Scrollable AttributedString component

ScrollableTextView.cpp

#include "ScrollableTextView.h"

struct ScrollableTextContainerView : public Component
{
    void refreshSize()
    {
        int width = _parentViewport->getWidth() - 2*_spacing;
        _drawingLayout.createLayoutWithBalancedLineLengths(_attributedString, width);
        this->setSize(width, _drawingLayout.getHeight() + 2.0*_spacing);
    }
    
    virtual void paint(Graphics& g) override
    {
        g.setColour(Colours::black);
        if (_attributedString.getText().length() == 0)
            return;
        
        _drawingLayout.draw(g, Rectangle<float>(_spacing, _spacing, getWidth(),
                                                getHeight()-2*_spacing));
    }
    
    virtual void resized() override
    {
        Component::resized();
        this->refreshSize();
    }
    
    const int _spacing = 10;
    AttributedString _attributedString;
    Viewport* _parentViewport;
    TextLayout _drawingLayout;
};

//----------------------------------------------------------------------//
// ScrollableTextView
//----------------------------------------------------------------------//
#pragma mark ScrollableTextView

ScrollableTextView::ScrollableTextView()
{
    ScrollableTextContainerView* container = new ScrollableTextContainerView();
    this->setViewedComponent(container);
    container->setBounds(0, 0, getWidth(), getHeight());
    container->_parentViewport = this;
}

ScrollableTextView::~ScrollableTextView()
{
    delete getViewedComponent();
}

void ScrollableTextView::paint(Graphics& g)
{
    g.fillAll(Colours::white);
}

void ScrollableTextView::resized()
{
    Viewport::resized();
    
    ScrollableTextContainerView* container = (ScrollableTextContainerView*) getViewedComponent();
    container->refreshSize();
}

void ScrollableTextView::setAttributedString(const AttributedString& string)
{
    ScrollableTextContainerView* container = (ScrollableTextContainerView*) getViewedComponent();
    container->_attributedString = string;
    container->refreshSize();
}

ScrollableTextView.h

class ScrollableTextView : public juce::Viewport
{
public:
            
	ScrollableTextView();
    virtual ~ScrollableTextView();
            
    void setAttributedString(const juce::AttributedString& string);
           
private:
            
    juce::AttributedString _attrString;
    virtual void paint(juce::Graphics& g) override;
   	virtual void resized() override;
};