Is there any way to center text with jsPDF? - javascript

I'm trying to create a simple pdf doc using javascript. I found jsPDF but I don't figure out how to center text. Is it possible?

Yes it's possible. You could write a jsPDF plugin method to use.
One quick example is this:
(function(API){
API.myText = function(txt, options, x, y) {
options = options ||{};
/* Use the options align property to specify desired text alignment
* Param x will be ignored if desired text alignment is 'center'.
* Usage of options can easily extend the function to apply different text
* styles and sizes
*/
if( options.align == "center" ){
// Get current font size
var fontSize = this.internal.getFontSize();
// Get page width
var pageWidth = this.internal.pageSize.width;
// Get the actual text's width
/* You multiply the unit width of your string by your font size and divide
* by the internal scale factor. The division is necessary
* for the case where you use units other than 'pt' in the constructor
* of jsPDF.
*/
txtWidth = this.getStringUnitWidth(txt)*fontSize/this.internal.scaleFactor;
// Calculate text's x coordinate
x = ( pageWidth - txtWidth ) / 2;
}
// Draw text at x,y
this.text(txt,x,y);
}
})(jsPDF.API);
And you use it like this
var doc = new jsPDF('p','in');
doc.text("Left aligned text",0.5,0.5);
doc.myText("Centered text",{align: "center"},0,1);

This works in the scratchpad on the jsPdf homepage:
var centeredText = function(text, y) {
var textWidth = doc.getStringUnitWidth(text) * doc.internal.getFontSize() / doc.internal.scaleFactor;
var textOffset = (doc.internal.pageSize.width - textWidth) / 2;
doc.text(textOffset, y, text);
}

I have found that the current version of jsPdf supports a parameter 'align' with the function signature like this:
API.text = function (text, x, y, flags, angle, align)
So the following should give you a center-aligned text:
doc.text('The text', doc.internal.pageSize.width, 50, null, null, 'center');
However, at the current point in time, an error is thrown in the library when strict mode is on because a 'var' is missing.
There is an issue and pull request for it, but the fix hasn't made it in:
https://github.com/MrRio/jsPDF/issues/575
Whoever is looking for this, one day, you might be able to use this to make it easier to center text.

WootWoot, just in case you need more layout options, you could also take a look at my pdfmake library
It supports:
text alignments, lists, margins
styling (with style inheritance)
tables with auto/fixed/star sized columns, auto-repeated headers, col/row spans
page headers and footers
font embedding, and a couple of other options
It works on client-side (pure JS) or server-side (an npm module)
Take a look at the playground to see what's possible
Good luck

I had the same problem and a lot of others while creating PDF-Files (e.g. auto-pagebreak, total-pageCount). So i started writing a little lib, which depends on jsPDF but gives you a lot of features in a way you know them (form HTML/CSS and jQuery). You can find it on GitHub. I hope it makes PDF-Creating easier... =)

Based on #Tsilis answer I have snippet out a plugin here https://gist.github.com/Purush0th/7fe8665bbb04482a0d80 which can align the text left, right and center in the given text container width.
(function (api, $) {
'use strict';
api.writeText = function (x, y, text, options) {
options = options || {};
var defaults = {
align: 'left',
width: this.internal.pageSize.width
}
var settings = $.extend({}, defaults, options);
// Get current font size
var fontSize = this.internal.getFontSize();
// Get the actual text's width
/* You multiply the unit width of your string by your font size and divide
* by the internal scale factor. The division is necessary
* for the case where you use units other than 'pt' in the constructor
* of jsPDF.
*/
var txtWidth = this.getStringUnitWidth(text) * fontSize / this.internal.scaleFactor;
if (settings.align === 'center')
x += (settings.width - txtWidth) / 2;
else if (settings.align === 'right')
x += (settings.width - txtWidth);
//default is 'left' alignment
this.text(text, x, y);
}
})(jsPDF.API, jQuery);
Usage
var doc = new jsPDF('p', 'pt', 'a4');
//Alignment based on page width
doc.writeText(0, 40 ,'align - center ', { align: 'center' });
doc.writeText(0, 80 ,'align - right ', { align: 'right' });
//Alignment based on text container width
doc.writeText(0, 120 ,'align - center : inside container',{align:'center',width:100});

maybe... just for easy way, you can read this jsPdf text api doc
doc.text(text, x, y, optionsopt, transform)
where optionspot is an option objet, so, you can do this
{align:"center"}
i.e:
doc.text("Hello Sun", doc.internal.pageSize.getWidth()/2, 10, { align: "center" })
where: doc.internal.pageSize.getWidth() is the page width for pdf sheet

