[Game] Raise rubber band above count label and collapse multi-selection on click (#7451)

* [Game] Raise rubber band above count label and collapse multi-selection on click

Raise rubber band on start and collapse multi-selection to clicked card when left-clicking an already-selected card with no modifiers.

* [Game] Collapse multi-selection on release instead of press

Collapsing at press time dropped the selection before the drag started,
which broke dragging multiple cards. Keep the selection on press and
collapse it on release when the pointer stayed within the drag
distance.

* [Game] Defer selection collapse until the double-click window passes

A release without drag collapsed the multi-selection immediately, so a
double-click that followed (playSelected acts on scene()->selectedItems())
only ever saw the single clicked card. When the card handles
double-clicks on the selection, arm the collapse on a single-shot timer
for QApplication::doubleClickInterval() instead and cancel it from the
double-click handler; a new press disarms the other cards and a
selection-count guard covers rubber-band/ctrl changes meanwhile.

* [Game] Keep sideboard multi-selection on double-click

DeckViewCard overrides doubleClickActsOnSelection to preserve the
selection, restoring master behavior where double-clicking moves all
selected cards between main and side. DeckView cancels any pending
collapse before reading the selection.

* [Game] Remove duplicated inline selection-collapse declarations

* [Game] Fix DeckView collapse call visibility and multi-selection collapse

Make cancelPendingSelectionCollapse() public so DeckView can call it on
selected DeckViewCards. Always arm the deferred collapse on release
instead of skipping cards whose double-click acts on the selection;
the double-click-interval timer plus the cancel calls in
CardItem::mouseDoubleClickEvent and DeckView::mouseDoubleClickEvent
already preserve the selection for double-clicks.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/game_graphics/board/abstract_card_item.cpp

@@ -12,6 +12,7 @@
 #include "libcockatrice/card/printing/exact_card.h"
 #include "libcockatrice/utility/card_ref.h"
 
+#include <QApplication>
 #include <QBrush>
 #include <QChar>
 #include <QCursor>
@@ -28,6 +29,7 @@
 #include <QPixmap>
 #include <QPointF>
 #include <QRectF>
+#include <QTimer>
 #include <QTransform>
 #include <QVariant>
 #include <QtGlobal>
@@ -42,7 +44,7 @@ class QSizeF;
 
 AbstractCardItem::AbstractCardItem(QGraphicsItem *parent, const CardRef &cardRef, PlayerLogic *_owner, int _id)
     : ArrowTarget(_owner, parent), id(_id), cardRef(cardRef), tapped(false), facedown(false), tapAngle(0),
-      bgColor(Qt::transparent), isHovered(false), realZValue(0)
+      bgColor(Qt::transparent), isHovered(false), realZValue(0), pendingSelectionCollapse(false)
 {
     setCursor(Qt::OpenHandCursor);
     setFlag(ItemIsSelectable);
@@ -344,6 +346,16 @@ void AbstractCardItem::setFaceDown(bool _facedown)
 
 void AbstractCardItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 {
+    cancelPendingSelectionCollapse();
+    if (scene() != nullptr) {
+        // A new press starts a new gesture: no card may collapse the selection out from under it afterwards.
+        for (QGraphicsItem *selectedItem : scene()->selectedItems()) {
+            auto *selectedCard = qgraphicsitem_cast<AbstractCardItem *>(selectedItem);
+            if (selectedCard != nullptr && selectedCard != this) {
+                selectedCard->cancelPendingSelectionCollapse();
+            }
+        }
+    }
     if ((event->modifiers() & Qt::AltModifier) && event->button() == Qt::LeftButton) {
         emit cardShiftClicked(cardRef.name);
     } else if ((event->modifiers() & Qt::ControlModifier)) {
@@ -351,6 +363,10 @@ void AbstractCardItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
     } else if (!isSelected()) {
         scene()->clearSelection();
         setSelected(true);
+    } else if (event->button() == Qt::LeftButton && scene()->selectedItems().count() > 1) {
+        // Part of a multi-selection; collapse only if this turns out to be a click rather than a drag,
+        // so that dragging the whole selection keeps it intact.
+        pendingSelectionCollapse = true;
     }
     if (event->button() == Qt::LeftButton) {
         setCursor(Qt::ClosedHandCursor);
@@ -362,6 +378,32 @@ void AbstractCardItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
 
 void AbstractCardItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 {
+    if (pendingSelectionCollapse) {
+        pendingSelectionCollapse = false;
+        bool dragged = (event->screenPos() - event->buttonDownScreenPos(event->button())).manhattanLength() >=
+                       2 * QApplication::startDragDistance();
+        if (!dragged) {
+            if (doubleClickActsOnSelection()) {
+                // A double-click may still arrive and must act on the whole multi-selection, so collapse only
+                // once the double-click window has passed without one. The generation guard (and the receiver
+                // context) drops the collapse if the item is gone, deselected, or a double-click cancelled it;
+                // the count guard drops it if the selection changed meanwhile (rubber band, ctrl-toggle).
+                const int generation = ++selectionCollapseGeneration;
+                const int armedSelectionCount = scene()->selectedItems().count();
+                QTimer::singleShot(QApplication::doubleClickInterval(), this, [this, generation, armedSelectionCount] {
+                    if (generation == selectionCollapseGeneration && scene() != nullptr && isSelected() &&
+                        scene()->selectedItems().count() == armedSelectionCount && armedSelectionCount > 1) {
+                        scene()->clearSelection();
+                        setSelected(true);
+                    }
+                });
+            } else {
+                scene()->clearSelection();
+                setSelected(true);
+            }
+        }
+    }
+
     if (event->button() == Qt::MiddleButton) {
         emit deleteCardInfoPopup(cardRef.name);
     }
@@ -370,6 +412,17 @@ void AbstractCardItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
     event->accept();
 }
 
+void AbstractCardItem::cancelPendingSelectionCollapse()
+{
+    pendingSelectionCollapse = false;
+    ++selectionCollapseGeneration;
+}
+
+bool AbstractCardItem::doubleClickActsOnSelection() const
+{
+    return false;
+}
+
 void AbstractCardItem::processHoverEvent()
 {
     emit hovered(this);