I'm facing some problems at the time of painting a circle with the SkiaSharp API in one of the children pages of a Tabbed Page in Xamarin Forms.
Although I get no errors during the building of the project, whenever I enter the page in which the circle is supposed to be drawn during the on device debugging, the application throws a "System.InvalidCastException: Specified cast is not valid" message and it crashes.
This is the XAML code of the Tabbed Page:
<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:me="clr-namespace:TestBth;assembly=TestBth"
x:Class="TestBth.MyTabbedPage">
<TabbedPage.Children>
<me:ConnectPage />
<me:LissajousPage />
<me:ParametersPage />
</TabbedPage.Children>
<!--Pages can be added as references or inline-->
</TabbedPage>
This is the XAML code of the page that's causing the trouble:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:skia="clr-namespace:SkiaSharp.Views.Forms;assembly=SkiaSharp.Views.Forms"
xmlns:local="clr-namespace:TestBth"
x:Class="TestBth.LissajousPage"
Title="Lissajous">
<skia:SKCanvasView x:Name="canvasView"
PaintSurface="canvasView_PaintSurface" />
</ContentPage>
And this is the internal code of the same page:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using SkiaSharp;
using SkiaSharp.Views.Forms;
namespace TestBth
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class LissajousPage : ContentPage
{
SKPaint blackFillPaint = new SKPaint
{
Style = SKPaintStyle.Fill,
Color = SKColors.Black
};
public LissajousPage()
{
InitializeComponent();
}
private void canvasView_PaintSurface(object sender, SKPaintSurfaceEventArgs e)
{
SKSurface surface = e.Surface;
SKCanvas canvas = surface.Canvas;
canvas.Clear(SKColors.CornflowerBlue);
int width = e.Info.Width;
int height = e.Info.Height;
//Set transforms
canvas.Translate(width / 2, height / 2);
canvas.Scale(width / 200f);
//Clock Background
canvas.DrawCircle(0, 0, 100, blackFillPaint);
}
}
}
Any idea about why could this be happening?
Thanks in advance.
For my surprise, it turns out the SkiaSharp.Views.Forms Nuget package was not installed for Android.
I specified that I wanted to install it in all my projects but there must have been a problem during the installation.
I installed the package individually for Android and it works fine now.
Sorry for the inconvenience.
I have tried to search both the forum and Google extensively, but I have problems understanding how I should make this work:
PrimeFaces6
I have a BarchartModel based on the tutorial in the ShowCase:
CODE: SELECT ALL
private BarChartModel initStatusBarChart() {
BarChartModel model = new BarChartModel();
ChartSeries statusMessages = new ChartSeries();
statusMessages.setLabel("Label"));
statusMessages.set("Some String 1", list1.size());
statusMessages.set("Some String 2", list2.size());
model.addSeries(statusMessages);
return model;
}
The issue is that on render, I get tooltips the format of
"1, 515" and "2, 432", where 515 and 432 are the sizes of list1 and list2, respectively.
How can I replace 1 and 2 with the values "Some String" 1 and 2 ? Have tried extending highlighter and using dataTipFormat, with no success.
I solved the problem using the datatip editor of the chart model (with Primefaces 6.1, by the way). I used this for a stacked bar chart.
I needed to apply this solution at two places: the backing bean and the JSF page.
In the backing bean I had to set a JavaScript function name this way:
barModel.setDatatipEditor("chartDatatipEditor");
I tried to set it using the corresponding tag attribute in the JSF page but to no effect.
In the JSF I inserted this JavaScript code:
<script type="text/javascript">
function chartDatatipEditor(str, seriesIndex, pointIndex, plot) {
//console.log('chartDatatipEditor: '+str+" - "+seriesIndex+" - "+pointIndex);
var point = seriesIndex+','+pointIndex;
#{bean.datatipsJs}
}
</script>
This JS function gets the chart coordinates as parameters. I concat them so that the following JS code gets easier.
seriesIndex is the index of the chart series. pointIndex is the index on the X scale of the diagram.
