Layouts

What is this all about?

When young children learn how to count, they need to understand that the position of the objects doesn't matter. For example, if I show 10 objects in a line, and then move them around to form a circle, there are still 10 objects!

Requirements & dependencies

All scripts are implemented in Python. I've only tested this with Python 2.7.12. There are 2 dependencies to external libraries that are not included in the Python standard library:

• Pillow - an imaging library used to create visual representation of the layout
• mock - mocking library used in unit tests

To install all 3rd-party dependencies run:

$ pip install -r requirements.txt

Running the CLI script

To interact with the layout generator you can use the provided main.py CLI script. To list all the available options use -h command line switch:

$ python main.py -h
usage: main.py [-h] [-t {horizontal_line,random,grid,circle}] [-r RADIUS]
               width height num_items

Arrange circles of RADIUS in the selected layout.

positional arguments:
  width                 container width
  height                container height
  num_items             number of items to add to container

optional arguments:
  -h, --help            show this help message and exit
  -t {horizontal_line,random,grid,circle}, --layout-type {horizontal_line,random,grid,circle}
                        type of layout to generate. default: horizontal_line
  -r RADIUS, --radius RADIUS
                        radius of the items. default: 10px

This script prints out coordinates of items laid out in different layouts within the container of specified size. The format of the output is:

[(x0, y0, r0), (x1, y1, r1), (xN, yN, rN), ...]

The layout image is also saved as bitmap file in plot.bmp and placed in the current working directory.

If the number of items can't be arranged in the container of specified size or the items would overlap then an error message will be printed.

Example layouts:

Layout	Command	Output	Plot
Horizontal line	python main.py -t grid 100 100 3	[(33, 33, 10), (33, 67, 10), (67, 33, 10)]
Grid	python main.py -r 5 100 20 5	[(10, 9, 5), (30, 9, 5), (50, 9, 5), (70, 9, 5), (90, 9, 5)]
Circle	python main.py -r 4 -t circle 70 50 3	[(30, 36, 4), (29, 15, 4), (47, 25, 4)]
Random	python main.py -t random 100 100 10	[(59, 25, 10), (22, 64, 10), (88, 77, 10), (82, 54, 10), (31, 41, 10), (59, 49, 10), (31, 88, 10), (81, 18, 10), (60, 79, 10), (32, 14, 10)]

Running unit tests

$ make test