Merge branch 'card-list': the thread pane as a list of cards

Replaces the five-column grid with a single column of three-line cards. Item 53
recorded that the columns, not the cues drawn inside them, were what made the
list read as a table of records; item 20 had already shipped finished, tested
and green and been rejected on sight for exactly that reason.

A card is sender and date, subject with the flag, attachment and reply-count
marks, and tags, at one uniform height. Replies indent under a continuous spine
and show only the tags their thread does not carry. The account colour runs down
the card's left edge, replacing the chip that used to eat a third of every
subject line, with matching swatches in the account dropdown. Sorting newest or
oldest first is new and remembered.

Closes items 20, 51, 53 and 60.

The four defects that mattered were all found by rendering cards to an image and
looking at them, with the suite green through every one: a date clipped on unread
cards because bold is wider than the font the layout measured, an accent bar
painted in a colour identical to the background, an expander pill in a palette
role a theme had made equal to Base, and three separate faults from trusting
notmuch's reply depth to mean structure when it only means how notmuch happened
to thread the mail.

1 files changed, 36 insertions, 0 deletions

diff --git a/src/keymap.cpp b/src/keymap.cpp
index 29a5f71..cdd26a1 100644
--- a/src/keymap.cpp
+++ b/src/keymap.cpp
@@ -18,6 +18,8 @@
 
 #include "keymap.h"
 
+#include <algorithm>
+
 #include <QSettings>
 
 QStringList KeyMap::knownActions()
@@ -64,6 +66,18 @@ QList<QPair<QString, QString>> KeyMap::defaultBindings()
     return {
         { QStringLiteral("Ctrl+J"),       QStringLiteral("next_thread") },
         { QStringLiteral("Ctrl+K"),       QStringLiteral("prev_thread") },
+        // Alt, because Shift+Up/Down is QTreeView's built-in extend-selection,
+        // which multi-row tagging depends on, and plain Up/Down is the view's
+        // own navigation, which already steps INTO an expanded thread's
+        // replies and is what gives message-to-message movement for free.
+        //
+        // These must stay chords. Every action is a QAction with
+        // WindowShortcut, dispatched before the focused widget sees the key,
+        // and Qt withholds only plain LETTERS from editable widgets: a bare
+        // Up bound here would break the arrow keys in the query bar, the tag
+        // dialog and the web view at once, exactly as Return did.
+        { QStringLiteral("Alt+Down"),      QStringLiteral("next_thread") },
+        { QStringLiteral("Alt+Up"),        QStringLiteral("prev_thread") },
         { QStringLiteral("Return"),       QStringLiteral("open_thread") },
         { QStringLiteral("Ctrl+E"),       QStringLiteral("archive") },
         { QStringLiteral("Ctrl+D"),       QStringLiteral("delete") },
@@ -153,6 +167,28 @@ void KeyMap::loadDefaults()
         m_bindings.insert(normalizeSequence(binding.first), binding.second);
 }
 
+QList<QKeySequence> KeyMap::sequencesFor(const QString &action) const
+{
+    const QKeySequence primary = sequenceFor(action);
+    if (primary.isEmpty())
+        return {};
+
+    QList<QKeySequence> all{ primary };
+    QList<QKeySequence> rest;
+    for (auto it = m_bindings.cbegin(); it != m_bindings.cend(); ++it) {
+        if (it.value() == action && it.key() != primary)
+            rest.append(it.key());
+    }
+    // QHash iteration order is unspecified, so the tail is sorted rather than
+    // left to chance: an action's shortcut list must not reorder between runs.
+    std::sort(rest.begin(), rest.end(),
+              [](const QKeySequence &a, const QKeySequence &b) {
+                  return a.toString() < b.toString();
+              });
+    all += rest;
+    return all;
+}
+
 QKeySequence KeyMap::sequenceFor(const QString &action) const
 {
     // Several sequences can reach one action: the built-in default, which