feat(qt): add global zoom shortcuts

doc/release-notes-7216.md

@@ -0,0 +1,19 @@
+GUI changes
+-----------
+
+- The Window menu has new Zoom In, Zoom Out and Reset Zoom entries that change
+  the font scale of the whole application, bound to the platform zoom
+  shortcuts (Ctrl++ / Ctrl+= and Ctrl+- / Ctrl+_; Cmd on macOS) and Ctrl+0.
+  The new scale is saved like the Appearance tab's font scale setting. Like
+  that slider, the entries are disabled when `-font-scale` is given on the
+  command line. Inside the RPC console window the zoom-in/out keys still resize
+  only the console text, and when the console is the main window
+  (`-disablewallet` or builds without wallet support) the keys stay with the
+  console while the menu entries keep zooming the whole application. (#7216)
+
+- The font scale range is now -50 to 100, both for `-font-scale` and the
+  Appearance tab slider, which used to stop at -30 and 30. `-font-scale` values
+  below -50 on the command line or in the configuration file, which earlier
+  versions accepted down to -100 although they shrank text towards zero size,
+  are now rejected at startup. A font scale saved in `settings.json`
+  outside the range is clamped on load and the clamped value is saved. (#7216)

src/qt/appearancewidget.cpp

@@ -88,6 +88,7 @@ AppearanceWidget::AppearanceWidget(QWidget* parent) :
     prevWeightBoldArg{GUIUtil::currentWeightArg(GUIUtil::FontWeight::Bold)}
 {
     ui->setupUi(this);
+    ui->fontScaleSlider->setRange(GUIUtil::FONT_SCALE_MIN, GUIUtil::FONT_SCALE_MAX);
 
     for (const QString& entry : GUIUtil::listThemes()) {
         ui->theme->addItem(entry, QVariant(entry));

src/qt/bitcoin.cpp

@@ -493,7 +493,7 @@ static void SetupUIArgs(ArgsManager& argsman)
         if (selectable) selectable_fonts.push_back(name);
     }
     argsman.AddArg("-font-family", QObject::tr("Set the font family. Possible values: %1. (default: %2)").arg(Join(selectable_fonts, ", ")).arg(GUIUtil::defaultFontFamily()).toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
-    argsman.AddArg("-font-scale", QObject::tr("Set a scale factor which gets applied to the base font size. Possible range %1 (smallest fonts) to %2 (largest fonts). (default: %3)").arg(-100).arg(100).arg(GUIUtil::defaultFontScale()).toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
+    argsman.AddArg("-font-scale", QObject::tr("Set a scale factor which gets applied to the base font size. Possible range %1 (smallest fonts) to %2 (largest fonts). (default: %3)").arg(GUIUtil::FONT_SCALE_MIN).arg(GUIUtil::FONT_SCALE_MAX).arg(GUIUtil::defaultFontScale()).toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
     argsman.AddArg("-font-weight-bold", QObject::tr("Set the font weight for bold texts. Possible range %1 to %2 (default: %3)").arg(0).arg(8).arg(GUIUtil::defaultWeightArg(GUIUtil::FontWeight::Bold)).toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
     argsman.AddArg("-font-weight-normal", QObject::tr("Set the font weight for normal texts. Possible range %1 to %2 (default: %3)").arg(0).arg(8).arg(GUIUtil::defaultWeightArg(GUIUtil::FontWeight::Normal)).toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
     argsman.AddArg("-lang=<lang>", QObject::tr("Set language, for example \"de_DE\" (default: system locale)").toStdString(), ArgsManager::ALLOW_ANY, OptionsCategory::GUI);
@@ -720,15 +720,10 @@ int GuiMain(int argc, char* argv[])
         }
     }
     // Validate/set font scale
-    if (gArgs.IsArgSet("-font-scale")) {
-        const int nScaleMin = -100, nScaleMax = 100;
-        int nScale = gArgs.GetIntArg("-font-scale", GUIUtil::fontScale());
-        if (nScale < nScaleMin || nScale > nScaleMax) {
-            QMessageBox::critical(nullptr, PACKAGE_NAME,
-                                  QObject::tr("Error: Specified font-scale invalid. Valid range %1 to %2.").arg(nScaleMin).arg(nScaleMax));
-            return EXIT_FAILURE;
-        }
-        GUIUtil::setFontScale(nScale);
+    if (!GUIUtil::setFontScaleFromArg()) {
+        QMessageBox::critical(nullptr, PACKAGE_NAME,
+                              QObject::tr("Error: Specified font-scale invalid. Valid range %1 to %2.").arg(GUIUtil::FONT_SCALE_MIN).arg(GUIUtil::FONT_SCALE_MAX));
+        return EXIT_FAILURE;
     }
     // Apply font changes
     GUIUtil::updateFonts();

