[plasma/kwin] src: Remove snapping logic in checkWorkspacePosition()

Git commit 2793b44003e20c8c81a57b02751078203d977ee9 by Vlad Zahorodnii.
Committed on 10/08/2026 at 12:47.
Pushed by vladz into branch 'master'.

Remove snapping logic in checkWorkspacePosition()

It's been working unreliably, sometimes it works, sometimes it doesn't.
Overall, the net gain from this feature is minor.

M  +0    -146  src/window.cpp
M  +0    -18   src/workspace.cpp
M  +0    -2    src/workspace.h

https://invent.kde.org/plasma/kwin/-/commit/2793b44003e20c8c81a57b02751078203d977ee9

diff --git a/src/window.cpp b/src/window.cpp
index a934b783e2a..ecc6940a61a 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -4020,9 +4020,6 @@ void Window::checkWorkspacePosition(RectF oldGeometry, LogicalOutput *oldOutput)
         oldOutput = moveResizeOutput();
     }
 
-    // If the window was touching an edge before but not now move it so it is again.
-    // Old and new maximums have different starting values so windows on the screen
-    // edge will move when a new strut is placed on the edge.
     RectF oldScreenArea;
     RectF screenArea;
     if (workspace()->inRearrange()) {
@@ -4050,149 +4047,6 @@ void Window::checkWorkspacePosition(RectF oldGeometry, LogicalOutput *oldOutput)
         return;
     }
 
-    const RectF oldGeomTall = RectF(QPointF(oldGeometry.left(), oldScreenArea.top()), QPointF(oldGeometry.right(), oldScreenArea.bottom())); // Full screen height
-    const RectF oldGeomWide = RectF(QPointF(oldScreenArea.left(), oldGeometry.top()), QPointF(oldScreenArea.right(), oldGeometry.bottom())); // Full screen width
-    qreal oldTopMax = oldScreenArea.top();
-    qreal oldRightMax = oldScreenArea.right();
-    qreal oldBottomMax = oldScreenArea.bottom();
-    qreal oldLeftMax = oldScreenArea.left();
-    qreal topMax = screenArea.top();
-    qreal rightMax = screenArea.right();
-    qreal bottomMax = screenArea.bottom();
-    qreal leftMax = screenArea.left();
-    const RectF newGeomTall(QPointF(newGeom.left(), screenArea.top()), QPointF(newGeom.right(), screenArea.bottom())); // Full screen height
-    const RectF newGeomWide(QPointF(screenArea.left(), newGeom.top()), QPointF(screenArea.right(), newGeom.bottom())); // Full screen width
-    // Get the max strut point for each side where the window is (E.g. Highest point for
-    // the bottom struts bounded by the window's left and right sides).
-
-    // These 4 compute old bounds ...
-    auto moveAreaFunc = workspace()->inRearrange() ? &Workspace::previousRestrictedMoveArea : //... the restricted areas changed
-        &Workspace::restrictedMoveArea; //... when e.g. active desktop or screen changes
-
-    const auto oldStrutsTop = (workspace()->*moveAreaFunc)(StrutAreaTop);
-    for (const RectF &r : oldStrutsTop) {
-        RectF rect = r & oldGeomTall;
-        if (!rect.isEmpty()) {
-            oldTopMax = std::max(oldTopMax, rect.bottom());
-        }
-    }
-    const auto oldStrutsRight = (workspace()->*moveAreaFunc)(StrutAreaRight);
-    for (const RectF &r : oldStrutsRight) {
-        RectF rect = r & oldGeomWide;
-        if (!rect.isEmpty()) {
-            oldRightMax = std::min(oldRightMax, rect.left());
-        }
-    }
-    const auto oldStrutsBottom = (workspace()->*moveAreaFunc)(StrutAreaBottom);
-    for (const RectF &r : oldStrutsBottom) {
-        RectF rect = r & oldGeomTall;
-        if (!rect.isEmpty()) {
-            oldBottomMax = std::min(oldBottomMax, rect.top());
-        }
-    }
-    const auto oldStrutsLeft = (workspace()->*moveAreaFunc)(StrutAreaLeft);
-    for (const RectF &r : oldStrutsLeft) {
-        RectF rect = r & oldGeomWide;
-        if (!rect.isEmpty()) {
-            oldLeftMax = std::max(oldLeftMax, rect.right());
-        }
-    }
-
-    // These 4 compute new bounds
-    const auto newStrutsTop = workspace()->restrictedMoveArea(StrutAreaTop);
-    for (const RectF &r : newStrutsTop) {
-        RectF rect = r & newGeomTall;
-        if (!rect.isEmpty()) {
-            topMax = std::max(topMax, rect.bottom());
-        }
-    }
-    const auto newStrutsRight = workspace()->restrictedMoveArea(StrutAreaRight);
-    for (const RectF &r : newStrutsRight) {
-        RectF rect = r & newGeomWide;
-        if (!rect.isEmpty()) {
-            rightMax = std::min(rightMax, rect.left());
-        }
-    }
-    const auto newStrutsBottom = workspace()->restrictedMoveArea(StrutAreaBottom);
-    for (const RectF &r : newStrutsBottom) {
-        RectF rect = r & newGeomTall;
-        if (!rect.isEmpty()) {
-            bottomMax = std::min(bottomMax, rect.top());
-        }
-    }
-    const auto newStrutsLeft = workspace()->restrictedMoveArea(StrutAreaLeft);
-    for (const RectF &r : newStrutsLeft) {
-        RectF rect = r & newGeomWide;
-        if (!rect.isEmpty()) {
-            leftMax = std::max(leftMax, rect.right());
-        }
-    }
-
-    // Check if the sides were inside or touching but are no longer
-    enum {
-        Left = 0,
-        Top,
-        Right,
-        Bottom,
-    };
-    bool keep[4] = {false, false, false, false};
-    bool save[4] = {false, false, false, false};
-    if (oldGeometry.x() >= oldLeftMax) {
-        save[Left] = newGeom.x() < leftMax;
-    }
-    if (oldGeometry.x() == oldLeftMax) {
-        keep[Left] = newGeom.x() != leftMax;
-    }
-
-    if (oldGeometry.y() >= oldTopMax) {
-        save[Top] = newGeom.y() < topMax;
-    }
-    if (oldGeometry.y() == oldTopMax) {
-        keep[Top] = newGeom.y() != topMax;
-    }
-
-    if (oldGeometry.right() <= oldRightMax) {
-        save[Right] = newGeom.right() > rightMax;
-    }
-    if (oldGeometry.right() == oldRightMax) {
-        keep[Right] = newGeom.right() != rightMax;
-    }
-
-    if (oldGeometry.bottom() <= oldBottomMax) {
-        save[Bottom] = newGeom.bottom() > bottomMax;
-    }
-    if (oldGeometry.bottom() == oldBottomMax) {
-        keep[Bottom] = newGeom.bottom() != bottomMax;
-    }
-
-    // if randomly touches opposing edges, do not favor either
-    if (keep[Left] && keep[Right]) {
-        keep[Left] = keep[Right] = false;
-    }
-    if (keep[Top] && keep[Bottom]) {
-        keep[Top] = keep[Bottom] = false;
-    }
-
-    if (save[Left] || keep[Left]) {
-        newGeom.moveLeft(std::max(leftMax, screenArea.x()));
-    }
-    if (save[Top] || keep[Top]) {
-        newGeom.moveTop(std::max(topMax, screenArea.y()));
-    }
-    if (save[Right] || keep[Right]) {
-        newGeom.moveRight(std::min(rightMax, screenArea.right()));
-    }
-    if (save[Bottom] || keep[Bottom]) {
-        newGeom.moveBottom(std::min(bottomMax, screenArea.bottom()));
-    }
-
-    if (oldGeometry.x() >= oldLeftMax && newGeom.x() < leftMax) {
-        newGeom.setLeft(std::max(leftMax, screenArea.left()));
-    }
-    if (oldGeometry.y() >= oldTopMax && newGeom.y() < topMax) {
-        newGeom.setTop(std::max(topMax, screenArea.top()));
-    }
-
     checkOffscreenPosition(&newGeom, screenArea);
     // Obey size hints. TODO: We really should make sure it stays in the right place
     newGeom.setSize(constrainFrameSize(newGeom.size()));
diff --git a/src/workspace.cpp b/src/workspace.cpp
index 17fe718b2f0..b585f809f69 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -2462,7 +2462,6 @@ void Workspace::rearrange(const QHash<Window *, LogicalOutput *> &oldOutputs)
         m_screenAreas = screenAreas;
 
