当通过Checker检测到update以后,会通知UpdatePrompt中的updateCheckListener。
1. UpdateCheckListener.onCheckComplete
onCheckComplete: function UCL_onCheckComplete(request, updates, updateCount) { if (Services.um.activeUpdate) { // We‘re actively downloading an update, that‘s the update the user should // see, even if a newer update is available. this._updatePrompt.setUpdateStatus("active-update"); this._updatePrompt.showUpdateAvailable(Services.um.activeUpdate); return; } if (updateCount == 0) { this._updatePrompt.setUpdateStatus("no-updates"); if (this._updatePrompt._systemUpdateListener) { this._updatePrompt._systemUpdateListener.onError("no-updates"); } return; } // Service.aus就是nsUpdateService.js里的UpdateService对象 // selectUpdate会通过一些预设的policy,返回updates中的某一个合适的update对象 let update = Services.aus.selectUpdate(updates, updateCount); if (!update) { this._updatePrompt.setUpdateStatus("already-latest-version"); if (this._updatePrompt._systemUpdateListener) { this._updatePrompt._systemUpdateListener.onError("already-latest-version"); } return; } this._updatePrompt.setUpdateStatus("check-complete"); // 通知UpdatePrompt有可用的update this._updatePrompt.showUpdateAvailable(update); },
2. UpdatePrompt.showUpdateAvailable(update)
showUpdateAvailable: function UP_showUpdateAvailable(aUpdate) { let packageInfo = {}; packageInfo.version = aUpdate.displayVersion; packageInfo.description = aUpdate.statusText; packageInfo.buildDate = aUpdate.buildID; // 返回一个被选择的patch,或者第一个patch let patch = aUpdate.selectedPatch; if (!patch && aUpdate.patchCount > 0) { // For now we just check the first patch to get size information if a // patch hasn‘t been selected yet. patch = aUpdate.getPatchAt(0); } if (patch) { packageInfo.size = patch.size; packageInfo.type = patch.type; } else { log("Warning: no patches available in update"); } this._pendingUpdateAvailablePackageInfo = packageInfo; if (this._systemUpdateListener) { this._systemUpdateListener.onUpdateAvailable(packageInfo.type, packageInfo.version, packageInfo.description, packageInfo.buildDate, packageInfo.size); // Set null since the event is fired. this._pendingUpdateAvailablePackageInfo = null; } // 发送‘update-available‘ event,其实就是通过SystemAppProxy发送一个‘mozChromeEvent‘, // 还有发送一些附带信息,比如selected patch size和patch type。接收方是谁呢?可以猜到,就是前几篇分析的SystemApp中的UpdateManager。 if (!this.sendUpdateEvent("update-available", aUpdate)) { log("Unable to prompt for available update, forcing download"); this.downloadUpdate(aUpdate); } },
时间: 2024-11-07 08:00:19