Tuesday, February 26, 2013

A Fat Stack of Bodhi Linux

When I first started preparing Bodhi ISO images almost two and a half years ago I set out with the goal of providing a clutter free operating system powered by the latest Enlightenment desktop. We call what we do "minimalist" meaning it doesn't come with a whole lot by default. This ideology isn't for everyone, though. Thankfully, the power of choice is something that greatly empowers free software development.

Today, I would like to offer a bit more choice for Bodhi users. I would like to share with you all my "friends and family" version of Bodhi Linux. You can grab the ISO image for this fat stack of Bodhi on source forge here. I call it my "friends and family" disc because when I am pressed for time I can't always sit down and install all the extra software "normal" people need to use their PC. This image allows me to skip the installing software step after I install the operating system.

This ISO image is something I've been working on and using as an install media for my non-personal systems for awhile now and I think it is finally in a state that I am happy sharing it. It is simply a Bodhi 2.x branch live/install CD powered by a Linux 3.5 kernel and the latest E17.1 Enlightenment desktop. It comes with a bunch of software pre-installed that should keep most people happy:

This is a 32bit disc image and no I will not be preparing a similar 64bit disc. I intend this disc for home systems, for which I recommend 32bit operating systems. Users installing from this disc can get support on the Bodhi Forums just as if they had installed from the normal disc.

~Jeff Hoogland

Saturday, February 16, 2013

Comparison of Linux Desktops OpenGL Performance

With Steam officially being released for Linux I took some time out this evening to run a few benchmarks on my Ubuntu 12.04 based Bodhi system to see how a few of the different modern Linux desktops compare in terms of OpenGL performance with the source engine. Please do not take my numbers to be anything super scientific or precise. I simply recorded a short demo using Team Fortress 2, loaded TF2 from Steam under each of the Linux desktops with no other background applications running and ran the demo through a built in source engine bench marking tool.

The benchmarks were run on my very modest gaming laptop which sports an i7 processor, 6GB of RAM, and an nVidia 330m GT graphics card. I utilized the Steam recommended nVidia 310 driver for these tests. All the desktop setups I used were "stock" from the Ubuntu 12.04 repos, minus E17 which is using the E17.1 snapshot and Bodhi's laptop profile with compositing enabled.

Lets get right to the data shall we? You all love charts I hope!

It is clear from the bar graph that E17 came out towards the top and Gnome Shell was near the bottom. Here are the numbers to a single decimal place:
  • Gnome Shell - 51.5 FPS
  • KDE   - 55.0 FPS
  • XFCE - 55.7 FPS
  • Unity  - 60.5 FPS
  • KDE, Disable Compositing on Full Screen - 63.2 FPS
  • LXDE - 66.5 FPS
  • E17     - 66.7 FPS
I was not surprised when I saw E17 and LXDE had the best performance, they are after all some of the best light desktops today. What did shock me though was that XFCE - which claims to be fairly light - was very low in terms of performance! 

Based on the above numbers XFCE performed around 17% slower than both LXDE and E17, while Unity was around 9% slower than the lighter desktops, and Gnome Shell was a staggering 23% behind.  One other thing worth noting is that KDE has a HUGE performance difference when you check the "disable compositing on full screen applications" box in your Kwin settings. In fact ignoring this setting loses you around 13% in performance:

Obviously someone should run some further tests (I know I plan to when I get some more time), but from my initial small test it is obvious - if you are looking to game on Linux your choice of desktop very clearly matters!

~Jeff Hoogland

Friday, February 1, 2013

Tutorial 2: ELM Images, File Selector and Popups

This is the second post in my series on developing GUI applications in Elementary using Python. Today we are going to continue building on the Hello Elementary example I started in the first tutorial. In today's post I will only be covering the code that is different from our previous examples, so if you haven't looked that one over yet please take a moment to do so now.

You can find the full source code for all of today's examples here.