doc.text(text,left,top,'center') can be used to center text. It can be used with array of lines as well but when it is used with array the center does not work right so I have used it in a loop for every object in the array.
var lMargin=15; //left margin in mm
var rMargin=15; //right margin in mm
var pdfInMM=210; // width of A4 in mm
var pageCenter=pdfInMM/2;
var doc = new jsPDF("p","mm","a4");
var paragraph="Apple's iPhone 7 is officially upon us. After a week of pre-orders, the latest in the iPhone lineup officially launches today.\n\nEager Apple fans will be lining up out the door at Apple and carrier stores around the country to grab up the iPhone 7 and iPhone 7 Plus, while Android owners look on bemusedly.\n\nDuring the Apple Event last week, the tech giant revealed a number of big, positive changes coming to the iPhone 7. It's thinner. The camera is better. And, perhaps best of all, the iPhone 7 is finally water resistant.\n\nStill, while there may be plenty to like about the new iPhone, there's plenty more that's left us disappointed. Enough, at least, to make smartphone shoppers consider waiting until 2017, when Apple is reportedly going to let loose on all cylinders with an all-glass chassis design.";
var lines =doc.splitTextToSize(paragraph, (pdfInMM-lMargin-rMargin));
var dim = doc.getTextDimensions('Text');
var lineHeight = dim.h
for(var i=0;i<lines.length;i++){
lineTop = (lineHeight/2)*i
doc.text(lines[i],pageCenter,20+lineTop,'center'); //see this line
}
doc.save('Generated.pdf');

Do this:
First get the page width, get half the page width and use it as the x value, use y value of your choice and pass center as the third param to center your text.
Read more from documentation
let doc = new jsPDF();
let pageWidth = doc.internal.pageSize.getWidth();
doc.text("My centered text",pageWidth / 2, 20, 'center');

This will work fine.
let pdf = new jspdf('p', 'mm', 'a4');
pdf.text("Text to display", pdf.internal.pageSize.getWidth() / 2, 50, null, 'center');
50 is the height i.e. y-axis.

This worked for me:
doc.styles.tableBodyEven = {
alignment: 'center'
}
doc.styles.tableBodyOdd = {
alignment: 'center',
color: '#555555',
fillColor: '#dedede'
}

Related

Data label not rendered on sapui5 viz dual y-axis graph when line and column intersect

I have a requirement to show data labels of two graphs on the same axes.
Only when they intersect, one of the two labels won't show. This can be demonstrated below:
As you can see on the 2nd, 5th and 6th columns from the left with values 0%, 7% and 8% respectively
only the orange line values are shown but the blue column values are missing.
This is the final html of the graph after rendering:
So data-datapoint-id 142, 145 and 146 are missing from the html.
I tried using the plotArea.dataLabel.renderer function as a manipulation of what was proposed here but nothing changed, still not rendering.
Anyone encountered a similar problem? Is that a sapui5 issue or can it be fixed by manually inserting the labels into the HTML if so how?
Thanks,
Ori
Using SVG text and jQuery I managed to manually insert the labels into the top middle of the blue rectangle columns.
This is the result, not perfect but works:
and this is the code:
chart.setVizProperties({
plotArea: {
dataLabel: {
formatString: {'פחת כללי': FIORI_PERCENTAGE_FORMAT_2},
renderer: function (oLabel) {
// Create empty text node to be returned by the function such that the label won't be rendered automatically
var node = document.createElement("text");
if (oLabel.ctx.measureNames === "כמות פחת כללי") {
var kamutLabelIdx = oLabel.ctx._context_row_number;
// Use jQuery and SVG to manipulate the HTML
var kamutLabelQuery = '[data-id=\"' + kamutLabelIdx + '\"]';
var kamutColumn = $(kamutLabelQuery)[0];
// Create text element as child of the column
kamutColumn.innerHTML += "<text>" + oLabel.text + "</text>";
var labelNode = $(kamutLabelQuery += ' text');
// Set the label position to be at the middle of the column
const labelLength = 60;
const xPos = (labelLength + oLabel.dataPointWidth) / 2;
const yPos = oLabel.styles['font-size'];
labelNode.attr({
"textLength" : labelLength,
"x" : xPos,
"y" : yPos,
"font-size" : yPos
});
return node;
}
}
}
}
});
The oLabel parameter of the renderer function provides useful info about the data label to be created:
I still wonder if that's a bug with sapui5 vizframe and if there is a simpler way to do this.
Please let me know of your thoughts

Add background to text in Pixi.js?

