Introduce Platform::outputAt()

With AbstractOutput being used more heavily, it makes sense to have
something like Screens::number() in the Platform class. As is, the steps
to get an output for a given point are awkward - first, get the screen
id, then use the screen id to get the output.

src/abstract_client.cpp

@@ -1327,11 +1327,11 @@ void AbstractClient::handleInteractiveMoveResize(int x, int y, int x_root, int y
         Q_ASSERT(mode == PositionCenter);
         if (!isMovable()) { // isMovableAcrossScreens() must have been true to get here
             // Special moving of maximized windows on Xinerama screens
-            int screen = screens()->number(globalPos);
+            AbstractOutput *output = kwinApp()->platform()->outputAt(globalPos);
             if (isFullScreen())
-                setMoveResizeGeometry(workspace()->clientArea(FullScreenArea, this, screen));
+                setMoveResizeGeometry(workspace()->clientArea(FullScreenArea, this, output));
             else {
-                QRect moveResizeGeom = workspace()->clientArea(MaximizeArea, this, screen);
+                QRect moveResizeGeom = workspace()->clientArea(MaximizeArea, this, output);
                 QSize adjSize = constrainFrameSize(moveResizeGeom.size(), SizeModeMax);
                 if (adjSize != moveResizeGeom.size()) {
                     QRect r(moveResizeGeom);
@@ -3382,8 +3382,7 @@ void AbstractClient::checkWorkspacePosition(QRect oldGeometry, QRect oldClientGe
             }
         }
     } else {
-        const int oldScreen = screens()->number(oldGeometry.center());
-        oldScreenArea = workspace()->clientArea(ScreenArea, kwinApp()->platform()->findOutput(oldScreen), oldDesktop);
+        oldScreenArea = workspace()->clientArea(ScreenArea, kwinApp()->platform()->outputAt(oldGeometry.center()), oldDesktop);
     }
     const QRect oldGeomTall = QRect(oldGeometry.x(), oldScreenArea.y(), oldGeometry.width(), oldScreenArea.height());   // Full screen height
     const QRect oldGeomWide = QRect(oldScreenArea.x(), oldGeometry.y(), oldScreenArea.width(), oldGeometry.height());   // Full screen width

src/platform.cpp

@@ -170,6 +170,28 @@ AbstractOutput *Platform::findOutput(const QUuid &uuid) const
     return nullptr;
 }
 
+AbstractOutput *Platform::outputAt(const QPoint &pos) const
+{
+    AbstractOutput *bestOutput = nullptr;
+    int minDistance = INT_MAX;
+    const auto candidates = enabledOutputs();
+    for (AbstractOutput *output : candidates) {
+        const QRect &geo = output->geometry();
+        if (geo.contains(pos)) {
+            return output;
+        }
+        int distance = QPoint(geo.topLeft() - pos).manhattanLength();
+        distance = std::min(distance, QPoint(geo.topRight() - pos).manhattanLength());
+        distance = std::min(distance, QPoint(geo.bottomRight() - pos).manhattanLength());
+        distance = std::min(distance, QPoint(geo.bottomLeft() - pos).manhattanLength());
+        if (distance < minDistance) {
+            minDistance = distance;
+            bestOutput = output;
+        }
+    }
+    return bestOutput;
+}
+
 bool Platform::usesSoftwareCursor() const
 {
     return m_softwareCursor;

src/platform.h

@@ -352,6 +352,7 @@ public:
     }
     AbstractOutput *findOutput(int screenId) const;
     AbstractOutput *findOutput(const QUuid &uuid) const;
+    AbstractOutput *outputAt(const QPoint &pos) const;
 
