From 5b7a3165932d9b3fced80fec17de01eb1ad89bf7 Mon Sep 17 00:00:00 2001 From: Berthold Stoeger Date: Sun, 23 Feb 2020 19:24:06 +0100 Subject: undo: reorder cylinders on remove-cylinder undo/redo The cylinders in the events must be reordered if we remove a cylinder. To avoid duplication of code, move the reordering function into qthelper.cpp, though it might not be ideal there. Signed-off-by: Berthold Stoeger --- core/qthelper.cpp | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'core/qthelper.cpp') diff --git a/core/qthelper.cpp b/core/qthelper.cpp index 7b879e7d6..10e62eabe 100644 --- a/core/qthelper.cpp +++ b/core/qthelper.cpp @@ -1661,3 +1661,36 @@ extern "C" char *get_changes_made() else return nullptr; } + +// Generate a cylinder-renumber map for use when the n-th cylinder +// of a dive with count cylinders is removed. It fills an int vector +// with 0..n, -1, n..count-1. Each entry in the vector represents +// the new id of the cylinder, whereby <0 means that this particular +// cylinder does not get any new id. This should probably be moved +// to the C-core, but using std::vector is simply more convenient. +// The function assumes that n < count! +std::vector get_cylinder_map_for_remove(int count, int n) +{ + // 1) Fill mapping[0]..mapping[n-1] with 0..n-1 + // 2) Set mapping[n] to -1 + // 3) Fill mapping[n+1]..mapping[count-1] with n..count-2 + std::vector mapping(count); + std::iota(mapping.begin(), mapping.begin() + n, 0); + mapping[n] = -1; + std::iota(mapping.begin() + n + 1, mapping.end(), n); + return mapping; +} + +// Generate a cylinder-renumber map for use when a cylinder is added +// before the n-th cylinder. It fills an int vector with +// with 0..n-1, n+1..count. Each entry in the vector represents +// the new id of the cylinder. This probably should be moved +// to the C-core, but using std::vector is simply more convenient. +// This function assumes that that n <= count! +std::vector get_cylinder_map_for_add(int count, int n) +{ + std::vector mapping(count); + std::iota(mapping.begin(), mapping.begin() + n, 0); + std::iota(mapping.begin() + n, mapping.end(), n + 1); + return mapping; +} -- cgit v1.2.3-70-g09d2