while(my_condition) {
 Ctrl::ProcessEvents();
 Sleep(20)
}

Sleep(2200)

#include <CtrlLib/CtrlLib.h>
#include <windows.h>

using namespace Upp;

static bool sClose;

struct MyApp : TopWindow {
	Button bt;
	MyApp()
	{
		CenterScreen().SetRect(0, 0, 640, 480);
		Add(bt.SetLabel("Click me!").HCenterPos().VCenterPos());
		WhenClose << [=] { sClose = true; };
		bt << [=] {
			Point p;
			GetCursorPos(p);
			while(p.y-- > 0 && !sClose) {
				ProcessEvents();
				SetCursorPos(p.x, p.y);
                                Title("Cursor pos (y): " << AsString(p.y));
				GuiSleep(20);
			}
		};
	}
};

GUI_APP_MAIN
{
	MyApp().Run();
}

#include <CtrlLib/CtrlLib.h>

using namespace Upp;

struct MyAppWindow : TopWindow {
	Rect  rect;
	Color color;
	
	MyAppWindow() {
		Zoomable().SetRect(0, 0, 200, 200);
		
		RandomizeRect();
		SetTimeCallback(-2000, [=] { OnTimer(); });
	}
	
	~MyAppWindow() {
		KillTimeCallback();
	}
	
	void Paint(Draw& w) override {
		Size sz = GetSize();
		
		w.DrawRect(sz, White());
		w.DrawRect(rect, color);
	}
	
	void OnTimer() {
		RandomizeRect();
		Refresh();
	}
	
	void RandomizeRect() {
		Size sz = GetSize();
		
		int length = 50;
		int x = Random() % (sz.cx - length);
		int y = Random() % (sz.cy - length);
		
		rect = Rect(x, y, x + length, y + length);
		color = Color(Random() % 255, Random() % 255, Random() % 255);
	}
};

GUI_APP_MAIN
{
	MyAppWindow().Run();
}

SetTimeCallback(-2000, [=] { OnTimer(); });

#include <CtrlLib/CtrlLib.h>

using namespace Upp;

class MyApp : public TopWindow {
	MyApp() {
		SetTimeCallback(1000, [=] { Action1(); }); // The first parameter is positive, time callback will be executed only once
	}
	
	void Action1() {
		SetTimeCallback(2000, [=] { Action2(); }); // Execute Action2 after 2 seconds...
	}
	
	void Action2() {
		SetTimeCallback(5000, [=] { Action3(); }); // Execute Action3 after 5 seconds...
	}
	
	void Action3() {
		// It's over no new time callbacks will be executed
	}
};

class MyApp : public TopWindow {
	MyApp() {
		// The third parameter of SetTimeCallback is id. If id's are different there are
		// separate entities and you can schedule multiple time callbacks at once.
		
		SetTimeCallback(1000, [=] { Action1(); }, 0); // Execute Action1() after 1s
		SetTimeCallback(4000, [=] { Action2(); }, 1); // Execute Action2() after 4s
		SetTimeCallback(7000, [=] { Action3(); }, 2); // Execute Action3() after 7s
	}
	
	void Action1() {}
	void Action2() {}
	void Action3() {}
};