Mindtree Osmosis 2007: An external view

 

 

Last weekend, I attended Mindtree’s annual tech fest, Osmosis. This year they had organized the fest in the unconference style. To quote from their site

“To foster greater participation and to cut through the air of formality, Osmosis 2007 has adopted the “unconference” mode. Unconference merges the distinction between the speaker and the audience, and everyone is a participant.”

Also, this year they opened the doors for external participants, which is why I could attend it. My brother invited me over and we both had a lot of fun, to say the least.

The day began with a talk by Ashok Soota, Chairman of Mindtree. This talk itself was in unconference style. Soota spoke for a few minutes and left the ground open for participants to ask him questions. After the short and sweet talk, unconference sessions began.

The first session I attended had a rather controversial title ‘Are software engineers getting extinct?‘ With great minds like Bagchi, Soota, KK, Partha, Kamran, Desmukh in the room, speakers had a tough time controlling the audience. The argument was basically that the magic of software industry is fading, and with automation being the talk of the town, software might become extinct. The session saw some good participation from the audience.

Twitter session caught my attention next. This session was like an introduction to twitter and micro-blogging. It was not very useful for me because I knew about twitter beforehand. This was more like one-way information flow, there was not much to argue or discuss, so no heated debate here.

I and my Project Manager was the next session which me and my brother wanted to attend. But by the time we reached the room, it was so jam packed, we didn’t have place even to stand. We got to rest our minds for half an hour before breaking for lunch. There was live music by MAG, Mindtree’s very own musical band and they belted out some good numbers.

Post lunch, it was the much awaited session on Google’s Android. It was meant to be an introductory session on Google’s mobile OS and SDK, but the session veered to the debate mode when one person decided to argue about every point the speakers made. The speakers were not prepared for this and it was clearly evident. Some good points made by Mindtree minds about why we need Android at all and why open source is scary!

Another controversial topic – Innovation. After being fed up of the ‘compulsary innovation’ at my organization, I was hoping this session will help in venting out the frustration. Sigh, it only added to it. I saw the same attitude in Mindtree too. People who belong to the innovation team are all ga-ga over it and always inspiring (read as forcing) people to think out of the box and innovate, whereas the rest of the world is fed up of it and cringe whenever they hear the word innovation. We had some good argument about what is an idea, an innovation and an invention.

This was followed by the grilling session of CTOs Vinod Desmukh, CTO of R&D Services and Kamran Ozair, CTO of IT Services. The two minds were bombarded with questions collected previously from Mindtree minds. There were some interesting questions and both of them handled it really well. This session gave a glimpse of how strong both of them are in their respective domains. I was floored.

Mr. Bagchi took over next and gave a totally different speech. The Bagchi on stage was completely different from what I had imagined him to be. The T-shirt clad bald man on stage cracking jokes on his colleagues and sometimes being not so politically right was different from the man who I had seen through his columns in TOI. With this the unconference session came to an end.

This was the first time I attended a fest in this format and honestly, I didn’t know what to expect. The moment I stepped into the conference hall, I knew I was going to like it. The atmosphere was electric and the attitude, contagious. When so many great minds (read as nerds) come together and discuss their passion, how can it be not good? It was a pity to see some girls touching and re-touching their make-ups in rest rooms when such serious debate was going behind closed doors. Apparently some people turned up to have fun in a different way.

The whole thing was organized very well. Every session started on time and ended on time – it is mind boggling to even imagine how this was achieved. Facilities like lunch, coffee, tea, handouts, badges – everything was in its place. As an external participant, I was awed! And I was told the whole credit goes to Shahnawaz Khan. Special thanks to him – he does make it look so easy. The standing ovation he got at the end of the day just goes on to say how much hard work and effort he had put in.

As an external participant, I am in awe of Mindtree. To try something like this and to let outsiders attend, takes a lot of guts. Mindtree took the plunge and came out victorious. I enjoyed every moment of it and this weekend was one of the very few weekends which I consider well spent. Now that the unconference is over, I wish it comes around soon. I can’t wait to attend Osmosis 2008.

Datagridview: Get SelectedIndex of DataGridViewComboBoxColumn

This seems to be a straight forward thing, but Microsoft only knows why this simple feature is not supported in DataGridView.

