Cannot set a style for clicked features in vector layer - openlayers-3

So in my Openlayers 3 I set a default style , that renders features the first time the layer loads
function styleFunction(feature, resolution) {
var color = feature.get('color');
var name = feature.get('name');
var fill = new ol.style.Fill({
color: color
});
var stroke = new ol.style.Stroke({
color: "black",
lineCap: "butt",
lineJoin: "bevel",
width:1
});
var text= new ol.style.Text({
font: '20px Verdana',
text: name,
fill: new ol.style.Fill({
color: [64, 64, 64, 0.5]
})
})
var cStyle = new ol.style.Style({
fill: fill,
stroke: stroke,
text: text
});
return [cStyle];
}
When a feature is clicked I want that feature to change its style and the rest to keep the default style above.
This is my attempt to do this
//add simple click interaction to the map
var select = new ol.interaction.Select();
map.addInteraction(select);
//for every clicked feature
select.on('select', function(e) {
var name = e.selected[0].get('name');
//set the clicked style
var fillClick= new ol.style.Fill({
color: "black"
});
var strokeClick = new ol.style.Stroke({
color: "white",
lineCap: "butt",
lineJoin: "bevel",
width:3
});
var textClick= new ol.style.Text({
font: '10px Verdana',
text: name,
fill: new ol.style.Fill({
color: [64, 64, 64, 1]
})
})
var styleClick = new ol.style.Style({
stroke: strokeClick,
fill : fillClick,
text : textClick
});
//set all to default
for (i in e.selected){
e.selected[i].setStyle(styleFunction);
}
//reset the first selected to the clicked style
e.selected[0].setStyle(styleClick);
I dont get any errors on the console, but this wont work. The clicked feature wont return to the default style when I click another one. All the clicked features keep the styleClick.
So, how do I fix this and also, is there a simpler way to do this? I think its a lot of code for this kind of functionality
Thanks
EDIT
I replaced
for (i in e.selected){
e.selected[i].setStyle(styleFunction);
}
with
var allfe = sourceVector.getFeatures();
for (i in allfe){
allfe[i].setStyle(styleFunction);
}
So now all the features will get the style defined in the styleFunction function.
This does not work. I get Uncaught TypeError: feature.get is not a function referring to the first line of the function, var color = feature.get('color'); this one.
I cannot just set a style, I need it to be a function so I can check the geomerty type in the future.
So my two problems,
I dont know how to debug and fix this error
If I have like 500 features, redrawing all of them for every click, will slow the rendering. Is there another solution to this?
Thanks

Layer and feature style functions are different
When using OpenLayers 3 style functions, you have to note the difference between an ol.FeatureStyleFunction and a ol.style.StyleFunction. They are very similar, since they both should return an array of ol.Styles based on a feature and a resolution. They are, however, not provided with that information in the same way.
When providing a style function to a feature, using it's setStyle method, the function should be an ol.FeatureStyleFunction. An ol.FeatureStyleFunction is called with this referencing the feature, and with the resolution as the only argument.
When providing a style function to a layer, it should be an ol.style.StyleFunction. They are called with two arguments, the feature and the resolution.
This is the cause of your error. You are using an ol.style.StyleFunction as a feature style. Later, when your style function is called, the first argument is the resolution and not the feature that you are expecting.
Solution 1: setStyle(null)
This solution has already been proposed in #jonatas-walker's answer. It works by setting a style on your selected features and removing the style from the unselected ones (instead of setting your style function to the unselected features).
OpenLayers will use the feature's style if it has one, and otherwise use the layer's style. So re-setting the unselected features' style to null will make them use the layer's style function again.
Solution 2: use the style option of your select interaction
ol.interaction.Select accepts a style option (an ol.style.StyleFunction), which is used to style the selected features.
Pros: Having one style function for the layer (normal view) and a style function for the select interaction makes the code more readable than mixing feature and layer styles. Also, you don't have to keep track of the events or modify the features.
It could be done similar to this:
var selectedStyleFunction = function(feature, resolution) {
return [new ol.style.Style({
stroke: new ol.style.Stroke({
color: "white",
lineCap: "butt",
lineJoin: "bevel",
width:3
}),
fill : new ol.style.Fill({
color: "black"
}),
text : new ol.style.Text({
font: '10px Verdana',
text: feature.get('name'),
fill: new ol.style.Fill({
color: [64, 64, 64, 1]
})
})
})];
};
var select = new ol.interaction.Select({
style: selectedStyleFunction
});
map.addInteraction(select);

