From febf550a2053c36c97626922fc2696faadb68ddb Mon Sep 17 00:00:00 2001
From: Vaxry <43317083+vaxerski@users.noreply.github.com>
Date: Thu, 2 Apr 2026 16:10:00 -0400
Subject: algo/scrolling: add expel, consume, and consume_or_expel (#13869)

ref https://github.com/hyprwm/Hyprland/discussions/13403\#discussioncomment-15972750
---
 .../tiled/scrolling/ScrollingAlgorithm.cpp         | 68 ++++++++++++++++++++--
 1 file changed, 62 insertions(+), 6 deletions(-)

(limited to 'src/layout/algorithm/tiled/scrolling')

diff --git a/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp b/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
index 93a83045..5685d650 100644
--- a/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
+++ b/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
@@ -1358,18 +1358,74 @@ std::expected<void, std::string> CScrollingAlgorithm::layoutMsg(const std::strin
                     g_pCompositor->warpCursorTo(pTargetData->target->window()->middle());
             }
         }
-    } else if (ARGS[0] == "promote") {
+    } else if (ARGS[0] == "promote" || ARGS[0] == "consume" || ARGS[0] == "expel" || ARGS[0] == "consume_or_expel") {
         const auto TDATA = dataFor(Desktop::focusState()->window() ? Desktop::focusState()->window()->layoutTarget() : nullptr);
-
         if (!TDATA)
             return std::unexpected("no window focused");
 
-        auto idx = m_scrollingData->idx(TDATA->column.lock());
-        auto col = idx == -1 ? m_scrollingData->add() : m_scrollingData->add(idx);
+        const auto CURRENT_COL = TDATA->column.lock();
+        if (!CURRENT_COL)
+            return std::unexpected("no current col");
 
-        TDATA->column->remove(TDATA->target.lock());
+        // expel a target from srcCol into its own new column at insertIdx
+        auto expelTarget = [&](SP<SScrollingTargetData> tdata, SP<SColumnData> srcCol, std::optional<int64_t> insertIdx) {
+            auto col = !insertIdx ? m_scrollingData->add() : m_scrollingData->add(*insertIdx);
+            srcCol->remove(tdata->target.lock());
+            col->add(tdata);
+            m_scrollingData->centerOrFitCol(col);
+        };
+
+        // consume the first target from adjCol into dstCol
+        auto consumeTarget = [&](SP<SColumnData> dstCol, SP<SColumnData> adjCol) {
+            const auto target = adjCol->targetDatas.front();
+            adjCol->remove(target->target.lock());
+            dstCol->add(target);
+            m_scrollingData->centerOrFitCol(dstCol);
+        };
+
+        if (ARGS[0] == "promote") {
+            auto idx = m_scrollingData->idx(CURRENT_COL);
+            expelTarget(TDATA, CURRENT_COL, idx == -1 ? std::nullopt : std::optional<int64_t>{idx});
+        } else if (ARGS[0] == "expel") {
+            if (CURRENT_COL->targetDatas.size() < 2)
+                return std::unexpected("column has only one window");
+
+            const auto lastTarget = CURRENT_COL->targetDatas.back();
+            const auto currentIdx = m_scrollingData->idx(CURRENT_COL);
+            const auto NEXT_COL   = m_scrollingData->next(CURRENT_COL);
+            const auto insertIdx  = !NEXT_COL ? std::nullopt : std::optional<int64_t>{currentIdx};
+
+            expelTarget(lastTarget, CURRENT_COL, insertIdx);
+        } else if (ARGS[0] == "consume") {
+            const auto NEXT_COL = m_scrollingData->next(CURRENT_COL);
+            if (!NEXT_COL)
+                return std::unexpected("no next column");
+
+            consumeTarget(CURRENT_COL, NEXT_COL);
+        } else if (ARGS[0] == "consume_or_expel") {
+            if (ARGS.size() < 2)
+                return std::unexpected("not enough args");
+
+            const std::string& direction = ARGS[1];
+            const bool         prev      = direction == "prev";
+            const bool         next      = direction == "next";
+
+            if (!prev && !next)
+                return std::unexpected("invalid direction, expected prev or next");
+
+            if (CURRENT_COL->targetDatas.size() > 1) {
+                const auto currentIdx = m_scrollingData->idx(CURRENT_COL);
+                expelTarget(TDATA, CURRENT_COL, prev ? currentIdx - 1 : currentIdx);
+            } else {
+                const auto ADJ_COL = prev ? m_scrollingData->prev(CURRENT_COL) : m_scrollingData->next(CURRENT_COL);
+                if (!ADJ_COL)
+                    return std::unexpected("no adjacent column");
 
-        col->add(TDATA);
+                CURRENT_COL->remove(TDATA->target.lock());
+                ADJ_COL->add(TDATA);
+                m_scrollingData->centerOrFitCol(ADJ_COL);
+            }
+        }
 
         m_scrollingData->recalculate();
     } else if (ARGS[0] == "swapcol") {
-- 
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