// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Copyright 2006 Google Inc. All Rights Reserved.
/**
* @fileoverview This behavior is applied to a text input and it shows a text
* message inside the element if the user hasn't entered any text.
*
* This is ported from http://go/labelinput.js
*
* Known issue: Safari does not allow you get to the window object from a
* document. We need that to listen to the onload event. For now we hard code
* the window to the current window.
*
* Known issue: We need to listen to the form submit event but we attach the
* event only once (when created or when it is changed) so if you move the DOM
* node to another form it will not be cleared correctly before submitting.
*
* @see ../demos/labelinput.html
*/
goog.provide('goog.ui.LabelInput');
goog.require('goog.Timer');
goog.require('goog.dom');
goog.require('goog.dom.classes');
goog.require('goog.events');
goog.require('goog.events.EventHandler');
goog.require('goog.events.EventType');
goog.require('goog.ui.Component');
/**
* This creates the label input object.
* @param {string} opt_label The text to show as the label.
* @param {goog.dom.DomHelper} opt_domHelper Optional DOM helper.
* @extends {goog.ui.Component}
* @constructor
*/
goog.ui.LabelInput = function(opt_label, opt_domHelper) {
goog.ui.Component.call(this, opt_domHelper);
/**
* The text to show as the label.
* @type {string}
* @private
*/
this.label_ = opt_label || '';
};
goog.inherits(goog.ui.LabelInput, goog.ui.Component);
/**
* Variable used to store the element value on keydown and restore it on
* keypress. See {@link #handleEscapeKeys_}
* @type {string?}
* @private
*/
goog.ui.LabelInput.prototype.ffKeyRestoreValue_ = null;
/**
* @type {goog.events.EventHandler}
* @private
*/
goog.ui.LabelInput.prototype.eventHandler_;
/**
* Creates the DOM nodes needed for the label input.
*/
goog.ui.LabelInput.prototype.createDom = function() {
this.setElementInternal(
this.getDomHelper().createDom('input', {'type': 'text'}));
};
/**
* Decorates an existing HTML input element as a label input. If the element
* has a "label" attribute then that will be used as the label property for the
* label input object.
* @param {HTMLInputElement} element The HTML input element to decorate.
*/
goog.ui.LabelInput.prototype.decorateInternal = function(element) {
goog.ui.LabelInput.superClass_.decorateInternal.call(this, element);
if (!this.label_) {
this.label_ = element.getAttribute('label') || '';
}
};
/**
* Called when the DOM for the component is for sure in the document.
*/
goog.ui.LabelInput.prototype.enterDocument = function() {
goog.ui.LabelInput.superClass_.enterDocument.call(this);
this.attachEvents_();
this.check_();
// Make it easy for other closure widgets to play nicely with inputs using
// LabelInput:
this.getElement().labelInput_ = this;
};
/**
* Called when the DOM for the component is removed from the document or
* when the component no longer is managing the DOM.
*/
goog.ui.LabelInput.prototype.exitDocument = function() {
goog.ui.LabelInput.superClass_.exitDocument.call(this);
this.detachEvents_();
this.getElement().labelInput_ = null;
};
/**
* Attaches the events we need to listen to.
* @private
*/
goog.ui.LabelInput.prototype.attachEvents_ = function() {
var eh = new goog.events.EventHandler(this);
eh.listen(this.getElement(), goog.events.EventType.FOCUS, this.handleFocus_);
eh.listen(this.getElement(), goog.events.EventType.BLUR, this.handleBlur_);
if (goog.userAgent.GECKO) {
eh.listen(this.getElement(), [goog.events.EventType.KEYPRESS,
goog.events.EventType.KEYDOWN, goog.events.EventType.KEYUP],
this.handleEscapeKeys_);
}
// IE sets defaultValue upon load so we need to test that as well.
var d = goog.dom.getOwnerDocument(this.getElement());
var w = goog.dom.getWindow(d);
eh.listen(w, goog.events.EventType.LOAD, this.handleWindowLoad_);
this.eventHandler_ = eh;
this.attachEventsToForm_();
};
/**
* Adds a listener to the form so that we can clear the input before it is
* submitted.
* @private
*/
goog.ui.LabelInput.prototype.attachEventsToForm_ = function() {
// in case we have are in a form we need to make sure the label is not
// submitted
if (!this.formAttached_ && this.eventHandler_ && this.getElement().form) {
this.eventHandler_.listen(this.getElement().form,
goog.events.EventType.SUBMIT,
this.handleFormSubmit_);
this.formAttached_ = true;
}
};
/**
* Stops listening to the events.
* @private
*/
goog.ui.LabelInput.prototype.detachEvents_ = function() {
if (this.eventHandler_) {
this.eventHandler_.dispose();
this.eventHandler_ = null;
}
};
/** @inheritDoc */
goog.ui.LabelInput.prototype.disposeInternal = function() {
goog.ui.LabelInput.superClass_.disposeInternal.call(this);
this.detachEvents_();
};
/**
* The CSS class name to add to the input when the user has not entered a
* value.
*/
goog.ui.LabelInput.prototype.LABEL_CLASS_NAME = 'label-input-label';
/**
* Handler for the focus event.
