logo
down
shadow

Load PDF into layer offscreen


Load PDF into layer offscreen

By : Yancyd
Date : January 10 2021, 01:57 PM
Hope that helps Note : you told that You need to load PDF into CALayer. But Here, I have the solution for loading entire pdf pages into images. Once images are in an array, you can view any of them as & when required. Add comment if you have any doubts.
You just have to copy & paste following code. It will almost work for you. I have tested.
code :


Share : facebook icon twitter icon
Why does my UIVIew load offscreen?

Why does my UIVIew load offscreen?


By : eadile
Date : March 29 2020, 07:55 AM
it fixes the issue You have to account for the height of the status bar when you add the view to the window:
code :
CGRect statusBarFrame = [[UIApplication sharedApplication] statusBarFrame];
CGSize statusBarSize = statusBarFrame.size;
CGFloat statusBarHeight = statusBarSize.height;

LViewController *aLViewController = [[LViewController alloc] initWithNibName:@"LViewController" bundle:[NSBundle mainBundle]];
self.viewController = aLViewController;
[aLViewController release];  

viewController.view.frame = CGRectMake(0.0f,
                                       statusBarHeight,
                                       window.bounds.size.width,
                                       window.bounds.size.height - statusBarHeight);

[window addSubview:[viewController view]];
When does a view (or layer) require offscreen rendering?

When does a view (or layer) require offscreen rendering?


By : sfg
Date : March 29 2020, 07:55 AM
it should still fix some issue I don't think there is a rule written down anywhere, but hopefully this will help:
First, let's clear up some definitions. I think offscreen vs onscreen rendering is not the overriding concern most of the time, because offscreen rendering can be as fast as onscreen. The main issue is whether the rendering is done in hardware or software.
Awesomium offscreen webview never load a page

Awesomium offscreen webview never load a page


By : user2112824
Date : March 29 2020, 07:55 AM
will be helpful for those in need I made some research and found instruction here
code :
static void Main(string[] args)
{
    Task t = new Task(() =>
    {
        WebCore.Initialize(new WebConfig(), true);
        WebView browser = WebCore.CreateWebView(1024, 768, WebViewType.Offscreen);
        browser.DocumentReady += browser_DocumentReady;
        browser.Source = new Uri("https://www.google.ru/");
        WebCore.Run();
    });
    t.Start();
    Console.ReadLine();
}
static void browser_DocumentReady(object sender, UrlEventArgs e)
{
    Console.WriteLine("DocumentReady");
}
Javascript load Image into Offscreen Canvas, perform webp conversion

Javascript load Image into Offscreen Canvas, perform webp conversion


By : user2708195
Date : March 29 2020, 07:55 AM
I wish this helpful for you You are facing an XY and even -Z problem here, but each may have an useful answer, so let's dig in.
code :
large.onclick = e => process('https://upload.wikimedia.org/wikipedia/commons/c/cf/Black_hole_-_Messier_87.jpg');
medium.onclick = e => process('https://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Black_hole_-_Messier_87.jpg/1280px-Black_hole_-_Messier_87.jpg');

function process(url) {
  convertToWebp(url)
    .then(prepareDownload)
    .catch(console.error);
}

async function convertToWebp(url) {
  if(!supportWebpExport())
  console.warn("your browser doesn't support webp export, will default to png");

  let img = await loadImage(url);
  if(typeof window.createImageBitmap === 'function') {
    img = await createImageBitmap(img);
  }
  const ctx = get2DContext(img.width, img.height);

  console.time('only sync part');
  ctx.drawImage(img, 0,0);
  console.timeEnd('only sync part');
  
  return new Promise((res, rej) => {
    ctx.canvas.toBlob( blob => {
      if(!blob) rej(ctx.canvas);
      res(blob);
    }, 'image/webp');
  });
}

// some helpers

function loadImage(url) {
  return new Promise((res, rej) => {
    const img = new Image();
    img.crossOrigin = 'anonymous';
    img.src = url;
    img.onload = e => res(img);
    img.onerror = rej;
  });
}

function get2DContext(width = 300, height=150) {
  return Object.assign(
    document.createElement('canvas'),
    {width, height}
  ).getContext('2d');
}

function prepareDownload(blob) {
  const a = document.createElement('a');
  a.href = URL.createObjectURL(blob);
  a.download = 'image.' + blob.type.replace('image/', '');
  a.textContent = 'download';
  document.body.append(a);
}

function supportWebpExport() {
  return get2DContext(1,1).canvas
    .toDataURL('image/webp')
    .indexOf('image/webp') > -1;
}
<button id="large">convert large image (7,416 × 4,320 pixels)</button>
<button id="medium">convert medium image (1,280 × 746 pixels)</button>
const img = new Image();
img.onload = e => {
  createImageBitmap(img).then(bmp => {
    // transfer it to your worker
    worker.postMessage({
      image: bmp // the key to retrieve it in `event.data`
    },
   [bmp] // transfer it
  );
};
img.src = url;
const blob = await fetch(url).then(r => r.blob());
const img = await createImageBitmap(blob);
ctx.drawImage(img,0,0);
Render layer offscreen

Render layer offscreen


By : Nandan
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , Render your content into an CGBitmapContext, pull a CGImageRef off of that and set that as the contents of the CALayer. Take a look at Creating a Bitmap Graphics Context for example code for most of this.
But if your real problem is that your drawInContext: is too slow, you should first look at breaking that up so that you pre-calculate everything when the data changes and only do drawing in drawInContext:. This is generally the better approach. Don't pre-render the layer itself; pre-calculate everything you need to render the layer quickly. But for very complicated drawing, the CGImageRef approach is useful.
Related Posts Related Posts :
  • What is the best approach for writing unit tests for iPhone / iPad?
  • I am getting the error Wrong type argument to unary minus and Expected ';' before ':' token
  • Custom logo on top of UINavigationBar?
  • Custom UISlider Image disappearing?
  • HTML5 on iPhone Safari - data stored by localStorage does not always persist. Why?
  • @synthesize comma separated list
  • Xcode iPhone Programming check if a server is online
  • objective c iphone : can we view console log on device
  • What are the sizes used for the iOS application splash screen?
  • UITableViewCell with custom gradient background, with another gradient as highlight color
  • Print a copy of my app in the iPhone Simulator?
  • NSNumberFormatter, how to remove blank spaces in currency symbol
  • Google Map Street view in Iphone app
  • How can i make a link to update my iPhone application?
  • Question Related to Custom control
  • get SSL Broken pipe error when try to make push notification
  • How to store UISegmentedControle state in NSUserdefaults
  • What developer conferences/code camps would one go for mobile development?
  • How can I intercept the StoreKit "buy dialog" to make a MBProgressHUD / UIProgressView show up correctly and a
  • Is Appcelerator Titanium now banned on the iPhone?
  • Data storing in plist works in simulaor but not in device
  • UISearchDisplayController and search performance with lots of data
  • Why is my UIViewController initializer never called?
  • Can you run a blender game on an iphone or droid?
  • CGBitmapContextCreate on the iPhone/iPad
  • Problem pushing multiple view controllers onto navigation controller stack
  • addSubview like modal
  • How create UIImage from bytes?
  • UITableView section index overlaps search bar
  • iPhone Mapkit: How can I get a real business name/address from a longitude/latitude?
  • animating adding/removing layers on iPhone
  • iPhone 4.0 Beta compile for 3.1.3
  • how to implement RSA algorithm in iphone application?
  • IPhone SDK Default NSUserDefaults
  • shadow
    Privacy Policy - Terms - Contact Us © 35dp-dentalpractice.co.uk