src/qt/bitcoingui.cpp

@@ -74,6 +74,7 @@
 #include <QVBoxLayout>
 #include <QWindow>
 
+#include <algorithm>
 #include <functional>
 
 namespace {
@@ -88,6 +89,8 @@ constexpr int GOV_CYCLE_FRAME_MS{STATUSBAR_ICON_CYCLE_MS / (GOV_CYCLE_FRAME_COUN
 
 // Per-frame interval for the spinner animation
 constexpr int SPINNER_FRAME_MS{STATUSBAR_ICON_CYCLE_MS / SPINNER_FRAMES};
+
+constexpr int FONT_SCALE_SHORTCUT_STEP{3};
 } // anonymous namespace
 
 BitcoinGUI::BitcoinGUI(interfaces::Node& node, const NetworkStyle* networkStyle, QWidget* parent) :
@@ -514,12 +517,53 @@ void BitcoinGUI::createActions()
     m_mask_values_action->setStatusTip(tr("Mask the values in the Overview tab"));
     m_mask_values_action->setCheckable(true);
 
+    m_zoom_in_action = new QAction(tr("Zoom &In"), this);
+    m_zoom_in_action->setObjectName("zoomInAction");
+    m_zoom_in_action->setStatusTip(tr("Increase the font size"));
+
+    m_zoom_out_action = new QAction(tr("Zoom &Out"), this);
+    m_zoom_out_action->setObjectName("zoomOutAction");
+    m_zoom_out_action->setStatusTip(tr("Decrease the font size"));
+
+    // Without a wallet the RPC console is the central widget and already binds these keys to its own font size
+    if (walletFrame) {
+        m_zoom_in_action->setShortcuts({QKeySequence(QKeySequence::ZoomIn), QKeySequence(tr("Ctrl+="))});
+        m_zoom_out_action->setShortcuts({QKeySequence(QKeySequence::ZoomOut), QKeySequence(tr("Ctrl+_"))});
+    }
+
+    m_zoom_reset_action = new QAction(tr("Reset &Zoom"), this);
+    m_zoom_reset_action->setObjectName("zoomResetAction");
+    m_zoom_reset_action->setShortcut(QKeySequence(tr("Ctrl+0")));
+    m_zoom_reset_action->setStatusTip(tr("Reset the font size to default"));
+
+    // Enabled by setClientModel() once the font scale can be persisted
+    for (QAction* action : {m_zoom_in_action, m_zoom_out_action, m_zoom_reset_action}) {
+        action->setEnabled(false);
+    }
+
     connect(quitAction, &QAction::triggered, this, &BitcoinGUI::quitRequested);
     connect(aboutAction, &QAction::triggered, this, &BitcoinGUI::aboutClicked);
     connect(aboutQtAction, &QAction::triggered, qApp, QApplication::aboutQt);
     connect(optionsAction, &QAction::triggered, this, &BitcoinGUI::optionsClicked);
     connect(showHelpMessageAction, &QAction::triggered, this, &BitcoinGUI::showHelpMessageClicked);
     connect(showCoinJoinHelpAction, &QAction::triggered, this, &BitcoinGUI::showCoinJoinHelpClicked);
+    // The macOS menu bar keeps these shortcuts live while the separate RPC console window has focus,
+    // so let them resize the console text there like its own shortcuts do on other platforms
+    connect(m_zoom_in_action, &QAction::triggered, this, [this] {
+        if (rpcConsole->isWindow() && rpcConsole->isActiveWindow()) {
+            rpcConsole->fontBigger();
+        } else {
+            adjustFontScale(FONT_SCALE_SHORTCUT_STEP);
+        }
+    });
+    connect(m_zoom_out_action, &QAction::triggered, this, [this] {
+        if (rpcConsole->isWindow() && rpcConsole->isActiveWindow()) {
+            rpcConsole->fontSmaller();
+        } else {
+            adjustFontScale(-FONT_SCALE_SHORTCUT_STEP);
+        }
+    });
+    connect(m_zoom_reset_action, &QAction::triggered, this, [this] { adjustFontScale(0); });
 
