Rewrite 'Preferences' to make it async

This commit is contained in:
Jonas Jenwald 2014-03-16 22:33:39 +01:00
parent bd11111465
commit c920372ff2
3 changed files with 173 additions and 92 deletions

View file

@ -14,51 +14,99 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* globals DEFAULT_PREFERENCES, PDFJS, isLocalStorageEnabled, Promise */
/* globals DEFAULT_PREFERENCES, isLocalStorageEnabled, Promise */
'use strict';
//#include default_preferences.js
var Preferences = (function PreferencesClosure() {
function Preferences() {
this.prefs = {};
this.isInitializedPromiseResolved = false;
this.initializedPromise = this.readFromStorage(DEFAULT_PREFERENCES).then(
function(prefObj) {
this.isInitializedPromiseResolved = true;
/**
* Preferences - Utility for storing persistent settings.
* Used for settings that should be applied to all opened documents,
* or every time the viewer is loaded.
*/
var Preferences = {
prefs: Object.create(DEFAULT_PREFERENCES),
isInitializedPromiseResolved: false,
initializedPromise: null,
/**
* Initialize and fetch the current preference values from storage.
* @return {Promise} A promise that is resolved when the preferences
* have been initialized.
*/
initialize: function preferencesInitialize() {
return this.initializedPromise =
this._readFromStorage(DEFAULT_PREFERENCES).then(function(prefObj) {
this.isInitializedPromiseResolved = true;
if (prefObj) {
this.prefs = prefObj;
}
}.bind(this));
},
/**
* Stub function for writing preferences to storage.
* NOTE: This should be overridden by a build-specific function defined below.
* @param {Object} prefObj The preferences that should be written to storage.
* @return {Promise} A promise that is resolved when the preference values
* have been written.
*/
_writeToStorage: function preferences_writeToStorage(prefObj) {
return Promise.resolve();
},
/**
* Stub function for reading preferences from storage.
* NOTE: This should be overridden by a build-specific function defined below.
* @param {Object} prefObj The preferences that should be read from storage.
* @return {Promise} A promise that is resolved with an {Object} containing
* the preferences that have been read.
*/
_readFromStorage: function preferences_readFromStorage(prefObj) {
return Promise.resolve();
},
/**
* Reset the preferences to their default values and update storage.
* @return {Promise} A promise that is resolved when the preference values
* have been reset.
*/
reset: function preferencesReset() {
return this.initializedPromise.then(function() {
this.prefs = Object.create(DEFAULT_PREFERENCES);
return this._writeToStorage(DEFAULT_PREFERENCES);
}.bind(this));
},
/**
* Replace the current preference values with the ones from storage.
* @return {Promise} A promise that is resolved when the preference values
* have been updated.
*/
reload: function preferencesReload() {
return this.initializedPromise.then(function () {
this._readFromStorage(DEFAULT_PREFERENCES).then(function(prefObj) {
if (prefObj) {
this.prefs = prefObj;
}
}.bind(this));
}
}.bind(this));
},
Preferences.prototype = {
writeToStorage: function Preferences_writeToStorage(prefObj) {
return;
},
readFromStorage: function Preferences_readFromStorage(prefObj) {
var readFromStoragePromise = Promise.resolve();
return readFromStoragePromise;
},
reset: function Preferences_reset() {
if (this.isInitializedPromiseResolved) {
this.prefs = {};
this.writeToStorage(DEFAULT_PREFERENCES);
}
},
set: function Preferences_set(name, value) {
if (!this.isInitializedPromiseResolved) {
return;
} else if (DEFAULT_PREFERENCES[name] === undefined) {
console.error('Preferences_set: \'' + name + '\' is undefined.');
return;
/**
* Set the value of a preference.
* @param {string} name The name of the preference that should be changed.
* @param {boolean|number|string} value The new value of the preference.
* @return {Promise} A promise that is resolved when the value has been set,
