I am developing a Qt Web Kit application to run on Raspberry Pi 2. When I run the application on Ubuntu 14.04 on desktop it runs as expected. However when I run it on my Raspberry only blank page is shown. I also tried setting other HTML pages in QWebView, but that also ended in blank pages. I tried local HTML files, the ones from the internet and I even tried setting HTML text from code myself with setHtml(const QString &html) function. Sometimes, and I don't know why, depending on QString I set as HTML i get "$66" written in top left corner of the screen. It just doesn't make sens to me. At the end of the question are functions which I use to set web kit and web view. Is the problem maybe that I need to enable something or set some other parameters of MainWindow, which is inherited from QWebView? In my HTML I have a lot of images, actually that is all there is. I thought that was the problem, but simple HTMLs and some sites like google don't work too, so I ruled that problem out. Here is the code. It is compiled and there are no exceptions while running it, but it doesn't work as expected.
void MainWindow::initializeWebKit()
{
_network = new QNetworkAccessManager(this);
_cache = new QNetworkDiskCache(this);
_cache->setCacheDirectory(CACHE_DIRECTORY);
_cache->setMaximumCacheSize(CACHE_SIZE);
_network->setCache(_cache);
page()->setNetworkAccessManager(_network);
}
void MainWindow::initializeFrontend()
{
QUrl startURL = QUrl("qrc:/Web/index.html");
setUrl(startURL);
}
Related
In my Uno UWP project, I can view an html Asset file (w/ Content BuildAction), stored in my shared project, using the following:
var myAssetUri = new Uri("ms-appx-web:///Assets/Html/index.html");
myWebView.Navigate(myAssetUri);
However, this does not work with Android or WASM (not yet tried on other platforms). On WASM, I get a blank page. On Android, I get a page with the message:
The webpage at ms-appx-web:///Assets/Html/index.html could not be loaded because:
net::ERR_UNKNOWN_URL_SCHEME
When I look at the package folders for both platforms, I do find my html file:
WASM: bin/Debug/netstardard2.0/dist/package_.../Assets/Html/index.html
Android: (unziping my app's apk) assets/Html/index.html
so, I am guessing I'm not doing something right ... but I don't know what that might be.
The cause is simple: WebView not implemented yet on Wasm nor Skia.
This is the solution after hours investing!!
For you proyect write this line:
var myAssetUri = new Uri("file:///android_asset/Assets/Assets/Html/index.html");
This work 100%
A coworker and I were having a discussion about what is and isn't possible within the browser.
Then a question came up that neither of us could answer with certainty.
Can you create a webpage such that when you navigate to it, it engages the client-side printer and attempts to print a document. For instance, whenever you visit my personal website, you'll be treated to a print out of a picture of me, smiling.
Now, this is a hideous idea. I'm aware. But the discussion intrigued me as to if it could be done, and how. My friend insisted that the best you could do was pop up the print dialog for the user, they would have to click print themselves.
Would it be possible to bypass this step? Or just some fancy script to move the mouse over the print button and click on it? Or use an activeX control to interface with a Printer API directly?
You have to prompt the user to print the current page, there's no way to bypass this step (possibly in activeX for IE). That said, there's two different ways you could prompt the user to print images of you smiling when the page is loaded.
Here's how to do it in JavaScript.
window.onload = function() {
var img = window.open("me-smiling.png");
img.print();
}
And here's how to do it in css/javascript/html (assuming your picture has the id 'me-smiling'):
CSS:
#media print {
* {
display:none;
}
img#me-smiling {
display:block;
}
}
Javascript:
window.onload = function() { window.print() }
The only solution to avoid print dialog that I found was creating a variable on Mozilla Firefox to set auto-print. Maybe is not the best solution if you need to use other browser, but in my case, I only need to print a report automatically and it works:
1- Open Firefox and type "about:config" in the address bar
2- Right click on any preference and select "New" > "Boolean"
3- Add a variable called "print.always_print_silent" with "true" value
4- Restart Firefox.
Hope help you!
AttendStar created a free add-on that suppresses the dialog box and removes all headers and footers for most versions of Firefox.
https://addons.mozilla.org/en-US/firefox/addon/attendprint/
With that feature on you can use $('img').jqprint(); and jqprint for jquery will only print that image automatically called from your web application.
As far as I know, there is no way to print a document directly, without some client intervention, like setting browser flags.
In our current project we need to print directly to the default printer, but at least with Chrome you can do it easily with additional startup arguments.
To print directly to the OS default printer you can use:
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --user-data-dir=c:\tmp --kiosk-printing http://www.contoso.com
Another option, which may also be useful, is tos use the native print dialog instead of chromes print preview.
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --user-data-dir=c:\tmp --disable-print-preview http://www.contoso.com
Note, that window.print() and/or Ctrl-P behave accordingly the mentioned settings.
I know, that this does not exactly answers the OPs question, but I think it somewhat related, and for web based enterprise applications this is a quite common use case. Maybe someone find it useful.
For Firefox I recommend Seamless Print Addon
You can't bypass the print dialog, as far as I know. That would be a pretty obvious security flaw if the browser allowed that. But you can bring up the print dialog with "window.print()".
I think at best you would need an ActiveX component using base windows API to obtain a device context for the default printer and try and print an embedded image using assumed values for the printer settings.
To print to the default printer automatically without seeing a print dialog prompt, I've shared some code in the following question that works in IE7, IE8 and IE9:
Bypass Printdialog in IE9
From lot of search from last few days,
I've found a best possible solution.