     // Jump directly to tabs in RPC-console
     connect(openInfoAction, &QAction::triggered, this, &BitcoinGUI::showInfo);
@@ -706,6 +750,11 @@ void BitcoinGUI::createMenuBar()
     });
 #endif
 
+    window_menu->addSeparator();
+    window_menu->addAction(m_zoom_in_action);
+    window_menu->addAction(m_zoom_out_action);
+    window_menu->addAction(m_zoom_reset_action);
+
     if (walletFrame) {
 #ifdef Q_OS_MACOS
         window_menu->addSeparator();
@@ -737,6 +786,27 @@ void BitcoinGUI::createMenuBar()
     help->addAction(aboutQtAction);
 }
 
+void BitcoinGUI::adjustFontScale(int delta)
+{
+    const int current_scale{GUIUtil::fontScale()};
+    const int new_scale{delta == 0
+            ? GUIUtil::defaultFontScale()
+            : std::clamp(current_scale + delta, GUIUtil::FONT_SCALE_MIN, GUIUtil::FONT_SCALE_MAX)};
+
+    if (new_scale == current_scale) {
+        return;
+    }
+
+    GUIUtil::setFontScale(new_scale);
+    GUIUtil::updateFonts();
+    updateWidth();
+
+    // With -nosettings there is no settings file to write, so the zoom only lasts for this session
+    if (clientModel && clientModel->getOptionsModel() && gArgs.GetSettingsPath()) {
+        clientModel->getOptionsModel()->setOption(OptionsModel::FontScale, new_scale);
+    }
+}
+
 void BitcoinGUI::createToolBars()
 {
 #ifdef ENABLE_WALLET
@@ -926,6 +996,11 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel, interfaces::BlockAndH
             unitDisplayControl->setOptionsModel(optionsModel);
             m_mask_values_action->setChecked(optionsModel->getOption(OptionsModel::OptionID::MaskValues).toBool());
 
+            const bool font_scale_overridden{optionsModel->isOptionOverridden("-font-scale")};
+            for (QAction* action : {m_zoom_in_action, m_zoom_out_action, m_zoom_reset_action}) {
+                action->setEnabled(!font_scale_overridden);
+            }
+
             connect(optionsModel, &OptionsModel::displayUnitChanged, this, [this]() { m_last_gov_cycle_height.reset(); updateGovernanceCycleIcon(); });
             connect(optionsModel, &OptionsModel::showCoinJoinChanged, this, &BitcoinGUI::updateCoinJoinVisibility);
             connect(optionsModel, &OptionsModel::showGovernanceChanged, this, &BitcoinGUI::updateGovernanceVisibility);
@@ -955,6 +1030,9 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel, interfaces::BlockAndH
         }
 #endif // ENABLE_WALLET
         unitDisplayControl->setOptionsModel(nullptr);
+        for (QAction* action : {m_zoom_in_action, m_zoom_out_action, m_zoom_reset_action}) {
+            action->setEnabled(false);
+        }
 
 #ifdef Q_OS_MACOS
         if(dockIconMenu)

src/qt/bitcoingui.h

@@ -187,6 +187,9 @@ class BitcoinGUI : public QMainWindow
     QAction* m_mask_values_action{nullptr};
     QAction* m_migrate_wallet_action{nullptr};
     QMenu* m_migrate_wallet_menu{nullptr};
+    QAction* m_zoom_in_action{nullptr};
+    QAction* m_zoom_out_action{nullptr};
+    QAction* m_zoom_reset_action{nullptr};
 
     QComboBox* m_wallet_selector = nullptr;
 
@@ -262,6 +265,9 @@ class BitcoinGUI : public QMainWindow
     /** Update UI with latest network info from model. */
     void updateNetworkState();
 
