access.cpp

很牛的GUI源码wxWidgets-2.8.0.zip 可在多种平台下运行.

///////////////////////////////////////////////////////////////////////////////
// Name:        src/msw/ole/access.cpp
// Purpose:     implementation of wxIAccessible and wxAccessible
// Author:      Julian Smart
// Modified by:
// Created:     2003-02-12
// RCS-ID:      $Id: access.cpp,v 1.24 2006/11/04 11:14:57 VZ Exp $
// Copyright:   (c) 2003 Julian Smart
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

// ============================================================================
// declarations
// ============================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#if defined(__BORLANDC__)
  #pragma hdrstop
#endif

#if wxUSE_OLE && wxUSE_ACCESSIBILITY

#include "wx/access.h"

#ifndef WX_PRECOMP
    #include "wx/msw/wrapwin.h"
    #include "wx/window.h"
    #include "wx/log.h"
#endif

// for some compilers, the entire ole2.h must be included, not only oleauto.h
#if wxUSE_NORLANDER_HEADERS || defined(__WATCOMC__)
    #include <ole2.h>
#endif

#include <oleauto.h>
#include <oleacc.h>
#include <winable.h>

#include "wx/msw/ole/oleutils.h"

#ifndef CHILDID_SELF
#define CHILDID_SELF 0
#endif

#ifndef OBJID_CLIENT
#define OBJID_CLIENT 0xFFFFFFFC
#endif

// Convert to Windows role
int wxConvertToWindowsRole(wxAccRole wxrole);

// Convert to Windows state
long wxConvertToWindowsState(long wxstate);

// Convert to Windows selection flag
int wxConvertToWindowsSelFlag(wxAccSelectionFlags sel);

// Convert from Windows selection flag
wxAccSelectionFlags wxConvertFromWindowsSelFlag(int sel);

#if wxUSE_VARIANT
// ----------------------------------------------------------------------------
// wxIEnumVARIANT interface implementation
// ----------------------------------------------------------------------------

class wxIEnumVARIANT : public IEnumVARIANT
{
public:
    wxIEnumVARIANT(const wxVariant& variant);
    virtual ~wxIEnumVARIANT() { }

    DECLARE_IUNKNOWN_METHODS;

    // IEnumVARIANT
    STDMETHODIMP Next(ULONG celt, VARIANT *rgelt, ULONG *pceltFetched);
    STDMETHODIMP Skip(ULONG celt);
    STDMETHODIMP Reset();
    STDMETHODIMP Clone(IEnumVARIANT **ppenum);

private:
    wxVariant m_variant;  // List of further variants
    int       m_nCurrent; // Current enum position

    DECLARE_NO_COPY_CLASS(wxIEnumVARIANT)
};

// ----------------------------------------------------------------------------
// wxIEnumVARIANT
// ----------------------------------------------------------------------------

BEGIN_IID_TABLE(wxIEnumVARIANT)
    ADD_IID(Unknown)
    ADD_IID(EnumVARIANT)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIEnumVARIANT)

// wxVariant contains a list of further variants.
wxIEnumVARIANT::wxIEnumVARIANT(const wxVariant& variant)
{
    m_variant = variant;
}

STDMETHODIMP wxIEnumVARIANT::Next(ULONG      celt,
                                    VARIANT *rgelt,
                                    ULONG     *pceltFetched)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumVARIANT::Next"));

    if ( celt > 1 ) {
        // we only return 1 element at a time - mainly because I'm too lazy to
        // implement something which you're never asked for anyhow
        return S_FALSE;
    }

    if (m_variant.GetType() != wxT("list"))
        return S_FALSE;

    if ( m_nCurrent < (int) m_variant.GetList().GetCount() ) {
        if (!wxConvertVariantToOle(m_variant[m_nCurrent++], rgelt[0]))
        {
            return S_FALSE;
        }

        // TODO: should we AddRef if this is an object?

