How to handle data from an external program on Mac OSx - c

I would like to make a program (I would prefer in C language) , but even in cocoa , that can take data from an external program (such as iTunes or adium) and will use them. For example i would like to take the data of a listbox or the text of the chat so as to manipulate it. I need a place to start. In windows I think it is possible with some apis that find the hWnd of a window and then find a pointer to the listbox or textbox. Please give me some info on how to start. Thanks you in advance.

It's not clear exactly what you want to do. It's either impossible or severely restricted.
For one thing, different applications use different ways of constructing a “listbox”—Cocoa applications use NSTableView, Carbon applications use DataBrowser, and GTK, Qt, and Java applications use even more different APIs. These do not all go through some common kind of list box thingy; each is an independent implementation.
(You could hope that either NSTableView or DataBrowser would be based on the other, but don't count on it.)
For another, it is impossible to obtain a pointer to that control. You cannot access another application's NSTableView or DataBrowser view or GTK/Qt/Java equivalent unless (and this only works for NSTableView) that application deliberately serves it up to you. It doesn't sound like that's your situation.
The closest you can get to that is Accessibility, which may be pretty close, but is unlikely to work with most applications not based on Cocoa.
Even then, the view may not be showing you all the data. A table view may be lazily populated, and a table view designed in imitation of the iOS UITableView may even never have all the data (because it only has what it can show).
(All of the above applies to every kind of view, not just table views. Collection views, text fields, buttons—same deal for all of them.)
The only way to get at the true, complete copy of the data is to ask the controller that owns it. And, again, that's impossible if the application is not specifically offering it to you. Not to mention, the application might not even have a controller (not object-oriented, not MVC, or just sloppily made).
… so as to manipulate it.
Getting the data in the first place is the easy part. It is nigh-impossible to mess with data in another application—for good reason.
The closest you're going to get to either of these goals is the Accessibility interfaces.

Related

Portlet event send array of objects

We have multiple projects with multiple portlets and need to send an array of objects between them.
Our situation:
One of the porlets is like a "Master-portlet", it will be responsible for all the REST-calls and consume json-data and parse it to Java-Objects.
All the other portlets will receive an array of objects and show them to the user.
Our thoughts and solution:
We wanted to implement this by sending arrays of objects trough events. One of the "smaller" portlets will send an event to the "Master-portlet" and the "Master-portlet" will then answer with a new event and send the right array of objects back.
Our problem:
We dont know how to send arrays of objects trough events. Is this even possible?
Also we are not sure if this is the right way to solve this. Are events ment to send a bigger amount of data?
Is there a better solution for our case? Maybe it would be better to implement a database and all the portlets get the information from there?
Consider portlet events (and portlets) the UI layer of your application. Based on this, judge if the amount of data that you send back and forth makes sense or not. Also, if you closely couple the portlets, you're just hiding the fact that they can only function together - at least a questionable idea. You rather want them to react to common circumstances (events), but not rely on a specific source of events (master portlet) being available.
That being said: The more complex the data is that you send as payload of a JSR-286 event, the easier you run into classloading problems in cases where your portlets are in different webapplications. If you restrict yourself to Java native types (e.g. String, Map, etc) you will omit problems with the classloader.
Typically you want to communicate changes to the current context (e.g. new "current customer" selected - and an identifier) but not all of the particular data (e.g. the new customer's name and order history). The rest of the data typically comes through the business layer anyway.
That's not to say that you absolutely must not couple your portlets - just that my preference is to rather have them very loosely coupled, so that I can add individual small portlets that replace those that I thought of yesterday.
If you have some time, I've covered a bit of this in a webinar last year, I hope that this adds some clarification where I was too vague in this quick answer.

Custom Hierarchy View-- NSTreeController or Not?

