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, 49 insertions, 0 deletions

diff --git a/src/messageview.h b/src/messageview.h
index 422869a..3e600f0 100644
--- a/src/messageview.h
+++ b/src/messageview.h
@@ -25,8 +25,10 @@
 #include "htmlbuilder.h"
 #include "marks.h"
 #include "mimeparser.h"
+#include "searchterm.h"
 
 class QLabel;
+class QMenu;
 class QPushButton;
 class QWebEngineView;
 class QWebEngineProfile;
@@ -127,6 +129,26 @@ public:
     /// is rendered or the notice is hidden.
     QString staleMessageId() const { return m_staleMessageId; }
 
+    /// What the header can be searched for, given what it is currently showing.
+    ///
+    /// From, To and Cc appear only for a single-message thread, which is
+    /// exactly when the header displays them: for a real thread the recipient
+    /// differs message to message and the header says only the subject and the
+    /// count. The menu must never offer a value the header is not stating.
+    ///
+    /// The values come from the same pass that renders the label, never from
+    /// parsing it back: rich text does not survive a second parse.
+    QList<SearchOffer> headerSearchOffers() const { return m_headerOffers; }
+
+    /// The offer for a body selection, its query empty when there is nothing
+    /// usable selected.
+    ///
+    /// Takes the text rather than reading the page, so the quoting is testable
+    /// without a live web engine and a rendered document. A selection is
+    /// arbitrary prose and can carry quotes, newlines and query syntax, none
+    /// of which notmuch reports as an error.
+    SearchOffer selectionSearchOffer(const QString &selectedText) const;
+
 public slots:
     void toggleHtml();
     void loadRemoteContent();
@@ -158,6 +180,18 @@ signals:
     void staleThreadRecoveryRequested(const QString &threadId,
                                       const QString &messageId);
 
+    /// The user chose a search from one of the pane's context menus.
+    ///
+    /// `extend` narrows the current query rather than replacing it. The view
+    /// does not know what the query bar holds and must not: the window owns
+    /// that field and does the combining.
+    ///
+    /// Separate from queryRequested(), which carries a gate against a link in
+    /// a rendered document driving the thread list. These menus are chrome
+    /// built by our own code from values we extracted, so they need no gate,
+    /// and widening the existing signal would change what that gate protects.
+    void searchRequested(const QString &query, bool extend);
+
 protected:
     /// Turns Ctrl+wheel over the body into zoom, and Ctrl+middle-click into a
     /// reset. Both events are delivered to the web view's internal QQuickWidget
@@ -207,6 +241,18 @@ private:
     /// Every attachment in the thread, in the order the messages render.
     QList<Attachment> allAttachments() const;
 
+    /// Builds and pops the header's menu at `pos`, in the label's coordinates.
+    void showHeaderContextMenu(const QPoint &pos);
+
+    /// Builds and pops the web view's menu, keeping its standard entries.
+    void showBodyContextMenu(const QPoint &pos);
+
+    /// Appends a "Search for ..." submenu per offer, each holding the replace
+    /// and the narrow operation.
+    ///
+    /// Shared with the web view's menu in a later task so the two cannot grow
+    /// different wording or a different pair of operations.
+    void addSearchEntries(QMenu *menu, const QList<SearchOffer> &offers);
 
     QList<ThreadRenderItem> m_items;
     bool m_preferHtml = true;
@@ -232,4 +278,7 @@ private:
     QPushButton *m_detailsButton = nullptr;
     QWidget *m_attachmentBar = nullptr;
     TagStrip *m_tagStrip = nullptr;
+
+    /// Populated by updateHeader(), consumed by the header's context menu.
+    QList<SearchOffer> m_headerOffers;
 };