         m_inRearrange = true;
-        m_oldRestrictedArea = m_restrictedArea;
         m_restrictedArea = restrictedArea;
 
 #if KWIN_BUILD_X11
@@ -2480,7 +2479,6 @@ void Workspace::rearrange(const QHash<Window *, LogicalOutput *> &oldOutputs)
             }
         }
 
-        m_oldRestrictedArea.clear(); // reset, no longer valid or needed
         m_inRearrange = false;
     }
 }
@@ -2554,22 +2552,6 @@ bool Workspace::inRearrange() const
     return m_inRearrange;
 }
 
-StrutRects Workspace::previousRestrictedMoveArea(StrutAreas areas) const
-{
-    if (areas == StrutAreaAll) {
-        return m_oldRestrictedArea;
-    }
-
-    StrutRects ret;
-    ret.reserve(m_oldRestrictedArea.size());
-    for (const StrutRect &rect : m_oldRestrictedArea) {
-        if (rect.area() & areas) {
-            ret.append(rect);
-        }
-    }
-    return ret;
-}
-
 QHash<const LogicalOutput *, Rect> Workspace::previousScreenSizes() const
 {
     return m_oldScreenGeometries;
diff --git a/src/workspace.h b/src/workspace.h
index 31bc016b014..3afc31f8873 100644
--- a/src/workspace.h
+++ b/src/workspace.h
@@ -237,7 +237,6 @@ public:
     // Unsorted
 
 public:
-    StrutRects previousRestrictedMoveArea(StrutAreas areas = StrutAreaAll) const;
     QHash<const LogicalOutput *, Rect> previousScreenSizes() const;
 
     /**
@@ -709,7 +708,6 @@ private:
     Rect m_geometry;
 
     QHash<const LogicalOutput *, Rect> m_oldScreenGeometries;
-    StrutRects m_oldRestrictedArea;
     QTimer m_rearrangeTimer;
     bool m_inRearrange = false;