traffic 3.1 examples for eiffel...

Traffic 3.1Examples for Eiffel Beginners

Semester Thesis

By: Roger ImbachSupervised by: Michela Pedroni

Prof. Bertrand Meyer

Student Number: 03-914-819

Table of Contents

1 Introduction 3-5

1.1 Personal Motivation 3

1.2 Overview 3

1.3 Scope of the Work 4

1.4 Initial Situation 5

2 Result 6-12

2.1 Road Creation Example 6-8

2.2 Changes in Touch library 8-12

3 Retrospective and future work 13-14

3.1 Retrospective 13

3.2 Future work 14

4 References 15

1 Introduction

1.1 Personal motivation

I can remember the time when I started working with Eiffel at the beginning of the

first semester during the class “Introduction to programming” [1] held by

Bertrand Meyer.

I was impressed by his easy to understand presentation of the core concepts of

software engineering and the well chosen examples, but also shocked by the

complexity of the teaching software “Flat Hunt” and the “Traffic” library [2, 3].

Together with the book “A TOUCH OF CLASS” [4] it was possible to follow the

lecture with the help of some additional examples, but, at least for me, it was

often relatively hard to do the programming exercises with flat hunt.

During the past 2 years some software examples out of the book “A TOUCH OF

CLASS” were implemented into the Traffic software, which, in my eyes, lead to a

better understanding and extended the often complex structure of Traffic / Flat

Hunt in a way that supports our first year students getting to know the concepts.

A good idea which shall be continued in the future ...

1.2 Overview

Bertrand Meyer uses in his class “Introduction to programming”[1] a teaching

approach called the “Inverted Curriculum” [5] which gives students already at the

beginning the opportunity to work with a large amount of software components

(including multimedia and graphics) to activate their curiosity and help them to

understand software in a different and more global way.

Guided by the book “TOUCH OF CLASS” [3], which is constantly in development,

the students see software from a more and more detailed side by “revealing the

magic” with each chapter they read.

This book contains many examples to help the students understand the basic

principles of good software design and these examples are also the subject of

this work.

For the success of the book, it is crucial that the examples are easy to

understand and help the students to get the essence of the concepts.

1.3 Scope of the work

Most of the examples in “TOUCH OF CLASS” are not compatible with the current

Traffic library [3] which makes it more difficult for the students to learn the taught

concepts, because they work with Traffic most of the time. So the key goal of

this semester thesis is to implement some of the examples as close as possible

to the book without destroying the design of the Traffic library or – if it can't be

achieved - to find and implement some new, more suitable examples covering

the same concept. The hope and motivation of this work is to help students to

understand the main concepts in a easy, comprehensible way.

The work included:

– Reading of TOUCH OF CLASS

– Getting familiar with the Traffic library

– Implementing an example focused on the mentioned properties

– Bug fixing and testing

– Documentation

1. 4 Initial situation

The traffic software was written to model and simulate a city and its

transportation system including maps, buildings, traffic lines and travelers.

Sample applications:

– Flat hunt: Implementation of the famous board game “Scotland Yard”.

– City_3D: 3D visualization of the city

– City_time: Introduction of time concept

– City_timetable: Introduction of timetable concept

Implemented TOUCH examples:

– Chapter2_preview: Illustrates feature calls

– Chapter3_commands: Illustrates commands

– Chapter3_queries: Illustrates queries

For more information see [3].

My thesis belongs to the implemented TOUCH examples and extends them

concerning object creation and linking of objects.

2 Result

2.1 Road creation example

The code example above is out of the book “TOUCH OF CLASS” (chapter 6)

covering the concepts of object creation and linking of objects, which are the

concepts I want to describe during this semester thesis. So I decided to

implement this example having in mind the properties the work should have (see

scope of the work).

We see that in this didactic example, ignoring the initialization, there are three

different parts in the code:

1. Object creation and assignment

2. Linking of objects through reference

3. Presentation (using the created line for highlighting)

These three parts are also present in my implementation, although in a slightly

different way.

explore_on_click is-- Create a road and animate it.

docreate places.make

-- Object creationcreate place1.make_with_pos ("Place 1", 50, 50)create place2.make_with_pos ("Place 2", 90, 50)create place3.make_with_pos ("Place 3", 130, 50)create place4.make_with_pos ("Place 4", 170, 50)create place5.make_with_pos ("Place 5", 210, 90)create place6.make_with_pos ("Place 6", 210, 130)create place7.make_with_pos ("Place 7", 210, 170)create place8.make_with_pos ("Place 8", 210, 210)create place9.make_with_pos ("Place 9", 210, 250)create place10.make_with_pos ("Place 10", 90, 150)

