introduce default offsetToXY/offsetToPoint2D methods in Editor interface

(with more effective implementation in EditorImpl)

platform/editor-ui-api/src/com/intellij/openapi/editor/Editor.java

@@ -284,6 +284,42 @@ public interface Editor extends UserDataHolder {
   @NotNull
   VisualPosition xyToVisualPosition(@NotNull Point2D p);
 
+  /**
+   * @since 2017.2
+   */
+  @NotNull
+  default Point offsetToXY(int offset) {
+    return offsetToXY(offset, false, false);
+  }
+
+  /**
+   * @see #offsetToVisualPosition(int, boolean, boolean)
+   * @since 2017.2
+   */
+  @NotNull
+  default Point offsetToXY(int offset, boolean leanForward, boolean beforeSoftWrap) {
+    VisualPosition visualPosition = offsetToVisualPosition(offset, leanForward, beforeSoftWrap);
+    return visualPositionToXY(visualPosition);
+  }
+
+  /**
+   * @since 2017.2
+   */
+  @NotNull
+  default Point2D offsetToPoint2D(int offset) {
+    return offsetToPoint2D(offset, false, false);
+  }
+
+  /**
+   * @see #offsetToVisualPosition(int, boolean, boolean)
+   * @since 2017.2
+   */
+  @NotNull
+  default Point2D offsetToPoint2D(int offset, boolean leanForward, boolean beforeSoftWrap) {
+    VisualPosition visualPosition = offsetToVisualPosition(offset, leanForward, beforeSoftWrap);
+    return visualPositionToPoint2D(visualPosition);
+  }
+
   /**
    * Adds a listener for receiving notifications about mouse clicks in the editor and
    * the mouse entering/exiting the editor.

platform/platform-impl/src/com/intellij/openapi/editor/impl/EditorImpl.java

@@ -1250,11 +1250,19 @@ public final class EditorImpl extends UserDataHolderBase implements EditorEx, Hi
     return myView.xyToVisualPosition(p);
   }
 
+  @Override
   @NotNull
-  Point2D offsetToXY(int offset, boolean leanTowardsLargerOffsets) {
-    return myView.offsetToXY(offset, leanTowardsLargerOffsets, false);
+  public Point2D offsetToPoint2D(int offset, boolean leanTowardsLargerOffsets, boolean beforeSoftWrap) {
+    return myView.offsetToXY(offset, leanTowardsLargerOffsets, beforeSoftWrap);
   }
-  
+
+  @Override
+  @NotNull
+  public Point offsetToXY(int offset, boolean leanForward, boolean beforeSoftWrap) {
+    Point2D point2D = offsetToPoint2D(offset, leanForward, beforeSoftWrap);
+    return new Point((int)point2D.getX(), (int)point2D.getY());
+  }
+
   @Override
   @NotNull
   public VisualPosition offsetToVisualPosition(int offset) {

platform/platform-impl/src/com/intellij/openapi/editor/impl/ImmediatePainter.java

@@ -144,7 +144,7 @@ class ImmediatePainter {
     final Font font1 = EditorUtil.fontForChar(c1, attributes1.getFontType(), editor).getFont();
     final Font font2 = EditorUtil.fontForChar(c1, attributes2.getFontType(), editor).getFont();
 
-    final Point2D p2 = editor.offsetToXY(offset, false);
+    final Point2D p2 = editor.offsetToPoint2D(offset);
     float p2x = (float)p2.getX();
     int p2y = (int)p2.getY();
     int width1i = (int)(p2x) - (int)(p2x - width1);

platform/platform-tests/testSrc/com/intellij/openapi/editor/impl/AbstractRtlTest.java

@@ -65,8 +65,8 @@ public abstract class AbstractRtlTest extends AbstractEditorTest {
                                visualPositionTowardsLargerOffsets, myEditor.offsetToVisualPosition(offset, true, false));
     assertEquals("Wrong afterOffset->visualLine calculation", 
                  visualPositionTowardsLargerOffsets.line, ((EditorImpl)myEditor).offsetToVisualLine(offset));
-    assertEquals("Wrong beforeOffset->xy calculation", xyTowardsSmallerOffsets, ((EditorImpl)myEditor).offsetToXY(offset, false));
-    assertEquals("Wrong afterOffset->xy calculation", xyTowardsLargerOffsets, ((EditorImpl)myEditor).offsetToXY(offset, true));
+    assertEquals("Wrong beforeOffset->xy calculation", xyTowardsSmallerOffsets, myEditor.offsetToXY(offset, false, false));
+    assertEquals("Wrong afterOffset->xy calculation", xyTowardsLargerOffsets, myEditor.offsetToXY(offset, true, false));
   }
 
   protected static void checkLPConversions(int logicalColumn, int offset,