To find out what are the correct values for your chart you can uncomment the console.log line above.
The inserted JS code is constructed in the backing bean this way:
private Map<String, String> chartDatatips;
public String getDatatipsJs() {
StringBuilder sb = new StringBuilder("switch ( point ) {\n");
for (String point : chartDatatips.keySet()) {
sb.append("case '").append(point).append("': return '").append(chartDatatips.get(point)).append("'; break;\n");
}
sb.append("default: return 'Unknown point'; break; }");
return sb.toString();
}
The map chartDatatips has the coordinate point as key (e.g., "2,1") and the tooltip as value.
During the chart setup you obviously have to fill this map with useful details ;-)
Like this:
chartDatatips.put("2,5", "Label ...");
...
Hope this helps, if you didn't already solved this.
~Alex
Based on Alex's answer I have come up with this. Only requiring javascript - it displays the label and value:
In the backing bean, set a JavaScript function name this way:
barModel.setDatatipEditor("chartDatatipEditor");
In the HTML file:
function chartDatatipEditor(str, seriesIndex, pointIndex, plot) {
return plot.series[seriesIndex].label + ' - ' + plot.data[seriesIndex][pointIndex];
}
Im using ITextRenderer to generate a pdf file from html and css, I have a footer with the current page on the right.
But now i would like to have the current date on the left.
I found this:
<div data-line="1"></div>
div[data-line]:after {
content: "[line " attr(data-line) "]";
}
But I dont know how to combine it with :
#bottom-left {
content: "Date: ";
}
Is this possible or is there any other way?
I would like the footer to look something like this:
Date: 2015-03-17 12:04
UPDATE 1:
I have a method createPDF(string html, String resourceUrl), that looks like this:
ByteArrayOutputStream out = new ByteArrayOutputStream();
HtmlCleaner cleaner = new HtmlCleaner();
TagNode node = cleaner.clean(html);
CleanerProperties props = cleaner.getProperties();
new SimpleXmlSerializer(props).writeToStream(node, out, "ISO-8859-1");
ITextRenderer renderer = new ITextRenderer();
renderer.setPDFVersion(PdfWriter.VERSION_1_7);
renderer.setDocumentFromString(new String(out.toByteArray(), "ISO-8859-1"));
renderer.getSharedContext().setBaseURL(resourceUrl);
renderer.layout();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
renderer.createPDF(outputStream);
renderer.finishPDF();
outputStream.flush();
outputStream.close();
return outputStream.toByteArray();
The example that you cite of using data-line in the CSS is an interesting way to dynamically generate CSS based on data-* HTML attributes. These in turn might be dynamically generated in a web page by a server-side or client-side script. But it seems like this might not be the appropriate method for your case.
If you are already using a Java class like ITextRenderer to generate this PDF, then the best method for you is probably just to use Java itself to generate the current date in the format that you want, then print that directly into the CSS as a string.
If you are loading the CSS from a manually created file, one way to do this would be to write your CSS with some text you intend to replace, for example INSERTDATE. Then in Java, load your document the way you normally do, then use some Java code like String.replace() to replace INSERTDATE with today's date.
Update 1:
Based on your sample code above, you could write INSERTDATE where you want the date to appear in your HTML/CSS, then call:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm"); # your desired format
String strDate = sdf.format(new Date()); # get the current date
html = html.replace("INSERTDATE", strDate);
at the top of your method.
You can use css string-set with content() and string() css functions , see https://www.w3.org/TR/css-gcpm-3/ like :
<div class="where-content-comes-from">1</div>
<div class="where-content-is-injected"></div>
.where-content-comes-from{
display:none;
string-set: am-just-a-var content();
}
.where-content-is-injected:after {
content: string(am-just-a-var);
}
bonus : you can also use css env() function to display date value see https://developer.mozilla.org/en-US/docs/Web/CSS/env
I am starting to implement MVVM in my application and got an issue of knowing when the user navigated to the view.
