Fix key preview wrong offset caused by 3870097

Author: yawnoc

app/src/main/java/io/github/yawnoc/strokeinput/InputContainer.java

@@ -239,11 +239,13 @@ public void showKeyPreviewPlane() {
     final int screenWidth = keyboard.getScreenWidth();
     final int screenHeight = keyboard.getScreenHeight();
     final int keyboardHeight = keyboard.getHeight();
+    final int popupBufferZoneHeight = keyboard.getPopupBufferZoneHeight();
 
     keyPreviewPlane.updateDimensions(
       screenWidth,
       screenHeight,
-      keyboardHeight
+      keyboardHeight,
+      popupBufferZoneHeight
     );
     keyPreviewPlanePopup.dismiss();
     keyPreviewPlanePopup.setWidth(screenWidth);

app/src/main/java/io/github/yawnoc/strokeinput/KeyPreviewPlane.java

@@ -33,6 +33,7 @@ public class KeyPreviewPlane extends View {
   private int width;
   private int height;
   private int keyboardHeight;
+  private int popupBufferZoneHeight;
   private final List<Key> keyList = new ArrayList<>();
   private Key latestKey;
   private int shiftMode = InputContainer.SHIFT_DISABLED;
@@ -90,12 +91,14 @@ private void initialiseDrawing(final Context context) {
   public void updateDimensions(
     final int width,
     final int height,
-    final int keyboardHeight
+    final int keyboardHeight,
+    final int popupBufferZoneHeight
   )
   {
     this.width = width;
     this.height = height;
     this.keyboardHeight = keyboardHeight;
+    this.popupBufferZoneHeight = popupBufferZoneHeight;
   }
 
   public void updateShiftMode(final int shiftMode) {
@@ -186,7 +189,7 @@ public void onDraw(final Canvas canvas) {
       final int previewY = (
         key.y
           - keyPreviewHeight - key.previewMarginY
-          + this.height - keyboardHeight
+          + this.height - keyboardHeight - popupBufferZoneHeight
       );
 
       canvas.translate(previewX, previewY);