feat(qt): add shift-click range selection to coin control dialog

Override mouse events in CoinControlTreeWidget to support shift-click for selecting/deselecting a contiguous range of UTXOs. Tracks an anchor item from the last normal click, and on shift-click sets all leaf items between anchor and target to the anchor's check state. Uses the existing setEnabled(false) bulk-update pattern to suppress per-item label recalculation.

Author: PastaPastaPasta

src/qt/coincontroldialog.cpp

@@ -166,6 +166,11 @@ CoinControlDialog::~CoinControlDialog()
     delete ui;
 }
 
+void CoinControlDialog::refreshLabels()
+{
+    CoinControlDialog::updateLabels(m_coin_control, model, this);
+}
+
 // ok button
 void CoinControlDialog::buttonBoxClicked(QAbstractButton* button)
 {
@@ -650,6 +655,7 @@ void CoinControlDialog::updateView()
 
     bool treeMode = ui->radioTreeMode->isChecked();
     ui->treeWidget->clear();
+    ui->treeWidget->resetAnchor();
     ui->treeWidget->setEnabled(false); // performance, otherwise updateLabels would be called for every checked checkbox
     ui->treeWidget->setAlternatingRowColors(!treeMode);
     QFlags<Qt::ItemFlag> flgCheckbox = Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable;

src/qt/coincontroldialog.h

@@ -48,6 +48,8 @@ class CoinControlDialog : public QDialog
     // static because also called from sendcoinsdialog
     static void updateLabels(wallet::CCoinControl& m_coin_control, WalletModel*, QDialog*);
 
+    void refreshLabels();
+
     static QList<CAmount> payAmounts;
     static bool fSubtractFeeFromAmount;
 

src/qt/coincontroltreewidget.cpp

@@ -5,12 +5,20 @@
 #include <qt/coincontroltreewidget.h>
 #include <qt/coincontroldialog.h>
 
+#include <QTreeWidgetItemIterator>
+
 CoinControlTreeWidget::CoinControlTreeWidget(QWidget *parent) :
     QTreeWidget(parent)
 {
 
 }
 
+void CoinControlTreeWidget::resetAnchor()
+{
+    m_lastClickedItem = nullptr;
+    m_lastClickedState = Qt::Unchecked;
+}
+
 void CoinControlTreeWidget::keyPressEvent(QKeyEvent *event)
 {
     if (event->key() == Qt::Key_Space) // press spacebar -> select checkbox
@@ -32,3 +40,91 @@ void CoinControlTreeWidget::keyPressEvent(QKeyEvent *event)
         this->QTreeWidget::keyPressEvent(event);
     }
 }
+
+// Helper: check if an item is a leaf node (UTXO) by its 64-char tx hash
+static bool isLeafItem(QTreeWidgetItem* item)
+{
+    int COLUMN_ADDRESS = 3;
+    return item && item->data(COLUMN_ADDRESS, Qt::UserRole).toString().length() == 64;
+}
+
+void CoinControlTreeWidget::mousePressEvent(QMouseEvent *event)
+{
+    QTreeWidgetItem* clickedItem = itemAt(event->pos());
+
+    // For shift+click on a leaf item with a valid anchor, suppress the default
+    // press handling to prevent Qt from setting up a single-item checkbox toggle
+    if ((event->button() == Qt::LeftButton)
+        && (event->modifiers() & Qt::ShiftModifier)
+        && m_lastClickedItem
+        && clickedItem
+        && clickedItem != m_lastClickedItem
+        && isLeafItem(clickedItem)) {
+        event->accept();
+        return;
+    }
+
+    QTreeWidget::mousePressEvent(event);
+}
+
+void CoinControlTreeWidget::mouseReleaseEvent(QMouseEvent *event)
+{
+    int COLUMN_CHECKBOX = 0;
+
+    QTreeWidgetItem* clickedItem = itemAt(event->pos());
+
+    bool isShiftClick = (event->button() == Qt::LeftButton)
+                        && (event->modifiers() & Qt::ShiftModifier)
+                        && m_lastClickedItem
+                        && clickedItem
+                        && clickedItem != m_lastClickedItem
+                        && isLeafItem(clickedItem);
+
+    if (!isShiftClick) {
+        // Normal click — let Qt handle the checkbox toggle on release
+        QTreeWidget::mouseReleaseEvent(event);
+        // Record anchor after toggle so we capture the post-toggle state
+        if (clickedItem && isLeafItem(clickedItem)) {
+            m_lastClickedItem = clickedItem;
+            m_lastClickedState = clickedItem->checkState(COLUMN_CHECKBOX);
+        }
+        return;
+    }
+
+    // Shift+click: select/deselect the range between anchor and target
+
+    // Collect all leaf items in display order
+    std::vector<QTreeWidgetItem*> leafItems;
+    int anchorIdx = -1;
+    int targetIdx = -1;
+    QTreeWidgetItemIterator it(this);
+    while (*it) {
+        if (isLeafItem(*it)) {
+            if (*it == m_lastClickedItem) anchorIdx = leafItems.size();
+            if (*it == clickedItem) targetIdx = leafItems.size();
+            leafItems.push_back(*it);
+        }
+        ++it;
+    }
+
+    if (anchorIdx < 0 || targetIdx < 0) {
+        QTreeWidget::mouseReleaseEvent(event);
+        return;
+    }
+
+    if (anchorIdx > targetIdx) std::swap(anchorIdx, targetIdx);
+
+    // Batch update: disable widget to suppress per-item updateLabels calls
+    setEnabled(false);
+    for (int i = anchorIdx; i <= targetIdx; ++i) {
+        QTreeWidgetItem* item = leafItems[i];
+        if (!item->isDisabled() && item->checkState(COLUMN_CHECKBOX) != m_lastClickedState) {
+            item->setCheckState(COLUMN_CHECKBOX, m_lastClickedState);
+        }
+    }
+    setEnabled(true);
+
+    // Single label update for the whole batch
+    CoinControlDialog* coinControlDialog = qobject_cast<CoinControlDialog*>(this->parentWidget());
+    if (coinControlDialog) coinControlDialog->refreshLabels();
+}

src/qt/coincontroltreewidget.h

@@ -6,6 +6,7 @@
 #define BITCOIN_QT_COINCONTROLTREEWIDGET_H
 
 #include <QKeyEvent>
+#include <QMouseEvent>
 #include <QTreeWidget>
 
 class CoinControlTreeWidget : public QTreeWidget
@@ -14,9 +15,16 @@ class CoinControlTreeWidget : public QTreeWidget
 
 public:
     explicit CoinControlTreeWidget(QWidget *parent = nullptr);
+    void resetAnchor();
 
 protected:
-    virtual void keyPressEvent(QKeyEvent *event) override;
+    void keyPressEvent(QKeyEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+
+private:
+    QTreeWidgetItem* m_lastClickedItem{nullptr};
+    Qt::CheckState m_lastClickedState{Qt::Unchecked};
 };
 
 #endif // BITCOIN_QT_COINCONTROLTREEWIDGET_H