#include <CtrlLib/CtrlLib.h>

using namespace Upp;

class MyEditorBar : public FrameLeft<Ctrl> {
public:
	virtual void Paint(Draw& w);
	LineEdit* editor; // we need to know who we work for, so we can 
	                  // read some necessary info (font, line positions etc.)
public:
	void SetEditor(LineEdit *e)           { editor = e; }

	MyEditorBar() {
		Width(27); // set some default width
		           // note that 27 will not work with more than 99 lines ;)
	};
	virtual ~MyEditorBar() {};
};

void MyEditorBar::Paint(Draw& w)
{
	Size sz = GetSize();
	w.DrawRect(0, 0, sz.cx, sz.cy, SColorLtFace); // paint background
	
	if(!editor)
		return; // can't work without editor
	
	// read some info from the associated editor
	int fy = editor->GetFontSize().cy;
	Font f = editor->GetFont();
	int line = editor->GetScrollPos().y;
	int linecount = editor->GetLineCount();
	
	// iterate over all the visible lines
	int y = 0;
	while(y < sz.cy) {
		if(line == linecount)
			break; // we reached last line
		
		if(editor->GetCaret().top == y) {
			// current line should be highlighted
			w.DrawRect(0, y, sz.cx, fy, Blend(SColorHighlight(), SColorLtFace(), 200));
			w.DrawText(2, y + 2, IntStr(line+1), f, SColorHighlightText());
		} else {
			//other lines should be rendered normally 
			w.DrawRect(0, y, sz.cx, fy, SColorLtFace());
			w.DrawText(2, y + 2, IntStr(line+1), f);
		}
		
		y += fy;
		line++;
	}
}

class LineEditExtended : public LineEdit {
	typedef LineEditExtended CLASSNAME;
	MyEditorBar bar;
public:
	LineEditExtended(){
		AddFrame(bar); // add the frame
		bar.SetEditor(this);
	}
	virtual bool Key(dword key, int count){
		// refresh every time user presses something (he might add/remove lines or scroll)
		bar.Refresh();
		// and forward the event to parent class
		return LineEdit::Key(key, count);
	}
	virtual Image MouseEvent(int event, Point p, int zdelta, dword keyflags){
		// refresh every time user uses mouse (he might cut/paste lines or scroll)
		bar.Refresh();
		// and forward the event to parent class
		return LineEdit::MouseEvent(event, p, zdelta, keyflags);
	}
};

class MainWindowDlg : public TopWindow {
	typedef MainWindowDlg CLASSNAME;
public:
	MainWindowDlg(){
		Add(edit.SizePos());
		edit <<= "Some\nsample\ntext...\n";
	}
private: 
	LineEditExtended edit;
};

GUI_APP_MAIN
{
    MainWindowDlg().Run();
}