qt: add console commands for clearing screen, clearing and viewing history

Adds the following console commands:

- `clear`: clears the console output area.
- `clear-all`: clears both output and command history.
- `history`: lists stored command history.
- `history-clear`: clears command history only.

These additions improve privacy and convenience in shared or long-lived
sessions by allowing users to remove sensitive commands and output from view.

Author: waketraindev

src/qt/rpcconsole.cpp

@@ -93,6 +93,9 @@ public Q_SLOTS:
 
 Q_SIGNALS:
     void reply(int category, const QString &command);
+    void clearScreen();
+    void clearHistory();
+    void printHistory();
 
 private:
     interfaces::Node& m_node;
@@ -402,7 +405,26 @@ void RPCExecutor::request(const QString &command, const QString& wallet_name)
                 "   example:    getblock(getblockhash(0) 1)[tx]\n\n"
 
                 "Results without keys can be queried with an integer in brackets using the parenthesized syntax.\n"
-                "   example:    getblock(getblockhash(0),1)[tx][0]\n\n")));
+                "   example:    getblock(getblockhash(0),1)[tx][0]\n\n"
+                "Console commands:\n"
+                "   clear               Clears the screen.\n"
+                "   clear-all           Clears the screen and command history.\n"
+                "   history             Prints all command history.\n"
+                "   history-clear       Clears the command history.\n\n"
+            )));
+            return;
+        } else if (executableCommand == "clear\n") {
+            Q_EMIT clearScreen();
+            return;
+        } else if (executableCommand == "clear-all\n") {
+            Q_EMIT clearHistory();
+            Q_EMIT clearScreen();
+            return;
+        } else if (executableCommand == "history-clear\n") {
+            Q_EMIT clearHistory();
+            return;
+        } else if (executableCommand == "history\n") {
+            Q_EMIT printHistory();
             return;
         }
         if (!RPCConsole::RPCExecuteCommandLine(m_node, result, executableCommand, nullptr, wallet_name)) {
@@ -728,6 +750,10 @@ void RPCConsole::setClientModel(ClientModel *model, int bestblock_height, int64_
         }
 
         wordList << "help-console";
+        wordList << "clear";
+        wordList << "clear-all";
+        wordList << "history";
+        wordList << "history-clear";
         wordList.sort();
         autoCompleter = new QCompleter(wordList, this);
         autoCompleter->setModelSorting(QCompleter::CaseSensitivelySortedModel);
@@ -1081,14 +1107,36 @@ void RPCConsole::startExecutor()
 {
     m_executor = new RPCExecutor(m_node);
     m_executor->moveToThread(&thread);
-
-    // Replies from executor object must go to this object
-    connect(m_executor, &RPCExecutor::reply, this, [this](int category, const QString& command) {
-        // Remove "Executing…" message.
+    const auto finish = [this](const auto action) {
         ui->messagesWidget->undo();
-        message(category, command);
+        action();
         scrollToEnd();
         m_is_executing = false;
+    };
+
+    // Replies from executor object must go to this object
+    connect(m_executor, &RPCExecutor::reply, this, [this, finish](int category, const QString& command) {
+        finish([this, category, command]() { message(category, command); });
+    });
+    connect(m_executor, &RPCExecutor::clearScreen, this, [this, finish]() {
+        finish([this]() { clear(false); });
+    });
+    connect(m_executor, &RPCExecutor::clearHistory, this, [this, finish]() {
+        finish([this]() {
+            history.clear();
+            message(CMD_REPLY, tr("History has been cleared."));
+        });
+    });
+    connect(m_executor, &RPCExecutor::printHistory, this, [this, finish]() {
+        finish([this]() {
+            QStringList out;
+            out.reserve(history.size());
+            qsizetype index = 0;
+            for (const QString& entry : history) {
+                out << tr("%1: %2").arg(++index).arg(entry);
+            }
+            message(CMD_REPLY, out.join(QStringLiteral("\n")));
+        });
     });
 
     // Make sure executor object is deleted in its own thread