To navigate between views, I can just use the navigationService.Navigate(...);
How do I check when I navigated to the view?
May I use the event navigationService.Navigated?
Is there no other method I can use like OnNavigatedTo that the page itself provide?
XAML:
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:cmd="clr-namespace:GalaSoft.MvvmLight.Command;assembly=GalaSoft.MvvmLight.Extras.WP71"
xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"
DataContext="{Binding titleSearchViewModel, Source={StaticResource Locator}}">
<i:Interaction.Triggers>
<i:EventTrigger>
<cmd:EventToCommand Command="{Binding PageLoaded, Mode=OneWay}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
VM:
private RelayCommand _PageLoaded;
public RelayCommand PageLoaded
{
get
{
if (_PageLoaded == null)
{
_PageLoaded = new RelayCommand(
() => Loaded()
);
}
return _PageLoaded;
}
}
In case this question is still actual, i prefer this solution: http://www.geoffhudik.com/tech/2010/10/10/another-wp7-navigation-approach-with-mvvm.html
If to use it, it is possible to send recipient ViewModel's parameters from the sender ViewModel:
SendNavigationMessage(Settings.NAVIGATION_PRODUCTS_SUBCATEGORIES,
new Dictionary<string, object> { { "SelectedIndex", Int32.Parse(item.id) } });
And receiver should define in xaml:
NavigatedToCommand="{Binding RefreshCommand}"
And then in receiver ViewModel:
public ICommand RefreshCommand // Should be set as NavigatedToCommand="{Binding RefreshCommand}" in xaml
{
get { return new RelayCommand(Refresh); }
}
public void Refresh()
{
_dataService.GetList(SelectedIndex, DownloadedCallback); // So, this would be called automatically after navigating is complete. SelectedIndex is updated at this moment.
}
Thanks for the answers provided. Both were helpful over a period of time until I decided to create a custom implementation of the navigation service that has been created by a few people.
I then made a contribution to the Cimbalino toolkit to suggest this and it has been introduced a while back.
I my personal opinion, that solves my issue the best. Have a look at the navigation service in there. The Navigated event pretty much solves my issue I had.
https://github.com/Cimbalino/Cimbalino-Toolkit
It basically comes down to this (in your viewmodel):
_navigationService.Navigated += OnNavigated;
I'm developing a web application.
I need to display some decimal data correctly so that it can be copied and pasted into a certain GUI application that is not under my control.
The GUI application is locale sensitive and it accepts only the correct decimal separator which is set in the system.
I can guess the decimal separator from Accept-Language and the guess will be correct in 95% cases, but sometimes it fails.
Is there any way to do it on server side (preferably, so that I can collect statistics), or on client side?
Update:
The whole point of the task is doing it automatically.
In fact, this webapp is a kind of online interface to a legacy GUI which helps to fill the forms correctly.
The kind of users that use it mostly have no idea on what a decimal separator is.
The Accept-Language solution is implemented and works, but I'd like to improve it.
Update2:
I need to retrive a very specific setting: decimal separator set in Control Panel / Regional and Language Options / Regional Options / Customize.
I deal with four kinds of operating systems:
Russian Windows with a comma as a DS (80%).
English Windows with a period as a DS (15%).
Russian Windows with a period as a DS to make poorly written English applications work (4%).
English Windows with a comma as a DS to make poorly written Russian applications work (1%).
All 100% of clients are in Russia and the legacy application deals with Russian goverment-issued forms, so asking for a country will yield 100% of Russian Federation, and GeoIP will yield 80% of Russian Federation and 20% of other (incorrect) answers.
