I am developing yet another bmi app and I want it to be useful also for Americans using non-SI units like foot and pound. But I don't like to add an extra button to switch between units. I would rather use the system settings to automate that. The class java.utils.locale seems to be useful. But how do I access that in my App Inventor program?
use the tools extension and its Country and/or Language method
Returns the country/region code of the current Locale, which should either be the empty string, an uppercase ISO 3166 2-letter code, or a UN M.49 3-digit code.
Returns the language code of the current Locale.
Full disclosure: I'm working on my libui GUI framework's text API. This wraps DirectWrite on Windows, Core Text on OS X, and Pango (which uses HarfBuzz for OpenType shaping) on other Unixes. One of the text formatting attributes I want to specify is a collection of OpenType features to use, which all three provide; DirectWrite's is IDWriteTypography.
Now, when you draw some text with these libraries, by default you'll get a few useful OpenType features enabled, such as the standard ligatures (liga) like the f+i ligature. I thought this was font-specific, but it turns out this is specific to the script of the text being shaped. Microsoft provides guidelines for all the scripts supported by OpenType (under "Script-specific Development"), and I can see rather complex logic for doing it all in HarfBuzz itself to confirm it.
On Core Text and Pango, if I enable other attributes, they'll be added on top of these defaults. But with DirectWrite, in particular IDWriteTextLayout::SetTypography(), doing so removes the defaults:
The program that produces this output is can be found here.
Obviously my first option would be to ask how to get the default features on DirectWrite. Someone did so already on this site, though, and the answer seems to be "no".
I am guessing that DirectWrite is allowing me to be in complete control of the list of features to apply to some text. This is nice, except that I can't do this with the other APIs unless I explicitly disable the default features somehow! Of course, I don't know if this list will ever change, so hardcoding it might not be the best idea.
Even if hardcoding is an option, I could just grab HarfBuzz's list for each script, but a) it's rather complicated b) there are multiple possible shapers for a script, depending on (I think) version compatibility (for instance, Myanmar).
So why not use HarfBuzz's lists to recreate the default list of features for DirectWrite anyway? It seems to want to be accurate to other shapers anyway, so this should work, right? Well I would need to do two things: figure out what script to use, and figure out which attributes to use on which characters for script where the position of a character in the word matters.
DirectWrite provides an interface IDWriteTextAnalyzer that provides facilities to perform shaping. I could use this, but it seems the script data is returned in a DWRITE_SCRIPT_ANALYSIS structure, and the description for the script ID says "The zero-based index representation of writing system script.".
This doesn't help, so I wrote a program to just dump the script numbers for text I type in. Running it on the input string
لللللللللللللاااااااااالا abcd محمد ابن بطوطة Отложения датского яруса
yields the output
0 - 26 script 3 shapes 0
26 - 5 script 49 shapes 0
31 - 14 script 3 shapes 0
45 - 2 script 1 shapes 1
47 - 25 script 22 shapes 0
I cannot match these script numbers to anything in any of the Windows headers: if there is a defined number for Arabic, Latin, or Cyrillic in any API, they don't match these. And even if I did get a mapping between script and script number, that still doesn't give me the data to apply intra-word features.
What about Uniscribe? Well, the documentation for the equivalent SCRIPT_ANALYSIS type says that its script ID is an "[opaque] value" whose "value for this member is undefined and applications should not rely on its value being the same from one release to the next". And while I can get a language code to identify the script by, there's still no defined value other than LANG_ENGLISH for "Western" (Latin?) scripts. Are the DirectWrite values the same as the Uniscribe ones? And it seems like I can at least figure the initial and final states of words by looking at the fLinkBefore and fLinkAfter fields, but is this enough to properly apply attributes per-script?
HarfBuzz does have an experimental DirectWrite backend that isn't intended to be used by real programs; I'm not yet sure whether it has the same feature-clobbering I specified above. If I find out, I'll update this part here.
Finally, if I enter the following equivalent test case to the first one above in something like kaxaml:
<Page
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Grid>
<FlowDocumentPageViewer>
<FlowDocument FontFamily="Constantia" FontSize="48">
<Paragraph>
afford afire aflight 1/4<LineBreak/>
<Run Typography.Fraction="1">afford afire aflight 1/4</Run>
</Paragraph>
</FlowDocument>
</FlowDocumentPageViewer>
</Grid>
</Page>
I see the ligatures being applied properly, even in the latter case:
(The fraction at the end is just to prove that that attribute is being applied.) If I assume XAML uses DirectWrite, then that proves my first option (simply overlaying my custom attributes on top of the defaults) should be possible... (I make this assumption based on the idea that XAML provides a strikingly similar API to Direct2D for drawing 2D graphics, and has a lot of holes filled in where I had to manually write a lot of glue code to do the same things with vanilla Direct2D, so I assume whatever is possible in XAML is possible with Direct2D, and by extension DirectWrite since they were technically introduced together...)
