testdoublebufferappview.cpp

Symbian双缓冲画界面

/*
 ============================================================================
 Name		: TestDoubleBufferAppView.cpp
 Author	  : 
 Copyright   : Your copyright notice
 Description : Application view implementation
 ============================================================================
 */

// INCLUDE FILES
#include <coemain.h>
#include <EIKENV.h>
#include "TestDoubleBufferAppView.h"

// ============================ MEMBER FUNCTIONS ===============================

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::NewL()
// Two-phased constructor.
// -----------------------------------------------------------------------------
//
CTestDoubleBufferAppView* CTestDoubleBufferAppView::NewL(const TRect& aRect)
	{
	CTestDoubleBufferAppView* self = CTestDoubleBufferAppView::NewLC(aRect);
	CleanupStack::Pop(self);
	return self;
	}

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::NewLC()
// Two-phased constructor.
// -----------------------------------------------------------------------------
//
CTestDoubleBufferAppView* CTestDoubleBufferAppView::NewLC(const TRect& aRect)
	{
	CTestDoubleBufferAppView* self = new ( ELeave ) CTestDoubleBufferAppView;
	CleanupStack::PushL(self);
	self->ConstructL(aRect);
	return self;
	}

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::ConstructL()
// Symbian 2nd phase constructor can leave.
// -----------------------------------------------------------------------------
//
void CTestDoubleBufferAppView::ConstructL(const TRect& aRect)
	{
	// Create a window for this application view
	CreateWindowL();

	// Set the windows size
	SetRect(aRect);

	InitDoubleBufferL();

	// Activate the window, which makes it ready to be drawn
	ActivateL();
	}

/**
 * 初始化双缓冲区
 */
void CTestDoubleBufferAppView::InitDoubleBufferL()
	{
	iBufBmp = new(ELeave)CWsBitmap(CEikonEnv::Static()->WsSession());
	CleanupStack::PushL(iBufBmp);
	User::LeaveIfError(iBufBmp->Create(Rect().Size(), CEikonEnv::Static()->ScreenDevice()->DisplayMode()));

	iBufDevice = CFbsBitmapDevice::NewL(iBufBmp);
	CleanupStack::PushL(iBufDevice);
	User::LeaveIfError(iBufDevice->CreateBitmapContext(iBufGc));

	CleanupStack::Pop(2); // iDevice, iBufBmp
	}

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::CTestDoubleBufferAppView()
// C++ default constructor can NOT contain any code, that might leave.
// -----------------------------------------------------------------------------
//
CTestDoubleBufferAppView::CTestDoubleBufferAppView()
	{
	// No implementation required
	}

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::~CTestDoubleBufferAppView()
// Destructor.
// -----------------------------------------------------------------------------
//
CTestDoubleBufferAppView::~CTestDoubleBufferAppView()
	{
	// No implementation required
	if (iBufBmp)
		{
		delete iBufBmp;
		iBufBmp = NULL;
		}

	if (iBufDevice)
		{
		delete iBufDevice;
		iBufDevice = NULL;
		}

	if (iBufGc)
		{
		delete iBufGc;
		iBufGc = NULL;
		}
	}

/**
 * 测试在缓冲区上绘制
 */
void CTestDoubleBufferAppView::DoTestDraw()
	{
	iBufGc->Clear(Rect());

	// 在buffer里画方块，而不是在屏幕上
	for (int i=0; i<100; i+=2)
		{
		iBufGc->DrawRect(TRect(TPoint(i, i), TSize(50, 50)));
		}

	}

/**
 * View的重绘事件
 */
void CTestDoubleBufferAppView::Draw(const TRect& /*aRect*/) const
	{
	// 以下代码忽略
	//	// Get the standard graphics context
	//	CWindowGc& gc = SystemGc();
	//
	//	// Gets the control's extent
	//	TRect drawRect(Rect());
	//
	//	// Clears the screen
	//	gc.Clear(drawRect);

	SystemGc().BitBlt(TPoint(0, 0), iBufBmp);

	}

// -----------------------------------------------------------------------------
// CTestDoubleBufferAppView::SizeChanged()
// Called by framework when the view size is changed.
// -----------------------------------------------------------------------------
//
void CTestDoubleBufferAppView::SizeChanged()
	{
	DrawNow();
	}
// End of File