Left Down in button Topic is solved

[mxoliveira73]

resarching in foruns here, I learn handle the left button down event, this form:

Code: Select all

BEGIN_EVENT_TABLE(MainFrame, wxFrame)	
	EVT_BUTTON(ID_Of_Action_Object, MainFrame :: CalledMethod)
END_EVENT_TABLE();

btn = new wxButton(this, BUTTON_ID, "Button", wxDefaultPosition, wxDefaultSize);
btn->Connect(BUTTON_ID, wxEVT_LEFT_DOWN, wxCommandEventHandler(MyFrame::OnDown));


void MainFrame :: OnDown(wxCommandEvent& event){

   //do something after clicking on the button;
};

Ok...

It works if // do something is: wxMessageBox("lalala"), for example

but,

if the action is btn-SetLabel("lalala"); or other action origin in object ___ btn->SetBackgroundColour...
doesn't work. Compile is normal, but in click the button is generate a fatal error...

Thanks if someone could help me...

[doublemax]

Replace

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btn->Connect(BUTTON_ID, wxEVT_LEFT_DOWN, wxCommandEventHandler(MyFrame::OnDown));

with

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btn->Connect(BUTTON_ID, wxEVT_LEFT_DOWN, wxCommandEventHandler(MyFrame::OnDown), NULL, this);

or

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Connect(BUTTON_ID, wxEVT_LEFT_DOWN, wxCommandEventHandler(MyFrame::OnDown));

It's also better to use Bind() instead of Connect(), as it would create an error at compile time.

[mxoliveira73]

Ok, lets go to Bind. I'm studying hard. Consulting the documentation event.h I found:
void Bind(const EventTag &eventType, void (Class::*method)(EventArg &), EventHandler *handler, int winid = wxID_ANY,int lastId = wxID_ANY,
wxObject *userData = NULL)

Then, i could make this:
btn->Bind( wxEVT_LEFT_DOWN,(MyFrame::OnDown), wxCommandEventHandler, ID_btn1, wxID_ANY, NULL);

is it?

[doublemax]

I can't test this right now, from the top of my head, try this:

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btn->Bind( wxEVT_LEFT_DOWN, &MyFrame::OnDown, NULL, this );

If it doesn't work, continue with one of my Connect solutions for now, they should work.

[mxoliveira73]

Doesn't work. Where can i search and study. Tips or links please...
I really don't understand, maybe the wrong it's mine, but 3 examples on this page
https://docs.wxwidgets.org/3.0/overview_events.html works fine with wxEVT_COMMAND_MENU_SELECTED etc.. but adapt to wxEvt_LEFT_DOWN doesn't work.... what pags, links do you recommend, please....

[doublemax]

What exactly does not work? Do you get a compile error (if yes, which one), or does it compile, but the event handler doesn't get called?

[ONEEYEMAN]

Hi,
Also curious - why do you need to handle low-level event, when the EVT_BUTTON() exist?

Thank you.

[mxoliveira73]

******************method 1 ************************************************************************
void OnDown(wxCommandEvent & event);
btn->Bind( wxEVT_LEFT_DOWN, &MyFrame::OnDown, NULL, this );
void MyFrame::OnDown(wxCommandEvent & event)
{
muteChannel1();
btn->SetBackgroundColour(*wxRED);
}

ERROR ON COMPILE:
error: no matching function for call to 'wxButton::Bind(const wxEventTypeTag<wxMouseEvent>&, void (MyFrame::*)(wxCommandEvent&), NULL, MyFrame*)
********************************************************************************************************

[mxoliveira73]

For oneeyeman,

I don't now if I can explain... but is that.

Evt_Button is a little bit diferent: if you click in the button and hold, the action don't happens; it only happens when you release the button(left mouse).

using left_down in the exact moment that you down the button left mouse, the action happens....

the feel is of more velocity in application...

i have success in this objective, using Connect, whit help of doublemax...
Now, i need use Bind, because it's more modern, flexible and previne errors and future problems...

Ok, I'm not expert in WxWidgets...

Im using examples of Bind (using wxEVT_LEFT_DOWN) and have no success; limit is mine...

sorry for the confusion of words, it's a little bit difficult to me explain in other language... ok?

[doublemax]

Try this:

Code: Select all

void OnDown(wxMouseEvent & event);

btn->Bind( wxEVT_LEFT_DOWN, &MyFrame::OnDown, this );
void MyFrame::OnDown(wxMouseEvent & event)
{
 muteChannel1();
 btn->SetBackgroundColour(*wxRED);
}

[mxoliveira73]

wxWidgets-3.1.2\include\wx\event.h|374|error: no matching function for call to 'wxEventFunctorMethod<wxEventTypeTag<wxMouseEvent>, MyFrame, wxCommandEvent, MyFrame>::CheckHandlerArgument(wxEventFunctorMethod<wxEventTypeTag<wxMouseEvent>, MyFrame, wxCommandEvent, MyFrame>::EventClass*)'|

event.h line 374:
CheckHandlerArgument(static_cast<EventClass *>(NULL));

[doublemax]

I tested the last piece of code i posted and it should have worked. Can you show more code in context?

[PB]

It seems that mxoliveira73 used wrong handler declaration in OnDown, using wxCommandEvent instead of wxMouseEvent as a parameter

[doublemax]

It seems that mxoliveira73 used wrong handler declaration in OnDown, using wxCommandEvent instead of wxMouseEvent as a parameter

Thanks, i missed that.

[mxoliveira73]

It seems that yoy are absolutelly right!!!!!!!!!!!!!!!!

Works fine now....

Thanks a lot...