Mouse Gestures for Internet Explorer

///////////////////////////////////////////////////////////////
//
// MouseTrail.h
//
// Created: 25/06/2005
// Copyright (c) 2005 Ralph Hare (ralph.hare@ysgyfarnog.co.uk)
// All rights reserved.
//
// The code and information is provided "as-is" without
// warranty of any kind, either expressed or implied.
//
///////////////////////////////////////////////////////////////

#ifndef __MOUSETRAIL_H_80C39B0E_0B0F_41F7_BA96_A16A7CE1851B_
#define __MOUSETRAIL_H_80C39B0E_0B0F_41F7_BA96_A16A7CE1851B_

#include "Gesture.h"

/**
 * MouseTrail is an abstract base class for objects
 * that draw mouse trails - as the user is performing
 * a gesture, the mouse trails object will be passed
 * the path the user transcribes with their mouse. The
 * concrete implementation of MouseTrail will (for example)
 * render the trail to the UI.
 **/
class MouseTrail
{
public:
    MouseTrail() {}
    virtual ~MouseTrail() {}

/**
 * Begin the trail
 * @param hWnd a handle to the window over which the trail is to
 *        be drawn, and to which the trail co-ordinates (@see 
 *        the path parameter in the Update method) relative.
 **/
    virtual void Begin( HWND hWnd ) = 0;

/**
 * End the trail i.e. remove it from the screen
 **/
    virtual void End() = 0;

/**
 * Called by the mouse tracker every time the user
 * updates the path (i.e. moves the mouse)
 * @param path the path subscribed by the mouse while performing
 *        the gesture. Note, all co-ordinates are relative to the
 *        top left of the window passed to the Begin method
 **/
    virtual void Update( const Path &path ) = 0;

/**
 * Called by the mouse tracker whenever the trail window
 * should be show (e.g. when the window being tracked
 * gains focus).
 **/
    virtual void Show() = 0;

/**
 * Called by the mouse tracker whenever the trail window
 * should be hidden (e.g. when the window being tracked
 * loses focus).
 **/
    virtual void Hide() = 0;
};

#endif // __MOUSETRAIL_H_80C39B0E_0B0F_41F7_BA96_A16A7CE1851B_