Merge: searching from the message pane (item 85)

Five surfaces in the message pane offer a search built from what they show:
the header's subject and date, its sender and recipients on a single-message
thread, a tag chip, a body selection, and every header per message in the
details dialog. Each offers Search for this, which replaces the query, and
Add to search, which narrows it.

The details dialog became labelled rows along the way, which the user wanted
independently of this feature.

Hand tested through every surface, including the case the parenthesising
exists for: adding a sender to 'tag:inbox or tag:flagged' narrows it rather
than widening it.

1 files changed, 145 insertions, 44 deletions

diff --git a/src/messageview.cpp b/src/messageview.cpp
index d2be380..2e7e694 100644
--- a/src/messageview.cpp
+++ b/src/messageview.cpp
@@ -22,14 +22,13 @@
 #include <QDesktopServices>
 #include <QDialog>
 #include <QDialogButtonBox>
-#include <QFontDatabase>
-#include <QPlainTextEdit>
 #include <QDir>
 #include <QBuffer>
 #include <QFileDialog>
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QLocale>
+#include <QMenu>
 #include <QMouseEvent>
 #include <QPushButton>
 #include <QStandardPaths>
@@ -49,7 +48,9 @@
 
 #include "cidschemehandler.h"
 #include "htmlbuilder.h"
+#include "messagedetailsdialog.h"
 #include "requestinterceptor.h"
+#include "searchterm.h"
 #include "tagstrip.h"
 #include "threadcidmap.h"
 #include "version.h"
@@ -151,6 +152,12 @@ MessageView::MessageView(QWidget *parent)
     settings->setAttribute(QWebEngineSettings::PluginsEnabled, false);
     settings->setAttribute(QWebEngineSettings::FullScreenSupportEnabled, false);
 
+    // Item 85: a selection in the body is searchable. CustomContextMenu so the
+    // page's standard entries survive and the search is added to them.
+    m_view->setContextMenuPolicy(Qt::CustomContextMenu);
+    connect(m_view, &QWidget::customContextMenuRequested,
+            this, &MessageView::showBodyContextMenu);
+
     // Ctrl+wheel zoom. The filter goes on the application rather than on
     // m_view: the wheel event is delivered to an internal QQuickWidget the
     // view creates lazily, so there is no child to filter at this point and a
@@ -163,6 +170,12 @@ MessageView::MessageView(QWidget *parent)
     m_headerLabel->setWordWrap(true);
     m_headerLabel->setTextInteractionFlags(Qt::TextSelectableByMouse);
 
+    // Item 85: the header's values are searchable. CustomContextMenu rather
+    // than an action list, since the entries depend on what is displayed.
+    m_headerLabel->setContextMenuPolicy(Qt::CustomContextMenu);
+    connect(m_headerLabel, &QWidget::customContextMenuRequested,
+            this, &MessageView::showHeaderContextMenu);
+
     // To the right of the header, per the user's decision: the summary answers
     // "who is this from", this answers "what actually happened to it". A button
     // and not only a shortcut, since "everything needs a memorized key" is the
@@ -239,6 +252,20 @@ MessageView::MessageView(QWidget *parent)
     m_tagStrip = new TagStrip(this);
     m_tagStrip->hide();
 
+    // Item 85: a tag chip is searchable. The strip reports which chip was hit
+    // and where; what a tag can do is decided here, beside the other menus, so
+    // all three surfaces offer the same pair of operations.
+    connect(m_tagStrip, &TagStrip::tagContextMenuRequested, this,
+            [this](const QString &tag, const QPoint &globalPos) {
+                const QString query = SearchTerm::tag(tag);
+                if (query.isEmpty())
+                    return;
+
+                QMenu menu(this);
+                addSearchEntries(&menu, { { tr("tag %1").arg(tag), query } });
+                menu.exec(globalPos);
+            });
+
     auto *layout = new QVBoxLayout(this);
     layout->addLayout(headerRow);
     layout->addLayout(blockedRow);
@@ -428,6 +455,11 @@ QString MessageView::headerMark(Marks::Mark mark) const
 
 void MessageView::updateHeader()
 {
+    // A stale offer list must not survive either exit: the early return below
+    // leaves nothing on screen to search, and the normal path rebuilds it from
+    // scratch a few lines down.
+    m_headerOffers.clear();
+
     if (m_items.isEmpty()) {
         m_headerLabel->clear();
         m_detailsButton->hide();
@@ -440,6 +472,30 @@ void MessageView::updateHeader()
     // Re: prefixes that add nothing.
     const QString subject = m_items.first().message.subject;
 