        * pceltFetched = 1;
        return S_OK;
    }
    else {
        // bad index
        return S_FALSE;
    }
}

STDMETHODIMP wxIEnumVARIANT::Skip(ULONG celt)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumVARIANT::Skip"));

    if (m_variant.GetType() != wxT("list"))
        return S_FALSE;

    m_nCurrent += celt;
    if ( m_nCurrent < (int) m_variant.GetList().GetCount() )
        return S_OK;

    // no, can't skip this many elements
    m_nCurrent -= celt;

    return S_FALSE;
}

STDMETHODIMP wxIEnumVARIANT::Reset()
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumVARIANT::Reset"));

    m_nCurrent = 0;

    return S_OK;
}

STDMETHODIMP wxIEnumVARIANT::Clone(IEnumVARIANT **ppenum)
{
    wxLogTrace(wxTRACE_OleCalls, wxT("wxIEnumVARIANT::Clone"));

    wxIEnumVARIANT *pNew = new wxIEnumVARIANT(m_variant);
    pNew->AddRef();
    *ppenum = pNew;

    return S_OK;
}

#endif // wxUSE_VARIANT

// ----------------------------------------------------------------------------
// wxIAccessible implementation of IAccessible interface
// ----------------------------------------------------------------------------

class wxIAccessible : public IAccessible
{
public:
    wxIAccessible(wxAccessible *pAccessible);

    DECLARE_IUNKNOWN_METHODS;

// IAccessible

// Navigation and Hierarchy

        // Retrieves the child element or child object at a given point on the screen.
        // All visual objects support this method; sound objects do not support it.

    STDMETHODIMP accHitTest(long xLeft, long yLeft, VARIANT* pVarID);

        // Retrieves the specified object's current screen location. All visual objects must
        // support this method; sound objects do not support it.

    STDMETHODIMP accLocation ( long* pxLeft, long* pyTop, long* pcxWidth, long* pcyHeight, VARIANT varID);

        // Traverses to another user interface element within a container and retrieves the object.
        // All visual objects must support this method.

    STDMETHODIMP accNavigate ( long navDir, VARIANT varStart, VARIANT* pVarEnd);

        // Retrieves the address of an IDispatch interface for the specified child.
        // All objects must support this property.

    STDMETHODIMP get_accChild ( VARIANT varChildID, IDispatch** ppDispChild);

        // Retrieves the number of children that belong to this object.
        // All objects must support this property.

    STDMETHODIMP get_accChildCount ( long* pCountChildren);

        // Retrieves the IDispatch interface of the object's parent.
        // All objects support this property.

    STDMETHODIMP get_accParent ( IDispatch** ppDispParent);

// Descriptive Properties and Methods

        // Performs the object's default action. Not all objects have a default
        // action.

    STDMETHODIMP accDoDefaultAction(VARIANT varID);

        // Retrieves a string that describes the object's default action.
        // Not all objects have a default action.

    STDMETHODIMP get_accDefaultAction ( VARIANT varID, BSTR* pszDefaultAction);

        // Retrieves a string that describes the visual appearance of the specified object.
        // Not all objects have a description.

    STDMETHODIMP get_accDescription ( VARIANT varID, BSTR* pszDescription);

        // Retrieves an object's Help property string.
        // Not all objects support this property.

    STDMETHODIMP get_accHelp ( VARIANT varID, BSTR* pszHelp);

        // Retrieves the full path of the WinHelp file associated with the specified
        // object and the identifier of the appropriate topic within that file.
        // Not all objects support this property.

    STDMETHODIMP get_accHelpTopic ( BSTR* pszHelpFile, VARIANT varChild, long* pidTopic);

        // Retrieves the specified object's shortcut key or access key, also known as
        // the mnemonic. All objects that have a shortcut key or access key support
        // this property.

    STDMETHODIMP get_accKeyboardShortcut ( VARIANT varID, BSTR* pszKeyboardShortcut);

        // Retrieves the name of the specified object.
        // All objects support this property.

    STDMETHODIMP get_accName ( VARIANT varID, BSTR* pszName);

        // Retrieves information that describes the role of the specified object.
        // All objects support this property.

