I built this sample which pretty much does what you're trying to do.
I tested this under Windows and Linux (GTK3). Under Windows is flickers heavily, but that's intentional in this case for demonstration purposes.
It's a drop-in replacement for the "minimal" sample that comes with wxWidgets.
I hope this helps.
Code: Select all
/////////////////////////////////////////////////////////////////////////////
// Name: minimal.cpp
// Purpose: Minimal wxWidgets sample
// Author: Julian Smart
// Modified by:
// Created: 04/01/98
// Copyright: (c) Julian Smart
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
// for all others, include the necessary headers (this file is usually all you
// need because it includes almost all "standard" wxWidgets headers)
#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif
// ----------------------------------------------------------------------------
// resources
// ----------------------------------------------------------------------------
// the application icon (under Windows it is in resources and even
// though we could still include the XPM here it would be unused)
#ifndef wxHAS_IMAGES_IN_RESOURCES
#include "../sample.xpm"
#endif
// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------
// Define a new application type, each program should derive a class from wxApp
class MyApp : public wxApp
{
public:
// override base class virtuals
// ----------------------------
// this one is called on application startup and is a good place for the app
// initialization (doing it here and not in the ctor allows to have an error
// return: if OnInit() returns false, the application terminates)
virtual bool OnInit() wxOVERRIDE;
};
// Define a new frame type: this is going to be our main frame
class MyFrame : public wxFrame
{
public:
// ctor(s)
MyFrame(const wxString& title);
// event handlers (these functions should _not_ be virtual)
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
void OnPaint(wxPaintEvent &event);
void OnTimer(wxTimerEvent &event);
private:
void UpdateBGBitmap();
wxPanel *m_panel;
wxTimer m_timer;
wxBitmap m_bgcache;
double m_progress;
// any class wishing to process wxWidgets events must use this macro
wxDECLARE_EVENT_TABLE();
};
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
// IDs for the controls and the menu commands
enum
{
// menu items
Minimal_Quit = wxID_EXIT,
// it is important for the id corresponding to the "About" command to have
// this standard value as otherwise it won't be handled properly under Mac
// (where it is special and put into the "Apple" menu)
Minimal_About = wxID_ABOUT
};
// ----------------------------------------------------------------------------
// event tables and other macros for wxWidgets
// ----------------------------------------------------------------------------
// the event tables connect the wxWidgets events with the functions (event
// handlers) which process them. It can be also done at run-time, but for the
// simple menu events like this the static method is much simpler.
wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(Minimal_Quit, MyFrame::OnQuit)
EVT_MENU(Minimal_About, MyFrame::OnAbout)
wxEND_EVENT_TABLE()
// Create a new application object: this macro will allow wxWidgets to create
// the application object during program execution (it's better than using a
// static object for many reasons) and also implements the accessor function
// wxGetApp() which will return the reference of the right type (i.e. MyApp and
// not wxApp)
wxIMPLEMENT_APP(MyApp);
// ============================================================================
// implementation
// ============================================================================
// ----------------------------------------------------------------------------
// the application class
// ----------------------------------------------------------------------------
// 'Main program' equivalent: the program execution "starts" here
bool MyApp::OnInit()
{
// call the base class initialization method, currently it only parses a
// few common command-line options but it could be do more in the future
if ( !wxApp::OnInit() )
return false;
// create the main application window
MyFrame *frame = new MyFrame("Minimal wxWidgets App");
// and show it (the frames, unlike simple controls, are not shown when
// created initially)
frame->Show(true);
// success: wxApp::OnRun() will be called which will enter the main message
// loop and the application will run. If we returned false here, the
// application would exit immediately.
return true;
}
// ----------------------------------------------------------------------------
// main frame
// ----------------------------------------------------------------------------
// frame constructor
MyFrame::MyFrame(const wxString& title)
: wxFrame(NULL, wxID_ANY, title)
{
// set the frame icon
SetIcon(wxICON(sample));
#if wxUSE_MENUBAR
// create a menu bar
wxMenu *fileMenu = new wxMenu;
// the "About" item should be in the help menu
wxMenu *helpMenu = new wxMenu;
helpMenu->Append(Minimal_About, "&About\tF1", "Show about dialog");
fileMenu->Append(Minimal_Quit, "E&xit\tAlt-X", "Quit this program");
// now append the freshly created menu to the menu bar...
