ImGui scrollable columns with header

Exemple.cpp

///////////////////////////////
// Exemple
///////////////////////////////

Core::ImGuiPlus::StackId oStackId( "Columns" );
				
ImGui::Columns( 3 );
ImGui::Text( "Header1" );
ImGui::NextColumn();
ImGui::Text( "Header2" );
ImGui::NextColumn();
ImGui::Text( "Header3" );
ImGui::NextColumn();
ImGui::Columns();
oStackId.Pop();

ImGui::Separator();

ImGui::BeginChild( "Columns", ImGui::GetContentRegionAvail() );
oStackId.Push();
ImGui::Columns( 3 );
for( int I = 0; I < 150; ++I )
{
	ImGui::Text( "Test1" );
	ImGui::NextColumn();
	ImGui::Text( "Test2" );
	ImGui::NextColumn();
	ImGui::Text( "Test3" );
	ImGui::NextColumn();
}
ImGui::Columns();
oStackId.Pop();
ImGui::EndChild();

StackId.cpp

///////////////////////////////
// Source
///////////////////////////////

StackId::StackId( const char* pString )
{
	m_bPushed = false;
	m_iId = ImGui::GetID( pString );
	Push();
}

StackId::StackId( void* pData )
{
	m_bPushed = false;
	m_iId = ImGui::GetID( pData );
	Push();
}

StackId::StackId( int iId )
{
	m_bPushed = false;
	m_iId = ImGui::GetID( (const void*)iId );
	Push();
}

StackId::~StackId()
{
	if( m_bPushed )
		Pop();
}

void StackId::Push()
{
	IM_ASSERT( m_bPushed == false );
	m_bPushed = true;
	ImGuiWindow* pWindow = ImGui::GetCurrentWindow();
	pWindow->IDStack.push_back( m_iId );
}

void StackId::Pop()
{
	IM_ASSERT( m_bPushed == true );
	m_bPushed = false;
	ImGuiWindow* pWindow = ImGui::GetCurrentWindow();
	pWindow->IDStack.pop_back();
}

StackId.h

///////////////////////////////
// Header
///////////////////////////////

class StackId
{
public:
	StackId( const char* pString );
	StackId( void* pData );
	StackId( int iId );
	~StackId();

	void Push();
	void Pop();
protected:
	ImGuiID		m_iId;
	bool		m_bPushed;
};