Here is a simple JavaScript function that will return this information. Tested in Firefox, IE6, and IE7. I had to close and restart my browser in between every change to the setting under Control Panel / Regional and Language Options / Regional Options / Customize. However, it picked up not only the comma and period, but also oddball custom things, like the letter "a".
function whatDecimalSeparator() {
var n = 1.1;
n = n.toLocaleString().substring(1, 2);
return n;
}
function whatDecimalSeparator() {
var n = 1.1;
n = n.toLocaleString().substring(1, 2);
return n;
}
console.log('You use "' + whatDecimalSeparator() + '" as Decimal seprator');
Does this help?
Retrieving separators for the current or a given locale is possible using Intl.NumberFormat#formatToParts.
function getDecimalSeparator(locale) {
const numberWithDecimalSeparator = 1.1;
return Intl.NumberFormat(locale)
.formatToParts(numberWithDecimalSeparator)
.find(part => part.type === 'decimal')
.value;
}
It only works for browsers supporting the Intl API. Otherwise it requires an Intl polyfill
Examples:
> getDecimalSeparator()
"."
> getDecimalSeparator('fr-FR')
","
Bonus:
We could extend it to retrieve either the decimal or group separator of a given locale:
function getSeparator(locale, separatorType) {
const numberWithGroupAndDecimalSeparator = 1000.1;
return Intl.NumberFormat(locale)
.formatToParts(numberWithGroupAndDecimalSeparator)
.find(part => part.type === separatorType)
.value;
}
Examples:
> getSeparator('en-US', 'decimal')
"."
> getSeparator('en-US', 'group')
","
> getSeparator('fr-FR', 'decimal')
","
> getSeparator('fr-FR', 'group')
" "
Ask the user, do not guess. Have a setting for it in your web application.
Edited to add:
I think it is ok to guess the default setting that works ok, say, 95% of the time. What I meant was that the user should still be able to override whatever guesses the software made. I've been frustrated too many times already when a software tries to be too smart and does not allow to be corrected.
Why not
console.log(0.1.toLocaleString().replace(/\d/g, ''));
function getDecimalSeparator() {
//fallback
var decSep = ".";
try {
// this works in FF, Chrome, IE, Safari and Opera
var sep = parseFloat(3/2).toLocaleString().substring(1,2);
if (sep === '.' || sep === ',') {
decSep = sep;
}
} catch(e){}
return decSep;
}
I can guess the decimal separator from
Accept-Language and the guess will be
correct in 95% cases, but sometimes it
fails.
This is IMO the best course of action. In order to handle the failures, add a link to set it manually next to the display area.
Using other people answers I compiled the following decimal and thousand separators utility functions:
var decimalSeparator = function() {
return (1.1).toLocaleString().substring(1, 2);
};
var thousandSeparator = function() {
return (1000).toLocaleString().substring(1, 2);
};
Enjoy!
Similar to other answers, but compressed as a constant:
const decimal=.1.toLocaleString().substr(1,1); //returns "." in Canada
Also, to get the thousands separator:
const thousands=1234..toLocaleString().substr(1,1); //returns "," in Canada
Just place the code at the top of your JS and then call as required to return the symbol.
For example (where I live), to remove commas from "1,234,567":
console.log( "1,234,567".replaceAll(thousands,"") ); //prints "1234567" to console.
I think you have to rely on JavaScript to give you the locale settings.
But apparently JS doesn't have direct access to this information.
I see Dojo Toolkit relies on an external database to find the locale information, although it might not take in account setting changes, for example.
Another workaround I see is to have a small silent Java applet that query this information from the system, and JavaScript to get it out of Java.
I can give more information if you don't know how to do it (if you want to go this convoluted route, of course).
[EDIT]
So I updated my knowledge of localization support in Java...
Unlike what I thought originally, you won't have directly the decimal separator or thousand separator characters directly, like you would do with line separator or path separator: instead Java offers APIs to format the numbers or dates you provide.
Somehow, it makes sense: in Europe you often put the currency symbol after the number, some countries (India?) have a more complex rule to separate digits, etc.
Another thing: Java correctly finds the current locale from the system, but doesn't take information from there (perhaps for above reasons). Instead it uses its own set of rules. So if you have a Spanish locale where you replaced decimal separator with an exclamation sign, Java won't use it (but perhaps neither your application, anyway...).
