working on GF integration (iv)

android/Pictogram/app/src/fernandoFlavor/java/com/yottacode/pictogram/grammar/SemanticGrammar.java

+package com.yottacode.pictogram.grammar;
+
+import android.util.Log;
+
+import com.yottacode.pictogram.dao.Picto;
+import com.yottacode.pictogram.tools.PCBcontext;
+
+import org.grammaticalframework.pgf.Concr;
+import org.grammaticalframework.pgf.PGF;
+import org.grammaticalframework.pgf.ParseError;
+import org.grammaticalframework.pgf.TokenProb;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Hashtable;
+import java.util.LinkedList;
+import java.util.Vector;
+
+/**
+ * Created by Fernando on 01/06/2016.
+ */
+public class SemanticGrammar {
+    private PGF pgf;
+    Concr language;
+    String current_msg;
+    Hashtable<String,Integer> exp_cat; //for a given expression, which is the category. It's required for predictive grammar
+
+
+    public SemanticGrammar(String grammar, String language) {
+        System.loadLibrary("jpgf");
+        this.exp_cat =  new Hashtable<>(Vocabulary.DEFAULT_VOCABULARY_SIZE);
+        try {
+            InputStream in = null;
+            in = PCBcontext.getContext().getAssets().open(grammar);
+            Log.i(this.getClass().getCanonicalName(), "Trying to open " + grammar);
+            this.language = this.pgf.getLanguages().get(language);
+            this.pgf = PGF.readPGF(in);
+            this.current_msg="";
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+    }
+
+    /**
+     * It adds a new expresion with a given cat
+     */
+    public void add_translation(String translation, int cat) {
+        this.exp_cat.put(translation,cat);
+    }
+
+    /**
+     * It returns the category for a given expression. It is required to implement the semantic grammar
+     * @param translation
+     * @return
+     */
+    public int get_expr_cat(String translation) {
+        return this.exp_cat.get(translation);
+    }
+
+    public LinkedList<Picto> startSentence() {
+        this.current_msg="";
+        return PCBcontext.getVocabulary().pictos.get(Picto.NO_CATEGORY);
+    }
+
+    public LinkedList<Picto> next_categories(String expression) {
+
+        LinkedList<Picto> next_cats;
+
+        this.current_msg += expression + " ";
+        try {
+            Iterable<TokenProb> next_tokens = language.complete(pgf.getStartCat(), this.current_msg, "");
+            if (!next_tokens.iterator().hasNext())
+                next_cats = startSentence();
+            else {
+                next_cats = new LinkedList<>();
+                java.util.LinkedList<Picto> categories = PCBcontext.getVocabulary().pictos.get(Picto.NO_CATEGORY);
+                for (TokenProb tk : next_tokens) {
+                    String translation = tk.getToken();
+                    int cat = get_expr_cat(tk.getToken());
+                    Log.i(this.getClass().getSimpleName(), "Next: " + translation + ". Cat: " + cat);
+                    if (!next_cats.contains(cat)) {
+                        next_cats.add(categories.get(cat));
+                    }
+                }
+            }
+        } catch (ParseError parseError) {
+            Log.e(this.getClass().getCanonicalName(), "Error parsing " + this.current_msg + ". Error:" + parseError.getMessage() + " (token " + parseError.getToken() + ")");
+            next_cats = startSentence();
+        }
+        return next_cats;
+    }
+}