-- Linkingplace1.link (place2)place2.link (place3)place3.link (place4)place4.link (place5)place5.link (place6)place6.link (place7)place7.link (place8)place8.link (place9)place9.link (place10)

-- Presentationmap_widget.disable_lines_shown -– Used for better contrastmake_colored_road(place1, 5, 10, 25)

end

2.1.1 Object creation

create place1.make_with_pos ("Place 1", 50, 50)create place2.make_with_pos ("Place 2", 90, 50)create place3.make_with_pos ("Place 3", 130, 50)create place4.make_with_pos ("Place 4", 170, 50)create place5.make_with_pos ("Place 5", 210, 90)create place6.make_with_pos ("Place 6", 210, 130)create place7.make_with_pos ("Place 7", 210, 170)create place8.make_with_pos ("Place 8", 210, 210)create place9.make_with_pos ("Place 9", 210, 250)create place10.make_with_pos ("Place 10", 90, 150)

The object creation is handled in a compact way creating a place object (of type

TOUCH_PLACE, see following explanation) in one step using a name and a x and

y coordinate.

create place.make_with_pos (place_name: STRING; x_coordinate: INTEGER; y_coordinate: INTEGER).

For a more general usage I did not use predefined objects (the original Touch

example) but used coordinates, which also makes testing easier.

2.1.2 Linking objects

place1.link (place2)place2.link (place3)place3.link (place4)place4.link (place5)place5.link (place6)place6.link (place7)place7.link (place8)place8.link (place9)place9.link (place10)

Linking is handled in exactly the same way as in the Touch example (specific

details are discussed later).

2.1.3 Visualization

map_widget.disable_lines_shown -– Used for better contrastmake_colored_road(place1, 5, 10, 25)

The call map_widget.disable_lines_shown is used to get a better view on the

changes adding more contrast between the transportation grid and the map.

For the highlighting of the road the call

make_colored_road(place: TOUCH_PLACE; r_mod: INTEGER; g_mod: INTEGER; b_mod: INTEGER)

is used. Where place is the “starting” place of type TOUCH_PLACE representing

the road (already linked) to be highlighted and r_mod, g_mod, b_mod are

integers indicating modifiers for a coloring of the places of the road with rgb-

colors.

2.2 Changes in the Touch library

TOUCH_PLACE

Is a class that combines TRAFFIC_NODE and TRAFFIC_PLACE providing an easy

way of accessing the two related objects.

A TOUCH_PLACE contains:

t_place: TRAFFIC_PLACE

t_node: TRAFFIC_NODE

next: TOUCH_PLACE

allowing to change traffic places/traffic nodes, which are connected together, via

t.place and t.node, also providing a possibility to link some TOUCH_PLACE,

which can make the creation of different transportation lines (for example a road)

easier.

Linking is made via :

link(a_place: like Current) is-- Links Current place with a_place

donext := a_place

ensure next_set: next = a_place

end

The creation feature of TOUCH_PLACE (like used in the implemented example)

can be seen here:

make_with_pos(a_name: STRING; x,y: INTEGER) is-- Creates a touch place with position x,y

requirename_set: a_name /= Voidinteger_set: x /= Void and y /= Void

localvector : EM_VECTOR_2D

docreate vector.make (x,y)create t_place.make_with_position (a_name,x,y)create t_node.make (t_place, vector)map_widget.map.add_place (t_place)

end

TOUCH_PLACE was also created to showcase the concept of information hiding

(these information are not necessary for the understanding of the implemented

example -> hide this information for increased easiness of the example).

This class can be extended by other features making the interface larger and

access into / manipulating of TRAFFIC_PLACE and TRAFFIC_NODE easier.

TOUCH_SHARED_MAP_WIDGET

This class contains a singleton variable map_widget: TOUCH_3D_MAP_WIDGET.

Map_widget provides a general way of accessing and manipulating a map widget

because it's generated once and is the same for all calls (in the Touch examples

only one map_widget is used).

It can be changed with set-methods or other methods (for example methods

changing representational issues) using a TOUCH_3D_MAP_WIDGET.

In general the TOUCH classes need the representation and therefore the map

widget.

