gecko/gfx/thebes/gfxFontInfoLoader.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gfxFontInfoLoader.h"
#include "nsCRT.h"
#include "nsIObserverService.h"

using namespace mozilla;
using mozilla::services::GetObserverService;

NS_IMPL_ISUPPORTS1(gfxFontInfoLoader::ShutdownObserver, nsIObserver)

NS_IMETHODIMP
gfxFontInfoLoader::ShutdownObserver::Observe(nsISupports *aSubject,
                                             const char *aTopic,
                                             const char16_t *someData)
{
    if (!nsCRT::strcmp(aTopic, "quit-application")) {
        mLoader->CancelLoader();
    } else {
        NS_NOTREACHED("unexpected notification topic");
    }
    return NS_OK;
}

void
gfxFontInfoLoader::StartLoader(uint32_t aDelay, uint32_t aInterval)
{
    mInterval = aInterval;

    // sanity check
    if (mState != stateInitial && mState != stateTimerOff) {
        CancelLoader();
    }

    // set up timer
    if (!mTimer) {
        mTimer = do_CreateInstance("@mozilla.org/timer;1");
        if (!mTimer) {
            NS_WARNING("Failure to create font info loader timer");
            return;
        }
    }

    // need an initial delay?
    uint32_t timerInterval;

    if (aDelay) {
        mState = stateTimerOnDelay;
        timerInterval = aDelay;
    } else {
        mState = stateTimerOnInterval;
        timerInterval = mInterval;
    }

    InitLoader();

    // start timer
    mTimer->InitWithFuncCallback(LoaderTimerCallback, this, timerInterval,
                                 nsITimer::TYPE_REPEATING_SLACK);

    nsCOMPtr<nsIObserverService> obs = GetObserverService();
    if (obs) {
        mObserver = new ShutdownObserver(this);
        obs->AddObserver(mObserver, "quit-application", false);
    }
}

void
gfxFontInfoLoader::CancelLoader()
{
    if (mState == stateInitial) {
        return;
    }
    mState = stateTimerOff;
    if (mTimer) {
        mTimer->Cancel();
        mTimer = nullptr;
    }
    RemoveShutdownObserver();
    FinishLoader();
}

void
gfxFontInfoLoader::LoaderTimerFire()
{
    if (mState == stateTimerOnDelay) {
        mState = stateTimerOnInterval;
        mTimer->SetDelay(mInterval);
    }

    bool done = RunLoader();
    if (done) {
        CancelLoader();
    }
}

gfxFontInfoLoader::~gfxFontInfoLoader()
{
    RemoveShutdownObserver();
}

void
gfxFontInfoLoader::RemoveShutdownObserver()
{
    if (mObserver) {
        nsCOMPtr<nsIObserverService> obs = GetObserverService();
        if (obs) {
            obs->RemoveObserver(mObserver, "quit-application");
            mObserver = nullptr;
        }
    }
}