Force keyboard in digits mode

Question

Hello,
with my team we are developing a C++ Windows application which is based on Qt library for the UI part
and on Win32 API for the rest.

The minimum Windows version supported is Windows 8.1.

In the application there are some text fields which accept numbers only. This is done with a Qt Validator.
I'd like to know if it's possible (with Win32 API) to force the Virtual Keyboard to be displayed in "digits" mode when focus is set on one of those text fields?
It would be helpful for users which spend time to always change the keyboard mode.

Regards,
M Vidoine

Answer 1

 if(lKeyboardElement != NULL)
{
VARIANT lVarProp;
lVarProp.vt = VT_BSTR;
lVarProp.bstrVal = SysAllocString(L"switchSymbol");
IUIAutomationCondition* lPCondition;
HRESULT lResult = mKeyboardDisplayModeManager->CreatePropertyCondition(UIA_AutomationIdPropertyId, lVarProp, &lPCondition);
if(SUCCEEDED(lResult))
{
IUIAutomationElement* lSwithButton = NULL;
lResult = lKeyboardElement->FindFirst(TreeScope_Subtree, lPCondition, &lSwithButton);
if(SUCCEEDED(lResult) && lSwithButton)
{
IUnknown* lActions = NULL;
lResult = lSwithButton->GetCurrentPattern(UIA_LegacyIAccessiblePatternId, &lActions);
if(SUCCEEDED(lResult) && lActions)
{
((IUIAutomationLegacyIAccessiblePattern*)lActions)->DoDefaultAction();
lActions->Release();
}
lSwithButton->Release();
}
if (lPCondition != NULL)
lPCondition->Release();
}
VariantClear(&lVarProp);
lKeyboardElement->Release();
}
      }

}

Answer 2

void GTabletInfo::initialize()
 {
     CoInitialize(NULL);
         HRESULT lResult = CoCreateInstance(
                 __uuidof(CUIAutomation), NULL, CLSCTX_INPROC_SERVER,
                 __uuidof(IUIAutomation), 
                 (void**)&mKeyboardDisplayModeManager);
 }

Answer 3

IUIAutomationElement* GTabletInfo::findElementByClassName(const wchar_t* aWindowName, IUIAutomationElement* aParent)
 {
     if (mKeyboardDisplayModeManager == NULL || aWindowName == NULL)
         return NULL;
     VARIANT lVarProp;
     lVarProp.vt = VT_BSTR;
     lVarProp.bstrVal = SysAllocString(aWindowName);
     IUIAutomationCondition* lPCondition;
     HRESULT lResult = 
        mKeyboardDisplayModeManager->CreatePropertyCondition(
                         UIA_ClassNamePropertyId, lVarProp, &lPCondition);
     if(SUCCEEDED(lResult))
     {
         IUIAutomationElement* lRootElement = aParent;
         if(lRootElement == NULL)
             lResult = mKeyboardDisplayModeManager->GetRootElement(
                                        &lRootElement);
      if(SUCCEEDED(lResult) && lRootElement)
         {
             IUIAutomationElement* lFoundElement = NULL;
             lResult = lRootElement->FindFirst(
                         TreeScope_Children, lPCondition, &lFoundElement);
             if(SUCCEEDED(lResult))
             {
                 VariantClear(&lVarProp);
                 if (lPCondition != NULL)
                     lPCondition->Release();
                 if(aParent == NULL)
                     lRootElement->Release();
                 return lFoundElement;
             }
             if(lFoundElement != NULL)
                 lFoundElement->Release();
             if(aParent == NULL)
                 lRootElement->Release();
         }
         if (lPCondition != NULL)
             lPCondition->Release();
     }
     VariantClear(&lVarProp);
     return NULL;
 }

Answer 4

void GTabletInfo::displayKeyboardDigitsMode()
{
if(mKeyboardVisible && mKeyboardDisplayModeManager != NULL)
{
IUIAutomationElement* lKeyboardElement = findElementByClassName(L"IPTip_Main_Window");
if(lKeyboardElement == NULL)
lKeyboardElement = findElementByClassName(L"IPTip_Main_Window",findElementByClassName(L"Windows.UI.Core.CoreWindow",findElementByClassName(L"ApplicationFrameWindow")));