Designing a custom progress bar

Barnacle offers the ability to easily design your own pogress bar. This section of the documentation details how this works.

Types of bars available

Several types of progress bars are available, and each can be customised. The types are:

• Simple objectslider
• Animated objectslider
• Interaction objectslider
• Textscroller
• Standard progressbar

Simple objectslider

The class: simple_objectslider that will slide a defined object across the progress bar, with settable leading and trailing characters and possible animations. As an example of the simplest form, consider this preset:

Example 1:

This bar is built from several parts:

To define this progress bar, a standardised dict{} object is used (the ‘start’ and ‘end’ characters are left to their default values:

{'icons': ['༼ つ ◕_◕ ༽つ', '༼ つ ◕_◕ ༽つ', ' ', '-']}

This dictionary contains a list of icons from which the progress bar will be built up. The icons need to be in the correct order, which is:

• icons: a list containing four elements at fixed indices:

0. the object to slide across the progress bar
1. the end-state of the object (what it looks like when it reaches the end of the progress bar)
2. trailing character: what to draw behind the object, use ‘ ‘ for blank
3. leading character: what to draw in front of the object, use ‘ ‘ for blank

So to use this progress bar, simply do:

import barnacle
import time

bar = barnacle.simple_objectslider()

custom_bar = {'icons': ['༼ つ ◕_◕ ༽つ', '༼ つ ◕_◕ ༽つ', ' ', '-']}
bar.load(custom_bar)

for i in range(0,51):
        bar.draw(i, 50) #update bar each step
        time.sleep(0.2) #simulate time consuming loop

Example 2:

As an example of the extra arguments in the dictionary, consider this preset:

Several things are happening here:

• The dude moving across the bar sometimes whistles
• A table is at the end of the bar
• When the dude reaches the end of the bar the table is flipped and the dude throws up his arms
• For example’s sake let’s use a custom bar terminator and custom trailing character

The preset dict is defined as:

{'icons': ['( °-°) ', '(╯°□°)╯', '.', ' ', '( °-°)♪'],
'target_icons': ['┳━┳    ', ' ~~ ┻━┻ '], 'extra_odds': 0.2,
    'start': '<', 'end': '>'}

Several arguments are in the dict:

• just like before, icons: a list containing four elements at fixed indices:

0. the object to slide across the progress bar
1. the end-state of the object (what it looks like when it reaches the end of the progress bar)
2. trailing character: what to draw behind the object, here we use ‘.’ for the example’s sake
3. leading character: what to draw in front of the object, use ‘ ‘ for blank
4. extra: the ‘extra_icon’, the dude whistling

• target_icons: list containing two objects to be placed at the end of the progress bar. The elements are:

0. target object default state: while the bar is progressing this is drawn (here: normal table)
1. target end state, when the bar reaches the last step, this is drawn in stead of the 0th index

• extra_odds: the odds that the last element in ‘icons’ is drawn when the :draw(): method is called (here: dude whistling). Needs to be 0 <= extra_odds <= 1.0, with 0.5 representing a 50% chance each draw update.
• start: the start character of the bar
• end: the end character of the bar

Full example:

import barnacle
import time

bar = barnacle.simple_objectslider()

custom_bar = {'icons': ['( °-°) ', '(╯°□°)╯', '.', ' ', '( °-°)♪'],
                          'target_icons': ['┳━┳    ', ' ~~ ┻━┻ '], 'extra_odds': 0.2,
                          'start': '<', 'end': '>'}
bar.load(custom_bar)

for i in range(0,51):
        bar.draw(i, 50) #update bar each step
        time.sleep(0.2) #simulate time consuming loop

Docs on other bar types coming ASAP