145 lines
3.1 KiB
JavaScript
145 lines
3.1 KiB
JavaScript
goog.provide('ol.has');
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goog.require('goog.dom');
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goog.require('goog.dom.TagName');
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goog.require('ol');
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goog.require('ol.dom');
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goog.require('ol.webgl');
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/**
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* The ratio between physical pixels and device-independent pixels
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* (dips) on the device (`window.devicePixelRatio`).
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* @const
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* @type {number}
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* @api stable
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*/
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ol.has.DEVICE_PIXEL_RATIO = goog.global.devicePixelRatio || 1;
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/**
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* True if the browser's Canvas implementation implements {get,set}LineDash.
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* @type {boolean}
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*/
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ol.has.CANVAS_LINE_DASH = false;
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/**
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* True if both the library and browser support Canvas. Always `false`
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* if `ol.ENABLE_CANVAS` is set to `false` at compile time.
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* @const
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* @type {boolean}
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* @api stable
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*/
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ol.has.CANVAS = ol.ENABLE_CANVAS && (
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/**
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* @return {boolean} Canvas supported.
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*/
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function() {
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if (!('HTMLCanvasElement' in goog.global)) {
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return false;
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}
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try {
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var context = ol.dom.createCanvasContext2D();
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if (goog.isNull(context)) {
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return false;
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} else {
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if (context.setLineDash !== undefined) {
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ol.has.CANVAS_LINE_DASH = true;
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}
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return true;
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}
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} catch (e) {
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return false;
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}
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})();
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/**
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* Indicates if DeviceOrientation is supported in the user's browser.
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* @const
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* @type {boolean}
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* @api stable
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*/
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ol.has.DEVICE_ORIENTATION = 'DeviceOrientationEvent' in goog.global;
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/**
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* True if `ol.ENABLE_DOM` is set to `true` at compile time.
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* @const
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* @type {boolean}
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*/
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ol.has.DOM = ol.ENABLE_DOM;
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/**
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* Is HTML5 geolocation supported in the current browser?
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* @const
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* @type {boolean}
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* @api stable
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*/
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ol.has.GEOLOCATION = 'geolocation' in goog.global.navigator;
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/**
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* True if browser supports touch events.
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* @const
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* @type {boolean}
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* @api stable
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*/
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ol.has.TOUCH = ol.ASSUME_TOUCH || 'ontouchstart' in goog.global;
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/**
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* True if browser supports pointer events.
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* @const
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* @type {boolean}
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*/
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ol.has.POINTER = 'PointerEvent' in goog.global;
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/**
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* True if browser supports ms pointer events (IE 10).
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* @const
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* @type {boolean}
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*/
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ol.has.MSPOINTER = !!(goog.global.navigator.msPointerEnabled);
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/**
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* True if both OpenLayers and browser support WebGL. Always `false`
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* if `ol.ENABLE_WEBGL` is set to `false` at compile time.
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* @const
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* @type {boolean}
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* @api stable
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*/
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ol.has.WEBGL;
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(function() {
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if (ol.ENABLE_WEBGL) {
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var hasWebGL = false;
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var textureSize;
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var /** @type {Array.<string>} */ extensions = [];
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if ('WebGLRenderingContext' in goog.global) {
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try {
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var canvas = /** @type {HTMLCanvasElement} */
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(goog.dom.createElement(goog.dom.TagName.CANVAS));
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var gl = ol.webgl.getContext(canvas, {
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failIfMajorPerformanceCaveat: true
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});
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if (!goog.isNull(gl)) {
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hasWebGL = true;
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textureSize = /** @type {number} */
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(gl.getParameter(gl.MAX_TEXTURE_SIZE));
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extensions = gl.getSupportedExtensions();
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}
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} catch (e) {}
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}
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ol.has.WEBGL = hasWebGL;
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ol.WEBGL_EXTENSIONS = extensions;
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ol.WEBGL_MAX_TEXTURE_SIZE = textureSize;
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}
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})();
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