\012\015\012The output looks like this:\015\012\015\012\015\012\015\012The lines starting with @ show the defined instanced variables, the lines with (1) the callable methods.\015\012\015\012h3. Install and submit\015\012\015\012Once you are satisfied with your work you need to build your sublet: @sur build hello/hello.spec\015\012\015\012This will create a hello-0.0.sublet file that can either be installed locally sur install ./hello-0.0.sublet or uploaded to the sur repository sur submit ./hello-0.0.sublet and installed from there.\015\012\015\012h2. Components\015\012\015\012h3. Configure\015\012\015\012A sublet starts with the configure block, which tells subtle the name and does basic initialization like the interval time if it's used. Assignment of instance variables must be done like s.value = "something" or otherwise the DSL can't keep track of it.\015\012\015\012

{{hide}}configure :sublet do |s|\015\012  s.interval = 60\015\012  s.variable = "something"\015\012end

\015\012\015\012Generally there are two different types of Sublets:\015\012\015\012* sublets that are updated by given interval in seconds (default 60s)\015\012* sublets that are updated when a file is modified (via inotify) or via socket\015\012* sublets that are updated via SUBTLE_SUBLET_DATA client message\015\012\015\012The sublet data must be of type String, everything else will be ignored.\015\012\015\012h3. Helper\015\012\015\012Custom methods need to be written inside of a helper block to be used a instance method. Inside of this helpers, instance variables must be accessed via the self keyword:\015\012\015\012

{{hide}}helper do\015\012  def something(test)\015\012    self.variable = test\015\012    self.data     = test\015\012  end\015\012end

\015\012\015\012h3. Events\015\012\015\012Sublets are event driven, so there are some specific events only for sublets:\015\012\015\012|_. Name |_. Description |_. Arguments |\015\012| :mouse_over | Whenever the pointer is over the sublet | s |\015\012| :mouse_down | Whenever the pointer is pressed on the sublet. | s, x, y, button |\015\012| :mouse_out | Whenever the pointer leaves the sublet | s |\015\012| :run | Whenever either the interval time is expired | s |\015\012| :watch | Whenever the watched file is modified/socket has data ready | s |\015\012| :data | Whenever subtle receives a SUBTLE_SUBLET_DATA client message for this sublet | s |\015\012| :unload | Whenever the sublet is unloaded | s |\015\012\015\012

{{hide}}on :mouse_down do |s, x, y, button|\015\012  puts "button %d at x=%d and y=%d" % [ x, y, button ]\015\012end

\015\012\015\012h3. Hooks\015\012\015\012Sublets can use all hooks that are useable in the main config too, the syntax is almost the same:\015\012\015\012

{{hide}}on :client_create do |s, c|\015\012  puts s.name #< Name of the sublet\015\012  puts c.name #< Name of the client\015\012end

\015\012\015\012h3. Grabs\015\012\015\012Since r2608 sublets can provide grabs identified by symbols, that can be used in the main config.\015\012\015\012

{{hide}}\015\012configure :grabby do |s|\015\012  s.interval = 5\015\012end\015\012\015\012grab :GrabbyGrab do |s, c|\015\012  puts "sublet name: %s" % [ s.name ]\015\012  puts "pressed on : %s" % [ c.name ]\015\012end\015\012

\015\012\015\012_Please use reasonable names for the grabs, there is no check or enforcement of names._\015\012\015\012h2. Configuration\015\012\015\012Configuration of a sublet can be done (since r2148) Subtle::Subtle#config, this returns a hash and can be used as in the following example:\015\012\015\012

{{hide}}# Config:\015\012sublet :configured do\015\012  interval    50\015\012  some_string "#00ff00"\015\012end\015\012\015\012# Sublet:\015\012configure :configured do |s|\015\012  s.interval    = s.config[:interval]    || 30\015\012  s.some_string = s.config[:some_string] || "default"\015\012\015\012  # Works with colors too\015\012  s.red = Subtlext::Color.new(s.config[:red] || "#ff0000")\015\012end\015\012\015\012on :run do |s|\015\012  s.data = s.red + s.some_string\015\012end

\015\012\015\012The specification contains an info field that can be displayed via sur config sublet, it's basically an array of hashes that contains information how to use it:\015\012\015\012

{{hide}}\015\012spec.config = [\015\012  { :name => "format_string", :type => "string", :def_value => "%y/%m/%d %H:%M", :description => "Format of the clock (man date)" },\015\012]\015\012

\015\012\015\012h2. Customization\015\012\015\012h3. Colors\015\012\015\012The color of the ouput of a Sublets can be changed in this way:\015\012\015\012

{{hide}}configure :colorful do |s|\015\012  s.red        = Subtlext::Color.new("#ff0000")\015\012  s.green      = Subtlext::Color.new("#00ff00")\015\012  s.blue       = Subtlext::Color.new("#0000ff")\015\012  s.background = "#303030"\015\012end\015\012\015\012on :run do |s|\015\012  s.data = s.red + "su" + s.green + "bt" + s.blue + "le"\015\012end

\015\012\015\012h3. Icons\015\012\015\012There is also a way to add a X bitmap to a sublet:\015\012\015\012

{{hide}}configure :iconized do |s|\015\012  s.icon = Subtlext::Icon.new("/usr/share/icons/subtle.xbm")\015\012end\015\012\015\012on :run do |s|\015\012  s.data = @icon + "subtle"\015\012end

\015\012\015\012A nice collection of this pixmap can be found Subtle" class="external">here</a> will add a padding of 3px left and right of the pixmap, so keep that in mind when using the click hooks._\015\012\015\012h2. Examples\015\012\015\012Below is the code of a shipped sublets that displays the time. It should be really straight forward:\015\012\015\012

{{hide}}configure :clock do |s|\015\012  s.interval = 60 #< Set interval time\015\012end\015\012\015\012on :run do |s|\015\012  s.data = Time.now.strftime("%d%m%y%H%M") #< Set data\015\012end

\015\012\015\012Another example for the inotify sublet which is also included within subtle:\015\012\015\012

{{hide}}configure :notify do |s|\015\012  s.file = "/tmp/watch"\015\012  s.watch(s.file)\015\012end\015\012\015\012on :watch do\015\012  begin\015\012    self.data = IO.readlines(@file).first.chop #< Read data and strip\015\012  rescue => err #< Catch error\015\012    puts err\015\012    self.data = "subtle"\015\012  end\015\012end

\015\012\015\012The watch command also works with Ruby sockets, but be aware of blocking I/O:\015\012\015\012

{{hide}}configure :socket do |s|\015\012  s.socket = TCPSocket.open("localhost", 6600)\015\012  s.watch(s.socket)\015\012end\015\012\015\012on :watch do |s|\015\012  begin\015\012    s.data = s.socket.readline.chop #< Read data and strip\015\012  rescue => err #< Catch error\015\012    puts err\015\012    s.data = "subtle"\015\012  end\015\012end\015\012\015\012on :run do |s|\015\012  #  Do nothing\015\012end

\015\012\015\012_Subtle will automatically set sockets to O_NONBLOCK._\015\012\015\012And finally an example with a click callback:\015\012\015\012

{{hide}}configure :click do |s|\015\012  s.interval = 999 #< Do nothing\015\012end\015\012\015\012on :mouse_down do |s, x, y, button|\015\012  Subtlext::Client["xterm"].raise\015\012  puts x, y, button\015\012end\015\012\015\012on :run do |s|\015\012  # Do nothing here\015\012end

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