gecko/dom/fm/DOMFMRadioParent.jsm
2012-10-11 21:31:39 -04:00

460 lines
14 KiB
JavaScript

/* 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/. */
"use strict"
let DEBUG = 0;
if (DEBUG)
debug = function(s) { dump("-*- DOMFMRadioParent component: " + s + "\n"); };
else
debug = function(s) {};
const Cu = Components.utils;
const Cc = Components.classes;
const Ci = Components.interfaces;
const MOZ_SETTINGS_CHANGED_OBSERVER_TOPIC = "mozsettings-changed";
const PROFILE_BEFORE_CHANGE_OBSERVER_TOPIC = "profile-before-change";
const BAND_87500_108000_kHz = 1;
const BAND_76000_108000_kHz = 2;
const BAND_76000_90000_kHz = 3;
const FM_BANDS = { };
FM_BANDS[BAND_76000_90000_kHz] = {
lower: 76000,
upper: 90000
};
FM_BANDS[BAND_87500_108000_kHz] = {
lower: 87500,
upper: 108000
};
FM_BANDS[BAND_76000_108000_kHz] = {
lower: 76000,
upper: 108000
};
const BAND_SETTING_KEY = "fmRadio.band";
const CHANNEL_WIDTH_SETTING_KEY = "fmRadio.channelWidth";
// Hal types
const CHANNEL_WIDTH_200KHZ = 200;
const CHANNEL_WIDTH_100KHZ = 100;
const CHANNEL_WIDTH_50KHZ = 50;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
"@mozilla.org/parentprocessmessagemanager;1",
"nsIMessageListenerManager");
XPCOMUtils.defineLazyGetter(this, "FMRadio", function() {
return Cc["@mozilla.org/fmradio;1"].getService(Ci.nsIFMRadio);
});
XPCOMUtils.defineLazyServiceGetter(this, "gSettingsService",
"@mozilla.org/settingsService;1",
"nsISettingsService");
let EXPORTED_SYMBOLS = ["DOMFMRadioParent"];
let DOMFMRadioParent = {
QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
Ci.nsISettingsServiceCallback]),
_initialized: false,
/* Indicates if the FM radio is currently enabled */
_isEnabled: false,
/* Indicates if the FM radio is currently being enabled */
_enabling: false,
/* Current frequency in KHz */
_currentFrequency: 0,
/* Current band setting */
_currentBand: BAND_87500_108000_kHz,
/* Current channel width */
_currentWidth: CHANNEL_WIDTH_100KHZ,
/* Indicates if the antenna is currently available */
_antennaAvailable: true,
_seeking: false,
_seekingCallback: null,
init: function() {
if (this._initialized === true) {
return;
}
this._initialized = true;
this._messages = ["DOMFMRadio:enable", "DOMFMRadio:disable",
"DOMFMRadio:setFrequency", "DOMFMRadio:getCurrentBand",
"DOMFMRadio:getPowerState", "DOMFMRadio:getFrequency",
"DOMFMRadio:getAntennaState",
"DOMFMRadio:seekUp", "DOMFMRadio:seekDown",
"DOMFMRadio:cancelSeek"
];
this._messages.forEach(function(msgName) {
ppmm.addMessageListener(msgName, this);
}.bind(this));
Services.obs.addObserver(this, PROFILE_BEFORE_CHANGE_OBSERVER_TOPIC, false);
Services.obs.addObserver(this, MOZ_SETTINGS_CHANGED_OBSERVER_TOPIC, false);
this._updatePowerState();
// Get the band setting and channel width setting
let lock = gSettingsService.createLock();
lock.get(BAND_SETTING_KEY, this);
lock.get(CHANNEL_WIDTH_SETTING_KEY, this);
this._updateAntennaState();
let self = this;
FMRadio.onantennastatechange = function onantennachange() {
self._updateAntennaState();
};
debug("Initialized");
},
// nsISettingsServiceCallback
handle: function(aName, aResult) {
if (aName == BAND_SETTING_KEY) {
this._updateBand(aResult);
} else if (aName == CHANNEL_WIDTH_SETTING_KEY) {
this._updateChannelWidth(aResult);
}
},
handleError: function(aErrorMessage) {
this._updateBand(BAND_87500_108000_kHz);
this._updateChannelWidth(CHANNEL_WIDTH_100KHZ);
},
_updateAntennaState: function() {
let antennaState = FMRadio.isAntennaAvailable;
if (antennaState != this._antennaAvailable) {
this._antennaAvailable = antennaState;
ppmm.broadcastAsyncMessage("DOMFMRadio:antennaChange", { });
}
},
_updateBand: function(band) {
switch (parseInt(band)) {
case BAND_87500_108000_kHz:
case BAND_76000_108000_kHz:
case BAND_76000_90000_kHz:
this._currentBand = band;
break;
}
},
_updateChannelWidth: function(channelWidth) {
switch (parseInt(channelWidth)) {
case CHANNEL_WIDTH_50KHZ:
case CHANNEL_WIDTH_100KHZ:
case CHANNEL_WIDTH_200KHZ:
this._currentWidth = channelWidth;
break;
}
},
/**
* Update and cache the current frequency.
