/*
* Copyright 2015-2017 WorldWind Contributors
*
* 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.
*/
/**
* @exports TextAttributes
*/
define([
'../util/Color',
'../util/Font',
'../util/Offset'
],
function (Color,
Font,
Offset) {
"use strict";
/**
* Constructs a text attributes bundle.
* @alias TextAttributes
* @constructor
* @classdesc Holds attributes applied to [Text]{@link Text} shapes and [Placemark]{@link Placemark} labels.
*
* @param {TextAttributes} attributes Attributes to initialize this attributes instance to. May be null,
* in which case the new instance contains default attributes.
*/
var TextAttributes = function (attributes) {
this._color = attributes ? attributes._color : new Color(1, 1, 1, 1);
this._font = attributes ? attributes._font : new Font(14);
this._offset = attributes ? attributes._offset
: new Offset(WorldWind.OFFSET_FRACTION, 0.5, WorldWind.OFFSET_FRACTION, 0.0);
this._scale = attributes ? attributes._scale : 1;
this._depthTest = attributes ? attributes._depthTest : false;
/**
* Indicates whether this object's state key is invalid. Subclasses must set this value to true when their
* attributes change. The state key will be automatically computed the next time it's requested. This flag
* will be set to false when that occurs.
* @type {boolean}
* @protected
*/
this.stateKeyInvalid = true;
};
/**
* Computes the state key for this attributes object. Subclasses that define additional attributes must
* override this method, call it from that method, and append the state of their attributes to its
* return value.
* @returns {String} The state key for this object.
* @protected
*/
TextAttributes.prototype.computeStateKey = function () {
return "c " + this._color.toHexString(true) +
" f " + this._font.toString() +
" o " + this._offset.toString() +
" s " + this._scale +
" dt " + this._depthTest;
};
Object.defineProperties(TextAttributes.prototype, {
/**
* A string identifying the state of this attributes object. The string encodes the current values of all
* this object's properties. It's typically used to validate cached representations of shapes associated
* with this attributes object.
* @type {String}
* @readonly
* @memberof TextAttributes.prototype
*/
stateKey: {
get: function () {
if (this.stateKeyInvalid) {
this._stateKey = this.computeStateKey();
this.stateKeyInvalid = false;
}
return this._stateKey;
}
},
/**
* The text color.
* @type {Color}
* @default White (1, 1, 1, 1)
* @memberof TextAttributes.prototype
*/
color: {
get: function () {
return this._color;
},
set: function (value) {
this._color = value;
this.stateKeyInvalid = true;
}
},
/**
* The text size, face and other characteristics, as described in [Font]{@link Font}.
* @type {Font}
* @default Those of [Font]{@link Font}, but with a font size of 14.
* @memberof TextAttributes.prototype
*/
font: {
get: function () {
return this._font;
},
set: function (value) {
this._font = value;
this.stateKeyInvalid = true;
}
},
/**
* Indicates the location of the text relative to its specified position.
* May be null, in which case the text's bottom-left corner is placed at the specified position.
* @type {Offset}
* @default 0.5, 0.0, both fractional (Places the text's horizontal center and vertical bottom at the
* specified position.)
* @memberof TextAttributes.prototype
*/
offset: {
get: function () {
return this._offset;
},
set: function (value) {
this._offset = value;
this.stateKeyInvalid = true;
}
},
/**
* Indicates the amount to scale the text. A value of 0 makes the text disappear.
* @type {Number}
* @default 1.0
* @memberof TextAttributes.prototype
*/
scale: {
get: function () {
return this._scale;
},
set: function (value) {
this._scale = value;
this.stateKeyInvalid = true;
}
},
/**
* Indicates whether the text should be depth-tested against other objects in the scene. If true,
* the text may be occluded by terrain and other objects in certain viewing situations. If false,
* the text will not be occluded by terrain and other objects.
* @type {Boolean}
* @default false
* @memberof TextAttributes.prototype
*/
depthTest: {
get: function () {
return this._depthTest;
},
set: function (value) {
this._depthTest = value;
this.stateKeyInvalid = true;
}
}
});
return TextAttributes;
});