OpenLayers3 : Draggable OverviewMapControl - controls

Question

In OpenLayers 2, in the OverviewMapControl, you can drag the "box" to move the map.
You can not do this in OpenLayers 3.
I've tried to implement a custom control based on https://github.com/openlayers/ol3/blob/master/src/ol/control/overviewmapcontrol.js, but you can not use goog.xxx or other fancy stuff like ol.extent.scaleFromCenter when you are not in debug !
How should I proceed ?
basically, implementing drag'n drop is fairly "simple" :
var dragging = null;
var getMap = this.getMap.bind(this); //during ctor of a control, we have no access to the map !
$(document.body).on("mousemove", function (e) {
if (dragging) {
dragging.el.offset({
top: e.pageY,
left: e.pageX
});
}
});
$(box).on("mousedown", function (e) {
dragging = {
el: $(e.target)
};
});
$(document.body).on("mouseup", function (e) {
if (dragging) {
debugger;
var coords = ovmap.getEventCoordinate(e.originalEvent);
//TODO: taking event coordinates is not good, we must use center of the box coordinates
//the problem is that ovmap.getCoordinateFromPixel(dragging.el.offset()) is not working at all because we need to adjust ovmap viewport
getMap().getView().setCenter(coords);
dragging = null;
}
});

Answer 1

For those interested (which does not seem to be the case at the moment :)), here is the way I solved
/**
* Mostly a big copy/paste from https://raw.githubusercontent.com/openlayers/ol3/master/src/ol/control/overviewmapcontrol.js
* without rotation and zoom/dezoom plus some adapations from http://ol3.qtibia.ro/build/examples/overviewmap-custom-drag.html
* to add the possibility to drag the box on the minimap to move the main map
*/
ol.control.CustomOverviewMap = function (opt_options) {
var options = typeof opt_options !== 'undefined' ? opt_options : {};
this.collapsed_ = typeof options.collapsed !== 'undefined' ? options.collapsed : true;
this.onCollapseOrExpand = options.onCollapseOrExpand || function () { };
this.needFirstRenderUpdate_ = this.collapsed_; //prepare the hack to render the map when uncollapsed the first time
var tipLabel = typeof options.tipLabel !== 'undefined' ? options.tipLabel : 'Overview map';
this.collapseLabel_ = $('<span>\u00BB</span>').get(0);
this.label_ = $('<span>\u00AB</span>').get(0);
var activeLabel = (!this.collapsed_) ? this.collapseLabel_ : this.label_;
var button = $('<button type="button" title="{0}"></button>'.replace('{0}', tipLabel)).append(activeLabel);
button.on('click', this.handleClick_.bind(this));
//ol.control.Control.bindMouseOutFocusOutBlur(button);
button.on('mouseout', function () { this.blur(); });
button.on('focusout', function () { this.blur(); });
var ovmapDiv = $('<div class="ol-overviewmap-map"></div>').get(0);
this.ovmap_ = new ol.Map({
controls: new ol.Collection(),
interactions: new ol.Collection(),
layers: [options.tileLayer],
target: ovmapDiv,
view: new ol.View(opt_options.view)
});
var box = $('<div class="ol-overviewmap-box"></div>');
this.boxOverlay_ = new ol.Overlay({
position: [0, 0],
positioning: 'bottom-left',
element: box.get(0)
});
this.ovmap_.addOverlay(this.boxOverlay_);
var cssClasses = 'ol-overviewmap ol-unselectable ol-control' +
(this.collapsed_ ? ' ol-collapsed' : '');
var element = $('<div class="{0}"></div>'.replace('{0}', cssClasses)).append(ovmapDiv).append(button).get(0);
ol.control.Control.call(this, {
element: element,
render: ol.control.CustomOverviewMap.render
});
// deal with dragable minimap
this.dragging = null;
box.on("mousedown", this.onStartDrag.bind(this));
$(document.body).on("mousemove", this.onDrag.bind(this));
$(document.body).on("mouseup", this.onEndDrag.bind(this));
};
ol.inherits(ol.control.CustomOverviewMap, ol.control.Control);
ol.control.CustomOverviewMap.prototype.onStartDrag = function (e) {
// remember some data to use during onDrag or onDragEnd
var box = $(e.target);
this.dragging = {
el: box,
evPos: { top: e.pageY, left: e.pageX },
elPos: box.offset()
};
}
ol.control.CustomOverviewMap.prototype.onDrag = function (e) {
if (this.dragging) {
//set the position of the box to be oldPos+translation(ev)
var curOffset = this.dragging.el.offset();
var newOffset = {
top: curOffset.top + (e.pageY - this.dragging.evPos.top),
left: curOffset.left + (e.pageX - this.dragging.evPos.left)
};
this.dragging.evPos = { top: e.pageY, left: e.pageX };
this.dragging.el.offset(newOffset);
}
}
ol.control.CustomOverviewMap.prototype.onEndDrag = function (e) {
if (this.dragging) {
//see ol3.qtibia.ro href at the top of the class to understand this
var map = this.getMap();
var offset = this.dragging.el.position();
var divSize = [this.dragging.el.width(), this.dragging.el.height()];
var mapSize = map.getSize();
var c = map.getView().getResolution();
var xMove = offset.left * (Math.abs(mapSize[0] / divSize[0]));
var yMove = offset.top * (Math.abs(mapSize[1] / divSize[1]));
var bottomLeft = [0 + xMove, mapSize[1] + yMove];
var topRight = [mapSize[0] + xMove, 0 + yMove];
var left = map.getCoordinateFromPixel(bottomLeft);
var top = map.getCoordinateFromPixel(topRight);
var extent = [left[0], left[1], top[0], top[1]];
map.getView().fitExtent(extent, map.getSize());
map.getView().setResolution(c);
//reset the element at the original position so that when the main map will trigger
//the moveend event, this event will be replayed on the box of the minimap
this.dragging.el.offset(this.dragging.elPos);
this.dragging = null;
}
}
ol.control.CustomOverviewMap.render = function (mapEvent) {
//see original OverviewMap href at the top of the class to understand this
var map = this.getMap();
var ovmap = this.ovmap_;
var mapSize = map.getSize();
var view = map.getView();
var ovview = ovmap.getView();
var overlay = this.boxOverlay_;
var box = this.boxOverlay_.getElement();
var extent = view.calculateExtent(mapSize);
var ovresolution = ovview.getResolution();
var bottomLeft = ol.extent.getBottomLeft(extent);
var topRight = ol.extent.getTopRight(extent);
overlay.setPosition(bottomLeft);
// set box size calculated from map extent size and overview map resolution
if (box) {
var boxWidth = Math.abs((bottomLeft[0] - topRight[0]) / ovresolution);
var boxHeight = Math.abs((topRight[1] - bottomLeft[1]) / ovresolution);
$(box).width(boxWidth).height(boxHeight);
}
};
ol.control.CustomOverviewMap.prototype.handleClick_ = function (event) {
event.preventDefault();
this.collapsed_ = !this.collapsed_;
$(this.element).toggleClass('ol-collapsed');
// change label
if (this.collapsed_) {
this.collapseLabel_.parentNode.replaceChild(this.label_, this.collapseLabel_);
} else {
this.label_.parentNode.replaceChild(this.collapseLabel_, this.label_);
}
// manage overview map if it had not been rendered before and control is expanded
if (!this.collapsed_ && this.needFirstRenderUpdate_) {
this.needFirstRenderUpdate_ = false;
this.ovmap_.updateSize();
this.ovmap_.once("postrender", function () {
this.render();
}.bind(this));
}
//trigger event
this.onCollapseOrExpand(this.collapsed_);
};