Example 3:
We are going to start off by displaying a static, pre-defined image in our GUI:

It only takes us 8 lines of actual code to create and display the above image in our program:

    #Creates an Image object that displays an image
    ic = elementary.Image(window)

    #Use the os module to get the current path to our .py file. Our image is relative to our .py We do this because it is best to use the absolute file path to images for the best results.
    location = os.path.dirname(os.path.abspath(__file__))

    #Tell our icon to auto-fill open space
    ic.size_hint_weight_set(evas.EVAS_HINT_EXPAND, evas.EVAS_HINT_EXPAND)
    ic.size_hint_align_set(evas.EVAS_HINT_FILL, evas.EVAS_HINT_FILL)

    #Here we set the image we want our icon to display

    #Optional, lets add mouse over text to our image
    ic.tooltip_text_set("Look a pretty picture!")

    #Lets show our icon

    #Pack our icon between our text and button

In this example we utilize the elementary Image object to display our selected .png file.

Example 4:
Very rarely do we want to simply display a single image for as long as our program is running. So lets give the user the ability to change the image we display in our program:

Elementary has a built in FileselectorButton object that when clicked presents our user with a nice file selector GUI:

The new code to add this file selector button looks like:

    #Creates a "FileselectorButton" object. This is a button (just like we have created before) except that when it is click it automatically opens a file selector window
    fsb = elementary.FileselectorButton(window)

    #We can set the text of our fsb just like a normal button text
    fsb.text = "Change Image"

    #Tooltip for mouse over
    fsb.tooltip_text_set("Click Me!")

    #This tells our file selector window what to do when our user selects a file. The first argument is the callback function we want run and our second argument is our image object we want to change the display of
    fsb.callback_file_chosen_add(change_image, ic)

    #Show our button

    #Pack our file selector button between our image and button




#Our fileselector callback. The file argument is the fileselectbutton object. The second argument is the full path to the file that was selected. The final argument is the image object we passed to this callback
def change_image(fsb, file_selected, image):
    #Check to make sure a file of some sort was selected. If nothing was selected file_selected will equal None type
    if file_selected:
        #These are the extensions we will allow our program to display
        validExtensions = [".png", ".jpg", ".gif"]

        #Use the os module to easily get the extension of our file
        fileName, fileExtension = os.path.splitext(file_selected)

        #If the extension is in our validExtenions lets check the image we are displaying!
        if fileExtension in validExtensions:

Example 5:
Lets add one finishing touch to our application. If our user selects a file to display that doesn't have a valid image extension lets send them a popup telling them why the image displayed wasn't changed:

Showing a popup of this nature is fairly easy using elementary's Popup object. So the final edit to our code looks like this:

#This time we also pass the window object to our change image function. The reason for this is that our popup object needs a parent window object
def change_image(fsb, file_selected, image, window):
    if file_selected:
        validExtensions = [".png", ".jpg", ".gif"]

        fileName, fileExtension = os.path.splitext(file_selected)

        if fileExtension in validExtensions:
            #if we have an invalid extension lets give the user a popup message telling them why the image didn't change

            #Create a popup message
            popup = elementary.Popup(window)

            #Set the title of our popup
            popup.part_text_set("title,text", "Invalid File Extension")

            #Set the text of our popup
            popup.text = "File %s has an invalid file extension of %s"%(fileName, fileExtension)

            #Create a button object
            bt = elementary.Button(window)

            #Set it's text
            bt.text = "OK"

            #Define a callback that is called when the button is clicked, lets pass our popup object to this call back so we can close the popup when the user presses OK
            bt.callback_clicked_add(bnt_close, popup)

            #Sets content for our popup. The first argument is an arbitrary name for the content piece and the second argument is the elementary object you would like displayed for the content
            popup.part_content_set("button1", bt)

            #Show the popup to our user

#The callback for our popup's OK button. The first agurment is the button object itself and the second object is the popup we passed to it
def bnt_close(bt, popup):
    #Lets delete the popup so it goes away

Hope everyone learned something today! Have any questions feel free to drop a comment below or start a discussion on our user boards.

Resources for this Lesson:
~Jeff Hoogland