[wicket] 01/01: Save info about Locale direction LTR/RTL to Session metadata

[so...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

solomax pushed a commit to branch session-locale-rtl
in repository https://gitbox.apache.org/repos/asf/wicket.git

commit a9cf794db1b42af32aad5bf2488dc2d623326eac
Author: Maxim Solodovnik <so...@gmail.com>
AuthorDate: Thu Dec 23 23:57:52 2021 +0700

    Save info about Locale direction LTR/RTL to Session metadata
---
 .../src/main/java/org/apache/wicket/Session.java   |  7 +++
 .../apache/wicket/core/util/lang/LocaleUtils.java  | 51 ++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/wicket-core/src/main/java/org/apache/wicket/Session.java b/wicket-core/src/main/java/org/apache/wicket/Session.java
index c4152c9..4f63eaa 100644
--- a/wicket-core/src/main/java/org/apache/wicket/Session.java
+++ b/wicket-core/src/main/java/org/apache/wicket/Session.java
@@ -30,6 +30,7 @@ import java.util.function.Supplier;
 import org.apache.wicket.application.IClassResolver;
 import org.apache.wicket.authorization.IAuthorizationStrategy;
 import org.apache.wicket.core.request.ClientInfo;
+import org.apache.wicket.core.util.lang.LocaleUtils;
 import org.apache.wicket.core.util.lang.WicketObjects;
 import org.apache.wicket.event.IEvent;
 import org.apache.wicket.event.IEventSink;
@@ -126,6 +127,11 @@ public abstract class Session implements IClusterable, IEventSink, IMetadataCont
 	{
 		private static final long serialVersionUID = 1L;
 	};
+	/** records if pages have been unlocked for the current request */
+	public static final MetaDataKey<Boolean> IS_RTL = new MetaDataKey<>()
+	{
+		private static final long serialVersionUID = 1L;
+	};
 
 	/** Name of session attribute under which this session is stored */
 	public static final String SESSION_ATTRIBUTE_NAME = "session";
@@ -606,6 +612,7 @@ public abstract class Session implements IClusterable, IEventSink, IMetadataCont
 		if (!Objects.equal(getLocale(), locale))
 		{
 			this.locale.set(locale);
+			setMetaData(IS_RTL, LocaleUtils.isRtlLanguage(locale));
 			dirty();
 		}
 		return this;
diff --git a/wicket-core/src/main/java/org/apache/wicket/core/util/lang/LocaleUtils.java b/wicket-core/src/main/java/org/apache/wicket/core/util/lang/LocaleUtils.java
new file mode 100644
index 0000000..e8cd605
--- /dev/null
+++ b/wicket-core/src/main/java/org/apache/wicket/core/util/lang/LocaleUtils.java
@@ -0,0 +1,51 @@
+package org.apache.wicket.core.util.lang;
+
+import java.util.Locale;
+import java.util.regex.Pattern;
+
+import org.apache.wicket.util.lang.Args;
+
+public class LocaleUtils {
+	/**
+	 * taken from BidiUtils
+	 *
+	 * A regular expression for matching right-to-left language codes. See
+	 * {@link #isRtlLanguage} for the design.
+	 */
+	private static final Pattern RtlLocalesRe = Pattern.compile("^(ar|dv|he|iw|fa|nqo|ps|sd|ug|ur|yi|.*[-_](Arab|Hebr|Thaa|Nkoo|Tfng))"
+					+ "(?!.*[-_](Latn|Cyrl)($|-|_))($|-|_)");
+
+	private LocaleUtils() {
+		// utility class
+	}
+
+	/**
+	 * Check if a BCP 47 / III language code indicates an RTL language, i.e.
+	 * either: - a language code explicitly specifying one of the right-to-left
+	 * scripts, e.g. "az-Arab", or
+	 * <p>
+	 * - a language code specifying one of the languages normally written in a
+	 * right-to-left script, e.g. "fa" (Farsi), except ones explicitly
+	 * specifying Latin or Cyrillic script (which are the usual LTR
+	 * alternatives).
+	 * <p>
+	 * The list of right-to-left scripts appears in the 100-199 range in
+	 * http://www.unicode.org/iso15924/iso15924-num.html, of which Arabic and
+	 * Hebrew are by far the most widely used. We also recognize Thaana, N'Ko,
+	 * and Tifinagh, which also have significant modern usage. The rest (Syriac,
+	 * Samaritan, Mandaic, etc.) seem to have extremely limited or no modern
+	 * usage and are not recognized. The languages usually written in a
+	 * right-to-left script are taken as those with Suppress-Script:
+	 * Hebr|Arab|Thaa|Nkoo|Tfng in
+	 * http://www.iana.org/assignments/language-subtag-registry, as well as
+	 * Sindhi (sd) and Uyghur (ug). The presence of other subtags of the
+	 * language code, e.g. regions like EG (Egypt), is ignored.
+	 *
+	 * @param languageString - locale string
+	 * @return <code>true</code> in case passed locale is right-to-left
+	 */
+	public static boolean isRtlLanguage(final Locale locale) {
+		Args.notNull(locale, "locale");
+		return RtlLocalesRe.matcher(locale.toLanguageTag()).find();
+	}
+}