EVT_PAINT not repainting whole window after SetSize Topic is solved

[Peri]

In my app, I'm calling SetSize to change the size of a child window. (This is happening during a EVT_MOTION while the user is dragging a sizing handle.)

The child window is initially displayed correctly. As well, during dragging, the newly exposed parts of the child window are painting correctly. However, parts already displayed are not repainted.

My code relevant to painting, for the child window, currently consists of an empty EVT_ERASE_BACKGROUND handler:

Code: Select all

void SizeableTextCtrl::onEraseBackground (wxEraseEvent& WXUNUSED(event))
{
}

The EVT_PAINT handler looks something like this (I've simplified it):

Code: Select all

void SizeableTextCtrl::onPaint (wxPaintEvent& WXUNUSED(event))
{
  wxPaintDC dc (this);

  dc.DestroyClippingRegion();
  wxRect rect = GetRect();
  dc.SetPen (*wxRED);
  dc.SetBrush (*wxYELLOW);
  dc.DrawRectangle (0, 0, rect.width, rect.height);
}

Each time onPaint is called, I think the entire window should be entirely refilled with yellow and a red border. Instead, one sees a trail of red borders left behind that are not painted over as the window grows. I've tried with and without the call to DestroyClippingRegion. No difference.

I've also tried putting this code in onEraseBackground, but I get the same effect.

Thanks.

[Radek]

DrawRectangle() draws a rectangle, it does not fill. Use Clear() or put FloodFill() behind the DrawRectangle().

[PB]

I believe that DrawRectangle fills the rectangle using the current brush. I think you should add wxFULL_REPAINT_ON_RESIZE to the style of your custom control. When you do that, everything seems to work as it should, tested with code attached below (Wndows XP).

Code: Select all

#include <wx/wxprec.h>

#ifndef WX_PRECOMP
    #include <wx/wx.h>
#endif

class RectPanel : public wxPanel
{
public:
    RectPanel(wxFrame* parent, const wxPen& pen, const wxBrush& brush)
        : wxPanel(parent, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxFULL_REPAINT_ON_RESIZE | wxTAB_TRAVERSAL),
        m_pen(pen), m_brush(brush)
    {
        wxASSERT(m_pen.IsOk());
        wxASSERT(m_brush.IsOk());        
        
        SetBackgroundStyle(wxBG_STYLE_PAINT);

        Bind(wxEVT_PAINT, &RectPanel::OnPaint, this);
    }
private:
    wxPen   m_pen;
    wxBrush m_brush;
    
    void OnPaint(wxPaintEvent& event)
    {
        wxPaintDC dc(this);

        dc.SetPen(m_pen);
        dc.SetBrush(m_brush);
        dc.DrawRectangle(GetClientRect());
    }
};


class MyFrame : public wxFrame
{
public:
    MyFrame()
        : wxFrame(NULL, wxID_ANY, _("Test"))
    {                        
        wxBoxSizer* bSizer = new wxBoxSizer(wxVERTICAL);
        
        RectPanel* rp = new RectPanel(this, wxPen(*wxRED), wxBrush(*wxYELLOW));
        bSizer->Add(rp, 1, wxEXPAND);

        SetSizer(bSizer);
        Layout();
        Centre();     
    }	
};

/**** MyApp ****/
class MyApp : public wxApp
{
public:	
	virtual bool OnInit()
	{
		if (!wxApp::OnInit())
			return false;       	

        MyFrame* frame = new MyFrame();
        frame ->Show();

        return true;
	}
};

IMPLEMENT_APP(MyApp)

[Peri]

Yea! Adding wxFULL_REPAINT_ON_RESIZE works. That makes me happy.