Windows Touch 操作範例 (MTManipulation)
本節說明 Windows Touch 操作範例。
Windows Touch 操作範例示範如何使用 IManipulationProcessor 介面轉譯、旋轉及調整物件，以及實作 _IManipulationEvents 事件接收。 下列螢幕擷取畫面顯示執行範例時的外觀。
在此範例中，會建立 CDrawingObject 類別，以程式設計方式翻譯、旋轉或縮放。 IManipulationProcessor介面已具現化。 建立操作事件接收，接受 CDrawingObject 類別的指標，以及其建構函式上的 IManipulationProcessor 介面。 在操作事件接收實作中會建立 IManipulationProcessor 的連接點，以便事件接收接收端接收 IManipulationProcessor 所引發的事件。 觸控資料會饋送至 IManipulationProcessor 介面，然後介面會引發 _IManipulationEvent 事件。 CManipulationEventSink類別中的事件處理常式會藉由呼叫CDrawingObject 指標上的存取子來更新 CDrawingObject的方向。
下列程式碼示範如何設定觸控視窗，以及 CDrawingObject 和 IManipulationProcessor 如何具現化並傳遞至 CManipulationEventSink 建構函式。
CDrawingObject g_cRect; // CDrawingObject class holds information about the rectangle
// and it is responsible for painting the rectangle.
(...)
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
(...)
// Register application window for receiving multi-touch input. Use default settings.
if (!RegisterTouchWindow(hWnd, 0))
{
MessageBox(hWnd, L"Cannot register application window for multi-touch input", L"Error", MB_OK);
return FALSE;
}
ASSERT(IsTouchWindow(hWnd, NULL));
// Instantiate the ManipulationProcessor object
HRESULT hr = CoCreateInstance(__uuidof(ManipulationProcessor), NULL, CLSCTX_ALL, IID_PPV_ARGS(&g_pIManipProc));
if (FAILED(hr))
{
ASSERT(SUCCEEDED(hr) && L"InitInstance: failed to instantiate the ManipulationProcessor object");
return FALSE;
}
// Instantiate the event sink with the manipulation processor and pointer to the rectangle object
g_pManipulationEventSink = new CManipulationEventSink(&g_cRect);
if (g_pManipulationEventSink == NULL)
{
ASSERT(g_pManipulationEventSink && L"InitInstance: failed to instantiate the CManipulationEventSink class");
g_pIManipProc->Release();
g_pIManipProc = NULL;
return FALSE;
}
// Establish the link between ManipulationEventSink and ManipulationProcessor
if (!g_pManipulationEventSink->Connect(g_pIManipProc))
{
ASSERT(FALSE && L"InitInstance: failed to connect ManipulationEventSink and ManipulationProcessor");
g_pIManipProc->Release();
g_pIManipProc = NULL;
g_pManipulationEventSink->Release();
g_pManipulationEventSink = NULL;
return FALSE;
}
下列程式碼顯示操作事件接收器 CManipulationEventSink的建構函式。
CManipulationEventSink::CManipulationEventSink(CDrawingObject* pcDrawingObject)
: m_cRefCount(1),
m_pConnection(NULL),
m_dwCookie(0),
m_pcDrawingObject(pcDrawingObject)
{
ASSERT((pcDrawingObject != NULL) && L"CManipulationEventSink constructor: incorrect argument");
}
下列程式碼示範事件接收如何連接到操作處理器。
bool CManipulationEventSink::Connect(IManipulationProcessor* pManipulationProcessor)
{
// Check input arguments
if (pManipulationProcessor == NULL)
{
ASSERT((pManipulationProcessor != NULL) && L"CManipulationEventSink::Create : incorrect arguments");
return false;
}
// Check object state
if ((m_dwCookie != 0) || (m_pConnection != NULL))
{
ASSERT((m_dwCookie == 0) && (m_pConnection == NULL) && L"CManipulationEventSink::Connect : connection already established");
return false;
}
// Get the container with the connection points.
IConnectionPointContainer* pConnectionContainer = NULL;
HRESULT hr = pManipulationProcessor->QueryInterface(&pConnectionContainer);
if (FAILED(hr))
{
ASSERT(SUCCEEDED(hr) && L"CManipulationEventSink::Connect : failed to get the container with the connection points");
return false;
}
// Get a connection point.
hr = pConnectionContainer->FindConnectionPoint(__uuidof(_IManipulationEvents), &m_pConnection);
if (FAILED(hr))
{
ASSERT(SUCCEEDED(hr) && L"CManipulationEventSink::Connect : failed to get a connection point");
pConnectionContainer->Release();
return false;
}
// Release the connection container.
pConnectionContainer->Release();
// Advise. Establishes an advisory connection between the connection point and the
// caller's sink object.
hr = m_pConnection->Advise(this, &m_dwCookie);
if (FAILED(hr))
{
ASSERT(SUCCEEDED(hr) && L"CManipulationEventSink::Connect : failed to Advise");
m_pConnection->Release();
m_pConnection = NULL;
return false;
}
return true;
}
下列程式碼示範如何將觸控資料傳遞至操作事件接收。
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
(...)
switch (message)
{
(...)