I have a hierarchy of stuff I want to display (at the same time) in both outline view and a custom view. Sort of analagous to the Buck and Yacktman (Cocoa Design Patterns) example in CH. 29, but with Outline instead of Table. I'll most likely have a detail view available also.
I've only used NSTreeController with a single outline view before. Now I have found that "arrangedObjects" aren't what one would like them to be. Also found that (for some reason) all the 'canInsert' and it's relatives have value NO (for some reason I can't find (or find with google)). So so far, it appears that NSTreeController is little help in coordinating my two views. (By the way, I've always had my add, delete functions work directly on the model in the past.)
it seems to me now it would be better and simpler to go back to using a data source approach, and use an architecture more like Buck and Yacktman's figure 29.4 (page 357) with a handmade mediating controller.
This has been hanging around for quite a while with no takers.
Just to close this out:
I've tried both NSTreeController and data source versions. Currently, I'm sticking with data source, since it seems to give me more flexibility.
-- The program I'm working on has been very much experimental, trying a number of different things. A secondary goal is to make an application I will find useful, and ternaryily :-) maybe make a cleaned up version for distribution.

Class between database and UI

I have a class that handles writing and reading data from my database. What is a proper name to call this class?
There are a couple of conventions. Assuming a Person model, you could use:
PersonDataAccessObject,
PersonDao,
PersonRepository,
PersonDataAccess,
...
It is also dependent on the technology you are using. I mean, who knows what conventions exist for the language you are using. Let us know what language and what data access framework and the answer may vary.
I used to append "Dao" because it's short and clear. But then I moved over more to Martin Fowler's vocabulary and patterns, so now I use Repository. A little more long winded, but I'm long winded by nature, so it fits my style. In the end, that's the key. It's stylistic and there is no across the board standard that I'm aware of. What's most important is that you pick something that is clear and you use it consistently. If you decide, later on, to switch to something else, have mercy on any programmers that may follow you and rename everything so that all your data access components are consistently named.
Edit: in rereading this, I realized I am assuming you are going to have multiple such classes, one for each of your model entities. Who knows what your setup is. If you aren't going to do it like that, and you're just looking for a standard name for a single point of entry to all data access, you could use:
DataMapper
Gateway
Typically, the assumption is that you are going to have several of these around, one for each of your "tables"/model entities. More than a naming convention, that is probably a standard coding convention. This way, when you change or add some aspect of how you interact with your "persons" table, you don't have to modify a class in which you have code to access the "addresses" table. Check out Martin Fowler's Patterns of Enterprise Application Architecture (PofEAA), for more
PofEAA catalog of patterns (check out Data Source Architectural Patterns
and
Domain Driven Design Quickly (free pdf) esp. Ch. 3
Depending on the entity this class represents it could be for example Person. Then you design a PersonViewModel which is passed to the GUI. So the Person you got from the database is mapped to a PersonViewModel which is passed to the UI layer for being shown under some form. The view model is just a representation of the domain model you fetched from the database and containing only the necessary information that you need to display on the given UI.

Using Flyweight Pattern in database-driven application

Can anyone please give me any example of situation in a database-driven application where I should use Flyweight pattern?
How can I know that, I should use flyweight pattern at a point in my application?
I have learned flyweight pattern. But not able to understand an appropriate place in my database-driven business applications to use it.
Except for a very specialized database application, the Flyweight might be used by your application, but probably not for any class that represents an entity which is persisted in your database. Flyweight is used when there otherwise might be a need for so many instantiations of a class that if you instantiated one every discrete time you needed it performance would suffer. So instead, you instantiate a much smaller number of them and reuse them for each required instance by just changing data values for each use. This would be useful in a situation where, for example, you might have to instantiate thousands of such classes each second, which is generally not the case for entities persisted in a database.
You should apply any pattern when it naturally suggests itself as a solution to a concrete problem - not go looking for places in your application where you can apply a given pattern.
Flyweight's purpose is to address memory issues, so it only makes sense to apply it after you have profiled an application and determined that you have a ton of identical instances.
Colors and Brushes from the Base Class Library come to mind as examples.
Since a very important part of Flyweight is that the shared implementation is immutable, good candidates in a data-driven application would be what Domain-Driven Design refers to as Value Objects - but it only becomes relevant if you have a lot of identical values.
[Not a DB guy so this is my best guess]
The real bonus to the flyweight pattern is that you can reuse data if you need to; Another example is word processing where ideally you would have an object per "character" in your document, but that wuld eat up way too much memory so the flyweight memory lets you only store one of each unique value that you need.
A second (and perhaps simplest) way to look at it is like object pooling, only you're pooling on a "per-field" level as opposed to a "per-object" level.
In fact, now that i think about it, it's not unlike using a (comparatively small) chunk of memory in c(++) so store some raw data which you do pointer manipulation to get stuff out of.
[See this wikpedia article].