* provided that the preference exists and the types match.
*/
set: function preferencesSet(name, value) {
return this.initializedPromise.then(function () {
if (DEFAULT_PREFERENCES[name] === undefined) {
throw new Error('preferencesSet: \'' + name + '\' is undefined.');
} else if (value === undefined) {
console.error('Preferences_set: no value is specified.');
return;
throw new Error('preferencesSet: no value is specified.');
}
var valueType = typeof value;
var defaultType = typeof DEFAULT_PREFERENCES[name];
@ -67,71 +115,79 @@ var Preferences = (function PreferencesClosure() {
if (valueType === 'number' && defaultType === 'string') {
value = value.toString();
} else {
console.error('Preferences_set: \'' + value + '\' is a \"' +
valueType + '\", expected a \"' + defaultType + '\".');
return;
throw new Error('Preferences_set: \'' + value + '\' is a \"' +
valueType + '\", expected \"' + defaultType + '\".');
}
} else {
if (valueType === 'number' && (value | 0) !== value) {
console.error('Preferences_set: \'' + value +
'\' must be an \"integer\".');
return;
throw new Error('Preferences_set: \'' + value +
'\' must be an \"integer\".');
}
}
this.prefs[name] = value;
this.writeToStorage(this.prefs);
},
return this._writeToStorage(this.prefs);
}.bind(this));
},
get: function Preferences_get(name) {
var defaultPref = DEFAULT_PREFERENCES[name];
/**
* Get the value of a preference.
* @param {string} name The name of the preference whose value is requested.
* @return {Promise} A promise that is resolved with a {boolean|number|string}
* containing the value of the preference.
*/
get: function preferencesGet(name) {
return this.initializedPromise.then(function () {
var defaultValue = DEFAULT_PREFERENCES[name];
if (defaultPref === undefined) {
console.error('Preferences_get: \'' + name + '\' is undefined.');
return;
} else if (this.isInitializedPromiseResolved) {
var pref = this.prefs[name];
if (defaultValue === undefined) {
throw new Error('preferencesGet: \'' + name + '\' is undefined.');
} else {
var prefValue = this.prefs[name];
if (pref !== undefined) {
return pref;
if (prefValue !== undefined) {
return prefValue;
}
}
return defaultPref;
}
};
return Preferences;
})();
return defaultValue;
}.bind(this));
}
};
//#if B2G
//Preferences.prototype.writeToStorage = function(prefObj) {
// asyncStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
//Preferences._writeToStorage = function (prefObj) {
// return new Promise(function (resolve) {
// asyncStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj),
// resolve);
// });
//};
//
//Preferences.prototype.readFromStorage = function(prefObj) {
// var readFromStoragePromise = new Promise(function (resolve) {
// asyncStorage.getItem('pdfjs.preferences', function(prefStr) {
//Preferences._readFromStorage = function (prefObj) {
// return new Promise(function (resolve) {
// asyncStorage.getItem('pdfjs.preferences', function (prefStr) {
// var readPrefs = JSON.parse(prefStr);
// resolve(readPrefs);
// });
// });
// return readFromStoragePromise;
//};
//#endif
//#if !(FIREFOX || MOZCENTRAL || B2G)
Preferences.prototype.writeToStorage = function(prefObj) {
if (isLocalStorageEnabled) {
localStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
}
Preferences._writeToStorage = function (prefObj) {
return new Promise(function (resolve) {
if (isLocalStorageEnabled) {
localStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
}
resolve();
});
};
Preferences.prototype.readFromStorage = function(prefObj) {
var readFromStoragePromise = new Promise(function (resolve) {
Preferences._readFromStorage = function (prefObj) {
return new Promise(function (resolve) {
var readPrefs;
if (isLocalStorageEnabled) {
var readPrefs = JSON.parse(localStorage.getItem('pdfjs.preferences'));
resolve(readPrefs);
readPrefs = JSON.parse(localStorage.getItem('pdfjs.preferences'));
}
resolve(readPrefs);
});
return readFromStoragePromise;
};
//#endif