feat: resolve a selection's scope from what each row is

One resolver replacing the scopeFor/messageScopeFor pair. The caller no
longer chooses the scope, which is what let one gesture mean two things.

2 files changed, 45 insertions, 0 deletions

diff --git a/src/threadlistmodel.cpp b/src/threadlistmodel.cpp
index 4a75d47..ddddf0b 100644
--- a/src/threadlistmodel.cpp
+++ b/src/threadlistmodel.cpp
@@ -1117,6 +1117,43 @@ ActionScope ThreadListModel::scopeFor(const QModelIndexList &selection) const
     return scope;
 }
 
+ActionScope ThreadListModel::scopeForSelection(
+    const QModelIndexList &selection) const
+{
+    ActionScope scope;
+
+    for (const QModelIndex &index : selection) {
+        if (isConversationRow(index)) {
+            const ThreadSummary &summary = m_threads.at(index.row()).summary;
+            if (scope.threadIds.contains(summary.threadId))
+                continue;
+            scope.threadIds.append(summary.threadId);
+            // totalCount, not the loaded children: an unexpanded conversation
+            // still has all of its messages, and the count is what the status
+            // bar names after the fact.
+            scope.messageCount += summary.totalCount;
+            scope.wholeThread = true;
+            continue;
+        }
+
+        const QString messageId =
+            isMessageRow(index)
+                ? messageAt(index).messageId
+                : (index.row() >= 0 && index.row() < m_threads.size()
+                       ? m_threads.at(index.row()).summary.firstMessageId
+                       : QString());
+
+        // Skipped rather than widened. Falling back to the thread would
+        // silently act on messages the row does not stand for.
+        if (messageId.isEmpty() || scope.messageIds.contains(messageId))
+            continue;
+        scope.messageIds.append(messageId);
+        scope.messageCount += 1;
+    }
+
+    return scope;
+}
+
 ThreadSummary ThreadListModel::threadAt(int row) const
 {
     if (row < 0 || row >= m_threads.size())
diff --git a/src/threadlistmodel.h b/src/threadlistmodel.h
index 5cd1392..fcbb8f5 100644
--- a/src/threadlistmodel.h
+++ b/src/threadlistmodel.h
@@ -361,6 +361,14 @@ public:
     /// thread instead would be the silent escalation this exists to remove.
     ActionScope messageScopeFor(const QModelIndexList &selection) const;
 
+    /// What a selection means, resolved per row from what that row IS.
+    ///
+    /// Replaces the scopeFor()/messageScopeFor() pair, which made the caller
+    /// choose the scope and so let one gesture mean two things (item 177). A
+    /// conversation row contributes its thread, any other row its message, and
+    /// a mixed selection carries both.
+    ActionScope scopeForSelection(const QModelIndexList &selection) const;
+
     /// The account keys behind a thread's account tags, for item 49's
     /// per-account sync.
     ///