datawinners/media/javascript/ol3-layerswitcher.js
/**
* OpenLayers 3 Layer Switcher Control.
* See [the examples](./examples) for usage.
* @constructor
* @extends {ol.control.Control}
* @param {Object} opt_options Control options, extends olx.control.ControlOptions adding:
* **`tipLabel`** `String` - the button tooltip.
*/
ol.control.LayerSwitcher = function(opt_options) {
var options = opt_options || {};
var tipLabel = options.tipLabel ?
options.tipLabel : 'Legend';
this.mapListeners = [];
this.hiddenClassName = 'ol-unselectable ol-control layer-switcher';
if (ol.control.LayerSwitcher.isTouchDevice_()) {
this.hiddenClassName += ' touch';
}
this.shownClassName = this.hiddenClassName + ' shown';
var element = document.createElement('div');
element.className = this.hiddenClassName;
var button = document.createElement('button');
button.setAttribute('title', tipLabel);
element.appendChild(button);
this.panel = document.createElement('div');
this.panel.className = 'panel';
element.appendChild(this.panel);
ol.control.LayerSwitcher.enableTouchScroll_(this.panel);
var this_ = this;
button.onmouseover = function(e) {
//this_.showPanel();
};
button.onclick = function(e) {
e = e || window.event;
//this_.showPanel();
if($('.panel').css('display')!='none'){
$(this).css('background-image','url("/media/images/map_show_panel.png")');
}
else{
$(this).css('background-image','url("/media/images/map_hide_panel.png")');
}
$('.panel').toggle('slow');
e.preventDefault();
};
this_.panel.onmouseout = function(e) {
e = e || window.event;
if (!this_.panel.contains(e.toElement || e.relatedTarget)) {
//this_.hidePanel();
}
};
ol.control.Control.call(this, {
element: element,
target: options.target
});
};
ol.inherits(ol.control.LayerSwitcher, ol.control.Control);
/**
* Show the layer panel.
*/
ol.control.LayerSwitcher.prototype.showPanel = function() {
if (this.element.className != this.shownClassName) {
this.element.className = this.shownClassName;
this.renderPanel();
}
};
/**
* Hide the layer panel.
*/
ol.control.LayerSwitcher.prototype.hidePanel = function() {
if (this.element.className != this.hiddenClassName) {
this.element.className = this.hiddenClassName;
}
};
/**
* Re-draw the layer panel to represent the current state of the layers.
*/
ol.control.LayerSwitcher.prototype.renderPanel = function() {
this.ensureTopVisibleBaseLayerShown_();
while(this.panel.firstChild) {
this.panel.removeChild(this.panel.firstChild);
}
var ul = document.createElement('ul');
this.panel.appendChild(ul);
this.renderLayers_(this.getMap(), ul);
};
/**
* Set the map instance the control is associated with.
* @param {ol.Map} map The map instance.
*/
ol.control.LayerSwitcher.prototype.setMap = function(map) {
// Clean up listeners associated with the previous map
for (var i = 0, key; i < this.mapListeners.length; i++) {
this.getMap().unByKey(this.mapListeners[i]);
}
this.mapListeners.length = 0;
// Wire up listeners etc. and store reference to new map
ol.control.Control.prototype.setMap.call(this, map);
if (map) {
var this_ = this;
this.mapListeners.push(map.on('pointerdown', function() {
this_.hidePanel();
}));
this.renderPanel();
}
};
/**
* Ensure only the top-most base layer is visible if more than one is visible.
* @private
*/
ol.control.LayerSwitcher.prototype.ensureTopVisibleBaseLayerShown_ = function() {
var lastVisibleBaseLyr;
ol.control.LayerSwitcher.forEachRecursive(this.getMap(), function(l, idx, a) {
if (l.get('type') === 'base' && l.getVisible()) {
lastVisibleBaseLyr = l;
}
});
if (lastVisibleBaseLyr) this.setVisible_(lastVisibleBaseLyr, true);
};
/**
* Toggle the visible state of a layer.
* Takes care of hiding other layers in the same exclusive group if the layer
* is toggle to visible.