The singleton variable makes it unnecessary to pass the map_widget to every

instance of a TOUCH_... class and therefore, makes it easier to create

transportation lines (for example roads). Can be changed using a set-method.

map_widget: TOUCH_3D_MAP_WIDGET is-- Traffic Map Widget singleton

indexingonce_status: global

oncecreate Result.make

end

TOUCH_ROAD

Like TOUCH_PLACE this class is used for information hiding.

It contains two different creation features, one which creates a “normal” road out

of a list of TOUCH_PLACE and one creating a colored road as used in the road

creation example.

This class can also be extended like TOUCH_PLACE.

Here the second creation feature:

make_colored_road(a_place: TOUCH_PLACE; x: INTEGER; y: INTEGER; z: INTEGER) is

-- Creates a road out of a list of Touch places using x,y,z for coloring of places

localtemp_road : TRAFFIC_ROAD

doif

a_place.next /= Voidthen

create temp_road.make (a_place.t_node, a_place.next.t_node, create {TRAFFIC_TYPE_STREET}.make, 1, "directed")map_widget.map.add_road (temp_road)map_widget.places_representation.highlight_place (a_place.t_place, create {EM_COLOR}.make_with_rgb (x,y,z))make_colored_road(a_place.next, x+5, y+10, z+25)

endend

We see that for creation present and next place are combined to a road and

added to the map (singleton map_widget), plus a coloring of the present place

using the 3 integer values x,y and z as rgb-modifiers and the position in the list

(places are linked) for the creation of the color.

Changes in other classes

In all other classes using a TOUCH_3D_MAP_WIDGET in a feature or a related

object (like a representation) this widget was replaced by the singleton variable

map_widget and all other necessary changes were made.

The other implemented examples were also updated concerning the changes.

3 Retrospective and future work

3.1 Retrospective

Starting the semester project with reading the book and studying the traffic library

since it gave a good basis for selecting adequate examples and estimating

whether they are implementable.

But the initial phase of the work led to more problems than expected, because

there were some other people working on the same software in related classes.

So every couple of days committed changes led to problems concerning my

software development often making it impossible (without external help) to

continue the work. I can not deny that it was quite hard fighting with this

problems, but I'm quite happy I managed (thanks to the help of Michela) to finish

the project. I'm also glad I had the opportunity to make this experience having in

mind that in companies it will probably be comparable.

In retrospective, ignoring the problems with committed wrong code, it was

interesting to work on the traffic library using learned concepts and getting to

know some new ones (singleton variables, factories etc.) and I do not want to

miss this experience.

3.2 Future work

While this semester project helped to increase the support of the examples from

“TOUCH OF CLASS” [4] significantly, a lot of work remains to be done. In

particular, the implementation of examples of higher chapters of “TOUCH OF

CLASS” covering for example genericity and the event-driven design are needed.

These concepts often give first semester students a headache and a well

designed, thought through implementation of these examples can help the

students understand the core of these designs / concepts.

Furthermore, I want to inspire some people to extend my created classes such

as the TOUCH_PLACE or TOUCH_ROAD.

Possible extensions are the widening of the interface of TOUCH_PLACE to extend

the possibilities for manipulating it's contents ->

– Place coloring / animation

– Representational changes

– Querying

– etc.

and the same could be made for TOUCH_ROAD.

In my opinion, it would also be a good step to try generalizing the access on

transportation lines like a route by creating singleton variables for general objects

as was done for map_widget: TOUCH_3D_MAP_WIDGET.

4 References

[1] Found on lecture page : http://se.inf.ethz.ch/teaching/index.html

[2] Flat hunt downloadable from:

http://se.inf.ethz.ch/download/index.html

[3] Traffic: http://traffic.origo.ethz.ch/

[4] Bertrand Meyer: TOUCH OF CLASS, Learning to program well with Object Technology and Design by Contract, AN INTRODUCTION TO SOFTWARE ENGINEERING http://se.inf.ethz.ch/touch

[5] Bertrand Meyer. Towards an object-oriented curriculum. Journal of Object-Oriented Programming, 6(2):76–81, May 1993. Revised version in TOOLS 11

(Technology of object oriented Languages and Systems), eds. R. Edge, M. Singh

and B. Meyer, Prentice Hall, Englewood Cliffs (N.J.), 1993, pages 585-594.

http://se.inf.ethz.ch/teaching/index.html

http://se.inf.ethz.ch/touch

http://traffic.origo.ethz.ch/

http://se.inf.ethz.ch/download/index.html

TrafficINDEX >> Overview

Introduction

Traffic is a software system used for teaching introductory programming. It consists of a library - the Traffic library - and several example applications that use the Traffic library: Flathunt,City3D, CityTime, and the Touch applications accompanying the textbook A Touchof Class. The goal of Traffic is to make learning to program exciting, interesting and realistic.