     /**
      * A string of information to include in kwin debug output

src/pointer_input.cpp

@@ -9,6 +9,7 @@
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "pointer_input.h"
+#include "abstract_output.h"
 #include "platform.h"
 #include "x11client.h"
 #include "effects.h"
@@ -813,8 +814,8 @@ void PointerInputRedirection::updatePosition(const QPointF &pos)
         const QRectF unitedScreensGeometry = screens()->geometry();
         p = confineToBoundingBox(p, unitedScreensGeometry);
         if (!screenContainsPos(p)) {
-            const QRectF currentScreenGeometry = screens()->geometry(screens()->number(m_pos.toPoint()));
-            p = confineToBoundingBox(p, currentScreenGeometry);
+            const AbstractOutput *currentOutput = kwinApp()->platform()->outputAt(m_pos.toPoint());
+            p = confineToBoundingBox(p, currentOutput->geometry());
         }
     }
     p = applyPointerConfinement(p);
@@ -903,9 +904,9 @@ void PointerInputRedirection::updateAfterScreenChange()
         return;
     }
     // pointer no longer on a screen, reposition to closes screen
-    const QPointF pos = screens()->geometry(screens()->number(m_pos.toPoint())).center();
+    const AbstractOutput *output = kwinApp()->platform()->outputAt(m_pos.toPoint());
     // TODO: better way to get timestamps
-    processMotion(pos, waylandServer()->seat()->timestamp());
+    processMotion(output->geometry().center(), waylandServer()->seat()->timestamp());
 }
 
 QPointF PointerInputRedirection::position() const

src/screens.cpp

@@ -295,24 +295,7 @@ int Screens::number(const QPoint &pos) const
     Q_UNUSED(pos)
     return -1;
 #else
-    int bestScreen = 0;
-    int minDistance = INT_MAX;
-    const auto outputs = kwinApp()->platform()->enabledOutputs();
-    for (int i = 0; i < outputs.size(); ++i) {
-        const QRect &geo = outputs[i]->geometry();
-        if (geo.contains(pos)) {
-            return i;
-        }
-        int distance = QPoint(geo.topLeft() - pos).manhattanLength();
-        distance = qMin(distance, QPoint(geo.topRight() - pos).manhattanLength());
-        distance = qMin(distance, QPoint(geo.bottomRight() - pos).manhattanLength());
-        distance = qMin(distance, QPoint(geo.bottomLeft() - pos).manhattanLength());
-        if (distance < minDistance) {
-            minDistance = distance;
-            bestScreen = i;
-        }
-    }
-    return bestScreen;
+    return kwinApp()->platform()->enabledOutputs().indexOf(kwinApp()->platform()->outputAt(pos));
 #endif
 }
 

src/workspace.cpp

@@ -2433,9 +2433,9 @@ QPoint Workspace::adjustClientPosition(AbstractClient* c, QPoint pos, bool unres
     if (options->windowSnapZone() || !borderSnapZone.isNull() || options->centerSnapZone()) {
 
         const bool sOWO = options->isSnapOnlyWhenOverlapping();
-        const int screen = screens()->number(pos + c->rect().center());
+        const AbstractOutput *output = kwinApp()->platform()->outputAt(pos + c->rect().center());
         if (maxRect.isNull())
-            maxRect = clientArea(MovementArea, c, screen);
+            maxRect = clientArea(MovementArea, c, output);
         const int xmin = maxRect.left();
         const int xmax = maxRect.right() + 1;             //desk size
         const int ymin = maxRect.top();

src/xdgshellclient.cpp

@@ -1565,8 +1565,8 @@ void XdgToplevelClient::setFullScreen(bool set, bool user)
     updateDecoration(false, false);
 
     if (set) {
-        const int screen = m_fullScreenRequestedOutput ? kwinApp()->platform()->enabledOutputs().indexOf(m_fullScreenRequestedOutput) : screens()->number(moveResizeGeometry().center());
-        moveResize(workspace()->clientArea(FullScreenArea, this, screen));
+        const AbstractOutput *output = m_fullScreenRequestedOutput ? m_fullScreenRequestedOutput.data() : kwinApp()->platform()->outputAt(moveResizeGeometry().center());
+        moveResize(workspace()->clientArea(FullScreenArea, this, output));
     } else {
         m_fullScreenRequestedOutput.clear();
         if (fullscreenGeometryRestore().isValid()) {