Highlights

• Thread-safe progress bars and spinners
• Header-only library. Grab a copy of include/indicators
• Source for the above GIF can be found here
• MIT License

git clone https://github.com/p-ranav/indicators
cd indicators
mkdir build && cd build
cmake -DINDICATORS_SAMPLES=ON -DINDICATORS_DEMO=ON ..
make

Table of Contents

• Progress Bar
• Block Progress Bar
• Multi Progress
• Dynamic Progress
• Progress Spinner
• Contributing
• License

Progress bar

To introduce a progress bar in your application, include indicators/progress_bar.hpp and create a ProgressBar object. Here's the general structure of a progress bar:

{prefix} {start} {fill} {lead} {remaining} {end} {percentage} [{elapsed}<{remaining}] {postfix}
         ^^^^^^^^^^^^^ Bar Width ^^^^^^^^^^^^^^^   

The amount of progress in ProgressBar is maintained as a float in range [0, 100]. When progress reaches 100, the progression is complete.

From application-level code, there are two ways in which you can update this progress:

Update progress using bar.tick()

You can update the progress bar using bar.tick() which increments progress by exactly 1%.

#include <indicators/progress_bar.hpp>
#include <thread>
#include <chrono>

int main() {
  using namespace indicators;
  ProgressBar bar{
    option::BarWidth{50},
    option::Start{"["},
    option::Fill{"="},
    option::Lead{">"},
    option::Remainder{" "},
    option::End{"]"},
    option::PostfixText{"Extracting Archive"},
    option::ForegroundColor{Color::green}
  };
  
  // Update bar state
  while (true) {
    bar.tick();
    if (bar.is_completed())
      break;
    std::this_thread::sleep_for(std::chrono::milliseconds(100));
  }

  return 0;
}

The above code will print a progress bar that goes from 0 to 100% at the rate of 1% every 100 ms.

Updating progress using bar.set_progress(value)

If you'd rather control progress of the bar in discrete steps, consider using bar.set_progress(value). Example:

#include <chrono>
#include <indicators/progress_bar.hpp>
#include <thread>

int main() {

  // Hide cursor
  std::cout << "\e[?25l";
  using namespace indicators;
  ProgressBar bar{
    option::BarWidth{50},
    option::Start{"["},
    option::Fill{"■"},
    option::Lead{"■"},
    option::Remainder{"-"},
    option::End{" ]"},
    option::PostfixText{"Loading dependency 1/4"},
    option::ForegroundColor{Color::cyan}  
  };

  // Update bar state
  bar.set_progress(10); // 10% done

  // do some work
  std::this_thread::sleep_for(std::chrono::milliseconds(800));

  bar.set_option(option::PostfixText{"Loading dependency 2/4"});  

  bar.set_progress(30); // 30% done

  // do some more work
  std::this_thread::sleep_for(std::chrono::milliseconds(700));

  bar.set_option(option::PostfixText{"Loading dependency 3/4"});  

  bar.set_progress(65); // 65% done

  // do final bit of work
  std::this_thread::sleep_for(std::chrono::milliseconds(900));

  bar.set_option(option::PostfixText{"Loaded dependencies!"});

  bar.set_progress(100); // all done

  bar.mark_as_completed();

  // Show cursor
  std::cout << "\e[?25h";  

  return 0;
}

Showing Time Elapsed/Remaining

All progress bars and spinners in indicators support showing time elapsed and time remaining. Inspired by python's tqdm module, the format of this meter is [{elapsed}<{remaining}]:

#include <chrono>
#include <indicators/progress_bar.hpp>
#include <thread>

int main() {
  using namespace indicators;
  indicators::ProgressBar bar{
    option::BarWidth{50},
    option::Start{" ["},
    option::Fill{"█"},
    option::Lead{"█"},
    option::Remainder{"-"},
    option::End{"]"},
    option::PrefixText{"Training Gaze Network 👀"},
    option::ForegroundColor{Color::yellow},
    option::ShowElapsedTime{true},
    option::ShowRemainingTime{true}
  };

  // Update bar state
  while (true) {
    bar.tick();
    if (bar.is_completed())
      break;
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
  }

  // Show cursor
  std::cout << "\e[?25h";  

  return 0;
}

Block Progress Bar

Are you in need of a smooth block progress bar using unicode block elements? Use BlockProgressBar instead of ProgressBar. Thanks to this blog post for making BlockProgressBar an easy addition to the library.