Installation

InstallationGetting started with Traffic

Getting Started Guide

GuideGetting started with Traffic

Traffic library Documentation

Developer DocumentationDeveloper documentation for the Traffic library

Touch library

Developer DocumentationDescriptions of the classes found in the Touch library

Touch examples

Preview, Queries, CommandsDescription of the available examples found in Touch of Class

Traffic 3D example applications

Traffic 3D examplesDescription of the 3d example applications such as City_3D, City_time, City_timetable

Traffic 2D example application

Traffic 2d example: FlathuntUser and developer documentation of the Flathunt application

References

ReferencesReferences to other documents such as thesis reports and webpages

Team

TeamList of people that contributed

INDEX >> Overview

Copyright © 2005, Michela Pedronimailto:[email protected]://traffic.origo.ethz.chLast Updated: $Date: 2006-12-14 15:23:55 +0100 (Do, 14 Dez 2006) $

Touch Library ClassesINDEX >> TOUCH LIBRARY >> Overview

Overview over the classes

In the following sections, the classes of the Touch Library are described. Each class description consistsof: Requirements, Description and Class Overview. In the Requirements, the name of classes you needto know, in order to understand the described class is given. Description is a short description of whatthe class does. It is more detailed than just the class description that you find in the class header. TheClass Overview provides a class diagram.

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Most important classes for developers

TOUCH_BUILDINGTOUCH_CONSOLETOUCH_LINETOUCH_MAPTOUCH_PARIS_OBJECTSTOUCH_ROUTETOUCH_SIMPLE_LINETOUCH_3D_APPLICATIONTOUCH_3D_CONTSTANTSTOUCH_3D_MAP_WIDGETTOUCH_3D_SCENETOURISMTOUCH_PLACETOUCH_SHARED_MAP_WIDGETTOUCH_ROAD

TOUCH_BUILDING

Description

The class represents buildings in a touch application which can be spotlighted and are created at aspecific place.

The features make_at_place takes a traffic_place and the singleton variable map_widget fromTOUCH_SHARED_MAP_WIDGET and creates a building at the location of the place. The center of thebuilding is at (place_position.x, place_position.y + 1).

The other calls are forwarded to the corresponding object of type TRAFFIC_BUILDING.

Class overview

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TOUCH_CONSOLE

Description

The console displays results of feature calls or ordinary text. It inherits from EM_TEXTAREA which itself isinheriting from EM_TEXTBOX.

The features append_text and put_string append the new text which is passed as string-argument at theend of the text already existing in the console. The feature prepend_text inserts the new text at the beginning of the already present text. Feature show displays the text in the area specified as console.

The console is created in the TOUCH_3D_SCENE and is disabled, that the user can not write into it.

Class overview

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TOUCH_LINE

Description

The class TOUCH_LINE represents a traffic line in a touch application.

The touch line connects the TRAFFIC_LINE with the singleton variable map_widget fromTOUCH_SHARED_MAP_WIDGET. The calls are forwarded to an object of type TRAFFIC_LINE.

Class overview

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TOUCH_MAP

Description

This class forwards calls to the TRAFFIC_MAP and the singleton variable map_widget fromTOUCH_SHARED_MAP_WIDGET.

Class overview

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TOUCH_PARIS_OBJECTS

Description

The class TOUCH_PARIS_OBJECTS is a collection of all predefined objects used by the examples of theTouch of Class book.

The lines and places are singeltons.

To access the predifined objects in TOUCH_PARIS_OBJECTS the map of Paris muest be loaded. The queryprovides information about this

Class overview

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TOUCH_ROUTE

Description

This class forwards calls to the class TRAFFIC_ROUTE and provides a traveler which travels along theroute.

The feature animate triggers the traveler to travel along the route. After reaching its destination, thetraveler is removed again.

Class overview

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TOUCH_SIMPLE_LINE

Description

This class forwards calls to the class TRAFFIC_SIMPLE_LINE and its representation.

The creation feature make_with_line_and_represenation takes a TRAFFIC_SIMPLE_LINE and the singleton variable map_widget from TOUCH_SHARED_MAP_WIDGET to set the internal implementationfeatures.

The connection from the line to it's representation (via the singleton variable map_widget) is needed forthe highlighting of the line.

Class overview

Suppliers:

Clients:

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TOUCH_3D_APPLICATION

Description

The TOUCH_3D_APPLICATION sets the first scene of the example. Feature make initializes the screen and sets the scene. All the individual examples are inheriting from this class.

