1 files changed, 136 insertions, 0 deletions
diff --git a/src/tagstrip.cpp b/src/tagstrip.cpp
new file mode 100644
index 0000000..bad116a
--- /dev/null
+++ b/src/tagstrip.cpp
@@ -0,0 +1,136 @@
+/*
+ * qtmaildir - a Qt6 mail client for notmuch-indexed Maildirs
+ * Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "tagstrip.h"
+
+#include <QFontMetrics>
+#include <QPainter>
+
+#include "tagchip.h"
+#include "tagcolors.h"
+
+namespace {
+
+/// Text of the chip standing in for tags that did not fit.
+QString overflowText(int count)
+{
+    return QStringLiteral("+%1").arg(count);
+}
+
+}  // namespace
+
+TagStrip::TagStrip(QWidget *parent)
+    : QWidget(parent)
+{
+    setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+}
+
+void TagStrip::setTagColors(const TagColors *colours)
+{
+    m_tagColors = colours;
+    update();
+}
+
+void TagStrip::setTags(const QStringList &tags)
+{
+    m_tags.clear();
+    for (const QString &tag : tags) {
+        // The account tag is shown as a chip in the thread list instead: it
+        // says which mailbox the thread came from, not what state it is in.
+        if (!TagColors::isAccountTag(tag))
+            m_tags.append(tag);
+    }
+    m_tags.sort();
+
+    relayout();
+    setVisible(!m_tags.isEmpty());
+    update();
+}
+
+void TagStrip::relayout()
+{
+    m_visible.clear();
+    m_hidden.clear();
+    if (m_tags.isEmpty())
+        return;
+
+    const QFontMetrics metrics(font());
+    // Reserve room for the overflow chip up front. Sizing it for the worst
+    // case avoids the loop having to back out a chip it already placed.
+    const int overflowWidth =
+        TagChip::sizeFor(metrics, overflowText(m_tags.size())).width()
+        + TagChip::kSpacing;
+
+    int used = 0;
+    for (int i = 0; i < m_tags.size(); ++i) {
+        const int chipWidth =
+            TagChip::sizeFor(metrics, m_tags.at(i)).width() + TagChip::kSpacing;
+        const bool isLast = (i == m_tags.size() - 1);
+        // Every chip but the last must also leave room for the overflow chip,
+        // since anything after it will be hidden.
+        const int needed = used + chipWidth + (isLast ? 0 : overflowWidth);
+        if (needed > width() && !m_visible.isEmpty()) {
+            m_hidden = m_tags.mid(i);
+            break;
+        }
+        m_visible.append(m_tags.at(i));
+        used += chipWidth;
+    }
+
+    setToolTip(m_hidden.isEmpty() ? QString()
+                                  : m_hidden.join(QStringLiteral(", ")));
+}
+
+QSize TagStrip::sizeHint() const
+{
+    const QFontMetrics metrics(font());
+    return QSize(0, metrics.height() + TagChip::kPaddingY * 2
+                        + TagChip::kSpacing * 2);
+}
+
+void TagStrip::resizeEvent(QResizeEvent *event)
+{
+    QWidget::resizeEvent(event);
+    relayout();
+}
+
+void TagStrip::paintEvent(QPaintEvent *)
+{
+    if (m_visible.isEmpty())
+        return;
+
+    QPainter painter(this);
+    const QFontMetrics metrics(font());
+    const int top = (height() - (metrics.height() + TagChip::kPaddingY * 2)) / 2;
+
+    int x = 0;
+    for (const QString &tag : m_visible) {
+        const QSize size = TagChip::sizeFor(metrics, tag);
+        const QColor colour = m_tagColors ? m_tagColors->colourFor(tag)
+                                          : TagColors().colourFor(tag);
+        TagChip::paint(&painter, QRect(QPoint(x, top), size), tag, colour);
+        x += size.width() + TagChip::kSpacing;
+    }
+
+    if (!m_hidden.isEmpty()) {
+        const QString text = overflowText(m_hidden.size());
+        const QSize size = TagChip::sizeFor(metrics, text);
+        TagChip::paint(&painter, QRect(QPoint(x, top), size), text,
+                       QColor(0x44, 0x44, 0x4c));
+    }
+}