@geoext/geoext
Version:
GeoExt is Open Source and enables building desktop-like GIS applications through the web. It is a JavaScript framework that combines the GIS functionality of OpenLayers with the user interface savvy of the ExtJS library provided by Sencha.
111 lines (103 loc) • 3.84 kB
JavaScript
/* Copyright (c) 2015-present The Open Source Geospatial Foundation
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* A utility class for working with OpenLayers layers.
*
* @class GeoExt.util.Layer
*/
Ext.define('GeoExt.util.Layer', {
inheritableStatics: {
/**
* Cascades down a given LayerGroup, calling the given function for
* each LayerGroup / Layer.
*
* @param {ol.layer.Group} lyrGroup The layer group to cascade down
* @param {Function} fn A function to call on every LayerGroup / Layer
* @return {void}
*/
cascadeLayers: function (lyrGroup, fn) {
if (!(lyrGroup instanceof ol.layer.Group)) {
// skip on wrong input type
Ext.Logger.warn(
'No ol.layer.Group given to ' +
'BasiGX.util.Layer.cascadeLayers. It is unlikely that ' +
'this will work properly. Skipping!',
);
return;
}
if (!Ext.isFunction(fn)) {
Ext.Logger.warn(
'No function passed ' + 'this will not work. Skipping!',
);
return;
}
lyrGroup.getLayers().forEach(function (layerOrGroup) {
fn(layerOrGroup);
if (layerOrGroup instanceof ol.layer.Group) {
GeoExt.util.Layer.cascadeLayers(layerOrGroup, fn);
}
});
},
/**
* A utility method to find the `ol.layer.Group` which is the direct
* parent of the passed layer. Searching starts at the passed
* startGroup. If `undefined` is returned, the layer is not a child of
* the `startGroup`.
*
* @param {ol.layer.Base} childLayer The layer whose group we want.
* @param {ol.layer.Group} startGroup The group layer that we will start
* searching in.
* @return {ol.layer.Group} The direct parent group or undefined if the
* group cannot be determined.
*/
findParentGroup: function (childLayer, startGroup) {
let parentGroup;
const findParentGroup = GeoExt.util.Layer.findParentGroup;
const getLayerIndex = GeoExt.util.Layer.getLayerIndex;
if (getLayerIndex(childLayer, startGroup) !== -1) {
parentGroup = startGroup;
} else {
startGroup.getLayers().forEach(function (layer) {
if (!parentGroup && layer instanceof ol.layer.Group) {
parentGroup = findParentGroup(childLayer, layer);
// sadly we cannot abort the forEach-iteration here
}
});
}
return parentGroup;
},
/**
* A utility method to determine the zero based index of a layer in a
* layer group. Will return `-1` if the layer isn't a direct child of
* the group.
*
* @param {ol.layer.Base} layer The layer whose index we want.
* @param {ol.layer.Group} group The group to search in.
* @return {number} The index or `-1` if the layer isn't a direct child
* of the group.
*/
getLayerIndex: function (layer, group) {
let index = -1;
group.getLayers().forEach(function (candidate, idx) {
if (index === -1 && candidate === layer) {
index = idx;
// sadly we cannot abort the forEach-iteration here
}
});
return index;
},
},
});