Internationalizing Desktop App within a couple years... What should we do now?

So we are sure that we will be taking our product internationally and will eventually need to internationalize it. How much internationalizing would you recommend we do as we go along?
I guess in other words, is there any internationalization that is easy now but can be much worse if we let the code base mature and that won't slow us down very much if we choose to start doing it now?
Tech used: C#, WPF, WinForms
Prepare it now, before you write all the strings in the codebase itself.
Everything after now will be too late. It's now or never!
It's true that it is a bit of extra effort to prepare well now, but not doing it will end up being a lot more expensive.
If you won't follow all the guidelines in the links below, at least heed points 1,2 and 7 of the summary which are very cheap to do now and which cause the most pain afterwards in my experience.
Check these guidelines and see for yourself why it's better to start now and get everything prepared.
Developing world ready applications
Best practices for developing world ready applications
Little extract:
Move all localizable resources to separate resource-only DLLs. Localizable resources include user interface elements such as strings, error messages, dialog boxes, menus, and embedded object resources. (Moving the resources to a DLL afterwards will be a pain)
Do not hardcode strings or user interface resources. (If you don't prepare, you know you will hardcode strings)
Do not put nonlocalizable resources into the resource-only DLLs. This causes confusion for translators.
Do not use composite strings that are built at run time from concatenated phrases. Composite strings are difficult to localize because they often assume an English grammatical order that does not apply to all languages. (After the interface design, changing phrases gets harder)
Avoid ambiguous constructs such as "Empty Folder" where the strings can be translated differently depending on the grammatical roles of the strings' components. For example, "empty" can be either a verb or an adjective, and this can lead to different translations in languages such as Italian or French. (Same issue)
Avoid using images and icons that contain text in your application. They are expensive to localize. (Use text rendered over the image)
Allow plenty of room for the length of strings to expand in the user interface. In some languages, phrases can require 50-75 percent more space. (Same issue, if you don't plan for it now, redesign is more expensive)
Use the System.Resources.ResourceManager class to retrieve resources based on culture.
Use Microsoft Visual Studio .NET to create Windows Forms dialog boxes, so they can be localized using the Windows Forms Resource Editor (Winres.exe). Do not code Windows Forms dialog boxes by hand.
IMHO, to claim something is going to happens "in a few years" literally translates to "we hope one day" which really means "never". Although I would still skim over various tutorials to make sure you don't make any horrendous mistakes. Doing correct internationalization support now will mean less work in the future, and once you get use to it, it won't have any real affect on today's productivity. But if you can measure the goal in years, maybe it's not worth doing at all right now.
I have worked on two projects that did internationalization: a C# ASP.NET (existed before I joined the project) app and a PHP app (homebrewed my own method using a free Internationalization control and my own management app).
You should store all the text (labels, button text, etc etc) as data inside a database. Reference these with keys (I prefer to use the first 4 words, made uppercase, spaces converted to underscores and non alpha-numerics stripped out) and when you have a duplicate, append a number to the end. The benefit of this key method is the programmer has a pretty strong understanding of the content of the text just by looking at the key.
Write a utility to extract the data and build .NET resource files that you add into your project for compile. Create a separate resource file for each language. In your code, use the key to point to the proper entry.
I would skim over the MS documents on the subject:
http://www.microsoft.com/globaldev/getwr/dotneti18n.mspx
Some basic things to avoid:
never ever ever use translation software, hire a pro or an intern taking that language at a local college
never try to create text by appending two existing entries, because grammar differs greately in each language, this will never work. So if you have a string that says "Click" and want one that says "Click Now", do not try to create a setup that merges two entries, or during translation, copy the word for click and translate the word now. Treat every string as a totally new translation from scratch
