Opera : Java Glossary

A small, fast, free browser that can run Java via the Java Plug-in using standard <APPLET tags. The latest version is Opera 48.0.2685.52 Last revised/verified: 2017-10-26.

It comes only in a 32-bit version. The 64-bit version has been discontinued. This is the browser I formerly most often myself and my web host (Inter-Corporate) also uses. The Opera icon to use for the 64-bit version. It is one of the few browsers that directly supports RSS feeds. Dragonfly is a tool similar to Firefox Firebug to help you figure out how CSS (Cascading Style Sheets) style sheet entries interact to decide the attributes of a given bit of text.

The secret to Opera’s speed is a technique called pipelining which allows it to download many small files almost as fast as if there were one big one.

Benefits

• One of the nicest features of Opera is the fast file download. It gets on with the download in the background even before you have finished typing the file name to save as.
• Opera has a rich selection of root certificates pre-installed. Any certificate authority can submit root certificates to be included.
• Opera uses a server to cache web pages and serve them quickly in compressed form (from Sweden). It may even have look-ahead.
• Opera print options lets you control whether background colours are printed and whether there are headers and footers.

Disadvantages

• Opera does not support Java or Java Web Start.
• It sometimes refuses to load documents from local hard disk.
• It does not let you import or export bookmarks.
• It will not let you configure your own editor to replace view source. It now uses the Chromium engine. This restriction is a side effect of that choice.
• It sometimes gets the vertical positioning of text wrong.
• All the files are different.

Tips

• To check if there is a new version and automatically install it if there is one, click Opera ⇒ About Opera.
• To stop Opera from running the pages it was rendering when it crashed, start it up with opera.exe -nosession
• If your big O disappears from the top left corner, bring it by unchecking show menu in the File menu. This will simultaneously hide the menu tool bar. The expected ways to get this result will not work.
• You can jump to the address bar where you key in URLs (Uniform Resource Locators) with Alt-D.
• Configure your personal information in Tools ⇒ Preferences ⇒ Forms. Then you can rapidly fill in web forms with right click on each field.
• To search for something in Google type g xxxx on the address bar. This will give you plenty of room to type. To search the Wikipedia, type w xxxx on the address bar.
• If you don’t search history content (as opposed to looking at the history URLs ), you can speed opera up by clicking Opera ⇒ settings ⇒ preferences ⇒ advanced ⇒ History ⇒ untick remember content on visited pages.
• Opera refers to the home page as the start page. It uses a cryptic icon that looks like this .
• Opera 20 stores its data in "C:\Users\user\AppData\Roaming\Opera Software\Opera Stable\Preferences." in a quite different format from earlier versions (Jason).

Certificates

Opera maintains its own list of SSL (Secure Sockets Layer) root certificates independent of Windows. You can manage it with:

1. Click menu.
2. Click settings.
3. On the left, click Privacy and Security.
4. Under HTTPS/SSL click manage certificates.

Gotchas

• With Opera version 20, many familiar features have disappeared or are seriously hiding. Opera threw away its engine and wrote a new browser with a shell wrapped around the Chrome engine.

  • All the pages and pages of configuration have been replaced by three pages.
  • You can no longer configure your favourite editor for view source. The default one is a pure viewer.
  • There is no way to configure associations (I am happy that it use the system associations).
  • There is no way to configure which bars and panels you want to see.
  • There is no way to configure your suite of search engines.
  • There is no way to configure different behaviour for different web sites.
  • The newsreaders and mailreaders are gone.
  • The news.opera.com newsserver is gone.
  • The forums have gone where you used to be able to ask questions.
• Opera has recently revamped the user interface in a major way. Help has almost nothing in its index to help you figure out if a given feature has just moved, or been eliminated.
• The Canadian government income tax websites refuse to work with it.
• Opera often cannot access the printer with print selection. I have this problem both with local and remote printers. Firefox and IE (Internet Explorer) have no problem.
• Opera is not a good tool to proofread images because it does not reload images, even if they are changed on disk. To see the new version of an image, you must stop and restart Opera.
• Opera caches the results of redirects. If you watch it with Wireshark, it goes directly to the new URL (Uniform Resource Locator). This can be confusing if you are trying to trace the redirect process.

Bugs

• The trick to configuring view source is to set up as association with *.txt files to you favourite editor outside Opera. Then in Opera configure your source browser to use the default editor. Trying to configure Opera to use your editor directly does not work. Further, it ignores the editor association on *.html files.
• The main bug prior to Vista, was hitting view source sometimes does nothing. You have to click reload or clear cache or failing that restart to get it working again.

• browser colgroup support

  Browser Colgroup Support
  browser	version	col class supported	col align supported	HTML5 entities supported
  Firefox	59.0.3
  Chrome	53.0.2785.92
  Opera	48.0.2685.52
  SeaMonkey	2.49.2
  Safari	5.1.7
  Avant	2018:1
  Edge	25,10586.0.0
  IE 11	11.0.9600.17239
  IE 10	10.02.9200.16521
  IE 9	9.0.8112.16421
  IE 8	8.0.7601.17514
  IE 7	7.0.6000

  Those browsers marked with an x all have a bug. They will not render <col class="xxxx">s correctly. The ones with a tick render it correctly. The Opera people say this is a feature not a bug. The language lawyers claim the W3 spec says that the browser is supposed to ignore the color attribute from the <col class. Logically, I think the <col styles should apply to the entire column, but not to <th rows. In addition Firefox, SeaMonkey, Safari and Flock also ignore the <col align attribute. Opera and IE render it properly.

  Firefox, SeaMonkey and Opera support almost all the HTML5 entities. Chrome and Safari support many of them.

  colgroup test

  Colgroup Test
  	Style Test	Alignment Test
  On Every row	style	alignment
  Using Colgroup	style	alignment

  If both cells in the left hand Style Test column are the same colour, then your browser (the one you are using now to view this page) supports <col class=.

  If both cells in the right hand Alignment Test column right-align, then your browser supports <col align= correctly.

  Dreamweaver lets you apply a css style to all rows individually. Last revised/verified: 2018-05-06

Pet Tricks

Opera has an optional turbo mode. You can try it out to see if it speeds things up. It will help most if your Internet connection is very slow. It works by caching the web pages you visit on the Opera server and relaying them to you compressed and encrypted. You can turn the feature on and off with the Opera turbo toggle in the main menu.

DDE (Dynamic Data Exchange)