Trouble getting access to AudioProcessor Variable in Component

General JUCE discussion
1

I know, another noob who cannot do C++ :slight_smile:

I have a Component that sits on a Class that sits on a Tab that sits on the PluginEditor.

The Class that the Component sits on has access to the AudioProcessor variables via a reference passed in, Header File below:

class LibrarianPage  : public juce::Component,
                       public juce::Button::Listener,
                       public juce::Timer
{
public:
    LibrarianPage(KorgRadiasAudioProcessor&);
    ~LibrarianPage() override;

    void paint (juce::Graphics&) override;
    void resized() override;

private:
    KorgRadiasAudioProcessor& audioProcessor;

Then in the .cpp File:

#include <JuceHeader.h>
#include "LibrarianPage.h"
//#include "PluginEditor.h"

//==============================================================================
LibrarianPage::LibrarianPage(KorgRadiasAudioProcessor& p) : audioProcessor(p)
{
    // Librarian Components
    // --------------------
    addAndMakeVisible(librarianComponent);
    //addAndMakeVisible(librarianComponent(audioProcessor));
    addAndMakeVisible(librarianPatchHeaderComponent);
    addAndMakeVisible(librarianBankHeaderComponent);

And I will admit that I do not fully know how this works but it does!

But the librarianComponent that gets constructed on the LibrarianPage (above) has no access to variables in the AudioProcessor, I tried to copy the way that the LibrarianPage does it but it won’t work!

The LibrarianComponent is all in one header file, like:

#pragma once

#include <JuceHeader.h>
//#include "PluginEditor.h"

//==============================================================================
/*
*/
class LibrarianComponent  : public juce::Component
{
public:

    LibrarianComponent()//(KorgRadiasAudioProcessor& p) : audioProcessor(p)
    {
    }

    ~LibrarianComponent() override
    {
    }

	int startX;
	int startY;
	int dragX;
	int dragY;
	int endX;
	int endY;
	int mouse_down;
	int mouse_up;
	int mouse_drag;

	//KorgRadiasAudioProcessor& audioProcessor;

	void mouseDown(const juce::MouseEvent &event)
	{
		startX = event.getMouseDownX();
		startY = event.getMouseDownY();

		//DBG("Mouse Down X " << startX);
		//DBG("Mouse Down Y " << startY);

		mouse_down = 1;
		mouse_up = 0;
		repaint();		
	}

	void mouseDrag(const juce::MouseEvent &event)
	{
		mouse_drag = 1;
		mouse_up = 0;
		dragX = startX + event.getDistanceFromDragStartX();
		dragY = startY + event.getDistanceFromDragStartY();
		repaint();
	}

	void mouseUp(const juce::MouseEvent& event)
	{
		endX = startX + event.getDistanceFromDragStartX();
		endY= startY + event.getDistanceFromDragStartY();
	
		//DBG("Mouse Up X " << endX);
		//DBG("Mouse Up Y " << endY);
		mouse_down = 0;
		mouse_drag = 0;
		mouse_up = 1;
		repaint();
	}

	void paint(juce::Graphics& g) override
	{

		int comp_height = getHeight();
		int comp_width = getWidth();

		int margin = 10;

		int no_of_banks = 16;
		int no_of_patches = 16;

		int slot_width = comp_width / no_of_patches;
		int slot_height = comp_height / no_of_banks;

		int mem_width = (comp_width - (no_of_patches * margin)) / no_of_patches;
		int mem_height = (comp_height - (no_of_banks * margin)) / no_of_banks;


		// Draw the Background
		// -------------------
		g.fillAll(getLookAndFeel().findColour(juce::ResizableWindow::backgroundColourId));
		g.setColour(juce::Colours::black);
		juce::Rectangle <float> area = getLocalBounds().toFloat();
		g.fillRoundedRectangle(area, 8.0f);


		// Draw the Memory Slots & Patch Names
		// -----------------------------------
		for (int i = 0; i <= (no_of_patches - 1); i++)
		{
			for (int j = 0; j <= (no_of_banks - 1); j++)
			{
				g.setColour(juce::Colours::silver);
				juce::Rectangle <float> rect1(margin + ((mem_width * j) + (margin * j)), margin + ((mem_height * i) + (margin * i)), mem_width, mem_height);
				g.fillRoundedRectangle(rect1, 4.0f);

				g.setColour(juce::Colours::black);
				g.setFont(14.0);
				g.drawText(audioProcessor.librarianPatchNames_SA[1 + i + (j * 16)], margin + ((mem_width * j) + (margin * j)), margin + ((mem_height * i) + (margin * i)), mem_width, mem_height, juce::Justification::centred, true);

			}
		}

The reference to audioProcessor.librarianPatchNames_SA (just above) which is declared in the PluginProcessor is what I need to get access to!

You can see the commented out bits where I tried the same approach to try and pass a reference to the AudioProcessor in but just got ‘no default constructor exists’ type errors!

I know I’m doing something dumb, but could someone be so kind as to explain my error please?

2

If you uncomment the lines in your LibrarianComponent header, the ‘no default constructor’ error can be solved by explicitly initialising the librarianComponent on your LibrarianPage constructor:

LibrarianPage::LibrarianPage(KorgRadiasAudioProcessor& p) : audioProcessor(p), librarianComponent(p)

Does that help?

3

willcassidy7 you’re my hero :slight_smile:

I’ll admit my C++ skills need some polishing up, what exactly is happening here?

We are passing a reference to the AudioProcessor into the LibrarianPage Constructor and calling it p ?

We then give p the name audioProcessor which we then pass into the LibrarianComponent as well?

Most of the problems I’m having are coming from that fact that I need Global Variables (for want of a better phrase) variables that I can access from just about anywhere because they hold global things like a String Array of Patch Names for instance!

At the moment I declare them in the PluginProcessor and then access them in the other Classes using that audioProcessor reference.

When it doesn’t work I get a bit lost, it was never this hard in LUA Scripting :slight_smile: