/*

 * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "SharedTimer.h"

#include "Page.h"

#include "SystemTime.h"

#include "Widget.h"

#include <wtf/Assertions.h>

#include <windows.h>

namespace WebCore {

static UINT timerID;

static void (*sharedTimerFiredFunction)();

static HWND timerWindowHandle = 0;

static UINT timerFiredMessage = 0;

const LPCWSTR kTimerWindowClassName = L"TimerWindowClass";

static bool processingCustomTimerMessage = false;

LRESULT CALLBACK TimerWindowWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)

{

    if (message == timerFiredMessage) {

        processingCustomTimerMessage = true;

        sharedTimerFiredFunction();

        processingCustomTimerMessage = false;

    } else

        return DefWindowProc(hWnd, message, wParam, lParam);

    return 0;

}

static void initializeOffScreenTimerWindow()

{

    if (timerWindowHandle)

        return;

    WNDCLASSEX wcex;

    memset(&wcex, 0, sizeof(WNDCLASSEX));

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.lpfnWndProc    = TimerWindowWndProc;

    wcex.hInstance      = Page::instanceHandle();

    wcex.lpszClassName  = kTimerWindowClassName;

    RegisterClassEx(&wcex);

    timerWindowHandle = CreateWindow(kTimerWindowClassName, 0, 0,

       CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, HWND_MESSAGE, 0, Page::instanceHandle(), 0);

    timerFiredMessage = RegisterWindowMessage(L"com.apple.WebKit.TimerFired");

}

void setSharedTimerFiredFunction(void (*f)())

{

    sharedTimerFiredFunction = f;

}

static void CALLBACK timerFired(HWND, UINT, UINT_PTR, DWORD)

{

    sharedTimerFiredFunction();

}

void setSharedTimerFireTime(double fireTime)

{

    ASSERT(sharedTimerFiredFunction);

    double interval = fireTime - currentTime();

    unsigned intervalInMS;

    if (interval < 0)

        intervalInMS = 0;

    else {

        interval *= 1000;

        if (interval > USER_TIMER_MAXIMUM)

            intervalInMS = USER_TIMER_MAXIMUM;

        else

            intervalInMS = (unsigned)interval;

    }

    if (timerID) {

        KillTimer(0, timerID);

        timerID = 0;

    }

    // We don't allow nested PostMessages, since the custom messages will effectively starve

    // painting and user input. (Win32 has a tri-level queue with application messages > 

    // user input > WM_PAINT/WM_TIMER.)

    // In addition, if the queue contains input events that have been there since the last call to

    // GetQueueStatus, PeekMessage or GetMessage we favor timers.

    if (intervalInMS < USER_TIMER_MINIMUM && !processingCustomTimerMessage && 

        !LOWORD(::GetQueueStatus(QS_ALLINPUT))) {

        // Windows SetTimer does not allow timeouts smaller than 10ms (USER_TIMER_MINIMUM)

        initializeOffScreenTimerWindow();

        PostMessage(timerWindowHandle, timerFiredMessage, 0, 0);

    } else

        timerID = SetTimer(0, 0, intervalInMS, timerFired);

}

void stopSharedTimer()

{

    if (timerID) {

        KillTimer(0, timerID);

        timerID = 0;

    }

}

}