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);
},
}),
];
Related
I am embarrassed by how elementary this problem seems, but I can't seem to work out how to simply add a GeoJSON polygon feature to a vector source.
I'm using OpenLayers 5, and up until now I've been creating a separate source and layer for every feature I'm adding to the map. The reason being I needed to be able to turn the visibility of individual polygons on and off, and this seemed like the best way to do that at the time. This worked at first, but I'm sure it's not the best practice - in effect I'm creating 200 layers and 200 sources for 200 polygons. I'd prefer to be creating one layer which uses one source which contains those 200 polygons.
This is what I currently have:
window["srcCells"] = new ol.source.Vector({});
window["ftr1"] = new ol.Feature({
geometry: new ol.geom.Polygon({ // <--- this is where I'm getting an error
coordinates: geometry.coordinates[0]
})
});
window["srcCells"].addFeature(window["ftr1"]);
window["lyrCells"] = new ol.layer.Vector({
name: "lyrCells",
source: window["srcCells"],
visible: true,
style: new ol.style.Style({
stroke: new ol.style.Stroke({
color: 'rgba(255, 255, 255, 1)',
width: 0.5
}),
fill: new ol.style.Fill({
color: 'rgba(255, 255, 255, 0)'
}),
text: new ol.style.Text({
font: '11px Roboto',
overflow: false,
fill: new ol.style.Fill({
color: '#fff'
}),
stroke: new ol.style.Stroke({
color: '#333',
width: 2
})
})
})
});
map.addLayer(window["lyrCells"]);
console.dir(geometry.coordinates[0]); gives the following:
0: (3) [140.9528856796365, -37.00284635019008, 111.304]
1: (3) [140.9536707180603, -37.00304972058393, 113.03]
2: (3) [140.9537622719694, -37.00307250872015, 110.607]
3: (3) [140.95383548835147, -37.003105295678026, 110.64]
4: (3) [140.95393795398604, -37.003149857783384, 110.26276070403628]
5: (3) [140.95586925648476, -37.00401679761869, 111.192]
6: (3) [140.95644098404094, -37.00388629902322, 110.38710718081241]
7: (3) [140.95644582710668, -37.0051300157363, 111.17174176388276]
8: (3) [140.9528945167084, -37.00514320603378, 110.9445749409575]
9: (3) [140.95289318042316, -37.004769323489825, 113.688]
At the third line of the code above (where I've indicated), I'm getting this error:
SimpleGeometry.js:187 Uncaught TypeError: Cannot read property 'length' of undefined
at e.setLayout (SimpleGeometry.js:187)
at e.setCoordinates (Polygon.js:313)
at new e (Polygon.js:80)
geometry.coordinates[0] looks like an open linestring. To use it as a polygon you would need to close the ring and, as a polygon is an array of linear rings, enclose with []. Also the coordinates are the first parameter of the constructor, not an option:
geometry: new ol.geom.Polygon(
[ geometry.coordinates[0].concat([geometry.coordinates[0][0]]) ]
)
Alternatively you may need check that your data is polygon or linestring and use new ol.geom.LineString where appropriate
For clustered features I would like to make the following style in OL3:
A square, and on top of it another smaller square at the right-top corner. The bigger square would hold the symbol, and the smaller square would hold the number of the clustered features.
Similar to this
Is it possible to achieve this? In the API I've seen that ol.style.Icon and ol.style.Text has anchor and offset properties, but not RegularShape...
I have eventually overcome on this problem with using a single png image which included the square AND the smaller square, too, and overlayed the dynamic text on it, like this:
var clusterStyle = [new ol.style.Style({
image: new ol.style.Icon({
src: clustericon.png
}),
text: new ol.style.Text({
text: feature.get('features').length.size.toString(),
offsetY: -18,
offsetX: 18,
font: '12px Arial',
fill: new ol.style.Fill({
color: '#fff'
}),
scale: 1
}),
zIndex: 20
}), new ol.style.Style({
image: new ol.style.Icon({
src: 'overlayicon.png'
}),
zIndex: 21
})];
You can also insert an overlay image on it. Hope it helps you anyways
I would like to place images on a line. For example, instead of a dotted or dashed line, I could include a symbol of a ship or a character (e.g. |) repeated along the line.
Here is code:
lineStyle = new ol.style.Style({
image: new ol.style.Icon(({
opacity: 1,
size:20,
src: './icon.png'
})),
stroke: new ol.style.Stroke({
color: 'black',
width: 5,
lineDash: [10]
})
});
I want to get a result like this:
Here is my example, but it cannot show the image along with line. http://jsfiddle.net/Wenhua1224/jguxq4j0/
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);
});
});
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.