gistfile1.rb

# Copyright 2004-2005, @Last Software, Inc.

# This software is provided as an example of using the Ruby interface
# to SketchUp.

# Permission to use, copy, modify, and distribute this software for 
# any purpose and without fee is hereby granted, provided that the above
# copyright notice appear in all copies.

# THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
#-----------------------------------------------------------------------------
# Name        :   Parametric 1.0
# Description :   This file defines the Parametric module that lets you define parametric
#                 objects that you can edit.
# Menu Item   :   NONE
# Context Menu:   NONE
# Usage       :   N/A
# Date        :   9/10/2004
# Type        :   Tool
#-----------------------------------------------------------------------------

# This file defines the Parametric module that lets you define parametric
# objects that you can edit.

require 'sketchup.rb'

#=============================================================================
class Parametric

# Initialize a newly created instance of the object
def initialize(*args)

    data = args[0]
    
    data = self.prompt("Create") if not data
    return if not data
    
    if( data.kind_of? Sketchup::Entity )
        @entity = data
    else
        return if not validate_parameters(data)
        model = Sketchup.active_model
        model.start_operation self.class.name
        self.create_entity(model)
        container = self.get_container
        if not container
            model.abort_operation
            return
        end
    
        self.create_entities(data, container)

        # Set the parameters for the object
        self.set_attributes(data)
        
        # Apply the transform if one was given
        t = args[1]
        if( t.kind_of? Geom::Transformation )
            @entity.transformation = t
        end
    
        model.commit_operation
    
        @entity
    end
end

# The name to give to the new object
def compute_name
    self.class.name
end

# Create a new parametric Entity.  The default implementation creates
# a Group.  Derived classes can over-ride this method to create a
# ComponentDefinition or ComponentInstance instead.
def create_entity(model)
    @entity = model.active_entities.add_group
end

# Get the container in which to add new Entities.
# This method should not need to be over-ridden by derived classes
def get_container
    if( @entity.kind_of? Sketchup::Group )
        container = @entity.entities
    elsif( @entity.kind_of? Sketchup::ComponentInstance )
        container = @entity.definition.entities
    elsif( @entity.kind_of? Sketchup::ComponentDefinition )
        container = @entity.entities
    else
        container = nil
    end
    container
end

# Get the attribute dictionary
def Parametric.attribute_holder(entity)
    if( entity.kind_of? Sketchup::Group )
        return entity
    elsif( entity.kind_of? Sketchup::ComponentInstance )
        return entity.definition
    elsif( entity.kind_of? Sketchup::ComponentDefinition )
        return entity
    end
    nil
end

def attribute_dictionary(create_if_needed = false)
    attrib_holder = Parametric.attribute_holder(@entity)
    attrib_holder ? attrib_holder.attribute_dictionary("skpp", create_if_needed) : nil
end

# Get the parameter data from an entity
def parameters
    return nil if not @entity
    
    attribs = self.attribute_dictionary
    return nil if not attribs
    data = {}
    attribs.each do |key, value|
        if( key != "class" )
            data[key] = value
        end
    end
    data
end

# Show a dialog and get the values from the user
# TODO: The data variable is a Hash of values to get from the user.
# Because it is a Hash, the order is not specified.  I really need some way
# for the derived classes to control the order that the parameters are
# displayed to the user.
def prompt(operation)
    # get the parameters
    if( @entity )
        data = self.parameters
    else
        data = self.default_parameters
    end
    if( not data )
        puts "No parameters attached to the entity"
        return nil
    end
    title = operation + " " + self.class.name
    keys = []
    prompts = []
    values = []
    data.each do |key, value|
        if( key != "class" )
            keys.push key
            prompts.push self.translate_key(key)
            values.push value
        end
    end
    results = inputbox( prompts, values, title )
    return nil if not results
    
    # Store the results back into data
    # results will be an Array with one value for each prmopt
    results.each_index { |i| data[keys[i]] = results[i] }

    data
end

# Attach attributes to the object
def set_attributes(data)

    # Get the AttributeDictionary - create it if needed
    attribs = attribute_dictionary(true)
    
    # Set the class name
    attribs["class"] = self.class.name
    
    # now set the data values
    data.each { |key, value| attribs[key] = value }

    attribs
end

def entity
    @entity
end

# Edit the parameteric object.  This will prompt for the new values
# and then regenerate the geometry
def edit
    if( not @entity )
        puts "There is no Entity to Edit"
        return false
    end
    
    data = self.prompt "Edit"
    return false if not data
    
    # Make sure that valid values were entered
    ok = self.validate_parameters(data)
    if( not ok )
        return false
    end
    
    # Now clear the old definition and regen the entities
    container = self.get_container
    model = @entity.model
    model.start_operation "Edit " + self.class.name
    
    container.clear!
    self.create_entities(data, container)

    self.set_attributes(data)
    model.commit_operation
    
    @entity
end

#-----------------------------------------------------------------------------
# Class methods for editing parameteric objects

# Determine the class of a parametric entity
def Parametric.get_class(ent)
    attrib_holder = Parametric.attribute_holder(ent)
    return nil if not attrib_holder
    attrib_holder.get_attribute "skpp", "class"
end

# Determine if an Entity is a parametric object
def Parametric.parametric?(ent)
    klass = Parametric.get_class(ent)
    return false if not klass
    
    # Make sure that we can actually create an instance of this class.
    begin
        new_method = eval "#{klass}.method :new"
    rescue
        # If we couldn't find the new method, it probably means that
        # the code for this kind of parametric object wasn't loaded
        puts "Could not find implementation of #{klass}"
        return false
    end
    
    # return the class name
    klass
end

def Parametric.selection_parametric?
    ss = Sketchup.active_model.selection
    false if ss.count != 1
    Parametric.parametric? ss.first
end

def Parametric.edit(ent)
    if( not Parametric.parametric?(ent) )
        UI.beep
        puts "#{ent} is not a parametric Entity"
        return false
    end
    
    # Get the class of the parametric object
    klass = Parametric.get_class(ent)
    
    # Create a new parametric object of that class
    new_method = eval "#{klass}.method :new"
    obj = new_method.call ent
    if not obj
        puts "Could not create the parametric object for #{klass}"
        return false
    end
    
    # Now edit the object
    obj.edit
end

# Edit the current selection
def Parametric.edit_selection
    if not Parametric.selection_parametric?
        UI.beep
        puts "The selected Entity is not parametric"
        return false
    end

    Parametric.edit Sketchup.active_model.selection.first
end

#-----------------------------------------------------------------------------
# The following methods should be implemented by derived classes.  Some of them
# are required, and some are only optional

# create_entities is called to create the entities for the parametric object.
# the parameters needed to create the object are passed in as a Hash.
# This must be implemented by any class that includes Parametric
def create_entities(data, container)
    puts "create_entities must be implemented by #{self.class.name}"
end

# Get the default parameters for the object.
def default_parameters
    puts "default_parameters must be implemented by #{self.class.name}"
end

# Check that valid parameters were entered
# return true if the parameters are OK or false if they are not
def validate_parameters(data)
    true
end

# This allows the object to translate the keys used to store the parameters
# into different prompts to display in the UI.  If not implemented, the
# parameter keys will be used for the prompts
def translate_key(key)
    key
end

end

#=============================================================================
# Add a context menu handler that will add a menu choice to a context menu
# for editing parametric objects
if( not $parametric_loaded )

    UI.add_context_menu_handler do |menu|
        klass = Parametric.selection_parametric?
        if( klass )
            menu.add_separator
            menu.add_item("Edit #{klass}") { Parametric.edit_selection }
        end
    end
    
    $parametric_loaded = true
end