UPDATE - fiddle styling with ol.interaction.Select
How about - http://jsfiddle.net/jonataswalker/zz6d4z7d/
var select = new ol.interaction.Select();
map.addInteraction(select);
var styleClick = function() {
// `this` is ol.Feature
return [
new ol.style.Style({
image: new ol.style.Circle({
fill: new ol.style.Fill({ color: [245, 121, 0, 0.8] }),
stroke: new ol.style.Stroke({ color: [0,0,0,1] }),
radius: 7
}),
text: new ol.style.Text({
font: '24px Verdana',
text: this.get('name'),
offsetY: 20,
fill: new ol.style.Fill({
color: [255, 255, 255, 0.8]
})
})
})
];
};
select.on('select', function(evt){
var selected = evt.selected;
var deselected = evt.deselected;
selected.forEach(function(feature){
feature.setStyle(styleClick);
});
deselected.forEach(function(feature){
feature.setStyle(null);
});
});

Related

set different style for lines in vector openlayers layer

So, I use openlayers 3.9.0 and I have a vector layer that contains LineStrings, Polygons and Points.
By default LineStrings look like black lines, with litte stroke. I try to make them a bit thicker and their color have to be visible, so they not blend in, when many features are rendered.
This is my style
var stroke = new ol.style.Stroke({
color: 'rgba(0,0,0,0.4)',
lineCap: "butt",
lineJoin: "bevel",
width:1
});
function styleFunction(feature, resolution) {
var color = feature.get('color');
var name = feature.get('name');
var geom = feature.getGeometry().getType();
var fill = new ol.style.Fill({
color: color
});
//this does not work
if (geom == 'LineString') {
stroke.width=42;
}
var circle = new ol.style.Circle({
radius: 6,
fill: fill,
stroke: stroke,
color:color
});
var text= new ol.style.Text({
font: '20px Verdana',
text: name,
fill: new ol.style.Fill({
color: [64, 64, 64, 0.75]
})
})
var cStyle = new ol.style.Style({
fill: fill,
stroke: stroke,
image : circle,
text : text
});
return [cStyle];
}
I can not make this work. Any tips?
Thanks
OpenLayers 3 styles are immutable, they can not be changed.
Instead of trying to modify the width of the Stroke, create a new one with the options you want.

Is it possible to set different colors to each segment of a LineString without meeting a huge performance hit?

My openlayers 3 application draws several LineString features on the map (from a few dozen up to 2000-3000).
When setting different colors for each segment of the LineStrings, I meet a huge performance hit (starting from just a few LineStrings on the map). The zoom and pan become completely unresponsive making my aplication not usable in this form.
Since I don't want to set a new geometry for each segment (but only change its color), I imagine there must be a more performance effective way of achieving this ?
Here's my code :
var styleFunction = function(feature, resolution) {
var i = 0, geometry = feature.getGeometry();
geometry.forEachSegment(function (start, end) {
color = colors[i];
styles.push(new ol.style.Style({
geometry: new ol.geom.LineString([start, end]),
fill: new ol.style.Fill({
color: color
}),
stroke: new ol.style.Stroke({
color: color,
width: 2
})
}));
i++;
});
return styles;
}
var vectorLayer = new ol.layer.Vector({
source: vectorSource,
style: styleFunction
});
There are a few things that you can try to optimize:
Cache fill and stroke style
var fillStyles = colors.map(function(color, i) {
return new ol.style.Fill({
color: color
})
});
var strokeStyles = colors.map(function(color, i) {
return new ol.style.Stroke({
color: color,
width: 2
})
});
Cache the style for each feature
vectorSource.forEach(function(feature, i) {
var geometry = feature.getGeometry();
var styles = [];
var i = 0;
geometry.forEachSegment(function (start, end) {
styles.push(new ol.style.Style({
geometry: new ol.geom.LineString([start, end]),
fill: fillStyles[i],
stroke: strokeStyles[i]
}));
i++;
});
feature.setStyle(styles);
});
Disable that the rendering is updated during animations and interactions
var vectorLayer = new ol.layer.Vector({
source: vectorSource,
updateWhileAnimating: false,
updateWhileInteracting: false
});
See ol.layer.Vector.
If all this doesn't help, you might also want to take a look at ol.source.ImageVector(example).
Since we could not solve the problem, even with tsauerwein's recommendations, this feature was put to the fridge for a while. Now we got back to it with fresh ideas and actually found a "solution".
Something that I made not clear in the question is that segments of a LineString are colored according to a property of their starting point. Several consecutive segments may thus share the same color if the value of this property doesn't change between them.
The idea is to avoid creating a new style for each and every segment but rather to create a new style only when necessary (when the color changes) :
let i = 0,
color = '#FE2EF7', //pink. should not be displayed
previousColor = '#FE2EF7',
lineString,
lastCoordinate = geometry.getLastCoordinate();
geometry.forEachSegment(((start, end) => {
color = this.getColorFromProperty(LinePoints[i].myProperty);
//First segment
if (lineString == null) {
lineString = new ol.geom.LineString([start, end]);
} else {
//Color changes: push the current segment and start a new one
if (color !== previousColor) {
styles.push(new ol.style.Style({
geometry: lineString,
fill: new ol.style.Fill({
color: previousColor
}),
stroke: new ol.style.Stroke({
color: previousColor,
width: 2
})
}));
lineString = new ol.geom.LineString([start, end]);
} else {
//Color is same: continue the current segment
lineString.appendCoordinate(end);
}
//Last segment
if (end[0] === lastCoordinate[0] && end[1] === lastCoordinate[1]) {
styles.push(new ol.style.Style({
geometry: lineString,
fill: new ol.style.Fill({
color: color
}),
stroke: new ol.style.Stroke({
color: color,
width: 2
})
}));
}
}
previousColor = color;
i++;
}

