From 90cc6b8204d671bde9f59382c94729271c3d5e23 Mon Sep 17 00:00:00 2001
From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Sun, 22 Dec 2013 00:08:35 +0100
Subject: [PATCH] Improve Edit Position mode

Clear Board now cycles trough boards:
current -> empty -> some pieces -> all pieces -> current
were 'some pieces' sows every piece type once (ad no Pawns), while
'all pieces' is the stadard opening position. In the end you get the
position that was erased back (to recover from accidental erasure).
---
 backend.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/backend.c b/backend.c
index 5ad2562..aea15b5 100644
--- a/backend.c
+++ b/backend.c
@@ -14593,11 +14593,14 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 {
     char buf[MSG_SIZ];
     ChessSquare piece = boards[0][y][x];
+    static Board erasedBoard, currentBoard, menuBoard;
 
     if (gameMode != EditPosition && gameMode != IcsExamining) return;
 
     switch (selection) {
       case ClearBoard:
+	CopyBoard(currentBoard, boards[0]);
+	CopyBoard(menuBoard, initialPosition);
 	if (gameMode == IcsExamining && ics_type == ICS_FICS) {
 	    SendToICS(ics_prefix);
 	    SendToICS("bsetup clear\n");
@@ -14605,6 +14608,7 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 	    SendToICS(ics_prefix);
 	    SendToICS("clearboard\n");
 	} else {
+            int nonEmpty = 0;
             for (x = 0; x < BOARD_WIDTH; x++) { ChessSquare p = EmptySquare;
 		if(x == BOARD_LEFT-1 || x == BOARD_RGHT) p = (ChessSquare) 0; /* [HGM] holdings */
                 for (y = 0; y < BOARD_HEIGHT; y++) {
@@ -14615,9 +14619,30 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 			    SendToICS(buf);
 			}
 		    } else {
+			if(boards[0][y][x] != p) nonEmpty++;
 			boards[0][y][x] = p;
 		    }
 		}
+		menuBoard[1][x] = menuBoard[BOARD_HEIGHT-2][x] = p;
+	    }
+	    if(gameMode != IcsExamining) { // [HGM] editpos: cycle trough boards
+		for(x = BOARD_LEFT; x < BOARD_RGHT; x++) { // create 'menu board' by removing duplicates 
+		    ChessSquare p = menuBoard[0][x];
+		    for(y = x + 1; y < BOARD_RGHT; y++) if(menuBoard[0][y] == p) menuBoard[0][y] = EmptySquare;
+		    p = menuBoard[BOARD_HEIGHT-1][x];
+		    for(y = x + 1; y < BOARD_RGHT; y++) if(menuBoard[BOARD_HEIGHT-1][y] == p) menuBoard[BOARD_HEIGHT-1][y] = EmptySquare;
+		}
+		if(!nonEmpty) { // asked to clear an empty board
+		    CopyBoard(boards[0], menuBoard);
+		} else
+		if(CompareBoards(currentBoard, menuBoard)) { // asked to clear an empty board
+		    CopyBoard(boards[0], initialPosition);
+		} else
+		if(CompareBoards(currentBoard, initialPosition) && !CompareBoards(currentBoard, erasedBoard)) {
+		    CopyBoard(boards[0], erasedBoard);
+		} else
+		    CopyBoard(erasedBoard, currentBoard);
+
 	    }
 	}
 	if (gameMode == EditPosition) {
-- 
1.7.0.4