So I am writing an applet exposing a service (functions) to JavaScript, allowing to format numbers to the current locale. You can use it as such, using JavaScript to format numbers on the browser. Or you can just feed it with some sample number and extract the symbols from there, using them locally or feeding them back to the server.
I finish and test my applet and post it there soon.
OK, I have something to show, more a proof of concept than a finished product, but because of lack of precise specifications, I leave it this way (or I will over-engineer it). I post in a separate message because it will be a bit long.
I took the opportunity to try a bit more jQuery...
The Java code:
GetLocaleInfo.java
import java.applet.*;
import java.util.Locale;
import java.text.*;
public class GetLocaleInfo extends Applet
{
Locale loc;
NumberFormat nf;
NumberFormat cnf;
NumberFormat pnf;
// For running as plain application
public static void main(String args[])
{
final Applet applet = new GetLocaleInfo();
applet.init();
applet.start();
}
public void init() // Applet is loaded
{
// Use current locale
loc = Locale.getDefault();
nf = NumberFormat.getInstance();
cnf = NumberFormat.getCurrencyInstance();
pnf = NumberFormat.getPercentInstance();
}
public void start() // Applet should start
{
// Following output goes to Java console
System.out.println(GetLocaleInformation());
System.out.println(nf.format(0.1));
System.out.println(cnf.format(1.0));
System.out.println(pnf.format(0.01));
}
public String GetLocaleInformation()
{
return String.format("Locale for %s: country=%s (%s / %s), lang=%s (%s / %s), variant=%s (%s)",
loc.getDisplayName(),
loc.getDisplayCountry(),
loc.getCountry(),
loc.getISO3Country(),
loc.getDisplayLanguage(),
loc.getLanguage(),
loc.getISO3Language(),
loc.getDisplayVariant(),
loc.getVariant()
);
}
public String FormatNumber(String number)
{
double value = 0;
try
{
value = Double.parseDouble(number);
}
catch (NumberFormatException nfe)
{
return "!";
}
return nf.format(value);
}
public String FormatCurrency(String number)
{
double value = 0;
try
{
value = Double.parseDouble(number);
}
catch (NumberFormatException nfe)
{
return "!";
}
return cnf.format(value);
}
public String FormatPercent(String number)
{
double value = 0;
try
{
value = Double.parseDouble(number);
}
catch (NumberFormatException nfe)
{
return "!";
}
return pnf.format(value);
}
}
An example of HTML page using the above applet:
GetLocaleInfo.html
<!-- Header skipped for brevity -->
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.2.6/jquery.js"></script>
<script type="text/javascript">
var applet;
$(document).ready(function()
{
applet = document.getElementById('LocaleInfo');
$('#Results').text(applet.GetLocaleInformation());
});
</script>
<script type="text/javascript">
function DoFormatting()
{
$('table.toFormat').each(function()
{
var table = $(this);
$('td', table).each(function(cellId)
{
var val = $(this);
if (val.is('.number'))
{
val.text(applet.FormatNumber(val.text()));
}
else if (val.is('.currency'))
{
val.text(applet.FormatCurrency(val.text()));
}
else if (val.is('.percent'))
{
val.text(applet.FormatPercent(val.text()));
}
});
});
}
</script>
</head>
<body>
<div id="Container">
<p>Page to demonstrate how JavaScript can get locale information from Java</p>
<div id="AppletContainer">
<object classid="java:GetLocaleInfo.class"
type="application/x-java-applet" codetype="application/java"
name="LocaleInfo" id="LocaleInfo" width="0" height="0">
<param name="code" value="GetLocaleInfo"/>
<param name="mayscript" value="true"/>
<param name="scriptable" value="true"/>
<p><!-- Displayed if object isn't supported -->
<strong>This browser does not have Java enabled.</strong>
<br>
<a href="http://java.sun.com/products/plugin/downloads/index.html" title="Download Java plug-in">
Get the latest Java plug-in here
</a> (or enable Java support).
