CS 312 - Week 7 Class 1
CS 312 Audio Programming Winter 2020

Click the Project tool in the left toobar

Make these settings.

• Shadow build checked

• Click the Choose button and navigate to the build-hw71 folder.

  

Click the green arrow on the left toolbar to build and run the application.

Note:
The icon directly below Run is the "Debug Run" button. Qt comes with an excellent debugger based on llvm and clang.

A blank window will appear with the title "MainWindow".

• You can move it around and resize it.
• The red, yellow, and green buttons in the window title bar buttons work as expected.
• There is an hw711_cmidiin_gui menu that you can use to Quit the app.

• You can also quit by clicking the red close button in the window title bar.

  

The Edit tool gives you access to all your project files. The main.cpp file has been selected. You'll notice how few lines of code it uses. The mainwindow.cpp file is where you code responses to GUI actions like mouse clicks, key presses, and menu choices. The mainwindow.ui file contians the GUI design you've create.

Double click the mainwindow.ui file. The .ui extension is used for User Interface files that are built using the Design tool. A blank window representing the MainWindow will open. A list of widgets you can drag into the form are shown on the left.

Select the MainWindow form and name the window MIDI Monitor in the windowTitle field on the right. You'll have to scroll to find it.

Set the minimumSize and maximumSize to give the window a fixed dimension.

Drag a single Push Button widget into the ui window. Then create the other three by selecting the button you just placed and Option-dragging to create copies.

Add a plainTextEdit widget.

Arrange them like this.

Double click the push button text to change the button names as shown.

Or type the name in the object properties list.

Assign the the variable name pushButton_record to Record button. That name will be used to reference the Record button in your code.

Assign these variable names to the other three buttons.

• pushButton_play
• pushButton_stop
• pushButton_clear

The variable names and types of the UI objects appear in the upper right panel. This panel can also be used to select objects on the main form.

Select the plainTextEdit widget. We'll accept the default name, plainTextEdit, because it's the only on on the form.

Add the ScrollBar policies.

Build and Run
Click the green arrow on the left toolbar to build and run the application.

The window will appear with the title "MIDI Monitor".

• You can move it around but you cannot resize it.
• You can type into the text area.
• If you fill the text area a scroll bar will appear and you can scroll through the text.
• Copy and paste works.
• Undo works.
• Select all works.
• Text cursor movement using arrow keys works.
• Command-UpArrow takes you to the top of the text.
• Command-DownArrow takes you to the bottom of the text.
• You can click the buttons and they highlight as long as the mouse is held down.
• You can close the window using the red close button.
• You can close the window using the Quit command in the hw711_Qt_cmidiin_gui menu.

• All this comes for free.

  

Close the project from the Qt Creator File menu.

Open the hw712_Qt_cmidiin.pro file. You should see this.

Make these changes. Copy/paste snippets are shown below the screenshot.

You can copy/paste sections from here. Be sure to match up with the picture above.

#CONFIG += c++11
CONFIG += c++17

## Mac OS specific qmake options
macx {
TARGET = hw711_Qt_cmidiin
TEMPLATE = app
    CONFIG += app_bundle
    INCLUDEPATH += /Users/je/cs312/common
    INCLUDEPATH += /Library/Frameworks/
    QMAKE_LFLAGS += -F/Library/Frameworks
    QMAKE_CXXFLAGS += -D__MACOSX_CORE__
    LIBS += -framework CoreFoundation \
        -framework CoreMIDI \
        -framework CoreAudio
    QMAKE_CXXFLAGS_WARN_ON += -Wno-unknown-pragmas
    QMAKE_MACOSX_DEPLOYMENT_TARGET = 10.14
#    ICON = MIDIDisplay.icns
}

SOURCES += \
    main.cpp \
    mainwindow.cpp \
    RtMidi.cpp \
    hw332_CMidiPacket.cpp

HEADERS += \
    mainwindow.h \
    RtMidi.h \
    hw332_CMidiPacket.h
FORMS += \
    mainwindow.ui

After a short pause you should see the files appear in the Edit panel.

Change the project build folder to build-hw722
Click the Project tool and make these changes.

Build and run
You should have no errors at this point.

mainwindow.h
Make these changes.

VMPK and midiprobe

• If VMPK is not open, open it.
• Run /midiprobe.
• Make note of the VMPK Input and the DLSMusicDevice Output port numbers.

je$ midiprobe

Compiled APIs:
  OS-X CoreMIDI

Current input API: OS-X CoreMIDI

There are 2 MIDI input sources available.
  Input Port #0: IAC Driver Bus 1
  Input Port #1: VMPK Output

Current output API: OS-X CoreMIDI

There are 3 MIDI output ports available.
  Output Port #0: IAC Driver Bus 1
  Output Port #1: DLSMusicDevice
  Output Port #2: VMPK Input

It's slightly confusing the way MIDI is connected. This is true for both hardware and software.

• The device Output (VMPK Output) connects to the computer input (RtMidiIn).
• The computer output (DLSMusicDevice) connects to the device input (IAC Driver Bus 1).

mainwindow.cpp
Make these changes

Then copy and implement this code below the MIDI Utilities comment.

void mycallback( double deltatime, std::vector<unsigned char>* message, void* /*userData*/ )
{
    // This is the same callback you wrote for hw621_cmidiin_cmp33
    // to convert message into CMidiPacket data
    // up until you got to std::cout

    /*
      This is new
      You cannot use std::cout
      You have to use the QPlainTextEdit function insertPlainText.
      Click the Help icon in QtCreator and read about
      QPlainTextEdit
      QString
      Remember the variable pte is a pointer to a QPlainTextEdit widget
      You have to use this
      pte->insertPlainText(const QString &text)
      You've already got a CMidiPacket and you can use mp.to_string();
      Use Qt Help or google to find out how to convert a std::string into a QString.
    */

    // I did it in two lines of code
}

void MainWindow::init_midi_in( uint32_t num )
{
    // copy from c622_rt_cmidiin
    try
    {
       // gmidiin varaiable is in .h class
       // create gmidiin
    }

    catch ( RtMidiError& error )
    {
        error.printMessage();
        exit( EXIT_FAILURE );
    }

//    open midiin port( num ); // num is from result of midiprobe.
//    set midiin callback
//    maybe call ignoreTypes
}

void MainWindow::init_midi_out( uint32_t num )
{
    // copy from c623_rt_cmidiout
    try
    {
       // gmidiout varaiable is in .h class
       // create gmidiout
    }

    catch ( RtMidiError& error )
    {
        error.printMessage();
        exit( EXIT_FAILURE );
    }
//    open midiout port( num ); // num is from result of midiprobe.
}

You can use most of the same code you used the hw621_cmidiin_cmp33 callback function.

Eliminate any warnings displayed in the code
Type conversion warning can be fixed using static_cast.

Build and Run the project
If there are no errors the MIDI Monitor window will appear.

Play notes and move controls on the VMPK software keyboard. You should see CMidiPacket messages appear with timestamps in the QPlainTextEdit widget.