Class overview

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TOUCH_3D_CONSTANTS

Description

Here are all the constants defined which are used for the main window. The size of the main window isspecified as well as properties for the objects which are drawn on to the map (for example the line width,the place height, the plane size etc.).

The feature map_to_gl_coords transforms the coordinates specified in the xml file to the coordinates ofthe plane. The Louvre has for example the xml-coordinates ~ (530, 640). Transformed to the planewhich has coordinates between -25 and 25 in both axix, the Louvre has gl-coordinates of ~ (4.9, -1.6).

Class overview

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TOUCH_3D_MAP_WIDGET

Description

The class TOUCH_3D_MAP_WIDGET adds events and their handlers to the map fromTRAFFIC_3D_MAP_WIDGET.

The following event handlers are added: The wheel_down and wheel_up zoom into, respectively out ofthe map. The mouse_drag rotates the map.

Class overview

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TOUCH_3D_SCENE

Description

TOUCH_3D_SCENE specifies the widgets which are used for the main window. The feature make creates all buttons and subscribes its event handlers. It furthermore combines the buttons and the console to thepanel at the right side.

All the scenes of the touch examples inherit from this class in order to define its individual scene. Forexample, the PREVIEW_3D_SCENE from the preview example inherits from this class to subscribe theclick_here_button and to create and invoke the example code of preview.

Class overview

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TOURISM

Description

In this class, the TOUCH_MAP "Paris" is loaded. Features which are used in the individual examples(explore and explore_on_click) are defined as deferred.

The information, which map has been loaded can be retrieved by invoking the feature is_zurich_loadedor is_paris_loaded.

Access to the touch console is given through the feature console. Acces to the map widget is giventhrough the singleton variable map_widget form TOUCH_SHARED_MAP_WIDGET.

The feature run sets the console and invokes explore.

Class overview

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TOUCH_PLACE

Description

A TOUCH_PLACE contains a TRAFFIC_PLACE and a TRAFFIC_NODE which are created with a name and a position and are inserted into the singleton variable map_widget from TOUCH_SHARED_MAP_WIDGET.

A TOUCH_PLACE can be linked with another TOUCH_PLACE with the feature link.

Class overview

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TOUCH_SHARED_MAP_WIDGET

Description

Contains a singleton variable map_widget which is used by many classes using aTOUCH_3D_MAP_WIDGET allowing easy access for representational features and a general way ofaccessing maps in the touch applications.

Class overview

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TOUCH_ROAD

Requirements

NONE

Description

Allows to create a TRAFFIC_ROAD given a list of TOUCH_PLACES. It is possible to create a uncoloredroad using make_road or a colored one using make_colored_road which manipulates the rgb-color of theTRAFFIC_PLACES contained in the TOUCH_PLACE.

Class overview

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INDEX >> TOUCH LIBRARY >> Overview

Touch-Examples User GuideINDEX >> TOUCH EXAMPLES >> Overview

This document describes how to use the Touch examples and is structured as follows:

How to build a new exampleDescription of how a new Touch example can be built

Mouse and keyboard handling of Touch examplesExplanation of mouse and keyboard usage in the Touch examples

Supported examplesList of supported examples covering differences between the software and the book Touch of Class

INDEX >> TOUCH EXAMPLES >> Overview


Classes Needed for a New ExampleINDEX >> TOUCH EXAMPLES >> new_example

List of required classes

To create and add a new example to the TOUCH_EXAMPLES you have to provide the following 3 classes:

examplenameexamplename_3d_applicationexamplename_3d_scene

The following sections are based on the PREVIEW-example, the first example in the book "A Touch of Class". The neededclasses to create a new example and their relations to the touch library are described.

Overview of the needed Classes(considering the preview-example)

Figure 1: The class relations from the preview example.

EXAMPLENAME: preview

Every example, like the preview example, has to inherit from TOURISM. The class TOURISM contains all the predefined objects needed for the examples.

The feature explore is executed while starting the application. It has to contain the loading of the map.

The second feature explore_on_click contains the code which will be executed after pressing the button "click here". Inthe preview example, the line is highlighted again to have a look at it once more.

class PREVIEW

inherit TOURISM

feature -- Example

explore_on_click is -- Highlight line. do Line8.spotlight endend

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EXAMPLENAME_3D_APPLICATION: preview_3d_application

PREVIEW_3D_APPLICATION is the root class of the whole example. Inheriting from TOUCH_3D_APPLICATION requires the implementation of the two features set_first_scene and set_application_specifics which are deferred in the super class.