+    // Collected by the pass that renders the label, from the same values, so
+    // nothing has to parse the rendered markup back into structure.
+    auto elided = [](const QString &value) {
+        constexpr int kMaxLabel = 40;
+        return value.size() > kMaxLabel
+                   ? value.left(kMaxLabel) + QStringLiteral("...")
+                   : value;
+    };
+
+    auto offer = [this](const QString &label, const QString &query) {
+        if (query.isEmpty())
+            return;
+        m_headerOffers.append({ label, query });
+    };
+
+    offer(tr("subject \"%1\"").arg(elided(subject)),
+          SearchTerm::field(QStringLiteral("subject"), subject));
+
+    const QDateTime sent = MimeParser::parseDate(m_items.first().message.date);
+    if (sent.isValid()) {
+        offer(tr("mail from %1").arg(sent.date().toString(Qt::ISODate)),
+              SearchTerm::onDate(sent.date()));
+    }
+
     // Item 70's marks, beside the subject and OUTSIDE the message area. The
     // user asked for these two only: whether the thread is flagged and whether
     // it carries an attachment, which are the two states worth knowing before
@@ -489,6 +545,16 @@ void MessageView::updateHeader()
         row(tr("From:"), message.from);
         row(tr("To:"), message.to);
         row(tr("Cc:"), message.cc);
+
+        // Only here, sharing the condition with the header's own display: for
+        // a real thread these differ message to message, and the details
+        // dialog is where they are unambiguous.
+        offer(tr("sender %1").arg(elided(message.from)),
+              SearchTerm::field(QStringLiteral("from"), message.from));
+        offer(tr("recipient %1").arg(elided(message.to)),
+              SearchTerm::field(QStringLiteral("to"), message.to));
+        offer(tr("copied to %1").arg(elided(message.cc)),
+              SearchTerm::field(QStringLiteral("cc"), message.cc));
     } else {
         text += QStringLiteral("<br><small>%1</small>")
                     .arg(tr("%n message(s) in thread", "", m_items.size()));
@@ -497,58 +563,93 @@ void MessageView::updateHeader()
     m_headerLabel->setText(text);
 }
 
-void MessageView::showDetailsDialog()
+void MessageView::addSearchEntries(QMenu *menu, const QList<SearchOffer> &offers)
 {
-    if (m_items.isEmpty())
+    for (const SearchOffer &entry : offers) {
+        auto *sub = menu->addMenu(tr("Search for %1").arg(entry.label));
+
+        auto *replace = sub->addAction(tr("Search for this"));
+        connect(replace, &QAction::triggered, this,
+                [this, entry]() { emit searchRequested(entry.query, false); });
+
+        auto *narrow = sub->addAction(tr("Add to search"));
+        connect(narrow, &QAction::triggered, this,
+                [this, entry]() { emit searchRequested(entry.query, true); });
+    }
+}
+
+void MessageView::showHeaderContextMenu(const QPoint &pos)
+{
+    if (m_headerOffers.isEmpty())
         return;
 
-    QDialog dialog(this);
-    dialog.setWindowTitle(tr("Message details"));
+    QMenu menu(this);
+    addSearchEntries(&menu, m_headerOffers);
+    menu.exec(m_headerLabel->mapToGlobal(pos));
+}
 
-    auto *layout = new QVBoxLayout(&dialog);
+SearchOffer MessageView::selectionSearchOffer(const QString &selectedText) const
+{
+    const QString query = SearchTerm::quote(selectedText);
+    if (query.isEmpty())
+        return {};
 
