size the controls panel to the rows it is actually showing

src/ui/ControlsPanel.cpp

@@ -1,5 +1,6 @@
 #include "ControlsPanel.h"
 
+#include <QFont>
 #include <QFrame>
 #include <QHBoxLayout>
 #include <QLabel>
@@ -21,6 +22,20 @@ const int kRefreshMs     = 50;  // see the class comment on why this polls
 // Separates the heading's name from its detail, e.g. "BUILD MODE * Assembler".
 const QChar kHeadingSeparator(0x00B7);  // U+00B7 MIDDLE DOT
 
+// The upper-case heading and caption are tracked out a little so they read as labels
+// rather than as words. Set on the font because Qt's stylesheets have no letter-spacing
+// property -- writing one there is silently ignored apart from a warning per widget.
+QFont makeSpacedFont(QFont font, bool bold, int pointSizeDelta)
+{
+    font.setBold(bold);
+    if (pointSizeDelta != 0 && font.pointSize() > 0)
+    {
+        font.setPointSize(qMax(1, font.pointSize() + pointSizeDelta));
+    }
+    font.setLetterSpacing(QFont::AbsoluteSpacing, 1.0);
+    return font;
+}
+
 // One row: the chips for the bindings, then what the action is called. Built as a plain
 // widget rather than a class of its own -- it holds no state and answers no questions.
 QWidget* makeRow(ControlAction action, const ControlContext& context, QWidget* parent)
@@ -50,6 +65,18 @@ QWidget* makeRow(ControlAction action, const ControlContext& context, QWidget* p
     return row;
 }
 
+// Adds a freshly built widget to the rows and shows it.
+//
+// The show is what makes it count. A widget created under an already-visible parent
+// starts hidden, and a layout treats a hidden item as empty -- it contributes nothing
+// to the size hint until something shows it, which otherwise does not happen until the
+// event loop next runs, long after the panel has measured itself.
+void addAndShow(QVBoxLayout* layout, QWidget* widget)
+{
+    layout->addWidget(widget);
+    widget->show();
+}
+
 }  // namespace
 
 ControlsPanel::ControlsPanel(const GameWorldView* view, QWidget* parent)
@@ -63,19 +90,20 @@ ControlsPanel::ControlsPanel(const GameWorldView* view, QWidget* parent)
     // class scoped selector keeps the border on the panel rather than cascading onto
     // its children.
     setAttribute(Qt::WA_StyledBackground, true);
+    // Letter spacing is deliberately absent here: Qt's stylesheet syntax has no such
+    // property and warns on every widget it is applied to. The heading and the caption
+    // set it on their QFont instead.
     setStyleSheet(QStringLiteral(
         "ControlsPanel { background-color: palette(window);"
         " border: 1px solid palette(mid); border-radius: 4px; }"
-        "QLabel#controlHeading { font-weight: bold; letter-spacing: 1px;"
+        "QLabel#controlHeading { color: palette(text); }"
-        " color: palette(text); }"
         "QLabel#controlBadge { border: 1px solid palette(mid); border-radius: 3px;"
         " padding: 1px 5px; font-family: monospace; color: palette(text); }"
         "QLabel#controlLabel { color: palette(text); }"
         // The row that leaves the mode reads differently from the ones that act within
         // it (REQ-UI-CONTROLS-CARD).
         "QLabel#controlLabelExit { color: palette(bright-text); }"
-        "QLabel#controlCaption { color: palette(mid); font-size: 10px;"
+        "QLabel#controlCaption { color: palette(mid); }"));
-        " letter-spacing: 1px; }"));
 
     QVBoxLayout* outerLayout = new QVBoxLayout(this);
     outerLayout->setContentsMargins(kCardMarginPx, kCardMarginPx,
@@ -85,6 +113,7 @@ ControlsPanel::ControlsPanel(const GameWorldView* view, QWidget* parent)
     m_heading = new QLabel(this);
     m_heading->setObjectName(QStringLiteral("controlHeading"));
     m_heading->setCursor(Qt::PointingHandCursor);
+    m_heading->setFont(makeSpacedFont(font(), /*bold*/ true, /*pointSizeDelta*/ 0));
     outerLayout->addWidget(m_heading);
 
     m_rows       = new QWidget(this);
@@ -156,7 +185,7 @@ void ControlsPanel::rebuild(const ControlContext& context)
 
     for (ControlAction action : m_shownContextActions)
     {
-        m_rowsLayout->addWidget(makeRow(action, context, m_rows));
+        addAndShow(m_rowsLayout, makeRow(action, context, m_rows));
     }
 
     // The always-available block sits under a divider in every context, the General one
@@ -168,16 +197,17 @@ void ControlsPanel::rebuild(const ControlContext& context)
         divider->setFrameShape(QFrame::HLine);
         divider->setFrameShadow(QFrame::Plain);
         m_rowsLayout->addSpacing(6);
-        m_rowsLayout->addWidget(divider);
+        addAndShow(m_rowsLayout, divider);
 
         QLabel* caption = new QLabel(tr("ALWAYS AVAILABLE"), m_rows);
         caption->setObjectName(QStringLiteral("controlCaption"));
-        m_rowsLayout->addWidget(caption);
+        caption->setFont(makeSpacedFont(font(), /*bold*/ false, /*pointSizeDelta*/ -1));
+        addAndShow(m_rowsLayout, caption);
     }
 
     for (ControlAction action : m_shownAlwaysActions)
     {
-        m_rowsLayout->addWidget(makeRow(action, context, m_rows));
+        addAndShow(m_rowsLayout, makeRow(action, context, m_rows));
     }
 
     m_rows->setVisible(!m_collapsed);
@@ -221,16 +251,28 @@ void ControlsPanel::refit()
 {
     if (m_bandRect.isNull()) { return; }
 
-    // The layout drops hidden widgets from its size hint, but only once it has been
+    // Rows are torn down and rebuilt wholesale, and a widget added to a layout is only
-    // re-run: collapsing hides the rows before Qt would get around to it on its own.
+    // shown once that layout runs -- without this the new rows count for nothing and
-    layout()->activate();
+    // the card is measured for the context before it. The polish belongs to the same
+    // step: a freshly created label reports an unstyled size hint until the stylesheet
+    // has reached it, and the badge chips carry border and padding that change it.
+    m_rows->ensurePolished();
+    m_rowsLayout->invalidate();
+    m_rowsLayout->activate();
+
+    // Deliberately not activating the panel's own layout here. That lays the heading
+    // and the rows out inside the geometry the panel still has from the previous
+    // context, which is the wrong frame of reference for choosing the new one.
+    // totalSizeHint answers "how big does this need to be" without reference to how big
+    // it currently is; setGeometry below then re-runs the outer layout on its own.
+    layout()->invalidate();
+    const QSize needed = layout()->totalSizeHint();
 
     const QRect band = m_bandRect.adjusted(kMarginPx, kMarginPx, -kMarginPx, -kMarginPx);
     if (band.width() <= 0 || band.height() <= 0) { return; }
 
-    const QSize hint     = sizeHint();
+    const int widthPx  = qMin(needed.width(), band.width());
-    const int   widthPx  = qMin(hint.width(), band.width());
+    const int heightPx = qMin(needed.height(), band.height());
-    const int   heightPx = qMin(hint.height(), band.height());
 
     // Left edge of the band, sitting on its bottom edge, so the panel grows upward as
     // rows are added (REQ-UI-CONTROLS-PANEL).