* @param {goog.events.Event} e The event object passed in to the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleFocus_ = function(e) {
this.hasFocus_ = true;
goog.dom.classes.remove(this.getElement(), this.LABEL_CLASS_NAME);
if (!this.hasChanged() && !this.inFocusAndSelect_) {
var me = this;
var clearValue = function() {
me.getElement().value = '';
};
if (goog.userAgent.IE) {
goog.Timer.callOnce(clearValue, 10);
} else {
clearValue();
}
}
};
/**
* Handler for the blur event.
* @param {goog.events.Event} e The event object passed in to the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleBlur_ = function(e) {
this.ffKeyRestoreValue_ = null;
this.hasFocus_ = false;
this.check_();
};
/**
* Handler for key events in Firefox.
*
* If the escape key is pressed when a text input has not been changed manually
* since being focussed, the text input will revert to it's previous value.
* Firefox does not honor preventDefault for the escape key. The revert happens
* after the keydown event and before every keypress. We therefore store the
* element's value on keydown and restore it on keypress. The restore value is
* nullified on keyup so that {@link #getValue} returns the correct value.
*
* IE and Chrome don't have this problem, Opera blurs in the input box
* completely in a way that preventDefault on the escape key has no effect.
*
* @param {goog.events.BrowserEvent} e The event object passed in to
* the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleEscapeKeys_ = function(e) {
if (e.keyCode == 27) {
if (e.type == goog.events.EventType.KEYDOWN) {
this.ffKeyRestoreValue_ = this.getElement().value;
} else if (e.type == goog.events.EventType.KEYPRESS) {
this.getElement().value = /** @type {string} */ (this.ffKeyRestoreValue_);
} else if (e.type == goog.events.EventType.KEYUP) {
this.ffKeyRestoreValue_ = null;
}
e.preventDefault();
}
};
/**
* Handler for the submit event of the form element.
* @param {goog.events.Event} e The event object passed in to the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleFormSubmit_ = function(e) {
if (!this.hasChanged()) {
this.getElement().value = '';
// allow form to be sent before restoring value
goog.Timer.callOnce(this.handleAfterSubmit_, 10, this);
}
};
/**
* Restore value after submit
* @param {Event} e The event object passed in to the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleAfterSubmit_ = function(e) {
if (!this.hasChanged()) {
this.getElement().value = this.label_;
}
};
/**
* Handler for the load event the window. This is needed because
* IE sets defaultValue upon load.
* @param {Event} e The event object passed in to the event handler.
* @private
*/
goog.ui.LabelInput.prototype.handleWindowLoad_ = function(e) {
this.check_();
};
/**
* @return {boolean} Whether the value has changed been changed by the user.
*/
goog.ui.LabelInput.prototype.hasChanged = function() {
return this.getElement().value != '' &&
this.getElement().value != this.label_;
};
/**
* Clears the value of the input element without resetting the default text.
*/
goog.ui.LabelInput.prototype.clear = function() {
this.getElement().value = '';
// Reset ffKeyRestoreValue_ when non-null
if (this.ffKeyRestoreValue_ != null) {
this.ffKeyRestoreValue_ = '';
}
};
/**
* Use this to set the value through script to ensure that the label state is
* up to date
* @param {string} s The new value for the input.
*/
goog.ui.LabelInput.prototype.setValue = function(s) {
if (this.ffKeyRestoreValue_ != null) {
this.ffKeyRestoreValue_ = s;
}
this.getElement().value = s;
this.check_();
};
/**
* Returns the current value of the text box, returning an empty string if the
* search box is the default value
* @return {string} The value of the input box.
*/
goog.ui.LabelInput.prototype.getValue = function() {
if (this.ffKeyRestoreValue_ != null) {
// Fix the Firefox from incorrectly reporting the value to calling code
// that attached the listener to keypress before the labelinput
return this.ffKeyRestoreValue_;
}
return this.hasChanged() ? /** @type {string} */ (this.getElement().value) :
'';
};
/**
* Checks the state of the input element
* @private
*/
goog.ui.LabelInput.prototype.check_ = function() {
// if we haven't got a form yet try now
this.attachEventsToForm_();
if (!this.hasChanged()) {
if (!this.inFocusAndSelect_ && !this.hasFocus_) {
goog.dom.classes.add(this.getElement(), this.LABEL_CLASS_NAME);
}
// Allow browser to catchup with CSS changes before restoring the label.
goog.Timer.callOnce(this.restoreLabel_, 10, this);
} else {
goog.dom.classes.remove(this.getElement(), this.LABEL_CLASS_NAME);
}
};
/**
* This method focuses the input and if selects all the text. If the value
* hasn't changed it will set the value to the label so that the label text is
* selected.
*/
goog.ui.LabelInput.prototype.focusAndSelect = function() {
// We need to check whether the input has changed before focusing
var hc = this.hasChanged();
this.inFocusAndSelect_ = true;
this.getElement().focus();
if (!hc) {
this.getElement().value = this.label_;
}
this.getElement().select();
// set to false in timer to let IE trigger the focus event
goog.Timer.callOnce(this.focusAndSelect_, 10, this);
};
/**
* @private
*/
goog.ui.LabelInput.prototype.focusAndSelect_ = function() {
this.inFocusAndSelect_ = false;
};
/**
* Sets the value of the input element to label.
* @private
*/
goog.ui.LabelInput.prototype.restoreLabel_ = function() {
// Check again in case something changed since this was scheduled.
// We check that the element is still there since this is called by a timer
// and the dispose method may have been called prior to this.
if (this.getElement() && !this.hasChanged()) {
this.getElement().value = this.label_;
}
};