-    auto *details = new QPlainTextEdit(&dialog);
-    details->setReadOnly(true);
-    // A monospaced font keeps a long Received chain readable as the wrapped
-    // record it is.
-    details->setFont(QFontDatabase::systemFont(QFontDatabase::FixedFont));
-    details->setLineWrapMode(QPlainTextEdit::NoWrap);
-
-    // setPlainText, and a QPlainTextEdit rather than a label: this dialog shows
-    // header values verbatim, and those come from strangers. Plain text cannot
-    // interpret markup, so there is nothing here to escape and nothing that
-    // could render.
-    QString text;
-    for (int i = 0; i < m_items.size(); ++i) {
-        const ParsedMessage &message = m_items.at(i).message;
-
-        if (i > 0)
-            text += QLatin1Char('\n');
-        if (m_items.size() > 1)
-            text += tr("--- Message %1 of %2 ---")
-                        .arg(i + 1).arg(m_items.size()) + QLatin1Char('\n');
-
-        auto line = [&text](const QString &label, const QString &value) {
-            if (!value.isEmpty())
-                text += label + QLatin1Char(' ') + value + QLatin1Char('\n');
-        };
+    constexpr int kMaxLabel = 40;
+    const QString shown = selectedText.simplified();
+    return { shown.size() > kMaxLabel
+                 ? shown.left(kMaxLabel) + QStringLiteral("...")
+                 : shown,
+             query };
+}
 
-        line(tr("Subject:"), message.subject);
-        line(tr("From:"), message.from);
-        line(tr("To:"), message.to);
-        line(tr("Cc:"), message.cc);
-        line(tr("Date:"), message.date);
-        line(tr("Message-Id:"), message.messageId);
+void MessageView::showBodyContextMenu(const QPoint &pos)
+{
+    // The page's own menu first: copy, select all and the rest stay exactly as
+    // they were. This adds to that menu rather than replacing it.
+    QMenu *menu = m_view->createStandardContextMenu();
+    if (!menu)
+        menu = new QMenu(this);
+    menu->setAttribute(Qt::WA_DeleteOnClose);
+
+    // selectedText() reads the selection out of the render process with no
+    // script injection. JavaScript is disabled in this profile and stays so.
+    const SearchOffer offer = selectionSearchOffer(m_view->page()->selectedText());
+    if (!offer.query.isEmpty()) {
+        menu->addSeparator();
+        addSearchEntries(menu, { offer });
     }
-    details->setPlainText(text);
 
-    layout->addWidget(details);
+    // popup() rather than exec(): the menu owns itself via WA_DeleteOnClose and
+    // must not block this handler.
+    menu->popup(m_view->mapToGlobal(pos));
+}
 
-    auto *buttons = new QDialogButtonBox(QDialogButtonBox::Close, &dialog);
-    connect(buttons, &QDialogButtonBox::rejected, &dialog, &QDialog::reject);
-    layout->addWidget(buttons);
+void MessageView::showDetailsDialog()
+{
+    if (m_items.isEmpty())
+        return;
+
+    MessageDetailsDialog dialog(m_items, this);
+
+    // The dialog's searches are the pane's searches: one signal reaches the
+    // window whichever surface the user used.
+    //
+    // It CLOSES on the way out, and that is not tidiness. The dialog is modal,
+    // so without this the query runs and the thread list repaints behind a
+    // window the user still has to dismiss, making the search look like it did
+    // nothing.
+    //
+    // accept() BEFORE the emit, not after. The connection is direct, so the
+    // emit runs the query synchronously: the model clears and this pane blanks
+    // while the modal dialog is still up, holding the m_items it was built
+    // from. Closing first leaves no window in which the dialog describes a
+    // thread the pane has already dropped.
+    connect(&dialog, &MessageDetailsDialog::searchRequested, this,
+            [this, &dialog](const QString &query, bool extend) {
+                dialog.accept();
+                emit searchRequested(query, extend);
+            });
 
-    dialog.resize(700, 400);
     dialog.exec();
 }