* @private
* @param {ol.layer.Base} The layer whos visibility will be toggled.
*/
ol.control.LayerSwitcher.prototype.setVisible_ = function(lyr, visible) {
var map = this.getMap();
lyr.setVisible(visible);
if (visible && lyr.get('type') === 'base') {
// Hide all other base layers regardless of grouping
ol.control.LayerSwitcher.forEachRecursive(map, function(l, idx, a) {
if (l != lyr && l.get('type') === 'base') {
l.setVisible(false);
}
});
}
};
/**
* Render all layers that are children of a group.
* @private
* @param {ol.layer.Base} lyr Layer to be rendered (should have a title property).
* @param {Number} idx Position in parent group list.
*/
ol.control.LayerSwitcher.prototype.renderLayer_ = function(lyr, idx) {
var this_ = this;
var li = document.createElement('li');
var lyrTitle = lyr.get('title');
var lyrId = ol.control.LayerSwitcher.uuid();
var label = document.createElement('label');
if (lyr.getLayers && !lyr.get('combine')) {
li.className = 'group';
label.innerHTML = lyrTitle;
li.appendChild(label);
var ul = document.createElement('ul');
li.appendChild(ul);
this.renderLayers_(lyr, ul);
} else {
li.className = 'layer';
if (lyr.get('type') === 'base') {
var input = document.createElement('input');
input.type = 'radio';
input.name = 'base';
input.id = lyrId;
input.checked = lyr.get('visible');
input.onchange = function(e) {
this_.setVisible_(lyr, e.target.checked);
};
li.appendChild(input);
}
label.htmlFor = lyrId;
label.innerHTML = lyrTitle;
li.appendChild(label);
}
return li;
};
/**
* Render all layers that are children of a group.
* @private
* @param {ol.layer.Group} lyr Group layer whos children will be rendered.
* @param {Element} elm DOM element that children will be appended to.
*/
ol.control.LayerSwitcher.prototype.renderLayers_ = function(lyr, elm) {
var lyrs = lyr.getLayers().getArray().slice().reverse();
for (var i = 0, l; i < lyrs.length; i++) {
l = lyrs[i];
if (l.get('title') && l.get('displayInLayerSwitcher')!=false) {
elm.appendChild(this.renderLayer_(l, i));
}
}
};
/**
* **Static** Call the supplied function for each layer in the passed layer group
* recursing nested groups.
* @param {ol.layer.Group} lyr The layer group to start iterating from.
* @param {Function} fn Callback which will be called for each `ol.layer.Base`
* found under `lyr`. The signature for `fn` is the same as `ol.Collection#forEach`
*/
ol.control.LayerSwitcher.forEachRecursive = function(lyr, fn) {
lyr.getLayers().forEach(function(lyr, idx, a) {
fn(lyr, idx, a);
if (lyr.getLayers) {
ol.control.LayerSwitcher.forEachRecursive(lyr, fn);
}
});
};
/**
* Generate a UUID
* @returns {String} UUID
*
* Adapted from http://stackoverflow.com/a/2117523/526860
*/
ol.control.LayerSwitcher.uuid = function() {
return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
return v.toString(16);
});
}
/**
* @private
* @desc Apply workaround to enable scrolling of overflowing content within an
* element. Adapted from https://gist.github.com/chrismbarr/4107472
*/
ol.control.LayerSwitcher.enableTouchScroll_ = function(elm) {
if(ol.control.LayerSwitcher.isTouchDevice_()){
var scrollStartPos = 0;
elm.addEventListener("touchstart", function(event) {
scrollStartPos = this.scrollTop + event.touches[0].pageY;
}, false);
elm.addEventListener("touchmove", function(event) {
this.scrollTop = scrollStartPos - event.touches[0].pageY;
}, false);
}
};
/**
* @private
* @desc Determine if the current browser supports touch events. Adapted from
* https://gist.github.com/chrismbarr/4107472
*/
ol.control.LayerSwitcher.isTouchDevice_ = function() {
try {
document.createEvent("TouchEvent");
return true;
} catch(e) {
return false;
}
};