Hello World

The classic first window.
Component basics
Graphics drawing calls
A first paint and resized pair
Source: examples/GUI/HelloWorldDemo.h on GitHub.
HelloWorldDemo.h
cpp
/*******************************************************************************
 The block below describes the properties of this PIP. A PIP is a short snippet
 of code that can be read by the Projucer and used to generate a JUCE project.

 BEGIN_JUCE_PIP_METADATA

 name:             HelloWorldDemo
 version:          1.0.0
 vendor:           JUCE
 website:          http://juce.com
 description:      Simple HelloWorld application.

 dependencies:     juce_core, juce_data_structures, juce_events, juce_graphics,
                   juce_gui_basics
 exporters:        xcode_mac, vs2022, vs2026, linux_make, xcode_iphone

 moduleFlags:      JUCE_STRICT_REFCOUNTEDPOINTER=1

 type:             Component
 mainClass:        HelloWorldDemo

 useLocalCopy:     1

 END_JUCE_PIP_METADATA

*******************************************************************************/

#pragma once


//==============================================================================
class HelloWorldDemo final : public Component
{
public:
    //==============================================================================
    HelloWorldDemo()
    {
        addAndMakeVisible (helloWorldLabel);

        helloWorldLabel.setFont (FontOptions (40.00f, Font::bold));
        helloWorldLabel.setJustificationType (Justification::centred);
        helloWorldLabel.setEditable (false, false, false);
        helloWorldLabel.setColour (Label::textColourId, Colours::black);
        helloWorldLabel.setColour (TextEditor::textColourId, Colours::black);
        helloWorldLabel.setColour (TextEditor::backgroundColourId, Colour (0x00000000));

        addAndMakeVisible (quitButton);
        quitButton.onClick = [] { JUCEApplication::quit(); };

        setSize (600, 300);
    }

    //==============================================================================
    void paint (Graphics& g) override
    {
        g.fillAll (Colour (0xffc1d0ff));

        g.setColour (Colours::white);
        g.fillPath (internalPath);

        g.setColour (Colour (0xff6f6f6f));
        g.strokePath (internalPath, PathStrokeType (5.200f));
    }

    void resized() override
    {
        helloWorldLabel.setBounds (152, 80, 296, 48);
        quitButton.setBounds (getWidth() - 176, getHeight() - 60, 120, 32);

        internalPath.clear();
        internalPath.startNewSubPath (136.0f, 80.0f);
        internalPath.quadraticTo (176.0f, 24.0f, 328.0f, 32.0f);
        internalPath.quadraticTo (472.0f, 40.0f, 472.0f, 104.0f);
        internalPath.quadraticTo (472.0f, 192.0f, 232.0f, 176.0f);
        internalPath.lineTo (184.0f, 216.0f);
        internalPath.lineTo (200.0f, 168.0f);
        internalPath.quadraticTo (96.0f, 136.0f, 136.0f, 80.0f);
        internalPath.closeSubPath();
    }

private:
    //==============================================================================
    Label helloWorldLabel { {}, TRANS ("Hello World!") };
    TextButton quitButton { TRANS ("Quit") };
    Path internalPath;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (HelloWorldDemo)
};
Hello World ​

Hello World