Is there any way I can add a background to my text in Pixi.js? I'm looking for an effect like this:
Creating a background sprite, and giving it the same position and dimensions as the text object does not work here, as that would always give me a rectangle which is not what I want. I guess I could make on text object per line and use that approach, but since the text is arbitrarily set by the user I would have to work out my own linebreaking algorithm to be able to do that. That seems overly complicated.
Here is my code without any background (fiddle):
var app = new PIXI.Application({
width: window.innerWidth,
height: window.innerHeight,
backgroundColor: 0x2c3e50
});
document.body.appendChild(app.view);
var text = new PIXI.Text("HELLO\nWORLD!", {
align: "center"
})
text.anchor.set(0.5);
text.x = app.renderer.width / 2;
text.y = app.renderer.height / 2;
app.stage.addChild(text);

'Media-queries' for javascript - different code for different viewport height/widths

The problem
I'm using javascript to calculate widths of elements to achieve the layout I'm after. The problem is, I don't want to load the code on smaller screen sizes (when the screen width is less than 480px for example). I'd like this to work on load and on browser/viewport resize.
I'd consider small screen devices 'the default' and working up from there. So, none of the following script is called by default, then if the browser width is greater than 480px (for example), the following script would be called:
The code
$(document).ready(function() {
//Get the figures width
var figure_width = $(".project-index figure").css("width").replace("px", "");
//Get num figures
var num_figures = $(".project-index figure").length;
//Work out how manay figures per row
var num_row_figures = Math.ceil(num_figures / 2);
//Get the total width
var row_width = figure_width * num_row_figures;
//Set container width to half the total
$(".project-index").width(row_width);
x = null;
y = null;
$(".project-index div").mousedown(function(e) {
x = e.clientX;
y = e.clientY;
});
$(".project-index div").mouseup(function(e) {
if (x == e.clientX && y == e.clientY) {
//alert($(this).next().attr("href"));
window.location.assign($(this).next().attr("href"));
}
x = y = null;
});
});
// Drag-on content
jQuery(document).ready(function() {
jQuery('#main').dragOn();
});
The extra bit
The slight difference on larger screens is to do with the browser/viewport height. This is in regards to the line:
var num_row_figures = Math.ceil(num_figures / 2);
You can see once the calculation has a value, it divides it by 2. I only want this to happen when the browser/viewport height is above a certain amount - say 600px.
I'd be happy with this being the 1st state and then the value is divided by 2 if the height is greater than 600px if it's easier.
Can anyone help me/shed some light on how to manage my script this way. I know there's media queries for managing CSS but I can't seem to find any resources for how to manage javascript this way - hope someone can help.
Cheers,
Steve
You can use window.matchMedia, which is the javascript equivalent of media queries. The matchMedia call creates a mediaQueryList object. We can query the mediaQueryList object matches property to get the state, and attach an event handler using mediaQueryList.addListener to track changes.
I've added an example on fiddle of using matchMedia on load and on resize. Change the bottom left pane height and width (using the borders), and see the states of the two queries.
This is the code I've used:
<div>Min width 400: <span id="minWidth400"></span></div>
<div>Min height 600: <span id="minHeight600"></span></div>
var matchMinWidth400 = window.matchMedia("(min-width: 400px)"); // create a MediaQueryList
var matchMinHeight600 = window.matchMedia("(min-height: 600px)"); // create a MediaQueryList
var minWidth400Status = document.getElementById('minWidth400');
var minHeight600Status = document.getElementById('minHeight600');
function updateMinWidth400(state) {
minWidth400Status.innerText = state;
}
function updateMinHeight600(state) {
minHeight600Status.innerText = state;
}
updateMinWidth400(matchMinWidth400.matches); // check match on load
updateMinHeight600(matchMinHeight600.matches); // check match on load
matchMinWidth400.addListener(function(MediaQueryListEvent) { // check match on resize
updateMinWidth400(MediaQueryListEvent.matches);
});
matchMinHeight600.addListener(function(MediaQueryListEvent) { // check match on resize
updateMinHeight600(MediaQueryListEvent.matches);
});
#media screen and (max-width: 300px) {
body {
background-color: lightblue;
}
}
So i searched a bit and came up with this example from w3 schools .http://www.w3schools.com/cssref/tryit.asp?filename=trycss3_media_example1
i think this is something you are trying to achieve.
For pure js , you can get the screen width by screen.width

