Added foreign language input composition

richtextfx/src/main/java/org/fxmisc/richtext/GenericStyledArea.java

@@ -19,6 +19,7 @@
 import java.util.function.Predicate;
 import java.util.function.UnaryOperator;
 
+import javafx.application.ConditionalFeature;
 import javafx.application.Platform;
 import javafx.beans.NamedArg;
 import javafx.beans.binding.Bindings;
@@ -46,6 +47,9 @@
 import javafx.scene.Node;
 import javafx.scene.control.ContextMenu;
 import javafx.scene.control.IndexRange;
+import javafx.scene.input.InputMethodEvent;
+import javafx.scene.input.InputMethodRequests;
+import javafx.scene.input.InputMethodTextRun;
 import javafx.scene.input.MouseEvent;
 import javafx.scene.layout.Background;
 import javafx.scene.layout.BackgroundFill;
@@ -821,6 +825,81 @@ public GenericStyledArea(
 
         placeHolderProp.addListener( (ob,ov,newNode) -> displayPlaceHolder( showPlaceholder.getValue(), newNode ) );
         showPlaceholder.addListener( (ob,ov,show) -> displayPlaceHolder( show, getPlaceholder() ) );
+
+        if ( Platform.isFxApplicationThread() ) initInputMethodHandling();
+        else Platform.runLater( () -> initInputMethodHandling() );
+    }
+
+    private void initInputMethodHandling()
+    {
+        if( Platform.isSupported( ConditionalFeature.INPUT_METHOD ) )
+        {
+            setOnInputMethodTextChanged( event -> handleInputMethodEvent(event) );
+            // Both of these have to be set for input composition to work !
+            setInputMethodRequests( new InputMethodRequests()
+            {
+                @Override public Point2D getTextLocation( int offset ) {
+                    Bounds charBounds = getCaretBounds().get();
+                    return new Point2D( charBounds.getMaxX() - 5, charBounds.getMaxY() );
+                }
+
+                @Override public int getLocationOffset( int x, int y ) {
+                    return 0;
+                }
+
+                @Override public void cancelLatestCommittedText() {}
+
+                @Override public String getSelectedText() {
+                    return getSelectedText();
+                }
+            });
+        }
+    }
+
+    // Start/Length of the text under input method composition
+    private int imstart;
+    private int imlength;
+
+    protected void handleInputMethodEvent( InputMethodEvent event )
+    {
+        if ( isEditable() && !isDisabled() )
+        {
+            // remove previous input method text (if any) or selected text
+            if ( imlength != 0 ) {
+                selectRange( imstart, imstart + imlength );
+            }
+
+            // Insert committed text
+            if ( event.getCommitted().length() != 0 ) {
+                replaceText( getSelection(), event.getCommitted() );
+            }
+
+            // Replace composed text
+            imstart = getSelection().getStart();
+            StringBuilder composed = new StringBuilder();
+
+            for ( InputMethodTextRun run : event.getComposed() ) {
+                composed.append( run.getText() );
+            }
+
+            replaceText( getSelection(), composed.toString() );
+            imlength = composed.length();
+
+            if ( imlength != 0 )
+            {
+                int pos = imstart;
+                for ( InputMethodTextRun run : event.getComposed() ) {
+                    int endPos = pos + run.getText().length();
+                    pos = endPos;
+                }
+
+                // Set caret position in composed text
+                int caretPos = event.getCaretPosition();
+                if ( caretPos >= 0 && caretPos < imlength ) {
+                    selectRange( imstart + caretPos, imstart + caretPos );
+                }
+            }
+        }
     }
 
     private Node placeholder;