* Send frequency change message if the frequency is changed.
* The returned boolean value indicates if the frequency is changed.
*/
_updateFrequency: function() {
let frequency = FMRadio.frequency;
if (frequency != this._currentFrequency) {
this._currentFrequency = frequency;
ppmm.broadcastAsyncMessage("DOMFMRadio:frequencyChange", { });
return true;
}
return false;
},
/**
* Update and cache the power state of the FM radio.
* Send message if the power state is changed.
*/
_updatePowerState: function() {
let enabled = FMRadio.enabled;
if (this._isEnabled != enabled) {
this._isEnabled = enabled;
ppmm.broadcastAsyncMessage("DOMFMRadio:powerStateChange", { });
// If the FM radio is enabled, update the current frequency immediately,
if (enabled) {
this._updateFrequency();
}
}
},
_onSeekComplete: function(success) {
if (this._seeking) {
this._seeking = false;
if (this._seekingCallback) {
this._seekingCallback(success);
this._seekingCallback = null;
}
}
},
/**
* Seek the next channel with given direction.
* Only one seek action is allowed at once.
*/
_seekStation: function(direction, aMessage) {
let msg = aMessage.json || { };
let messageName = aMessage.name + ":Return";
// If the FM radio is disabled, do not execute the seek action.
if(!this._isEnabled) {
this._sendMessage(messageName, false, null, msg);
return;
}
let self = this;
function callback(success) {
debug("Seek completed.");
if (!success) {
self._sendMessage(messageName, false, null, msg);
} else {
// Make sure the FM app will get the right frequency.
self._updateFrequency();
self._sendMessage(messageName, true, null, msg);
}
}
if (this._seeking) {
// Pass a boolean value to the callback which indicates that
// the seek action failed.
callback(false);
return;
}
this._seekingCallback = callback;
this._seeking = true;
let self = this;
FMRadio.seek(direction);
FMRadio.addEventListener("seekcomplete", function FM_onSeekComplete() {
FMRadio.removeEventListener("seekcomplete", FM_onSeekComplete);
self._onSeekComplete(true);
});
},
/**
* Round the frequency to match the range of frequency and the channel width.
* If the given frequency is out of range, return null.
* For example:
* - lower: 87.5MHz, upper: 108MHz, channel width: 0.2MHz
* 87600 is rounded to 87700
* 87580 is rounded to 87500
* 109000 is not rounded, null will be returned
*/
_roundFrequency: function(frequencyInKHz) {
if (frequencyInKHz < FM_BANDS[this._currentBand].lower ||
frequencyInKHz > FM_BANDS[this._currentBand].upper) {
return null;
}
let partToBeRounded = frequencyInKHz - FM_BANDS[this._currentBand].lower;
let roundedPart = Math.round(partToBeRounded / this._currentWidth) *
this._currentWidth;
return FM_BANDS[this._currentBand].lower + roundedPart;
},
observe: function(aSubject, aTopic, aData) {
switch (aTopic) {
case PROFILE_BEFORE_CHANGE_OBSERVER_TOPIC:
this._messages.forEach(function(msgName) {
ppmm.removeMessageListener(msgName, this);
}.bind(this));
Services.obs.removeObserver(this, PROFILE_BEFORE_CHANGE_OBSERVER_TOPIC);
Services.obs.removeObserver(this, MOZ_SETTINGS_CHANGED_OBSERVER_TOPIC);
ppmm = null;
this._messages = null;
break;
case MOZ_SETTINGS_CHANGED_OBSERVER_TOPIC:
let setting = JSON.parse(aData);
this.handleMozSettingsChanged(setting);
break;
}
},
_sendMessage: function(message, success, data, msg) {
msg.manager.sendAsyncMessage(message + (success ? ":OK" : ":NO"), {
data: data,
rid: msg.rid,
mid: msg.mid
});
},
handleMozSettingsChanged: function(settings) {
switch (settings.key) {
case BAND_SETTING_KEY:
this._updateBand(settings.value);
break;
case CHANNEL_WIDTH_SETTING_KEY:
this._updateChannelWidth(settings.value);
break;
}
},
_enableFMRadio: function(msg) {
let frequencyInKHz = this._roundFrequency(msg.data * 1000);
// If the FM radio is already enabled or it is currently being enabled
// or the given frequency is out of range, return false.
if (this._isEnabled || this._enabling || !frequencyInKHz) {
this._sendMessage("DOMFMRadio:enable:Return", false, null, msg);
return;
}
this._enabling = true;
let self = this;
FMRadio.addEventListener("enabled", function on_enabled() {
debug("FM Radio is enabled!");
self._enabling = false;
FMRadio.removeEventListener("enabled", on_enabled);
// To make sure the FM app will get right frequency after the FM
// radio is enabled, we have to set the frequency first.