At this point I'm completely lost. I want to at least be predictable across platforms, and I'm not sure how programs are even supposed to, let alone going to, use OpenType features directly or not anyway. Am I making bad expectations of text layout APIs? Will I have to drop IDWriteTextLayout and do all the text shaping and layout myself if I want this?
Or do I have to drop vanilla Windows 7 support and upgrade to the Platform Update DirectWrite feature set? Or even Windows 7 entirely?
After some discussions with Peter Sikking and Ebrahim Byagowi, I went and debugged a more general-purpose program I built quickly to test things, and I figured out what's going on internally.
First, however, I will say this applies to Uniscribe and DirectWrite equally.
As it turns out, DirectWrite is always providing a set of default OpenType features, regardless of what feature set I use! The situation is that the list of default features provided differs depending on whether I load my own features or not, and depending on the shaping engine. For the latn script in horizontal writing mode and for English, this is done with the "generic engine".
If I don't provide any features, the generic engine will load script-specific features. For horizontal latn, this list is
locl
ccmp
rlig
rclt
calt
liga
clig
If I do provide features, the generic engine will use the same default list for all scripts:
locl
ccmp
rclt
rlig
mark
mkmk
dist
So I don't know what to do about this. I could probably just provide liga and a few others myself in libui code (marked as a HACK of course), but this is still weird. I'm not sure what the motivation is either. Either way, this explains the behavior I'm seeing.
Supposing your question in general is about programming or at least concerns programming, I will try and give answers to some of your interrogative sentences.
would I have to drop the use of IDWriteTextLayout entirely in my code if I want to be able to add typographical features on top of the defaults?
It depends. If an IDWriteTextLayout interface suits well your project tasks in all ways except ease of variation of DirectWrite default typographic features, learn what you should about typography and create an IDWriteTypography instance suitable for your needs. Developing a custom text layout for the program may require substantial time and effort, especially if the program is supposed to render bidirectional texts, complex scripts, inline objects, etc.
It may happen that the tasks of your project require to develop a text layout engine for reasons other than just controlling typographic features used in rendered text. For example, your manager/customer may ask for implementation of customized linebreaking opportunities or a glyph advance justification algorithm. In this scenario, you will implement an IDWriteTextAnalizer::GetGlyphs method. This method has parameters DWRITE_TYPOGRAPHIC_FEATURES ** features, const UINT32 * featureRangeLengths, UINT32 featureRanges, and this parameters enable you to supersede a set of "default" typography features for a range of the text to be rendered (see my answer to the other question What are the default typography settings used by IDWriteTextLayout?). Only affected features will be altered; the other features has their "default" values. Morever, if you omit this parameters in a GetGlyphs call for the next text range (for example, use values of NULL, NULL, 0), the features altered in the previous GetGlyphs call will not be altered by the call for this next range.
the documentation for the equivalent SCRIPT_ANALYSIS type says that its script ID is an "[opaque] value" whose "value for this member is undefined and applications should not rely on its value being the same from one release to the next". And while I can get a language code to identify the script by, there's still no defined value other than LANG_ENGLISH for "Western" (Latin?) scripts.
Strictly speaking, this is not an interrogative statement, but I guess you are dissatisfied with how these Unicode script IDs are defined and how one can use the API with so vaguely defined structures and constants.
It may be off topic, but I risk to hypothesize on the origin of the "Unicode script ID" values. As of 2010-07-17, the Unicode, Inc. published The Unicode 6.0 version. The standard contained the document
http://www.unicode.org/Public/6.0.0/ucd/PropertyValueAliases.txt, with a section containing a list of scripts. The list went so:
# Script (sc)
sc ; Arab ; Arabic
sc ; Armi ; Imperial_Aramaic
etc.
The Arabic script is #1, the Cyrillic script is #20, the Latin script is #47 in this list. Furthermore, elsewhere I saw this list starting with scripts Common and Inherited. It places the Arabic script to the 3rd, the Cyrillic to the 22nd, and the Latin to the 49th place. These ordinals are familiar to you, aren't they?
Fortunately, we need not rely on the "Unicode script ID" values; we need script properties, not script IDs or abbreviations. The API is self-consistent in that it gives actual script properties for the text range, when we pass to a GetScriptProperties method the number derived from an AnalyzeScript call.
So the question is can I point out that my application supports en-US, en-GB and use for all of them the single resource file?
The intention is that I want my application to be available for all english-speaking countries. But it's meaningless to have different translations, because there are no specific translations.
Does it have a sense considering the mentioned intention to point out all those specific cultures in a manifest?
Yes - just use one English file and make it as default culture. This way even when en-GB is selected, for example, the app will fallback to en-US :)
As for date formatting - just be sure to use CurrentCulture - it gets formatting from the Regional and Number settings (and not CurrentUICulture which is for language needs only). This way people with, say, en-US UI language and Number formatting set to de-DE will still see the app in English but have number formatting as German.