    STDMETHODIMP get_accRole ( VARIANT varID, VARIANT* pVarRole);

        // Retrieves the current state of the specified object.
        // All objects support this property.

    STDMETHODIMP get_accState ( VARIANT varID, VARIANT* pVarState);

        // Retrieves the value of the specified object.
        // Not all objects have a value.

    STDMETHODIMP get_accValue ( VARIANT varID, BSTR* pszValue);

// Selection and Focus

        // Modifies the selection or moves the keyboard focus of the
        // specified object. All objects that select or receive the
        // keyboard focus must support this method.

    STDMETHODIMP accSelect ( long flagsSelect, VARIANT varID );

        // Retrieves the object that has the keyboard focus. All objects
        // that receive the keyboard focus must support this property.

    STDMETHODIMP get_accFocus ( VARIANT* pVarID);

        // Retrieves the selected children of this object. All objects
        // selected must support this property.

    STDMETHODIMP get_accSelection ( VARIANT * pVarChildren);

// Obsolete

    STDMETHODIMP put_accName(VARIANT WXUNUSED(varChild), BSTR WXUNUSED(szName)) { return E_FAIL; }
    STDMETHODIMP put_accValue(VARIANT WXUNUSED(varChild), BSTR WXUNUSED(szName)) { return E_FAIL; }

// IDispatch

        // Get type info

    STDMETHODIMP GetTypeInfo(unsigned int typeInfo, LCID lcid, ITypeInfo** ppTypeInfo);

        // Get type info count

    STDMETHODIMP GetTypeInfoCount(unsigned int* typeInfoCount);

        // Get ids of names

    STDMETHODIMP GetIDsOfNames(REFIID riid, OLECHAR** names, unsigned int cNames,
        LCID lcid, DISPID* dispId);

        // Invoke

    STDMETHODIMP Invoke(DISPID dispIdMember, REFIID riid, LCID lcid,
                        WORD wFlags, DISPPARAMS *pDispParams,
                        VARIANT *pVarResult, EXCEPINFO *pExcepInfo,
                        unsigned int *puArgErr );

// Helpers

    // Gets the standard IAccessible interface for the given child or object.
    // Call Release if this is non-NULL.
    IAccessible* GetChildStdAccessible(int id);

    // Gets the IAccessible interface for the given child or object.
    // Call Release if this is non-NULL.
    IAccessible* GetChildAccessible(int id);

private:
    wxAccessible *m_pAccessible;      // pointer to C++ class we belong to

    DECLARE_NO_COPY_CLASS(wxIAccessible)
};

// ============================================================================
// Implementation
// ============================================================================

// ----------------------------------------------------------------------------
// wxIAccessible implementation
// ----------------------------------------------------------------------------
BEGIN_IID_TABLE(wxIAccessible)
  ADD_IID(Unknown)
  ADD_IID(Accessible)
  ADD_IID(Dispatch)
END_IID_TABLE;

IMPLEMENT_IUNKNOWN_METHODS(wxIAccessible)

wxIAccessible::wxIAccessible(wxAccessible *pAccessible)
{
    wxASSERT( pAccessible != NULL );

    m_pAccessible = pAccessible;
}

// Retrieves the child element or child object at a given point on the screen.
// All visual objects support this method; sound objects do not support it.

STDMETHODIMP wxIAccessible::accHitTest(long xLeft, long yLeft, VARIANT* pVarID)
{
    wxLogTrace(wxT("access"), wxT("accHitTest"));
    wxASSERT (m_pAccessible != NULL);
    if (!m_pAccessible)
        return E_FAIL;

    wxAccessible* childObject = NULL;
    int childId = 0;
    VariantInit(pVarID);

    wxAccStatus status = m_pAccessible->HitTest(wxPoint(xLeft, yLeft), & childId, & childObject);

    if (status == wxACC_FAIL)
        return E_FAIL;