how to make a div match a dynamically created google chart height

I have a page that dynamically loads a google timeline chart onto a div. The timeline increases in height as you add items on to it. If the chart is smaller than the div, it will be visible with empty space at the bottom. If the chart is larger, it will show scrollbars on the side.
What I would like is for the container div to always show the full chart or, another way, I would like the container div height to dynamically match the height of the chart.
I have tried to approximate the average size of each chart line and then adjust the div height when I load the chart with:
$("#gantt_chart").height(data['num_contents']*46);
But, although that somehow works, it's far from perfect because the approximation on height starts to accumulate with each additional line and the empty space at the bottom of the div increases which is not an elegant solution at all.
How would I ensure that the container div always shows the full chart?
I hope this is clear enough.
Many thanks.
The chart determines its height by either checking the height option passed into the draw call, or by checking the container height if the height option is not specified. I would suggest using the option instead of changing the div height via jQuery. I find the best method for dynamically calculating the chart height is to take the height of a row (typically 41px) times the number of rows, plus some padding for the top and bottom:
var height = data.getNumberOfRows() * 41 + 30;
Though in the doc they have shown to adjust height of div from where we are specifying the id of timeline but I recommend you to have set the height from the internal method.
// set the height for padding(padding height)
var pH = 40;
// get total height of rows (row height)
var rH = dataTable.getNumberOfRows() * 15;
// total chart height (chart height)
var cH = rH + pH;
// Now set this chart height to the timeline via option object
// apart from height, other attributes are just optional
var options = {
height: chartHeight,
colors: ['#339900', '#e6e600', '#B00000'],
tooltip: {
isHtml: true
},
timeline: {
colorByRowLabel: false
},
avoidOverlappingGridLines: true
};
Been trying to do the same thing myself. The top answer wasn’t exactly right and caused an inner scroll bar to appear at times.
Here’s what worked for me:
var barLabelFontSize = 12; //default font size for bar labels
try{barLabelFontSize = options.timeline.barLabelStyle.fontSize; //bar height is dependent on the bar label's font size that you set...
}catch(e){}
var barHeight = barLabelFontSize * 1.196; //found in google api as: this.PU = 1.916 * this.UF.fontSize;
var barMargin = barLabelFontSize * 0.75; //found in google api as: this.Rfa = .75 * this.UF.fontSize;
var rowHeight = barHeight + barMargin * 2; //found in google api as: b.height = 2 * this.Rfa + this.PU (+additional complication for grouped bars, if anyone wants to try work that out it was: b.height = 2 * this.Rfa + this.PU * a.SI.length + this.Qfa * (a.SI.length - 1); (where Qfa is 0.583 * font size, and a.SI.length is the number of grouped bars displayed on the row)
var chartAreaHeight = rowHeight * dataTable.getNumberOfRows();
var axisHeight = 24; //worked out by querying: document.getElementById('timelineChart') getElementsByTagName('svg')[0].getBBox().height;
var whiteSpaceHeight = 28; //trail-and-error to find how much whitespace was required to stop a scroll bar appearing, 27 works too, but I rounded up to play it safe
var chartHeight = chartAreaHeight + axisHeight + whiteSpaceHeight;
You can also reverse engineer this to set the height of the bars using the bar label font size.

Raphael.js centered text on path

What I have:
Text along a path made out of circle. It uses Raphael.js and a function called textOnPath (found here: Raphael JS Text Along path ):
var pathTest = r.path(getCircletoPath(286, 322, radius)).attr({stroke:"#b9b9b9"});
textOnPath(message, pathTest, fontSize, fontSpacing, kerning, kerning, point, textFill, fontNormal, fontFamily);
JSFiddle: http://jsfiddle.net/zorza/62hDH/1/
What I need:
The text to be centered on top of the circle.
My approach:
Try to calculate where the text should start depending on the arc size and text width. I tried to calculate the text width by creating it's invisible clone with text() function and get it's BBox width.
It doesn't quite work and the results vary depending on the web browser, font used and number of letters and spaces:
var length = r.text(100,400,message)
.attr({"font-size":fontSize,'opacity': 0, 'font-family': fontFamily})
.getBBox()
.width;
var point = (Math.PI*radius - length*fontSpacing)/2;
JSFiddle: http://jsfiddle.net/zorza/k8vBy/3/
Could anyone point me in the right direction?
The easiest way, IMHO, is to create additional helper path that is raised by half of text size. http://jsfiddle.net/p84VQ/
Also, I find it a bit more convenient to define a circle and then get points at specified angle:
var Circle = function(cx, cy, r) {
return function (a) {
return {
x: cx + r*Math.sin(Math.PI*-a/180),
y: cy - r*Math.cos(Math.PI*-a/180)
}
}
};

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