If you have a ComboBoxColumn in your DataGridView and you want to know what is the selected index of the combo box, then you need to do this:

1. Handle the EditingControlShowing event of DataGridView. In this event handler, check if the current column is of our interest. Then we create a temporary ComboBox object and get the selected index:

private void dataGridView1_EditingControlShowing(object sender,
DataGridViewEditingControlShowingEventArgs e)
{
if (dataGridView1.CurrentCell.ColumnIndex == 0)
{
// Check box column
ComboBox comboBox = e.Control as ComboBox;
comboBox.SelectedIndexChanged += new EventHandler(comboBox_SelectedIndexChanged);
}
}

void comboBox_SelectedIndexChanged(object sender, EventArgs e)
{
int selectedIndex = ((ComboBox)sender).SelectedIndex;
MessageBox.Show("Selected Index = " + selectedIndex);
}

A rather round-about solution where a simple one would have sufficed.

Right click on TreeView: Get the node clicked at

Problem:

There is a TreeView control with n number of nodes. When the user right clicks on the TreeView control, get the node on which the right click was performed.

Background:

In TreeView control, SelectedNode property is set whenever left click occurs. This is not true for right clicks. So, we need to have some workaround for this.

Solution 1:

The most popular solution is to handle the MouseDown event. Check if the click was a right click and then use the TreeView control’s GetNodeAt API to get the node which was clicked at.

private void treeView1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
TreeNode selectedNode = treeView1.GetNodeAt(e.X, e.Y);
MessageBox.Show("You clicked on node: " + selectedNode.Text);
}
}

Solution 2:

Handle the NodeMouseClick event. The TreeNodeMouseClickEventArgs has the node which was clicked at.

private void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
MessageBox.Show("You clicked on node: " + e.Node.Text, "Solution 2");
}
}

SelectedNode property of a treeview is set whenever a left click occurs. Why can’t the same be applied for right click? Right click on a treeview is such a common UI event, that users will benefit from it.

Removing items in a list while iterating through it

See the following code:

List list = new List();

for (int i = 1; i < 10; i++) { list.Add(i); } foreach (int i in list) { list.Remove(i); } [/source] Do you see anything wrong in this piece of code? No? Okay. Execute this code and you will get a System.InvalidOperationException with the message “Collection was modified; enumeration operation may not execute.”

The first time foreach loop executes, it deletes the first item and in the second iteration, this nasty exception is thrown. Reason? You deleted the first item and the list has changed. If not for the InvalidOperationException , you could have got a IndexOutOfRange exception while traversing the list.

So, how does one delete some items in the list while iterating through the list? I faced this problem in my project today and I couldn’t come up with an elegant solution. I did come up with a hack. I identify all items that need to be deleted and mark them with a flag (I need one iteration here). In another iteration, I create a new list and copy all those items which are not marked.

Sorry, I couldn’t come up with something better. If you have a solution or a better fix, please do let me know. Please note that if I want to remove all items, I can use list.Clear(). I am talking about a scenario where I want to delete only a select few items.

Update:

I read somewhere that if you use for loop instead of foreach, this problem does not arise. True, you will not get an exception, but you might not delete the items that you actually want to delete. Let’s see what happens in our case.

List list = new List();

for (int i = 1; i < 10; i++) { list.Add(i); } for (int i = 0; i < list.Count; i++) { int remove = list[i]; list.Remove(remove); } [/source] You will delete items 1, 3, 5, 7 and 9. After the for loop exits, your list will still have 2, 4, 6 and 8. Surprised? Let's see why this is so. First iteration: i = 0, remove = 1. Deleted item = 1 Once you delete this item, the list has changed. So, the first element in the list is now 2.
Second iteration: i = 1, remove = 3. Deleted item = 3
Third iteration: i = 2, remove = 5. Deleted item = 5

and so on….

So, replacing foreach with a for is not a solution.

Using App.Config for user defined runtime parameters

These are the steps involved in defining runtime parameters and using them in your code.

