ol-ext/control/canvastitlecontrol.js
2016-06-13 08:40:27 +02:00

125 lines
3.4 KiB
JavaScript

/* Copyright (c) 2015 Jean-Marc VIGLINO,
released under the CeCILL-B license (French BSD license)
(http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.txt).
*/
/**
* OpenLayers 3 Title Control integrated in the canvas (for jpeg/png export purposes).
*
* @constructor
* @extends {ol.control.Control}
* @param {Object=} Control options. The style {ol.style.Style} option is usesd to draw the text.
*/
ol.control.CanvasTitle = function(options)
{ if (!options) options={};
// Get style options
if (!options.style) options.style = new ol.style.Style();
this.setStyle(options.style);
// Initialize parent
var elt = $("<div>").text(this.text_)
.addClass("ol-title ol-unselectable")
.css(
{ font: this.font_,
position: 'absolute',
top:0, left:0, right:0,
display: 'block',
visibility: 'hidden'
});
ol.control.Control.call(this,
{ element: elt.get(0),
target: options.target
});
}
ol.inherits(ol.control.CanvasTitle, ol.control.Control);
/**
* Remove the control from its current map and attach it to the new map.
* Subclasses may set up event handlers to get notified about changes to
* the map here.
* @param {ol.Map} map Map.
* @api stable
*/
ol.control.CanvasTitle.prototype.setMap = function (map)
{ var oldmap = this.getMap();
if (oldmap) oldmap.un('postcompose', this.drawTitle_, this);
ol.control.Control.prototype.setMap.call(this, map);
if (oldmap) oldmap.renderSync();
// Get change (new layer added or removed)
if (map) map.on('postcompose', this.drawTitle_, this);
}
/**
* Change the control style
* @param {ol.style.Style}
*/
ol.control.CanvasTitle.prototype.setStyle = function (style)
{ var text = style.getText();
this.font_ = text ? text.getFont() || "20px Arial" : "20px Arial";
this.text_ = text ? text.getText() : "";
var stroke = text ? text.getStroke() : null;
var fill = text ? text.getFill() : null;
this.strokeStyle_ = stroke ? ol.color.asString(stroke.getColor()) : "#fff";
this.fillStyle_ = fill ? ol.color.asString(fill.getColor()) : "#000";
if (this.element)
{ $(this.element).text(this.text_).css ({font: this.font_});
}
// refresh
if (this.getMap()) this.getMap().render();
}
/**
* Set the ma title to display
* @param {string} map title.
* @api stable
*/
ol.control.CanvasTitle.prototype.setTitle = function (title)
{ this.text_ = title;
$(this.element).text(title);
if (this.getMap()) this.getMap().renderSync();
}
/**
* Get the ma title to display
* @param {string} map title.
* @api stable
*/
ol.control.CanvasTitle.prototype.getTitle = function (title)
{ return this.text_;
}
/** Draw scale line in the final canvas
*/
ol.control.CanvasTitle.prototype.drawTitle_ = function(e)
{ if (!this.text_) return;
var ctx = e.context;
// Retina device
var ratio = e.frameState.pixelRatio;
ctx.save();
ctx.scale(ratio,ratio);
var w = ctx.canvas.width/ratio;
var h = $(this.element).height();
var position = { top:0, left:w/2 };
ctx.beginPath();
ctx.fillStyle = this.strokeStyle_;
ctx.rect(0,0, w, h);
ctx.fill();
ctx.closePath();
ctx.beginPath();
ctx.fillStyle = this.fillStyle_;
ctx.textAlign = "center";
ctx.textBaseline = "middle";
ctx.font = this.font_;
ctx.fillText(this.text_, position.left, position.top +h/2);
ctx.closePath();
ctx.restore();
}