Canvas Challenge

This project is a test task for credit-suisse canvas challenge.

The Problem

__Description_

You're given the task of writing a simple console version of a drawing program. 
At this time, the functionality of the program is quire limited but this might change in the future. 
In a nutshell, the program should work as follows:
 1. Create a new canvas
 2. Start drawing on the canvas by issuing various commands
 3. Quit


Command 		Description
C w h           Should create a new canvas of width w and height h.
L x1 y1 x2 y2   Should create a new line from (x1,y1) to (x2,y2). Currently only
                horizontal or vertical lines are supported. Horizontal and vertical lines
                will be drawn using the 'x' character.
R x1 y1 x2 y2   Should create a new rectangle, whose upper left corner is (x1,y1) and
                lower right corner is (x2,y2). Horizontal and vertical lines will be drawn
                using the 'x' character.
B x y c         Should fill the entire area connected to (x,y) with "colour" c. The
                behaviour of this is the same as that of the "bucket fill" tool in paint
                programs.
Q               Should quit the program.

__Sample I/O__

Below is a sample run of the program. User input is prefixed with enter command:

enter command: C 20 4
----------------------
|                    |
|                    |
|                    |
|                    |
----------------------

enter command: L 1 2 6 2
----------------------
|                    |
|xxxxxx              |
|                    |
|                    |
----------------------

enter command: L 6 3 6 4
----------------------
|                    |
|xxxxxx              |
|     x              |
|     x              |
----------------------

enter command: R 14 1 18 3
----------------------
|             xxxxx  |
|xxxxxx       x   x  |
|     x       xxxxx  |
|     x              |
----------------------

enter command: B 10 3 o
----------------------
|oooooooooooooxxxxxoo|
|xxxxxxooooooox   xoo|
|     xoooooooxxxxxoo|
|     xoooooooooooooo|
----------------------

enter command: Q

My solution

Prerequisites

This project use gradle as build tool. JDK 1.8 is required to build and run the tool

How to build

###run tests linux: ./gradlew clean test windows: gradlew.bat clean test

###build fat jar linux: ./gradlew clean fatJar windows: gradlew.bat clean fatJar

distribute

linux: ./gradlew clean distZip

windows: gradlew.bat clean distZip

Running tool

compiled tool with all dependencies located in build/distributions/canvas-challenge-1.0-SNAPSHOT.zip unpack zip to any folder, navigate to bin/ directory and run ./canvas-challenge (canvas-challenge.bat for windows)

you can run fat jar directly, use java -jar build/libs/canvas-challenge-all-1.0-SNAPSHOT.jar to run tool

Parameters

-vt100 - I've added some support of VT100 terminals. It is not required in task, but it was a bit fancy. Support is not good and can behave differently on different systems. I didn't use curses library, there are just simple ESC-sequences; Does not work under windows. May work in Cygwin, but I'm not sure.

-h - show help

Logging

All logs are written to canvas.log. By default they are in debug mode. Apache log4j2 is used for logging log4j2.xml is located inside jar, to change log level specify standard -Dlog4j.configurationFile=path/to/log4j2.xml

Implementation

Limitations:

All commands are case-sensitive
No terminal size checking. If you specify canvas size wider that current terminal size, it will be displayed incorrectly. However, this affects only rendering, in logs you can observe correct image.

Known issue:

There are a bit messy error message if wrong command with coordinates on border of canvas (or outside canvas) is entered. Internal coordinates are started with zero-based coordinates, while user operates with 1-based coordinates. I found this just after submission, I believe it is a minor issue :)

zulkar/test-challenge-canvas