1. Create a App.Config file
2. Define the runtime parameters and provide values for these
3. Access these parameters in your code
4. Verify changing the parameter value at runtime affects the application

Step 1: Create App.Config file

1a. Create a Console Application
1b. In Solution Explorer, right click on project. Add->New Item. Select Application Configuration file. This file will be added to your project.

Step 2: Define the runtime parameters and provide values for these

2a. Open App.Config.
2b. Define the keys and values for your runtime parameters.

Example:

<configuration>
<appSettings>
<add key="OperatorName" value="Rita"></add>
<add key="LoggerLevel" value="5"></add>
</appSettings>
</configuration>

You can define any key and provide values. Ensure you don’t have duplicate keys.

Step 3: Access these parameters in your code

3a. Add a refernce System.Configuration DLL.¹
3b. Add the following lines in your code. You can directly add these lines in Main.

string name = System.Configuration.ConfigurationManager.AppSettings["OperatorName"];
Console.Writeline("Welcome " + name);
string level = System.Configuration.ConfigurationManager.AppSettings["LoggerLevel"];

Console.Writeline("Logger level: " + level);

3c. Build your project and execute it.The output should be:

Welcome Rita
Logger level: 5

Step 4: Verify changing the parameter value at runtime affects the application

4a. When you build your project, the App.Config file is copied to your Debug/Release folder with the name .exe.config. My project is named UseAppConfig. The App.Config in my Debug folder is UseAppConfig.exe.config

Open the .config file in your working directory (Debug/Release). Change the values to Mary and 1. In the same folder you will see your executbale. Double click on this and you should see the new values.²

You are all set. You can identify all those parameters that make sense as runtime parameters, define a meaningful key for each parameter and start using it. You no longer have to build your application every time you want to change the parameter value.

Notes

1: You need this reference only if you are using .NET 2.0
2: If you change the App.Config from Visual Studio IDE, then you need to rebuild your project to see the new values.

Ever heard of birthday blues?

It was my friend’s birthday yesterday. As usual, I didn’t realize it until he came up to me with a stretched out hand and said, “Today is my birthday. Wish me.” This rarely happens with me. My friends very well know I don’t care about birthdays and hence don’t bother to remember dates. My good friends don’t expect any wish from me and they move on as if nothing happened. My other category of friends (politically correct word for ‘bad’) know that I don’t remember their birthdays, and don’t remind me about it, but they still expect me to wish them, as if I will remember it all of a sudden.

Why is there an inherent assumption that you are good friends only if you remember each other’s important dates? I have never wished my best friend on her birthday. Does that mean I am not her friend? Knowing me, she doesn’t care – she just ignores this tiny incident (or the absence of it). Why is it so difficult for people to get this? If it is your birthday, you have all the right to celebrate your feat of burdening this world and its inhabitants with your existence. I might not appreciate it enough to participate in your celebrations. Okay? Good.

Why is it that every birthday comes attached with this custom of giving gifts? I hate it when someone gives me a gift. I am obligated to reciprocate and buy something equally aweful (if I can’t find something more awful) for them. Why not do away with this ritual? For all those who know me, if you give me a gift, don’t expect the same from me. I might not even remember about your gift the next day, forget remembering it till your birthday!

Another annoying thing is ‘treat’. ‘Treat me because it’s your birthday’. Either that or get loads of sweets so that your friends can gorge on it. This is being on the other side of the fence. Why do you assume I am celebrating this day and even if I am celebrating, what makes you think I want to include you in that?

Something which I was not aware of until recently: face painting. For ignorant people like me, face painting refers to that vulgar act of smearing the birthday boy’s (or girl’s) face with cream taken off the cake. This is the silliest of the lot. First off, it’s cream – it’s edible, don’t waste it. Think of all those people who don’t have a square meal in months and here you squander because you want to have fun. Secondly, these things shouldn’t be done in your workplace. Heard of the word professionalism? Bet you haven’t. Third point, of course, is to follow this ritual for every soul in your team. Ask the poor guy if he wants to celebrate his birthday at all?

Sun signs. They are side-effects of birthdays, right? What on earth can you find out about a person by knowing his/her sun sign? Oh you are a Taurian? oh good… we will get along well. You are a scorpion? I better stay away from you. This is more prevalent among the fair skinned species. I mean, give me a break! You choose friends depending on their sun signs?

