vertical text in d3 (not rotated) - svg

I am trying to get text to display vertically in svg using d3. I do not want to rotate it, however: I want the letters to remain horizontal, but one above the other. Setting writing-mode=tb does not seem to do anything. Here is what I tried:
svg.append("text")
.attr("x", 1000)
.attr("y", 400)
.attr("id", "title")
.attr("font-size", 50)
.attr("style", "font-family: arial; fill: lightgreen; writing-mode: tb")
.text("Top 100 Mentions");
The text shows up in the right location, with the right font etc, but it is horizontal.

When talking about rotating SVG text, there are multiple different aspects:
how the browser determines where to position the next character based on the previous character's position;
how the characters are rotated relative to the baseline (rotate attribute);
how the final text block as a whole is rotated relative to the coordinate system (transform attribute).
Full, rather difficult to comprehend, specs here.
The 'writing-mode' property is supposed to change the first aspect without affecting the others, but as you discovered it's not implemented at all in Firefox, while IE rotates the text but doesn't respect the horizontal-glyph rule.
Theoretically, you should be able to get the same effect by combining the rotate and transform attributes: transform the entire <text> element to rotate it into a vertical position, then reverse-rotate the individual characters to get them back to horizontal. But in practice, it gets messy...
For starters, the double rotations cause the text to be end up on the left of your (x,y) point, so if (x,y) is (0,0) it will be clipped outside the SVG without supplemental shift. Because of the transforms, you'll need a negative dy value to move the text back to the right of the anchor point.
Second, there is the fact that the rotation is applied to each character in place, the spacing of the characters isn't adjusted to account for the fact that an "l" is much taller than it is wide. So unless you're using monospace, things look pretty jumbled up. You're supposed to be able to change the letter spacing with the kerning and letterspacing properties, but browser support for those is also poor: IE11 doesn't seem to acknowledge the kerning value, and Firefox doesn't acknowledge either.
A final option is to take control of the layout yourself: use the power of d3 and the string .split("") method to break your title into single-character <tspan> elements that can be positioned one below each other and centered neatly within the <text> element. The downside is that this adds extra DOM elements, you can still select the block of text as a whole, just the same as you could select a phrase in an HTML paragraph even if each letter was styled as a separate <span>. I'm not sure if screen readers will automatically assume that there are spaces between the letters, though...
Comparison
This fiddle tries out the three ways to get horizontal characters in a vertical text label (writing-mode vs double rotate vs splitting into <tspan>s):
http://jsfiddle.net/hx5Th/11/
Code:
var svg = d3.select("body").append("svg");
//Green text, uses writing-mode property //
svg.append("text")
.attr("x", 40)
.attr("y", 40)
.attr("id", "title")
.attr("font-size", 50)
.attr("style", "fill: lightgreen; writing-mode: tb; glyph-orientation-vertical: 0")
.text("Top 100 Mentions");
//Black text, uses a double rotate //
svg.append("text")
.attr("x", 40)
.attr("y", 40)
.attr("id", "title")
.attr("font-size", 50)
.attr("rotate", -90)
.attr("dx", "1em")
.attr("dy", "-1em")
.attr("kerning", 0)
.attr("letter-spacing", "0.5em")
.attr("transform", "translate(150,0) rotate(90)")
.text("Top 100 Mentions");
//Blue text, uses d3 to create a series of tspans//
svg.append("text")
.attr("x", 40)
.attr("y", 40)
.attr("font-size", 50)
.attr("id", "title")
.style("fill", "blue")
.attr("transform", "translate(300,0)")
.attr("text-anchor", "middle")
.selectAll("tspan")
.data("Top 100 Mentions".split(""))
.enter().append("tspan")
.attr("x", 0)
.attr("dy", "0.8em")
.text(function(d){return d;});
Results (all on a Windows 7 system):
Chrome 33
IE 11
Firefox
I think this is d3 for the win...

html embedded in svg:
<svg
x="0px" y="0px"
width="200px" height="200px"
viewbox="0 0 200 200"
>
<foreignObject
x="20" y="20"
width="160" height="160"
>
<!-- we must set xmlns attribute
for foreignObject.childNode -->
<div
xmlns="http://www.w3.org/1999/xhtml"
style="
/* HTML-CSS vertical text */
writing-mode: vertical-lr;
text-orientation: upright;
line-height: 2em;
font-family: sans-serif;
font-size: 150%;
"
>Hello<br/> World</div>
</foreignObject>
</svg>

