How to wxIsKindOf class check for a wxTextEntry derived classes? Topic is solved

[tomay3000]

Hello,
I know that doing it for a wxTextCtrl should work, but I want to make it work for all wxTextEntry derivatives as well, so I can call wxTextEntry::Clear()

Here is my code that worked for wxTextCtrl, and I want to make it work for wxTextEntry once for all its derivatives:

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void MyFrame::Btn_VK_Clear_OnButtonClick(wxCommandEvent& WXUNUSED(event))
{
    if (m_pWndLastFocused)
    {
        m_pWndLastFocused->SetFocus();
    }

    //wxUIActionSimulator actionSimulator;
    //actionSimulator.Char(WXK_CLEAR);

    if (wxIsKindOf(m_pWndLastFocused, wxTextCtrl))
    {
        wxTextCtrl * const pTxtCtrlLastFocused = wxStaticCast(m_pWndLastFocused, wxTextCtrl);
        pTxtCtrlLastFocused->Clear();
    }

    // Process the resulting char events
    wxYield();
}

Any ideas on how to achieve this?
TIA.

[doublemax]

I can't think of any elegant way using wxWidgets' RTTI. I would just write a small helper function that checks for all eight classes that derive from wxTextEntry. And if it's a match, cast the object to wxTextEntry.

[tomay3000]

I can't think of any elegant way using wxWidgets' RTTI. I would just write a small helper function that checks for all eight classes that derive from wxTextEntry. And if it's a match, cast the object to wxTextEntry.

That is exactly what came to my mind, using like:

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bool wxHasTextEntry(const wxWindow *pWindow);

and

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wxTextEntry *wxGetTextEntry(const wxWindow *pWindow);

What I am struggling about is what kinda cast should I use!? wxDynamicCast or wxStaticCast?
TIA.

[PB]

I am probably missing something here: wny not use C++ RTTI? I would just do

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wxTextEntry* te = dynamic_cast<wxTextEntry*>(m_pWndLastFocused);

if ( te )
   te->Clear();

I have just tested it and works as expected

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#include <wx/wx.h>

class MyDialog : public wxDialog
{
public:
    MyDialog() : wxDialog(NULL, wxID_ANY, "Test", wxDefaultPosition, wxSize(600, 600))
    {
        wxBoxSizer* mainSizer = new wxBoxSizer(wxVERTICAL);

        wxCheckBox* checkBox = new wxCheckBox(this, wxID_ANY, "CheckBox");
        mainSizer->Add(checkBox, wxSizerFlags().Expand().Border());
        
        wxTextCtrl* textCtrl = new wxTextCtrl(this, wxID_ANY, "TextCtrl");
        mainSizer->Add(textCtrl, wxSizerFlags().Expand().Border());

        wxRadioButton* radioButton = new wxRadioButton(this, wxID_ANY, "RadioButton");
        mainSizer->Add(radioButton, wxSizerFlags().Expand().Border());

        wxComboBox* comboBox = new wxComboBox(this, wxID_ANY, "ComboBox");
        mainSizer->Add(comboBox, wxSizerFlags().Expand().Border());

        wxButton* button = new wxButton(this, wxID_ANY, "Clear Text Entries");            
        mainSizer->Add(button, wxSizerFlags().Expand().Border());
        Bind(wxEVT_BUTTON, &MyDialog::OnClearTextEntries, this);

        m_logCtrl = new wxTextCtrl(this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize,
            wxTE_MULTILINE | wxTE_READONLY | wxTE_RICH2);
        wxLog::SetActiveTarget(new wxLogTextCtrl(m_logCtrl));
        wxLog::SetTimestamp("");
        mainSizer->Add(m_logCtrl, wxSizerFlags().Proportion(1).Expand().DoubleBorder());

        SetSizer(mainSizer);
    }
private:        
    wxTextCtrl* m_logCtrl;

    void OnClearTextEntries(wxCommandEvent&)
    {                
        const wxWindowList& children = GetChildren();

        for ( wxWindowList::Node* node = children.GetFirst(); node; node = node->GetNext() )
        {
            wxWindow* window = dynamic_cast<wxWindow*>(node->GetData());
            wxTextEntry* te = dynamic_cast<wxTextEntry*>(window);

            wxLogMessage("Window type = %s, is derived from wxTextEntry: %s",
                window->GetClassInfo()->GetClassName(), te ? wxS("Yes") : wxS("No"));  

            if ( te && te != m_logCtrl )
            {
                wxLogMessage("Clearing value '%s'", te->GetValue());
                te->Clear();
            }
        }        
    }
};

class MyApp : public wxApp
{
public:
    bool OnInit()
    {
        MyDialog().ShowModal();
        return false;
    }
}; wxIMPLEMENT_APP(MyApp);

textentry.png (16.55 KiB) Viewed 1105 times

[tomay3000]

I can see from this post: https://stackoverflow.com/questions/159 ... d-of-macro,
Vadim Zeitlin is advising the use of wxDynamicCast() instead of wxIS_KIND_OF or wxIsKindOf.