FMRadio.setFrequency(frequencyInKHz);
// Update the current frequency without sending 'frequencyChange'
// msg, to make sure the FM app will get the right frequency when the
// 'enabled' event is fired.
self._currentFrequency = FMRadio.frequency;
self._updatePowerState();
self._sendMessage("DOMFMRadio:enable:Return", true, null, msg);
// The frequency is changed from 'null' to some number, so we should
// send the 'frequencyChange' message manually.
ppmm.broadcastAsyncMessage("DOMFMRadio:frequencyChange", { });
});
FMRadio.enable({
lowerLimit: FM_BANDS[self._currentBand].lower,
upperLimit: FM_BANDS[self._currentBand].upper,
channelWidth: self._currentWidth // 100KHz by default
});
},
_disableFMRadio: function(msg) {
// If the FM radio is already disabled, return false.
if (!this._isEnabled) {
this._sendMessage("DOMFMRadio:disable:Return", false, null, msg);
return;
}
let self = this;
FMRadio.addEventListener("disabled", function on_disabled() {
debug("FM Radio is disabled!");
FMRadio.removeEventListener("disabled", on_disabled);
self._updatePowerState();
self._sendMessage("DOMFMRadio:disable:Return", true, null, msg);
// If the FM Radio is currently seeking, no fail-to-seek or similar
// event will be fired, execute the seek callback manually.
self._onSeekComplete(false);
});
FMRadio.disable();
},
receiveMessage: function(aMessage) {
let msg = aMessage.json || {};
msg.manager = aMessage.target;
let ret = 0;
let self = this;
switch (aMessage.name) {
case "DOMFMRadio:enable":
self._enableFMRadio(msg);
break;
case "DOMFMRadio:disable":
self._disableFMRadio(msg);
break;
case "DOMFMRadio:setFrequency":
let frequencyInKHz = self._roundFrequency(msg.data * 1000);
// If the FM radio is disabled or the given frequency is out of range,
// skip to set frequency and send back the False message immediately.
if (!self._isEnabled || !frequencyInKHz) {
self._sendMessage("DOMFMRadio:setFrequency:Return", false, null, msg);
} else {
FMRadio.setFrequency(frequencyInKHz);
self._sendMessage("DOMFMRadio:setFrequency:Return", true, null, msg);
this._updateFrequency();
}
break;
case "DOMFMRadio:getCurrentBand":
// this message is sync
return {
lower: FM_BANDS[self._currentBand].lower / 1000, // in MHz
upper: FM_BANDS[self._currentBand].upper / 1000, // in MHz
channelWidth: self._currentWidth / 1000 // in MHz
};
case "DOMFMRadio:getPowerState":
// this message is sync
return self._isEnabled;
case "DOMFMRadio:getFrequency":
// this message is sync
return self._isEnabled ? this._currentFrequency / 1000 : null; // in MHz
case "DOMFMRadio:getAntennaState":
// this message is sync
return self._antennaAvailable;
case "DOMFMRadio:seekUp":
self._seekStation(Ci.nsIFMRadio.SEEK_DIRECTION_UP, aMessage);
break;
case "DOMFMRadio:seekDown":
self._seekStation(Ci.nsIFMRadio.SEEK_DIRECTION_DOWN, aMessage);
break;
case "DOMFMRadio:cancelSeek":
// If the FM radio is disabled, or the FM radio is not currently
// seeking, do not execute the cancel seek action.
if (!self._isEnabled || !self._seeking) {
self._sendMessage("DOMFMRadio:cancelSeek:Return", false, null, msg);
} else {
FMRadio.cancelSeek();
// No fail-to-seek or similar event will be fired from the hal part,
// so execute the seek callback here manually.
this._onSeekComplete(false);
// The FM radio will stop at one frequency without any event, so we need to
// update the current frequency, make sure the FM app will get the right frequency.
this._updateFrequency();
self._sendMessage("DOMFMRadio:cancelSeek:Return", true, null, msg);
}
break;
}
}
};
DOMFMRadioParent.init();