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Lab 31: Fl_Progress bar and Timer events (Part II)

1. Description
2. Copying Visual Studio Project
3. Adding progress bar animation
4. How to submit

1. Description

• This project is Part II of the Lab 30. We add the logic to animate the progress bar according to the timer event notifications:

   

   

2. Copying Visual Studio Project

• The prototype for this project is Lab 30, the window with a progress bar and a button:

  
      c255labs\labs\c255_lab30_timer
  
  

• Make a copy of Lab 30 subfolder, or download and unzip c255_lab30_timer.zip

• Rename the new folder as c255_lab31_progress.

• Open solution file in Visual Studio and finish the usual steps to rename the project.

   

3. Adding progress bar animation

• Download the new versions of

  • CMainWindow.h

  • CMainWindow.cpp

• Compile and test the program.

• Open CMainWindow.h in the text editor and examine the code:

  • The progress bar label needs text, whereas our calculations use integer numbers. To convert numbers to text we use the standard library string and string stream:

    
        #include <string>
        #include <sstream>
    
    

  • The class also has new CMainWindow::progress_label string, which stores the text label for the progress bar widget.

• Open CMainWindow.cpp in the text editor and examine the code:

  • CMainWindow::show() hides the progress bar widget. When the application starts, only the "Animate" button is shown on the screen. The progress bar is configured for its range and component colors.

  • CMainWindow::callback_btn_animate() is invoked by the "Animate" button. The function resets the initial progress bar label and numeric value to zero.

  • CMainWindow::animate() updates the progress bar label and computes the value according to the m_progress_count value.

   

4. How to submit

• This is a self-learning lab. There are no files to submit. Make sure to complete all required steps to build and test the project on your own home computer.