C++ Progress Bar

C++ class that implements a progress bar in console applications on both Linux and Windows platforms. The progress bar works by referencing an index that keeps updating when processing through a piece of code.

Key features

1. Control the number of updates the progress bar makes.
2. The ability to adjust the style of the progress bar.
3. The length of the progress bar displayed on screen adapts to the the width of the console.

Implementation

To use the progress bar, include the following header file:

#include "progress_bar.hpp"

Creating a progress bar

To create a progress bar, the total number of jobs need to be known.

int n = 10;
ProgressBar progress_bar(n);

Optionally, small descriptions can also be added to the progress bar.

int n = 10;
ProgressBar progress_bar(n, "Example 1");

Updating a progress bar

Updates to the progress bar are made using the increment operators.

Example 1:

int n = 10;
ProgressBar progress_bar(n, "Example 1");

int job_index = 0;

do_some_work();

job_index++;
progress_bar += 1;

do_some_more_work();

job_index++;
progress_bar += 1;

Example 2:

int n = 100;
ProgressBar bar1(n, "Example 1");

for (int i = 0; i <= n; ++i) {
    ++bar1;
    std::this_thread::sleep_for(std::chrono::milliseconds(10));
}

Setting the frequency of updates

If progressing through a large job list, iterating through every update will slow down the program. Using the method SetFrequencyUpdate(int freq) overcomes this problem by setting how many times the progress bar should be updated.

Example 3:

int n = 100000;
ProgressBar bar2(n, "Example 3");
bar2.SetFrequencyUpdate(10);

for (int i = 0; i <= n; ++i){
    ++bar2;
}

Changing the bar style

The progress bar can be customised using the SetStyle(const char*, const char*) method. This changes the ASCII/Unicode characters used for printing the progress bar.

Example 4

n = 1000;
ProgressBar bar3(n, "Example 4");
bar3.SetFrequencyUpdate(10);
bar3.SetStyle("\u2588", "-");

for (int i = 0; i <= n; ++i) {
    ++bar3;
}

Main Example

#include <iostream>
#include <thread>
#include <chrono>

#include "progress_bar.hpp"


int main() {

    int n;

    /// Example 1 ///

    n = 100;
    ProgressBar bar1(n, "Example 1");

    for (int i = 0; i <= n; ++i) {
        ++bar1;
        std::this_thread::sleep_for(std::chrono::milliseconds(10));
    }

    /// Example 2 ///

    n = 1000;
    ProgressBar bar2(n, "Example 2");
    bar2.SetFrequencyUpdate(10);
    bar2.SetStyle("|", "-");
    //bar2.SetStyle("\u2588", "-"); for linux

    std::cout << std::endl;
    for (int i = 0; i <= n; ++i) {
        ++bar2;
        std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }

    n = 5;
    ProgressBar bar3(n);
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    // following tests exception error
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;
    std::this_thread::sleep_for(std::chrono::milliseconds(200));
    ++bar3;

    return 0;
}