// WM_TOUCH message handlers
case WM_TOUCH:
{
// WM_TOUCH message can contain several messages from different contacts
// packed together.
// Message parameters need to be decoded:
UINT cInputs = (int) wParam; // Number of actual per-contact messages
TOUCHINPUT* pInputs = new TOUCHINPUT[cInputs]; // Allocate the storage for the parameters of the per-contact messages
if (pInputs == NULL)
{
break;
}
// Unpack message parameters into the array of TOUCHINPUT structures, each
// representing a message for one single contact.
if (GetTouchInputInfo((HTOUCHINPUT)lParam, cInputs, pInputs, sizeof(TOUCHINPUT)))
{
// For each contact, dispatch the message to the appropriate message
// handler.
for (unsigned int i = 0; i < cInputs; i++)
{
if (pInputs[i].dwFlags & TOUCHEVENTF_DOWN)
{
g_pIManipProc->ProcessDown(pInputs[i].dwID, (FLOAT)pInputs[i].x, (FLOAT)pInputs[i].y);
}
else if (pInputs[i].dwFlags & TOUCHEVENTF_MOVE)
{
g_pIManipProc->ProcessMove(pInputs[i].dwID, (FLOAT)pInputs[i].x, (FLOAT)pInputs[i].y);
}
else if (pInputs[i].dwFlags & TOUCHEVENTF_UP)
{
g_pIManipProc->ProcessUp(pInputs[i].dwID, (FLOAT)pInputs[i].x, (FLOAT)pInputs[i].y);
}
}
}
else
{
// error handling, presumably out of memory
ASSERT(FALSE && L"Error: failed to execute GetTouchInputInfo");
delete [] pInputs;
break;
}
if (!CloseTouchInputHandle((HTOUCHINPUT)lParam))
{
// error handling, presumably out of memory
ASSERT(FALSE && L"Error: failed to execute CloseTouchInputHandle");
delete [] pInputs;
break;
}
delete [] pInputs;
// Force redraw of the rectangle
InvalidateRect(hWnd, NULL, TRUE);
}
break;
下列程式碼示範事件處理常式如何更新操作差異事件的物件方向和大小。
HRESULT STDMETHODCALLTYPE CManipulationEventSink::ManipulationDelta(
/* [in] */ FLOAT /* x */,
/* [in] */ FLOAT /* y */,
/* [in] */ FLOAT translationDeltaX,
/* [in] */ FLOAT translationDeltaY,
/* [in] */ FLOAT scaleDelta,
/* [in] */ FLOAT /* expansionDelta */,
/* [in] */ FLOAT rotationDelta,
/* [in] */ FLOAT /* cumulativeTranslationX */,
/* [in] */ FLOAT /* cumulativeTranslationY */,
/* [in] */ FLOAT /* cumulativeScale */,
/* [in] */ FLOAT /* cumulativeExpansion */,
/* [in] */ FLOAT /* cumulativeRotation */)
{
m_pcDrawingObject->ApplyManipulationDelta(translationDeltaX,translationDeltaY,scaleDelta,rotationDelta);
return S_OK;
}
下列程式碼是CDrawingObject類別中ApplyManipulationDelta的實作。
// This function is responsible for manipulation of the rectangle.
// It is called from CManipulationEventSink class.
// in:
// translationDeltaX - shift of the x-coordinate (1/100 of pixel units)
// translationDeltaY - shift of the y-coordinate (1/100 of pixel units)
// scaleDelta - scale factor (zoom in/out)
// rotationDelta - rotation angle in radians
void CDrawingObject::ApplyManipulationDelta(
const FLOAT translationDeltaX,
const FLOAT translationDeltaY,
const FLOAT scaleDelta,
const FLOAT rotationDelta
)
{
_ptCenter.x += (LONG) (translationDeltaX / 100.0);
_ptCenter.y += (LONG) (translationDeltaY / 100.0);
_dScalingFactor *= scaleDelta;
_dRotationAngle -= rotationDelta; // we are subtracting because Y-axis is down
}
在 CDrawingObject的中心點、縮放比例和旋轉角度更新之後，物件會自行繪製轉換。