Till date Chrome do not support direct printing from javascript.
It has launched USB and serial API which might help.
But currently I'm using a JavaApplet solution which is open source.
https://github.com/qzind/qz-print - build
While I'm getting error in building it. I preferred a Prebuilt - QZ Print Plugin 1.9.3
desktop app, which works great.
Download it from here: https://qz.io/download/
Code Example:
/***************************************************************************
* Prototype function for printing an HTML screenshot of the existing page
* Usage: (identical to appendImage(), but uses html2canvas for png rendering)
* qz.setPaperSize("8.5in", "11.0in"); // US Letter
* qz.setAutoSize(true);
* qz.appendImage($("canvas")[0].toDataURL('image/png'));
***************************************************************************/
function printHTML5Page() {
$("#qz-status").html2canvas({
canvas: hidden_screenshot,
onrendered: function() {
if (notReady()) { return; }
// Optional, set up custom page size. These only work for PostScript printing.
// setPaperSize() must be called before setAutoSize(), setOrientation(), etc.
qz.setPaperSize("8.5in", "11.0in"); // US Letter
qz.setAutoSize(true);
qz.appendImage($("canvas")[0].toDataURL('image/png'));
//qz.setCopies(3);
qz.setCopies(parseInt(document.getElementById("copies").value));
// Automatically gets called when "qz.appendFile()" is finished.
window['qzDoneAppending'] = function() {
// Tell the applet to print.
qz.printPS();
// Remove reference to this function
window['qzDoneAppending'] = null;
};
}
});
}
Complete example can be found here:
https://gist.github.com/bkrajendra/c80de17b627e59287f7c
This is the best solution that I have found for firefox:
There is this awesome add-on Seamless Print.
It works like charm.
I have a QDialog that opens a QFileDialog like so:
QFileDialog fd(this);
fd.setFileMode(QFileDialog::AnyFile);
if (fd.exec()) {
// save data to a file
}
Unfortunately, the default behavior doesn't seem to be quite so default, and the file dialog doesn't prompt me about overwriting if I select a file that already exists. Calling setConfirmOverwrite(true) or setOption(QFileDialog::DontConfirmOverwrite, false) first doesn't help either. I've tested this both on Qt 4.7.3 and 4.7.4 on both Ubuntu 11.04 and Windows XP.
I looked around and found this bug report. QFileDialog::getSaveFileName() had this issue, but it was specific to Maemo and fixed well before Qt 4.7.3 came out. If I use that method in my application it works just fine, I get prompted about overwriting the file. (I don't want to use getSaveFileName() for unrelated reasons.)
I can't find anyone else complaining about this not working for them. Am I doing something wrong, or is this a bug? I think it might be due to the dialog not knowing whether it's just a simple Open dialog where prompting wouldn't make sense, but I don't see a way to tell it it's a Save dialog (beyond setting the confirm-overwrite option, which fails), and the documentation does say it should prompt by default.
You should also be sure that the dialog is in save mode, as it will not think you are overwriting a file when in open mode. You can do this by calling fd.setAcceptMode(QFileDialog::AcceptSave); in your code example. See QFileDialog::acceptMode.
I'm having an issue where certain controls are flipped, depending on the machine that I'm building my project on. On my development machine, when I build it, everything is okay. However, when I build it on our build server, some things are flipped. It seems to be things that are on a higher layer - for instance, options in the select control (see first image below), alerts/overlays (see second image below), etc. It's not just the text, either - the entire content is flipped, images and all.
I have verified that the code is exactly the same in both instances, so it must have something to do with settings or the flex SDK version. On my development machine, the Flex SDK version is 4.0.0.14159, and on the build server, the Flex SDK version is 4.1.0.16076. I can downgrade the SDK on the build server if needed - but could it really be an issue with the SDK? Any ideas?
Thanks!
It looks like this will be fixed in the 4.5 SDK--see SDK-26473 for workarounds.
I was able to fix the mirroring by turning off Flex 3 Compatibility Mode in the Flex compiler settings (if using mxmlc, -compatibility-version=4.0).
Your build machine must be set to a locale which uses right-to-left text, such as Hebrew or Arabic keyboard setting.
Oops - hadn't read all of dpstone's answer before I posted my comment to the question.
The answer to this problem is in the bug he linked to. You need to explicitly set the layout direction. You can do this in one of two ways.
1) in a .css file that you import into your main application file:
global
{
layoutDirection: "ltr";
}
OR
2) you can set it in a <style> tag in your main application file.
<mx:Style>
global
{
layoutDirection: "ltr";
}
</mx:Style>
I am developing a website that has product images on an external server. I have code that tests to see if the image exists like (pseudo code):
DynamicString = FunctionThatCreatesDynamicString()
' DynamicString = "http://external_server/path/to/file1.jpg"
If ImageExists(DyanmicString) = StatusCode.200 Then
' Embed link in ASP.NET page
Else
' Embed not found image in ASP.NET page
End If
My code builds fine and appears to execute. The problem occurs when I attempt to view the external link in a browser, the image appears properly (I have to authenticate first, but that's OK considering I'm on an internal network and this app will be used internally).
However, when I attempt the view the source in my generated HTML page, I am seeing the image to the "Not Found" image when I know the image is there.
I compared all the characters in my dynamically assembled to the external link and all the characters are matching up correctly.
I'm wondering if the authentication has anything to do with why the image is not rendering properly on my rendered HTML.
Any thoughts?
It turns out the problem was the authentication to the images. I tried and was able to use a completely different approach. But thanks for the tip tangurena.