With all these qualms I have, I cringe whenever someone asks me about my birthday. I have decided I am going to say ‘February 29’. Yeah, I thought of February 30th, but some people are actually smart enough to see through this trick. February 29th it is. That way, I have to endure only one fourth of this torture.

Disable Close button in Windows form

To disable that little close button in your Windows form, either you can set the ControlBox field in Properties window to False or or add this two line in the contructor:

this.ControlBox = false;

Same goes for Maximize and Minimize boxes. Set it using Properties window or add these lines:

this.MaximizeBox = false;
this.MinimizeBox = false;

Simple, huh?

Setting up Darwin Streaming Server – Part 2

Part 1 can be found here.

Darwin Streaming Server documentation states that the video clips that need to be streamed should be under the Movies folder. This, on Windows, is C:\Program Files\Darwin Streaming Server\Movies. When the server receives a RTSP request for a video clip, it checks this folder for that file. What is not documented is that the server looks recursively under the sub-folders for the requested video clip.

So, if you have folders like Songs, FunnyVideos etc. under Movies folder, Darwin server will be able to stream all video clips under these sub-folders. Catch: These sub-folders should not contain spaces! If a sub-folder ‘Funny Videos’ is present under Movies folder and you request for a file which is under ‘Funny Videos’, Darwin server will return a 404 Not Found error.

I wonder why this is not included in Darwin Streaming Server documentation.

Main Form loses focus

Apologies if this post comes across as naive. I recently put my foot into the Windows Forms world and I have been learning new things. This might be a problem which all GUI programmers have encountered on day one and also know the solution to it. This post is to those souls like me who make a late entry into this magical world and seem to get lost, err… lose focus.

Problem:

We have a main form called MainForm. Whenever the user clicks a button on this MainForm, a method Copy in a class HelperClass is called. This method Copy uses the kernel call FileSystem.CopyFile to carry out the copying. One reason to use the kernel call is you need not re-write the progress bar and cancel features, just reuse the features provided by the kernel call. This will display the standard Windows file copying dialog with a cancel button.

The problem is, whenever you click Cancel on the file copying dialog, the MainForm loses focus.

Solution:

Since we are using the file copying dialog provided by the kernel, we have no access to the dialog directly. Hence, we cannot set the MainForm as the owner of the file copying dialog.

The solution to this problem is, in MainForm, right after we make a call to Copy method, set the focus back to MainForm.

    Copy(source, destination);
this.Focus();

Problem solved.

How to setup Darwin Streaming Server on Windows

PS: Part 2 of this article can be found here.

What is Darwin Streaming Server?

Darwin Streaming Server is an open source, free to use streaming server from Apple. The commercial version of this server is the Quick Time Streaming Server.

Where do I get it from?

The Darwin streaming server source code can be downloaded here. You need an Apple ID for this. Registration is free – go get an Apple ID for yourself.

How do I install?

Once you download the source code, you will see a install.bat in the root directory. Just double click on it and the batch file will copy the necessary files under C:\Program Files\Darwin Streaming Server. This is all the installation required.

How do I start streaming?

Along with the source code, Apple ships a few sample video clips which are ready to be streamed. All these video clips are under the C:\Program Files\Darwin Streaming Server\Movies folder. You can stream any of these video clips and view it on a player. Open up a command prompt. Go to C:\Program Files\Darwin Streaming Server and start Darwin server by typing DarwinStreamingServer.exe -d. If all is fine, you will get some INFO messages and a message that says ‘Streaming Server done starting up’. This means the server is up and ready to accept client connections.

If you get an error something like ‘WARNING: Another process is already using the following RTSP port: 554’, then the Darwin Service is already running in the background and you don’t have to start the server explicitly.

Your server is ready and all set to stream.

How do I connect using a player?

VLC Player: File->Open Network Stream. Select RTSP and give the URL as rtsp://localhost:554/sample_100kbit.mp4

QuickTime player: File->Open URL. Give the URL as rtsp://localhost:554/sample_100kbit.mp4

If all is fine, you should see an animated ‘Q’ – logo of Quick Time.

More info?

Google is of course there.

Administrator’s guide.

FAQ.

Darwin users mailing list.