Daniel 'MaTachi' Jonsson

Category Archives: Firefox

Firefox is Getting Slow and Uses Much Memory? Check This!

I read an interesting Mozilla page about zombie compartments:

Basically it’s allocated JavaScript memory for pages that wasn’t released when the pages were closed. Apparently these zombie compartments can be caused by poorly written add-ons and userscripts. If you visit about:compartments and see compartments for sites you have closed, you have zombie compartments.

To solve this, you can start by open Firefox in safe mode and see if the problem persist. If it doesn’t, enable the add-ons one after another to pinpoint which one is causing the memory leak.

Make Screenshots of Whole Web Pages Without an Extension

Mozilla has added a Command Line for developers to Firefox Nightly and Aurora. To activate it, do the following steps:

  1. Go to about:config.
  2. Search for devtools.toolbar.enable and double-click to enable that.
  3. Restart the browser.
  4. Press Ctrl + Shift + V to open the developer toolbar with the command line.

(I suppose it will be enabled and available on the Tools menu by default in Firefox 16 – 17.)

With this command line, you can make a screenshot of a whole web page by typing:

screenshot filename.png 0 true

How to Enable Incompatible Firefox Add-ons

If you regularly use Firefox Aurora and Firefox Nightly it happens once in a while that add-ons become marked as incompatible. To enable those add-ons, follow these steps:

  1. Install the add-on Nightly Tester Tools (you don’t have to run Firefox Nightly to use it) and restart the browser.
  2. Now click the menu option Force Addon Compatibility under Tools > Nightly Tester Tools.
  3. Restart the browser and you should be able to enable the add-ons that earlier were incompatible.

YouTube Now Playing Notifications Firefox Add-on

I just got my very first self-made Firefox add-on approved on AMO (https://addons.mozilla.org). It’s a simple add-on that shows a notification in the operating system when a YouTube video starts playing. Maybe a bit pointless if you are watching videos, but it may be useful if you are using YouTube to listen to music in the background. It’s called YouTube – Now Playing Notifications and can be found here:

As I said, this is my very first add-on, and I must say that I really like Mozilla’s developer tools. Developing an add-on with their add-on SDK is really easy and it’s also really easy to upload add-ons to AMO.

How to Fix Ugly Japanese Fonts in Firefox

The other day I took and reinstalled Ubuntu on my computer. So now I’m running 12.04, and I have to say that it’s a really nice OS.

Anyway, in Firefox I encountered an ugly Japanese font on some pages. It looked like an old/jagged serif font. However, on some other pages it looked much better and modern.

After looking around I finally managed to fix that ugly font problem by doing these steps:

  1. Open Firefox’s Preferences window.
  2. Select the Content tab.
  3. Click on the “Advanced…” button under “Fonts & Colors”.
  4. A new window appears with the title Fonts.
  5. Select Japanese in the “Fonts for:” drop-down list.
  6. Select “sans-serif” in the “Serif:” drop-down list.
  7. Finally close the window by clicking the OK button and you are done.

Disable Add-on Compatibility Checking In Firefox 7.0a1 Nightly

I just updated my Firefox installation under Linux Mint 10, so now I’m apparently using Firefox 7. Can’t say that I have seen anything new from what is in the Firefox 5 beta, but whatever.

Because I updated Firefox it disabled all my add-ons, as usually. To get them working again in Firefox 7.0a1, follow these steps:

  1. Open a new tab.
  2. Type about:config in the address bar.
  3. Right click anywhere on the page and click on Boolean under New.
  4. Enter this as the preference name: extensions.checkCompatibility.nightly
  5. Click OK.
  6. Choose false and then click OK again.
  7. Restart your browser and all your add-ons should be runnable again.

Since we don’t have to type in the version number in the preference name any longer (extensions.checkCompatibility.XXX), I suppose that we won’t need to update this in future versions of Firefox.

Change Back Google Search in Linux Mint

Apparently has the dudes behind Linux Mint decided that they want their own Google search engine in Firefox, which lacks many functions. Here follows some steps you shall take to change it back to the default search page:

  1. Open a terminal window.
  2. Type these lines after one another: 
    cd /usr/share/linuxmint/common/artwork/firefox/
sudo wget http://mxr.mozilla.org/firefox/source/browser/locales/en-US/searchplugins/google.xml?raw=1 -O google.xml.fixed
sudo mv google.xml google.xml.orig
sudo mv google.xml.fixed google.xml
sudo cp google.xml /usr/lib/firefox-addons/searchplugins/en-US/google.xml
  3. Maybe you have to restart Firefox now.

I found this solution on the Linux Mint forum: http://forums.linuxmint.com/viewtopic.php?f=29&t=17438

Disable “click selects all” in Firefox for Ubuntu

Anime Girl FirefoxIn Firefox for Windows, you are able to double click a segment of the URL in the address field to select it. By default, this isn’t possible in Firefox for Ubuntu, instead selects a single click the whole address. Luckily, this is easy to change, which you can do by following these steps:

  1. Open a new tab.
  2. Type about:config in the address bar.
  3. Press the I’will be careful, I promise! button.
  4. Type selects in the filter field.
  5. Change the browser.urlbar.clickSelectsAll entry to false by double clicking on the row.
  6. Do the same as above with the browser.urlbar.doubleClickSelectsAll, and make sure both are false.
  7. Done!

How to Fix Flickering Flash Videos in Firefox 4 in Ubuntu 64-bit

For long I have been having problem with flickering flash videos in the Firefox 4 beta in Ubuntu 10.10 64-bit. Today I found a solution, and I have no longer any reason to use Chrome. :)

It seems that the problem with flickering flash videos only occurs with Adobe Flash Player 10.1. So, by installing the beta 10.3 of Flash Player, the problem is now long gone.

I don’t know how you install the Flash beta in the 32-bit version of Ubuntu. But in the 64-bit version you just need to type these lines in the terminal:

sudo add-apt-repository ppa:sevenmachines/flash
sudo apt-get update
sudo apt-get install flashplugin64-installer

I hope this solution works for you guys!

Firefox Add-on of the Week: Custom Tab Width

Custom Tab WidthI don’t know why it doesn’t work to edit the tab width by editing the following two preferences in about:config in Firefox 4 Beta 4:

browser.tabs.tabMaxWidth
browser.tabs.tabMinWidth

But I found the add-on Custom Tab Width that does the job! The strange thing is that it looks like the add-on changes those two preferences, and that apparently works. I guess that the add-on edits something more… But it works!