You can control the position and orientation of text by binding it to a path element. Example below with a running version on jsFiddle:
var svg = d3.select("body").append("svg"),
pi = Math.PI;
var arc = d3.svg.arc()
.innerRadius(150)
.outerRadius(180)
.startAngle(0)
.endAngle(-pi/2)
var path = svg.append("path")
.attr("id","path1")
.attr("d","M150 150 L150 20 Z")
.attr("style","stroke:rgb(255,0,0);stroke-width:2")
// Add a text label.
var text = svg.append("text")
.attr("x", 6)
.attr("dy", 15);
text.append("textPath")
.attr("stroke","black")
.attr("xlink:href","#path1")
.text("abc");

This should do what you want (although I don't know how to express it in d3):
<text x="100" y="100" transform="rotate(90, 100, 100)" style="glyph-orientation-horizontal: 270;">Some vertical text not rotated</text>
Obviously change the x and y coords to your own values.

For Firefox, the only thing I can find that they have implemented as of FF 30 is textLength. I added a fourth append of text to AmeliaBR's jsfiddle to demonstrate. It still looks like crap thought and D3 is still the winner. http://jsfiddle.net/hx5Th/11/
//Black text, uses a double rotate //
svg.append("text")
.attr("x", 40)
.attr("y", 40)
.attr("id", "title")
.attr("font-size", 50)
.attr("rotate", -90)
.attr("dx", "1em")
.attr("dy", "-1em")
.attr("textLength", "12.8em")
.attr("transform", "translate(450,0) rotate(90)")
.text("Top 100 Mentions");

Related

How to resize and position a map in Raphael js?

I am trying to include a world map in a dynamicaly crreated div using Raphael js. Once the path is defined, I am updating rapahel paper object's viewbox to scale the path. Although this part is working, I am not able to align the path to the center of the div. The following is what I have done so far according to this answer:
var paper = Raphael("map"),
path = paper.path(w_path).attr({fill: "#000", "stroke-width": 0, "stroke-linejoin": "round", opacity: 1}),
box = path.getBBox(),
margin = Math.max(box.width, box.height) * 0.025; // set the viewbox to match the bounding box of the path with 2.5% margins
paper.setViewBox(box.x - margin, box.y - margin, box.width + margin * 2, box.height + margin * 2);
My question is how can I align the path at the center of the div (map div), both vertically and horizontally?
UPDATE:
I have added a jsFiddle for this.

What is the difference between svg's x and dx attribute?

What is the difference between svg's x and dx attribute (or y and dy)? When would be a proper time to use the axis shift attribute (dx) versus the location attribute (x)?
For example, I have noticed a lot of d3 examples doing something like this
chart.append("text")
.attr("x", 0)
.attr("y", 0)
.attr("dy", -3)
.text("I am a label")
What is the advantage or reasoning for setting both y and dy when the following seems to do the same thing?
chart.append("text")
.attr("x", 0)
.attr("y", -3)
.text("I am a label")
x and y are absolute coordinates and dx and dy are relative coordinates (relative to the specified x and y).
In my experience, it is not common to use dx and dy on <text> elements (although it might be useful for coding convenience if you, for example, have some code for positioning text and then separate code for adjusting it).
dx and dy are mostly useful when using <tspan> elements nested inside a <text> element to establish fancier multi-line text layouts.
For more details you can check out the Text section of the SVG spec.
To add to Scott's answer, dy used with em (font size units) is very useful for vertically aligning text relative to the absolute y coordinate. This is covered in the MDN dy text element example.
Using dy=0.35em can help vertically centre text regardless of font size. It also helps if you want to rotate the centre of your text around a point described by your absolute coordinates.
<style>
text { fill: black; text-anchor: middle; }
line { stroke-width: 1; stroke: lightgray; }
</style>
<script>
dataset = d3.range(50,500,50);
svg = d3.select("body").append("svg");
svg.attr('width',500).attr('height', 500);
svg.append("line").attr('x1', 0).attr('x2', 500).attr('y1', 100).attr('y2', 100);
svg.append("line").attr('x1', 0).attr('x2', 500).attr('y1', 200).attr('y2', 200);
group = svg.selectAll("g")
.data(dataset)
.enter()
.append("g");
// Without the dy=0.35em offset
group.append("text")
.text("My text")
.attr("x",function (d) {return d;})
.attr("y",100)
.attr("transform", function(d, i) {return "rotate("+45*i+","+d+",100)";});
// With the dy=0.35em offset
group.append("text")
.text("My text")
.attr("x",function (d) {return d;})
.attr("y",200)
.attr("dy","0.35em")
.attr("transform", function(d, i) {return "rotate("+45*i+","+d+",200)";});
<script>
View it in Codepen
If you don't include "dy=0.35em", the words rotate around the bottom of the text and after 180 align below where they were before rotation. Including "dy=0.35em" rotates them around the centre of the text.
Note that dy can't be set using CSS.