Selectable Points of vector layer have an offset

I've got a vector layer with a GeoJSON source, consisting of Points and a LineString. When I click on a point I want to open a popup with additional information.
Here's some code:
var style = {
'Point': [new ol.style.Style({
image: new ol.style.Circle({
fill: new ol.style.Fill({
color: 'rgb(255,0,0)'
}),
radius: 5,
stroke: new ol.style.Stroke({
color: '#000000',
width: 1
}),
})
})],
'LineString': [new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#ff0000',
width: 3
})
})],
'MultiLineString': [new ol.style.Style({
stroke: new ol.style.Stroke({
color: '#0000ff',
width: 3
})
})]
};
var map = new ol.Map({
target: 'map-ol-canvas',
interactions: ol.interaction.defaults({mouseWheelZoom: false}),
layers: [new ol.layer.Tile({ source: new ol.source.OSM() })],
view: new ol.View({
zoom: 8,
maxZoom: 16
})
});
map.getView().fit(extent, map.getSize());
var trackSource = new ol.source.Vector({
url: '/test.geojson',
format: new ol.format.GeoJSON()
});
var track = new ol.layer.Vector({
source: trackSource,
style: function(feature, resolution) {
return style[feature.getGeometry().getType()];
}
});
map.addLayer(track);
var select = new ol.interaction.Select({
filter: function (feature, layer) {
return feature.getGeometry().getType() === 'Point';
}
});
map.addInteraction(select);
// When user clicks on a waypoint, show a tooltip.
function onMouseClick(browserEvent) {
var coordinate = browserEvent.coordinate;
var pixel = map.getPixelFromCoordinate(coordinate);
map.forEachFeatureAtPixel(pixel, function(feature) {
if (feature.getGeometry().getType() === 'Point') {
console.log(feature.get('date'));
}
});
}
map.on('click', onMouseClick);
The problem:
When I click directly on a point nothing happens. When I click a couple of pixels below and a bit right or left (depends on zoom level!), the point gets selected and the console.log is triggered.
I can fix this by using Firebox WebDeveloper Addon and activating "Disable all styles".
However, when I manually remove all CSS one by one that behavior never goes away.
In the first place I thought this might be some inherited padding or margin, but currently I think the canvas shouldn't be affected by any CSS at all.
Any ideas about what could be wrong?
I'm experiencing the same issue. It appears to be linked to navigating to the page from a specific modal (I'm using ajax hash paging). The footer doesn't load and after I interact with the first feature on the map the following happens;
The map jumps and stretches/smears slightly
The footer shows up on my page
The vertical scroll bar appears
The issue doesn't seem to occur when i link from another page.
I have the same problem.Here are some advices may help you:
check the the size of map's container(may be a Div).
check the size of map(openlayers's map object).
compare that two size to confirm whether the two size are equal.
if not, you can use the map.setSize([width,height])to adjust the map's size.

where can i find a thorough description of implementing custom ol.style.Style in openlayers 3?