I will add to store and manipulate string data as Unicode (NVARCHAR in MS SQL).
Some questions to think about…
How match can you afford to delay the shipment of the English version of your application to save a bit of cost internationalize later?
Will you still be trading if you don’t get the cash flow from shipping the English version quickly?
How will you get the UI right, if you don’t get feedback quickly from some customers about it?
How often will you rewrite the UI before you have to internationalize it?
Do you English customers wish to be able to customize strings in the UI, e.g. not everyone calls a “shipping note” the same think.
As a large part of the pain of internationalize is making sure you don’t break the English version, is automated system testing of the UI a better investment?
The only thing I think I will always do is: “Do not use composite strings that are built at run time from concatenated phrases” and if you do so, don’t spread the code that builds up the a single string over lots of methods.
Having your UI automatically resize (and layout) to cope with length of labels etc will save you lots of time over the years if you can do it cheaply. There a lots of 3rd party control sets for Windows Forms that lets you label text boxes etc without having to put the labels on as separate controls.
I just starting to internationalize a WinForms application, we hope to mostly be able to use the “name” of each control as the lookup key, without having to move lots into resource files etc. It is not always as hard as you think at first….
You could use NGettext.Wpf (it can be installed from NuGet, and yes I am the author, but I made it out of the frustrations listed in the other answers).
It is hosted this github repository, and here is the getting started section at the time of writing:
NGettext.Wpf is intended to work with dependency injection. You need to call the following at the entry point of your application:
NGettext.Wpf.CompositionRoot.Compose("ExampleDomainName");
The "ExampleDomainName" string is the domain name. This means that when the current culture is set to "da-DK" translations will be loaded from "Locale\da-DK\LC_MESSAGES\ExampleDomainName.mo" relative to where your WPF app is running (You must include the .mo files in your application and make sure they are copied to the output directory).
Now you can do something like this in XAML:
<Button CommandParameter="en-US"
Command="{StaticResource ChangeCultureCommand}"
Content="{wpf:Gettext English}" />
Which demonstrates two features of this library. The most important is the Gettext markup extension which will make sure the Content is set to the translation of "English" with respect to the current culture, and update it when the current culture is changed. The other feature it demonstrates is the ChangeCultureCommand which changes the current culture to the given culture, in this case "en-US".
I also highly recommend reading Preparing Strings from the gettext utilities manual.
Internationalization will let your product be usable in other countries, it's easy and should be done from the start (this way English speaking people all over the world can use your software), those 3 rules will get you most of the way there:
Support international characters - use only Unicode data types in files and databases.
Support international date, time and number formats - use CultureInfo.InvariantCulture when storing data to file or computer readable storage, use CultureInfo.CurrentCulture when displaying data or parsing user input, never do your own parsing, never use any other culture objects.
textual data entered by the user should be considered a black box, don't try to break it up into words or letters, especially when displaying it to the user - different languages have diffract rules and the OS knows how to display left-to-right text, you don't.
Localization is translating the software into different languages, this is difficult and expensive, a good start is to never hard code strings and never build sentences out of smaller strings.
If you use test data, use non-English (e.g.: Russian, Polish, Norwegian etc) strings.
Encoding peeks it's little ugly head at every corner. If not in your own libraries, then in external ones.
I personally favor Russian because although I don't speak a word Russian (despite my name's origin) it has foreign chars in it and it takes way more space then English and therefor tests your spacing too.
Don't know if that is something language specific, or just because our Russian translator likes verbose strings.

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