[PB]

The comment for wxDynamicCast says

// note that it still has different semantics from dynamic_cast<> and so can't
// be replaced by it as long as there are any compilers not supporting it

Do you really still use a compiler not supporting dynamic_cast? Perhaps it's time to upgrade it...

TBH, I do not see a reason for disabling C++ RTTI, I do not even know if MSVC supports that.

dynamic_cast also does not require all the custom controls you may use to use the wxDECLARE/IMPLEMENT_DYNAMIC_CLASS macros.

[tomay3000]

Actually the code won't compile at all using wxDynamicCast()

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||=== Build: Static Debug in S-SMS (compiler: GNU GCC Compiler) ===|
C:\Users\Tomay\Desktop\Projects\S-SMS\S_SMSMain.cpp||In member function 'virtual void S_SMSFrame::m_pBtn_VK_Clear_OnButtonClick(wxCommandEvent&)':|
C:\devel\wxWidgets\include\wx\object.h|147|error: invalid static_cast from type 'wxWindow*' to type 'const wxTextEntry*'|
C:\Users\Tomay\Desktop\Projects\S-SMS\S_SMSMain.cpp|1068|note: in expansion of macro 'wxDynamicCast'|
C:\devel\wxWidgets\include\wx\object.h|148|error: 'ms_classInfo' is not a member of 'wxTextEntry'|
C:\devel\wxWidgets\include\wx\object.h|148|note: in definition of macro 'wxDynamicCast'|
||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 5 second(s)) ===|

So I am forced to use dynamic_cast<>() instead.
And BTW I didn't know that wxDynamicCast() was invented to be used for weak old compilers.

I am using:

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gcc version 9.1.0 (Rev2, Built by MSYS2 project)

[alys666]

That is exactly what came to my mind, using like:

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bool wxHasTextEntry(const wxWindow *pWindow);

and

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wxTextEntry *wxGetTextEntry(const wxWindow *pWindow);

What I am struggling about is what kinda cast should I use!? wxDynamicCast or wxStaticCast?
TIA.

you can use static_cast<SomeType *> if you are SURE that object can be really casted to it.
for example you have a list of A class objects, but have included there ONLY objects of derived class B.
because you're sure that there is no any object of class A, but B, you can cast statically.
Or, if before static_cast<B*> you can somehow check if instance is really of class B.

[ONEEYEMAN]

Hi,

Actually the code won't compile at all using wxDynamicCast()

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||=== Build: Static Debug in S-SMS (compiler: GNU GCC Compiler) ===|
C:\Users\Tomay\Desktop\Projects\S-SMS\S_SMSMain.cpp||In member function 'virtual void S_SMSFrame::m_pBtn_VK_Clear_OnButtonClick(wxCommandEvent&)':|
C:\devel\wxWidgets\include\wx\object.h|147|error: invalid static_cast from type 'wxWindow*' to type 'const wxTextEntry*'|
C:\Users\Tomay\Desktop\Projects\S-SMS\S_SMSMain.cpp|1068|note: in expansion of macro 'wxDynamicCast'|
C:\devel\wxWidgets\include\wx\object.h|148|error: 'ms_classInfo' is not a member of 'wxTextEntry'|
C:\devel\wxWidgets\include\wx\object.h|148|note: in definition of macro 'wxDynamicCast'|
||=== Build failed: 2 error(s), 0 warning(s) (0 minute(s), 5 second(s)) ===|

So I am forced to use dynamic_cast<>() instead.
And BTW I didn't know that wxDynamicCast() was invented to be used for weak old compilers.

I am using:

Code: Select all

gcc version 9.1.0 (Rev2, Built by MSYS2 project)

wxWidgets was written in late 1980 -early 1990, when not all compilers/devices supported everything and STL was not a de-facto a standard.

Thank you.