I've read through the source, and looked at the examples but haven't found the answer yet.
I need to style the image that appears on the modify overlay beneath the mouse cursor.
i'm using a custom style function to add midpoints and custom endpoints to the layer used by ol.interaction.Modify. ol.interaction.Modify is applying styling to a point near the mouse cursor to indicate that the feature can be modified. This is great except the cursor styling falls beneath the custom endpoints. i can't find a way to alter the z-index.
so, i'm answering my question for myself. i guess that's what makes the internet wonderful. i'm not a dog.
// we'd normally pass feature & resolution parameters to the function, but we're going to
// make this dynamic, so we'll return a style function for later use which will take those params.
DynamicStyleFunction = ( function( /* no feat/res yet!*/ ) {
/**
you really only get style are rendered upon simple geometries, not features. features are made of different geometry types, and styleFunctions are passed a feature that has its geometries rendered. in terms of styling vector geometries, you have only a few options. side note: if there's some feature you expect to see on the the map and it's not showing up, you probably haven't properly styled it. Or, maybe it hasn't been put it in a collection that is included in the source layer... which is a hiccup for a different day.
*/
// for any geometry that you want to be rendered, you'll want a style.
var styles = {};
var s = styles;
/**
an ol.layer.Vector or FeatureOverlay, renders those features in its source by applying Styles made of Strokes, Fills, and Images (made of strokes and fills) on top of the simple geometries which make up the features
Stroke styles get applied to ol.geom.GeometryType.LINE_STRING
MULTI_LINE_STRING can get different styling if you want
*/
var strokeLinesWhite = new ol.style.Stroke({
color: [255, 255, 255, 1], // white
width: 5,
})
var whiteLineStyle new ol.style.Style({
stroke: strokeLinesWhite
})
styles[ol.geom.GeometryType.LINE_STRING] = whiteLineStyle
/**
Polygon styles get applied to ol.geom.GeometryType.POLYGON
Polygons are gonna get filled. They also have Lines... so they can take stroke
*/
var fillPolygonBlue = new ol.style.Style({
fill: new ol.style.Fill({
color: [0, 153, 255, 1], // blue
})
})
var whiteOutlinedBluePolygon = new ol.style.Style({
stroke: strokeLinesWhite,
fill: fillPolygonBlue,
})
styles[ol.geom.GeometryType.POLYGON] = fillPolygonBlue
/**
Circle styles get applied to ol.geom.GeometryType.POINT
They're made with a radius and a fill, and the edge gets stroked...
*/
var smallRedCircleStyle = new ol.style.Style({
image: new ol.style.Circle({
radius: 5,
fill: new ol.style.Fill({
color: '#FF0000', // red... but i had to look it up
})
})
})
var whiteBigCircleWithBlueBorderStyle = new ol.style.Style({
image: new ol.style.Circle({
radius: 10,
fill: new ol.style.Fill({
color: '#FFFFFF' // i guessed it
})
}),
stroke: new.ol.style.Stroke({
color: '#0000FF', // blue
width: 5
})
})
// render all points as small red circles
styles[ol.geom.GeometryType.POINT] = smallRedCircleStyle
// if you pass an array as the style argument, every rendering of the feature will apply every defined style style rendered with the geometry as the argument. that can be a whole lot of rendering in a FeatureOverlay...
smallRedCircleStyle.setZIndex(Infinity)
whiteBigCircleWithBlueBorderStyle.setZIndex(Infinity -1) // that prob wouldn't work, but i hope it's instructive that you can tinker with styles
// so...
var bullseyePointStyle = [ smallRedCircleStyle, whiteBigCircleWithBlueBorderStyle ];
return function dynamicStyleFunction (feature, resolution){
// this is the actual function getting invoked on each function call
// do whatever you want with the feature/resolution.
if (Array.indexOf(feature.getKeys('thisIsOurBullseyeNode') > -1) {
return bullseyePointStyle
} else if (feature.getGeometryName('whiteBlueBox')){
return whiteOutlinedBluePolygon
} else {
return styles[feature.getGeometryName()]
}
}
})()
ol.interaction.Modify, ol.interaction.Select and ol.interaction.Draw take a style argument to change the look of the sketching features.

What's "an array of ol.style.Style" good for?

A style of an ol.layer.Vector can be set as ol.style.Style, a style function or an array of ol.style.Style. What's the array for and what does it do -- compared to just passing an ol.style.Style object?
I cannot find any information on this, neither in the official API docs nor in the tutorials.
If you look at the draw features example, when drawing lines, they are displayed in blue with a white border/outline.
These is achieved by styling the line twice, first with a large white line, then a thin blue line above.
There are 2 styles for the same geometry. It can’t be done with a single ol.style.Style, so to achieve this you need to pass an array of 2 styles: see the source for this.
Because I think this is still relevant and the edit queue is full for the approved answer, I'm posting this with the links updated and with code examples.
The most common way to see the array of styles in action is when drawing features since this is default style in Openlayers. For the line to appear blue with a white border it has to have two styles since it can't be done with a single Style. Openlayers does this by default like this:
styles['LineString'] = [
new Style({
stroke: new Stroke({
color: white,
width: width + 2,
}),
}),
new Style({
stroke: new Stroke({
color: blue,
width: width,
}),
}),
];
source
To expand on how usefull this feature could be you could check the custom polygons example. To have the vertices highlighted, they use two styles, one for the vertices and another for the polygon contour itself. Relevant piece of code:
const styles = [
new Style({
stroke: new Stroke({
color: 'blue',
width: 3,
}),
fill: new Fill({
color: 'rgba(0, 0, 255, 0.1)',
}),
}),
new Style({
image: new CircleStyle({
radius: 5,
fill: new Fill({
color: 'orange',
}),
}),
geometry: function (feature) {
// return the coordinates of the first ring of the polygon
const coordinates = feature.getGeometry().getCoordinates()[0];
return new MultiPoint(coordinates);
},
}),
];

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