layout/xul/nsRepeatService.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 //
   8 // Eric Vaughan
   9 // Netscape Communications
  10 //
  11 // See documentation in associated header file
  12 //
  13
  14 #include "nsRepeatService.h"
  15 #include "mozilla/StaticPtr.h"
  16 #include "mozilla/dom/Document.h"
  17
  18 using namespace mozilla;
  19
  20 static StaticAutoPtr<nsRepeatService> gRepeatService;
  21
  22 nsRepeatService::nsRepeatService()
  23     : mCallback(nullptr), mCallbackData(nullptr) {}
  24
  25 nsRepeatService::~nsRepeatService() {
  26   NS_ASSERTION(!mCallback && !mCallbackData,
  27                "Callback was not removed before shutdown");
  28 }
  29
  30 /* static */
  31 nsRepeatService* nsRepeatService::GetInstance() {
  32   if (!gRepeatService) {
  33     gRepeatService = new nsRepeatService();
  34   }
  35   return gRepeatService;
  36 }
  37
  38 /*static*/
  39 void nsRepeatService::Shutdown() { gRepeatService = nullptr; }
  40
  41 void nsRepeatService::Start(Callback aCallback, void* aCallbackData,
  42                             dom::Document* aDocument,
  43                             const nsACString& aCallbackName,
  44                             uint32_t aInitialDelay) {
  45   MOZ_ASSERT(aCallback != nullptr, "null ptr");
  46
  47   mCallback = aCallback;
  48   mCallbackData = aCallbackData;
  49   mCallbackName = aCallbackName;
  50
  51   mRepeatTimer = NS_NewTimer(GetMainThreadSerialEventTarget());
  52
  53   if (mRepeatTimer) {
  54     InitTimerCallback(aInitialDelay);
  55   }
  56 }
  57
  58 void nsRepeatService::Stop(Callback aCallback, void* aCallbackData) {
  59   if (mCallback != aCallback || mCallbackData != aCallbackData) {
  60     return;
  61   }
  62
  63   // printf("Stopping repeat timer\n");
  64   if (mRepeatTimer) {
  65     mRepeatTimer->Cancel();
  66     mRepeatTimer = nullptr;
  67   }
  68   mCallback = nullptr;
  69   mCallbackData = nullptr;
  70 }
  71
  72 void nsRepeatService::InitTimerCallback(uint32_t aInitialDelay) {
  73   if (!mRepeatTimer) {
  74     return;
  75   }
  76
  77   mRepeatTimer->InitWithNamedFuncCallback(
  78       [](nsITimer* aTimer, void* aClosure) {
  79         // Use gRepeatService instead of nsRepeatService::GetInstance() (because
  80         // we don't want nsRepeatService::GetInstance() to re-create a new
  81         // instance for us, if we happen to get invoked after
  82         // nsRepeatService::Shutdown() has nulled out gRepeatService).
  83         nsRepeatService* rs = gRepeatService;
  84         if (!rs) {
  85           return;
  86         }
  87
  88         if (rs->mCallback) {
  89           rs->mCallback(rs->mCallbackData);
  90         }
  91
  92         rs->InitTimerCallback(REPEAT_DELAY);
  93       },
  94       nullptr, aInitialDelay, nsITimer::TYPE_ONE_SHOT, mCallbackName.Data());
  95 }