The feature set_first_scene sets the first scene which will be run.

The feature set_application_specifics defines the window title and the application id.

The example code for the preview example looks like this:

class

PREVIEW_3D_APPLICATION

inherit TOUCH_3D_APPLICATION

create make

feature -- Initialization

set_first_scene is -- Set 'scene' to PREVIEW_3D_SCENE. do set_scene (create {PREVIEW_3D_SCENE}.make) end

set_application_specifics is -- Set application specifics. do set_window_title ("Touch - Preview") set_application_id ("Touch_Preview") endend

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EXAMPLENAME_3D_SCENE: preview_3d_scene

The third class EXAMPLENAME_3D_SCENE, respectively PREVIEW_3D_SCENE makes the first scene and invokes theexamplecode from the corresponding example PREVIEW.

class PREVIEW_3D_SCENE

inherit TOUCH_3D_SCENE redefine initialize_scene end

create make_component_scene

feature -- Interface

initialize_scene is -- Initialize the scene. local preview: PREVIEW do Precursor

create preview preview.run (map_widget)

click_here_button.clicked_event.subscribe (agent preview.explore_on_click) end

end

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INDEX >> TOUCH EXAMPLES >> new_example


Touch-Examples User GuideINDEX >> TOUCH EXAMPLES >> userguide_main

Touch implements some of the examples of the book ''A Touch of Class''.

How does this application work?

Each chapter respectively each example has its own application. All examples look almost the same, except forsome minor changes to meet the requirements of the individual exercise.

The window contains a square to display the map and a control panel at the right side. The control panelconsists of two parts: One is for navigating throuch the map using for example zoom in or zoom out and theother is the console where possible output is displayed. Dependant on the exercise there are more buttons toclick (for example a restart button etc.).

The button ''click here'' starts the execution of the example.

Figure 1: Example Scene

Navigation

You navigate on the map by pressing the mouse buttons.

Pressing the left mouse button while moving the mouse up or down will lift the map up or push it down.Pressing the right mouse button while moving the mouse will scroll the map.Moving the mouse up or down while pressing the middle mouse button will zoom in or out.Clicking the left mouse button will select places or lines.

INDEX >> TOUCH EXAMPLES >> userguide_main


Supported Touch examplesINDEX >> TOUCH EXAMPLES >> supported_examples

Preview exampleQueries exampleCommands exampleRoad creation example

Preview example

class PREVIEW

inherit

TOURISM

feature -- Example

explore_on_click is -- Execute preview example. do Paris.display Louvre.lighten Route1.animate Line8.spotlight Paris.build Paris.equip Console.show (Line8) Console.show (Place_balard) end

end

Queries example

class QUERIES

inherit

TOURISM

feature -- Example

explore_on_click is -- Show some queries. do Paris.display Console.show (line8.count) Console.show (line8.i_th (1)) Console.show (line8.i_th (line8.count)) end

end

Commands example

class COMMANDS

inherit

TOURISM

feature -- Example

explore_on_click is -- Try some commands. do Paris.display Line8.remove_all_sections Line8.extend_place (Place_la_motte_picquet_grenelle) Line8.extend_place (Place_invalides) Line8.highlight end

end

Road creation example

class ROAD_CREATION inherit TOURISM redefine explore end TOUCH_ROAD feature -- Example explore is -- Some information. do console.set_text ("This is an example of a road creation. C paris.display end explore_on_click is -- Create a road and animate it. do create place1.make_with_pos ("Place 1", 50, 50) create place2.make_with_pos ("Place 2", 90, 50) create place3.make_with_pos ("Place 3", 130, 50) create place4.make_with_pos ("Place 4", 170, 50) create place5.make_with_pos ("Place 5", 210, 90) create place6.make_with_pos ("Place 6", 210, 130) create place7.make_with_pos ("Place 7", 210, 170) create place8.make_with_pos ("Place 8", 210, 210) create place9.make_with_pos ("Place 9", 210, 250) create place10.make_with_pos ("Place 10", 90, 150) place1.link (place2) place2.link (place3) place3.link (place4) place4.link (place5) place5.link (place6) place6.link (place7) place7.link (place8) place8.link (place9) place9.link (place10) map_widget.disable_lines_shown -- Used for better contrast make_colored_road(place1, 5, 10, 25) end end

INDEX >> TOUCH EXAMPLES >> supported_examples


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