Cure flashing of piece on from-square

In a drag-drop move the piece was flashed on the from square after the
user dropped it on the to-square, because highlights were set before the
move had updated the board. And highlighting with arrow can cause a redraw
of the last board. Same with setting or clearing marker dots.

diff --git a/backend.c b/backend.c
index c830d4e..4522ca1 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -7267,17 +7267,19 @@ LeftClick (ClickType clickType, int xPix, int yPix)
            ClearHighlights();
        }
     } else {
+#if 0
+// [HGM] this must be done after the move is made, as with arrow it could lead to a board redraw with piece still on from square
        /* Finish drag move */
        if (appData.highlightLastMove) {
            SetHighlights(fromX, fromY, toX, toY);
        } else {
            ClearHighlights();
        }
+#endif
        DragPieceEnd(xPix, yPix); dragging = 0;
        /* Don't animate move and drag both */
        appData.animate = FALSE;
     }
-    MarkTargetSquares(1);
 
     // moves into holding are invalid for now (except in EditPosition, adapting to-square)
     if(x >= 0 && x < BOARD_LEFT || x >= BOARD_RGHT) {
@@ -7302,6 +7304,7 @@ LeftClick (ClickType clickType, int xPix, int yPix)
        }
        ClearHighlights();
        fromX = fromY = -1;
+        MarkTargetSquares(1);
        DrawPosition(TRUE, boards[currentMove]);
        return;
     }
@@ -7335,6 +7338,7 @@ LeftClick (ClickType clickType, int xPix, int yPix)
        if(saveAnimate && !appData.animate && currentMove != oldMove && // drag-move was performed
           Explode(boards[currentMove-1], fromX, fromY, toX, toY))
            DrawPosition(TRUE, boards[currentMove]);
+        MarkTargetSquares(1);
        fromX = fromY = -1;
     }
     appData.animate = saveAnimate;
@@ -9721,9 +9725,6 @@ ShowMove (int fromX, int fromY, int toX, int toY)
                AnimateMove(boards[forwardMostMove - 1],
                            fromX, fromY, toX, toY);
            }
-           if (appData.highlightLastMove) {
-               SetHighlights(fromX, fromY, toX, toY);
-           }
        }
        currentMove = forwardMostMove;
     }
@@ -9732,6 +9733,11 @@ ShowMove (int fromX, int fromY, int toX, int toY)
 
     DisplayMove(currentMove - 1);
     DrawPosition(FALSE, boards[currentMove]);
+    if (!pausing || gameMode == PlayFromGameFile || gameMode == AnalyzeFile) {
+           if (appData.highlightLastMove) { // [HGM] moved to after DrawPosition, as with arrow it could redraw old board
+               SetHighlights(fromX, fromY, toX, toY);
+           }
+    }
     DisplayBothClocks();
     HistorySet(parseList,backwardMostMove,forwardMostMove,currentMove-1);
 }