#include <indicators/block_progress_bar.hpp>
#include <thread>
#include <chrono>

int main() {

  // Hide cursor
  std::cout << "\e[?25l";
  using namespace indicators;

  BlockProgressBar bar{
    option::BarWidth{80},
    option::Start{"["},
    option::End{"]"},
    option::ForegroundColor{Color::white}  
  };
  
  // Update bar state
  auto progress = 0.0f;
  while (true) {
    bar.set_progress(progress);
    progress += 0.25f;
    if (bar.is_completed())
      break;
    std::this_thread::sleep_for(std::chrono::milliseconds(50));
  }

  // Show cursor
  std::cout << "\e[?25h";  

  return 0;
}

MultiProgress

indicators supports management of multiple progress bars with the MultiProgress class template.

template <typename Indicator, size_t count> class MultiProgress is a class template that holds references to multiple progress bars and provides a safe interface to update the state of each bar. MultiProgress works with both ProgressBar and BlockProgressBar classes.

Below is an example MultiProgress object that manages three ProgressBar objects.

#include <indicators/multi_progress.hpp>
#include <indicators/progress_bar.hpp>

int main() {
  using namespace indicators;
  // Configure first progress bar
  ProgressBar bar1{
    option::BarWidth{50},
    option::Start{"["},
    option::Fill{"■"},
    option::Lead{"■"},
    option::Remainder{" "},
    option::End{" ]"},
    option::ForegroundColor{Color::yellow},
    option::ShowElapsedTime{true},
    option::ShowRemainingTime{true},
    option::PrefixText{"Progress Bar #1 "}
  };

  // Configure second progress bar

  ProgressBar bar2{
    option::BarWidth{50},
    option::Start{"["},
    option::Fill{"="},
    option::Lead{">"},
    option::Remainder{" "},
    option::End{" ]"},
    option::ForegroundColor{Color::cyan},
    option::ShowElapsedTime{true},
    option::ShowRemainingTime{true},
    option::PrefixText{"Progress Bar #2 "}
  };
  
  // Configure third progress bar
  indicators::ProgressBar bar3{
    option::BarWidth{50},
    option::Start{"["},
    option::Fill{"#"},
    option::Lead{"#"},
    option::Remainder{" "},
    option::End{" ]"},
    option::ForegroundColor{Color::red},
    option::ShowElapsedTime{true},
    option::ShowRemainingTime{true},
    option::PrefixText{"Progress Bar #3 "}
  };

  // Construct MultiProgress object
  indicators::MultiProgress<indicators::ProgressBar, 3> bars(bar1, bar2, bar3);

  std::cout << "Multiple Progress Bars:\n";

  auto job1 = [&bars]() {
    while (true) {
      bars.tick<0>();
      if (bars.is_completed<0>())
        break;
      std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
  };

  auto job2 = [&bars]() {
    while (true) {
      bars.tick<1>();
      if (bars.is_completed<1>())
        break;
      std::this_thread::sleep_for(std::chrono::milliseconds(200));
    }
  };

  auto job3 = [&bars]() {
    while (true) {
      bars.tick<2>();
      if (bars.is_completed<2>())
        break;
      std::this_thread::sleep_for(std::chrono::milliseconds(60));
    }
  };

  std::thread first_job(job1);
  std::thread second_job(job2);
  std::thread third_job(job3);

  first_job.join();
  second_job.join();
  third_job.join();

  return 0;
}

DynamicProgress

DynamicProgress is a container class, similar to MultiProgress, for managing multiple progress bars. As the name suggests, with DynamicProgress, you can dynamically add new progress bars. Simply call bars.push_back.

Below is an example DynamicProgress object that manages six ProgressBar objects. Three of these bars are added dynamically.

#include <indicators/dynamic_progress.hpp>
#include <indicators/progress_bar.hpp>
using namespace indicators;

int main() {

  ProgressBar bar1{option::BarWidth{50}, option::ForegroundColor{Color::red},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"5c90d4a2d1a8: Downloading "}};

  ProgressBar bar2{option::BarWidth{50}, option::ForegroundColor{Color::yellow},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"22337bfd13a9: Downloading "}};

  ProgressBar bar3{option::BarWidth{50}, option::ForegroundColor{Color::green},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"10f26c680a34: Downloading "}};

  ProgressBar bar4{option::BarWidth{50}, option::ForegroundColor{Color::white},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"6364e0d7a283: Downloading "}};

  ProgressBar bar5{option::BarWidth{50}, option::ForegroundColor{Color::blue},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"ff1356ba118b: Downloading "}};

  ProgressBar bar6{option::BarWidth{50}, option::ForegroundColor{Color::cyan},
                   option::ShowElapsedTime{true}, option::ShowRemainingTime{true},
                   option::PrefixText{"5a17453338b4: Downloading "}};

  std::cout << termcolor::bold << termcolor::white << "Pulling image foo:bar/baz\n";