wxMenuBar *menuBar = new wxMenuBar();
menuBar->Append(fileMenu, "&File");
menuBar->Append(helpMenu, "&Help");
// ... and attach this menu bar to the frame
SetMenuBar(menuBar);
#else // !wxUSE_MENUBAR
// If menus are not available add a button to access the about box
wxSizer* sizer = new wxBoxSizer(wxHORIZONTAL);
wxButton* aboutBtn = new wxButton(this, wxID_ANY, "About...");
aboutBtn->Bind(wxEVT_BUTTON, &MyFrame::OnAbout, this);
sizer->Add(aboutBtn, wxSizerFlags().Center());
SetSizer(sizer);
#endif // wxUSE_MENUBAR/!wxUSE_MENUBAR
#if wxUSE_STATUSBAR
// create a status bar just for fun (by default with 1 pane only)
CreateStatusBar(2);
SetStatusText("Welcome to wxWidgets!");
#endif // wxUSE_STATUSBAR
wxPanel *panel = new wxPanel(this, wxID_ANY);
wxBoxSizer *mainSizer = new wxBoxSizer(wxVERTICAL);
m_panel = new wxPanel(panel, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxFULL_REPAINT_ON_RESIZE);
m_panel->SetMinSize( wxSize(-1, 200) );
m_panel->SetBackgroundColour(*wxRED);
m_panel->Bind(wxEVT_PAINT, &MyFrame::OnPaint, this);
mainSizer->Add(m_panel, 0, wxEXPAND, 0);
panel->SetSizer(mainSizer);
m_progress = 0;
m_timer.SetOwner(this);
m_timer.Start(15);
Bind(wxEVT_TIMER, &MyFrame::OnTimer, this);
}
// event handlers
void MyFrame::OnPaint(wxPaintEvent &event)
{
wxPaintDC dc(m_panel);
const wxSize &size = m_panel->GetClientSize();
if(!m_bgcache.IsOk() || m_bgcache.GetWidth() != size.x || m_bgcache.GetHeight() != size.y)
{
wxLogDebug("creating new bitmap");
#if 0
m_bgcache = wxBitmap( wxImage(size.x, size.y), 24);
#else
m_bgcache.Create(size.x, size.y, 24);
#endif
UpdateBGBitmap();
}
dc.DrawBitmap(m_bgcache, 0, 0, false);
// draw progress indicator
int progress_x = (int)(m_progress * size.x);
dc.SetPen(*wxRED);
dc.DrawLine(progress_x, 0, progress_x, size.y - 1);
}
void MyFrame::OnTimer(wxTimerEvent &event)
{
m_progress += 0.003;
if(m_progress > 1.0 )
m_progress -= 1.0;
// wxLogDebug("timer %.2f", m_progress);
m_panel->Refresh();
}
void MyFrame::UpdateBGBitmap()
{
wxMemoryDC mdc(m_bgcache);
// clear background
mdc.SetBrush(*wxWHITE);
mdc.Clear();
mdc.SetPen(*wxBLUE);
int yBase = m_bgcache.GetHeight() / 2;
double x_scale = 0.1;
for(int x = 0; x < m_bgcache.GetWidth(); x++)
{
int y = (int)(sin(x_scale * x) * yBase);
mdc.DrawLine(x, yBase, x, yBase + y);
}
}
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
// true is to force the frame to close
Close(true);
}
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
wxMessageBox(wxString::Format
(
"Welcome to %s!\n"
"\n"
"This is the minimal wxWidgets sample\n"
"running under %s.",
wxVERSION_STRING,
wxGetOsDescription()
),
"About wxWidgets minimal sample",
wxOK | wxICON_INFORMATION,
this);
}