</p>
</object>
</div><!-- AppletContainer -->
<p>
Click on the button to format the table content to the locale rules of the user.
</p>
<input type="button" name="DoFormatting" id="DoFormatting" value="Format the table" onclick="javascript:DoFormatting()"/>
<div id="Results">
</div><!-- Results -->
<table class="toFormat">
<caption>Synthetic View</caption>
<thead><tr>
<th>Name</th><th>Value</th><th>Cost</th><th>Discount</th>
</tr></thead>
<tbody>
<tr><td>Foo</td><td class="number">3.1415926</td><td class="currency">21.36</td><td class="percent">0.196</td></tr>
<tr><td>Bar</td><td class="number">159263.14</td><td class="currency">33</td><td class="percent">0.33</td></tr>
<tr><td>Baz</td><td class="number">15926</td><td class="currency">12.99</td><td class="percent">0.05</td></tr>
<tr><td>Doh</td><td class="number">0.01415926</td><td class="currency">5.1</td><td class="percent">0.1</td></tr>
</tbody>
</table>
</div><!-- Container -->
</body>
</html>
Tested on Firefox 3.0, IE 6, Safari 3.1 and Opera 9.50, on Windows XP Pro SP3.
It works without problem with the first two, on Safari I have a strange error after init() call:
java.net.MalformedURLException: no protocol:
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at java.net.URL.<init>(Unknown Source)
at sun.plugin.liveconnect.SecureInvocation.checkLiveConnectCaller(Unknown Source)
at sun.plugin.liveconnect.SecureInvocation.access$000(Unknown Source)
at sun.plugin.liveconnect.SecureInvocation$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.plugin.liveconnect.SecureInvocation.CallMethod(Unknown Source)
but it still works.
I can't get it work with Opera: the applet loads correctly, as I can see the trace of init() call in the Java console, I have no errors when JavaScript calls the Java functions (except if I add and call a method getting a JSObject parameter, curiously), but the Java functions are not called (I added trace of the calls).
I believe Liveconnect works in Opera, but I don't see yet how. I will research a bit more.
[Update] I removed references to non-existing jar file (which doesn't stop other browsers) and I got a trace of the calls, but it doesn't update the page.
Mmm, if I do alert(applet.GetLocaleInformation()); I got the information, so it might be a jQuery issue.
Even if you knew what locale this "GUI Application" is running under, you still have to figure out how it is getting the current locale, and how it is determining the decimal separator.
i don't know how it is done on a Mac, but on Windows applications are supposed to interrogte the user's preferences set via the Control Panel. It's quite possible this mystery applicaiton is ignoring those settings, and using their own internal setup instead.
Or perhaps they're taking the current locale, and inferring the rest, rather than being told.
Even then, in english, numbers are given in groups of 3 digits, with a comma separating the groups. i.e.:
5,197,359,078
Unless the number was an integer that contains a phone number:
519-735-9078
Unless of course the number was an integer that contains an account number:
5197359078
In which case, you're back to hard-coded overridden logic.
Edit: Removed currency example, since currency has its own formatting rules.
"Is there any way to do it on server
side (preferably, so that I can
collect statistics), or on client
side?"
No you can't. That GUI is looking at some user or machine specific settings.
First, you probably do not know at what settings this UI is looking.
Second, with a webapplication you will probably not be able to check these settings (clientside --> Javacsript).
Is there any way to do it on server side (preferably, so that I can collect statistics), or on client side?
from Server side. That could get decimal separator from system by (.NET)
string x = CultureInfo.CurrentCulture.NumberFormat.NumberDsecimalSeparator;
The rest of work is check delimiter for exporting which is different from x
comma (",") or semicolon (";") in case csv export
Another possible solution: You could use something like GeoIP (example in PHP) to determine the user's location and decide based on these information.