  // Construct with 3 progress bars. We'll add 3 more at a later point
  DynamicProgress<ProgressBar> bars(bar1, bar2, bar3);
  
  // Do not hide bars when completed
  bars.set_option(option::HideBarWhenComplete{false});

  std::thread fourth_job, fifth_job, sixth_job;

  auto job4 = [&bars](size_t i) {
    while (true) {
      bars[i].tick();
      if (bars[i].is_completed()) {
        bars[i].set_option(option::PrefixText{"6364e0d7a283: Pull complete "});
        bars[i].mark_as_completed();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(50));
    }
  };

  auto job5 = [&bars](size_t i) {
    while (true) {
      bars[i].tick();
      if (bars[i].is_completed()) {
        bars[i].set_option(option::PrefixText{"ff1356ba118b: Pull complete "});
        bars[i].mark_as_completed();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
  };

  auto job6 = [&bars](size_t i) {
    while (true) {
      bars[i].tick();
      if (bars[i].is_completed()) {
        bars[i].set_option(option::PrefixText{"5a17453338b4: Pull complete "});
        bars[i].mark_as_completed();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(40));
    }
  };

  auto job1 = [&bars, &bar6, &sixth_job, &job6]() {
    while (true) {
      bars[0].tick();
      if (bars[0].is_completed()) {
        bars[0].set_option(option::PrefixText{"5c90d4a2d1a8: Pull complete "});
        // bar1 is completed, adding bar6
        auto i = bars.push_back(bar6);
        sixth_job = std::thread(job6, i);
        sixth_job.join();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(140));
    }
  };

  auto job2 = [&bars, &bar5, &fifth_job, &job5]() {
    while (true) {
      bars[1].tick();
      if (bars[1].is_completed()) {
        bars[1].set_option(option::PrefixText{"22337bfd13a9: Pull complete "});
        // bar2 is completed, adding bar5
        auto i = bars.push_back(bar5);
        fifth_job = std::thread(job5, i);
        fifth_job.join();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(25));
    }
  };

  auto job3 = [&bars, &bar4, &fourth_job, &job4]() {
    while (true) {
      bars[2].tick();
      if (bars[2].is_completed()) {
        bars[2].set_option(option::PrefixText{"10f26c680a34: Pull complete "});
        // bar3 is completed, adding bar4
        auto i = bars.push_back(bar4);
        fourth_job = std::thread(job4, i);
        fourth_job.join();
        break;
      }
      std::this_thread::sleep_for(std::chrono::milliseconds(50));
    }
  };

  std::thread first_job(job1);
  std::thread second_job(job2);
  std::thread third_job(job3);

  third_job.join();
  second_job.join();
  first_job.join();

  std::cout << termcolor::bold << termcolor::green << "✔ Downloaded image foo/bar:baz" << std::endl;
  std::cout << termcolor::reset;

  return 0;
}

In the above code, notice the option bars.set_option(option::HideBarWhenComplete{true});. Yes, you can hide progress bars as and when they complete by setting this option to true. If you do so, the above example will look like this:

Progress Spinner

To introduce a progress spinner in your application, include indicators/progress_spinner.hpp and create a ProgressSpinner object. Here's the general structure of a progress spinner:

{prefix} {spinner} {percentage} [{elapsed}<{remaining}] {postfix}

ProgressSpinner has a vector of strings: spinner_states. At each update, the spinner will pick the next string from this sequence to print to the console. The spinner state can be updated similarly to ProgressBars: Using either tick() or set_progress(value).

#include <indicators/progress_spinner.hpp>

int main() {
  using namespace indicators;
  indicators::ProgressSpinner spinner{
    option::PostfixText{"Checking credentials"},
    option::ForegroundColor{Color::yellow},
    option::SpinnerStates{std::vector<std::string>{"⠈", "⠐", "⠠", "⢀", "⡀", "⠄", "⠂", "⠁"}}
  };
 
  // Update spinner state
  auto job = [&spinner]() {
    while (true) {
      if (spinner.is_completed()) {
        spinner.set_option(option::ForegroundColor{Color::green});
        spinner.set_option(option::PrefixText{"✔"});
        spinner.set_option(option::ShowSpinner{false});
        spinner.set_option(option::ShowPercentage{false});
        spinner.set_option(option::PostfixText{"Authenticated!"});
        spinner.mark_as_completed();	
        break;
      } else
        spinner.tick();
      std::this_thread::sleep_for(std::chrono::milliseconds(40));
    }
  };
  std::thread thread(job);
  thread.join();  

  return 0;
}

Contributing

Contributions are welcome, have a look at the CONTRIBUTING.md document for more information.

License

The project is available under the MIT license.