    if (status == wxACC_NOT_IMPLEMENTED)
    {
        // Use standard interface instead.
        IAccessible* stdInterface = (IAccessible*)m_pAccessible->GetIAccessibleStd();
        if (!stdInterface)
            return E_NOTIMPL;
        else
            return stdInterface->accHitTest(xLeft, yLeft, pVarID);
    }

    if (childObject)
    {
        if (childObject == m_pAccessible)
        {
            pVarID->vt = VT_I4;
            pVarID->lVal = CHILDID_SELF;
            return S_OK;
        }
        else
        {
            wxIAccessible* childIA = childObject->GetIAccessible();
            if (!childIA)
                return E_NOTIMPL;

            if (childIA->QueryInterface(IID_IDispatch, (LPVOID*) & pVarID->pdispVal) != S_OK)
                return E_FAIL;

            pVarID->vt = VT_DISPATCH;
            return S_OK;
        }
    }
    else if (childId > 0)
    {
        pVarID->vt = VT_I4;
        pVarID->lVal = childId;
        return S_OK;
    }
    else
    {
        pVarID->vt = VT_EMPTY;
        return S_FALSE;
    }

    #if 0
    // all cases above already cause some return action so below line
    // is unreachable and cause unnecessary warning
    return E_NOTIMPL;
    #endif
}

// Retrieves the specified object's current screen location. All visual objects must
// support this method; sound objects do not support it.

STDMETHODIMP wxIAccessible::accLocation ( long* pxLeft, long* pyTop, long* pcxWidth, long* pcyHeight, VARIANT varID)
{
    wxLogTrace(wxT("access"), wxT("accLocation"));
    wxASSERT (m_pAccessible != NULL);
    if (!m_pAccessible)
        return E_FAIL;

    wxRect rect;

    wxAccStatus status = m_pAccessible->GetLocation(rect, varID.lVal);
    if (status == wxACC_FAIL)
        return E_FAIL;

    if (status == wxACC_NOT_IMPLEMENTED)
    {
        // Try to use child object directly.
        if (varID.lVal > 0)
        {
            IAccessible* childAccessible = GetChildAccessible(varID.lVal);
            if (childAccessible)
            {
                varID.lVal = 0;
                HRESULT hResult = childAccessible->accLocation(pxLeft, pyTop, pcxWidth, pcyHeight, varID);
                childAccessible->Release();
                return hResult;
            }
            else if (m_pAccessible->GetIAccessibleStd())
                return ((IAccessible*) m_pAccessible->GetIAccessibleStd())->accLocation(pxLeft, pyTop, pcxWidth, pcyHeight, varID);
        }
        else if (m_pAccessible->GetIAccessibleStd())
            return ((IAccessible*) m_pAccessible->GetIAccessibleStd())->accLocation(pxLeft, pyTop, pcxWidth, pcyHeight, varID);
    }
    else
    {
        *pxLeft = rect.x;
        *pyTop = rect.y;
        *pcxWidth = rect.width;
        *pcyHeight = rect.height;
        return S_OK;
    }

    return E_NOTIMPL;
}

// Traverses to another user interface element within a container and retrieves the object.
// All visual objects must support this method.

STDMETHODIMP wxIAccessible::accNavigate ( long navDir, VARIANT varStart, VARIANT* pVarEnd)
{
    wxASSERT (m_pAccessible != NULL);
    if (!m_pAccessible)
        return E_FAIL;
    wxLogTrace(wxT("access"), wxString(wxT("accNavigate for ")) + m_pAccessible->GetWindow()->GetClassInfo()->GetClassName());

    if ((varStart.vt != VT_I4 && varStart.vt != VT_EMPTY)
                                                          #if 0
                                                          // according to MSDN and sources varStart.vt is unsigned
                                                          // so below line cause warning "Condition is always false"
                                                          || varStart.vt < 0
                                                          #endif
                                                          )
    {
        wxLogTrace(wxT("access"), wxT("Invalid arg for accNavigate"));
        return E_INVALIDARG;
    }