Vertical scroll bar in d3

I'm trying to make a page using d3 such that the top half of the page can overfill and might need a scroll bar, but the bottom half does not. Would I need two separate svg elements to accomplish this? If so do I need to use css properties to get the scrollbar to appear. I've tried looking up similar questions on stackoverflow but they require the use of jQuery which I'm trying to avoid if possible.
So here's an example of what I'm trying to do:
http://jsfiddle.net/agANT/3/
In this I draw the green rectangle with a height 300px so it extends off the first svg, but no scroll bar appears.
var svg = d3.select("body")
.append("svg")
.attr("width", 400)
.attr("height", 200);
var svg2 = d3.select("body")
.append("svg")
.attr("width", 400)
.attr("height", 200);
svg.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 400)
.attr("height", 300)
.attr("fill", "green");
svg2.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 400)
.attr("height", 200)
.attr("fill", "gray");
Thanks!
You would need two separate SVGs to accomplish this. You don't need to use any CSS, all you should need to do is set the width of the top SVG appropriately.

Detecting visible nodes in d3.js force layout after zoom-pan

I use a force directed layout in d3.js once on load to position nodes and edges. Then I can zoom and pan the svg. When I zoom in I want to detect which nodes and edges are visible so I can implement lazy loading of additional data only for the visible nodes and edges.
Does anyone know what is the best way to get the (partialy) visible elements?
Code is below (just pasted some examples together):
var svg = d3.select("#chart")
.append("svg")
.attr("width", width)
.attr("height", height)
.attr("pointer-events", "all")
.append('svg:g')
.call(d3.behavior.zoom().on("zoom", redraw))
.append('svg:g')
svg.append('svg:rect')
.attr('width', width)
.attr('height', height)
.attr('fill', 'white')
function redraw() {
trans=d3.event.translate;
scale=d3.event.scale
svg.attr("transform", "translate(" + trans + ")" + " scale(" + scale + ")")
console.log(scale)
}
If you are using scales, you can find the currently visible range using scale.invert. So to find the visible values for an axis where the width is 600px, use x.invert(0) and x.invert(600).

SVG markers don't orient properly on a d3.svg.diagonal curve used as a D3 force layout link

I'm a bit new to SVG and d3.js.
While drawing a graph with D3 force layout, I'm using a simple diagonal line generator and using marker-end to draw arrow heads.
When using arc instead of diagonal generator the arrow heads appear just fine. But using diagonal generator like in the code below doesn't produce proper markers:
var vis = this.vis = d3.select(el).append("svg:svg")
.attr("width", w)
.attr("height", h);
var force = d3.layout.force()
.gravity(0.03)
.distance(120)
.charge(-800)
.size([w, h]);
var linkDiag = d3.svg.diagonal()
.projection(function(d)
{
return [d.x, d.y];
});
vis.append("svg:defs")
.selectAll("marker")
.data(["normal", "special", "resolved"])
.enter()
.append("svg:marker")
.attr("id", String)
.attr("viewBox", "0 -5 10 10")
.attr("refX", 15)
.attr("refY", -1.5)
.attr("markerWidth", 6)
.attr("markerHeight", 6)
.attr("orient", "auto")
.append("svg:path")
.attr("d", "M 0,-5 L 10,0 L0,5");
...and then also:
force.on("tick", function() {
link.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return d.target.x; })
.attr("y2", function(d) { return d.target.y; })
.attr("d", linkDiag)
.attr("marker-end", function(d) { return "url(#special)"; });
});
The markers are not oriented at all with the vertices.
Any help would be appreciated!
It only appears as if the arrows aren't pointing in the right direction because you're moving the arrowhead to a new position via refX and refY.
For example, check out this code which draws diagonals in various directions. The arrowheads appear correctly, with the exception of the one at 180 degrees, but that's probably due to a rounding error.
Now, try changing refX on line 10 to a value of, say, 5. Now, the arrowheads close to the horizontal appear incorrect. To see this more dramatically, try changing the value to 8.
What's happening is you're hiding part of the diagonal so the line appears to be ending at an earlier point, which is curved slightly differently from the actual end-point. The same thing will happen if the arrowhead is too large so that it overlays part of the curve. Note that for diagonals in d3, which are symmetrical bezier curves, the arrowheads should always appear pointing perfectly horizontally or vertically. You can see exactly what's happening by reducing the arrowhead's opacity.
Can you specify you question a little more?
However with even running you code I think you problem might be
.attr("orient", "auto")
Try to specify pos

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