There is a common confusion between CurrentCulture and CurrentUICulture and that Language equals formatting. That's why I see many 12-hour formats throughout Windows Phone/Store apps that simply ignore my Regional settings. A must-read regarding confusion about UI and Number formatting: http://forums.asp.net/post/1080435.aspx
I need to detect the language of the phone so that I can display the message accordingly. If it is english , then display english. Say, I target a few countries such as China,japan, Korea. How do I do it? here my incomplete code to show what I mean:
tring StrLanSetOnClient;
string strLanEng= "english Msg";
string strLanChn=" Msg in chinese character";
string strLanJpn= "Msg in Japanese character";
string strLanKor= "Msg in Korean character" ;
strLanSetOnClient = CultureInfo..........
If( strLanSetOnClient == "English")
{
txtBlkLan.Text = strLanEng;
}
elseif ( strLanSetOnClient == "Chinese")
{
txtBlkLan.Text = strLanChn
}
....
Thanks
--- Updated Questions:
1) Where should I detect the language? In App.xaml?
2) How all pages can refer to this global variable name?
3) Which is the best practise to detect ? use CultureInfo or thread.currentThread
Thanks
&#lt;?xml version="1.0" encoding="utf-8"?&#gt;
&#lt;Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"&#gt;
&#lt;ProjectExtensions&#gt;
&#lt;VisualStudio &#gt;
&#lt;FlavorProperties GUID="{C089C8C0-30E0-4E22-80C0-CE093F11xxxx}"&#gt;
&#lt;SilverlightMobileCSProjectFlavor&#gt;
&#lt;FullDeploy &#gt; True &#lt;/FullDeploy&#gt;
&#lt;/SilverlightMobileCSProjectFlavor&#gt;
&#lt;/FlavorProperties&#gt;
&#lt;/VisualStudio&#gt;
&#lt;/ProjectExtensions&#gt;
&#lt;/Project&#gt;
This is the vanila csproj file of my Wp7 App. There is no SupportCulture tags in it. So, I have to add this tag in it right when I open it with notepad? When I downloaded your sample app, I open the csproj file with notepad, i dont see this tag either? Thanks
The way you're trying to do localization is to get very complicated, have lots of duplication and be difficult to change in the future.
There is a built in way of supporting multiple languages/cultures/etc. See http://msdn.microsoft.com/en-us/library/ff637522(v=vs.92).aspx
I wrote a blog on this very subject just the other day. It describes how to localize from start to finish, and it is located at www.hopnet.mobi, click Blogs.
Once you get the hang of it, localization really isn't difficult at all. I've localized one app, and I'm waiting on a friend to validate my translations. While she's doing that, I'm localizing the other apps. More languages means wider distribution, which means more money. You're doing the right thing!
Use CurrentCulture which is in your System.Globalization namespace. It has properties like Name, EnglishName, DisplayName and NativeName so you pick which one suits you most.
EDIT: Detecting the language will depend on whether you want to allow users to change the language or not. If not then detect it in App.xaml.cs and store the information in an IsolatedStorage object so that you can share it among different pages. This way you can avoid detecting the language settings later and just rely on the saved settings. As for the best practice I stick to CultureInfo. I never tried going directly through Thread.CurrentThread.
I am trying to use ime (for hiragana input) in a flex 4 spark combo.
On creation complete I am setting the following.
cbx_text.textInput.imeMode = IMEConversionMode.JAPANESE_HIRAGANA;
And to check, tracing the following:
trace(cbx_text.textInput.enableIME); returns true;
trace(cbx_text.textInput.imeMode); returns JAPANESE_HIRAGANA;
However, when I select the text input and start to type some text I am unable to switch to hiragana.
I can set it to work on a textinput component with no problems.
<s:TextInput imeMode="JAPANESE_HIRAGANA"></s:TextInput>
Has anyone had any experience with this?
Any insights much appreciated.
Although I haven't had any experience with IME, I took a quick look at the documentation : http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/system/IME.html
Can it be that it's not enabled application wise? That, maybe what returns true is only valid for the component you are tracing from?
Obvious questions first:
Are you certain the TextInput is a member of cbx_text? I know this seems silly, but it's best to eliminate the obvious first.
Do you have an IME enabled on your computer? For example, do you regularly type in hiragana on your computer and have the appropriate language pack enabled?
Are you sending the IME the string appropriately? IME.setCompositionString() for windows computers?
Does your OS support the use of IMEs? Linux only supports the following methods:
Capabilities.hasIME
IME.enabled <= Can set or return value.
Try tracing hasIME and see if it's installed. Again, we're shotgunning here – trying to track down any possibility of a problem.
When all else fails, go to the source:
http://livedocs.adobe.com/flex/3/html/help.html?content=18_Client_System_Environment_6.html