+    /** Apply a global font scale delta or reset when delta is 0. */
+    void adjustFontScale(int delta);
+
     /** Regenerate all pre-cached governance clock pixmaps (e.g. after a theme change). */
     void refreshGovernanceCycleIcons();
 

src/qt/forms/appearancewidget.ui

@@ -183,10 +183,10 @@
           </size>
          </property>
          <property name="minimum">
-          <number>-30</number>
+          <number>-50</number>
          </property>
          <property name="maximum">
-          <number>30</number>
+          <number>100</number>
          </property>
          <property name="singleStep">
           <number>10</number>

src/qt/guiutil.h

@@ -212,8 +212,14 @@ namespace GUIUtil
     /** Known fonts and their "selectable in UI" flag, in registration order. */
     const std::vector<std::pair<QString, /*selectable=*/bool>>& knownFonts();
 
+    /** Supported font scale range; much below the minimum text becomes unreadably small. */
+    constexpr int FONT_SCALE_MIN{-50};
+    constexpr int FONT_SCALE_MAX{100};
     void setFontScale(int font_scale);
     int fontScale();
+    /** Apply `-font-scale` from the command line, config file or settings.json.
+     *  Returns false if it is out of range (no state change in that case). */
+    bool setFontScaleFromArg();
 
     /* Weight operations expressed as caller-friendly arg ints 0..8 -- the format used by
      * `-font-weight-*` CLI args and QSettings persistence. */

src/qt/guiutil_font.cpp

@@ -26,6 +26,7 @@
 #include <QWidget>
 
 #include <cmath>
+#include <cstdint>
 #include <map>
 #include <memory>
 #include <optional>
@@ -580,6 +581,15 @@ const std::vector<std::pair<QString, bool>>& knownFonts() { return g_fonts_known
 void setFontScale(int font_scale) { g_font_registry.SetFontScale(font_scale); }
 int fontScale() { return g_font_registry.GetFontScale(); }
 
+bool setFontScaleFromArg()
+{
+    if (!gArgs.IsArgSet("-font-scale")) return true;
+    const int64_t font_scale{gArgs.GetIntArg("-font-scale", fontScale())};
+    if (font_scale < FONT_SCALE_MIN || font_scale > FONT_SCALE_MAX) return false;
+    setFontScale(static_cast<int>(font_scale));
+    return true;
+}
+
 int currentWeightArg(FontWeight slot)
 {
     return weightToArg(slot == FontWeight::Bold ? g_font_registry.GetWeightBold()

src/qt/optionsmodel.cpp

@@ -34,6 +34,8 @@
 
 #include <univalue.h>
 
+#include <algorithm>
+
 const char *DEFAULT_GUI_PROXY_HOST = "127.0.0.1";
 
 static QString GetDefaultProxyAddress();
@@ -115,6 +117,14 @@ static void UpdateRwSetting(interfaces::Node& node, OptionsModel::OptionID optio
     }
 }
 
+//! Whether settings.json holds the setting, which then takes precedence over the config file.
+static bool IsSettingsFileValue(const std::string& name)
+{
+    bool found{false};
+    gArgs.LockSettings([&](const util::Settings& settings) { found = settings.rw_settings.count(name) > 0; });
+    return found;
+}
+
 //! Convert enabled/size values to bitcoin -prune setting.
 static util::SettingsValue PruneSetting(bool prune_enabled, int prune_size_gb)
 {
@@ -278,15 +288,24 @@ bool OptionsModel::Init(bilingual_str& error)
     }
 
     // Font Scale
-    if (node().isSettingIgnored("font-scale")) {
+    const bool font_scale_overridden{node().isSettingIgnored("font-scale")};
+    if (font_scale_overridden) {
         addOverriddenOption("-font-scale");
     }
+    int64_t font_scale;
+    try {
+        font_scale = SettingToInt(node().getPersistentSetting("font-scale"), GUIUtil::defaultFontScale());
+    } catch (const std::exception& e) {
+        return setting_error("font-scale", e);
+    }
+    const int clamped_scale{static_cast<int>(std::clamp<int64_t>(font_scale, GUIUtil::FONT_SCALE_MIN, GUIUtil::FONT_SCALE_MAX))};
+    // Save a clamped settings.json value so the -font-scale validation at startup accepts it;
+    // an out-of-range config file value is left for that validation to reject.
+    if (clamped_scale != font_scale && !font_scale_overridden && IsSettingsFileValue("font-scale")) {
+        UpdateRwSetting(node(), FontScale, /*suffix=*/"", clamped_scale);
+    }
     if (GUIUtil::fontsLoaded()) {
-        try {
-            GUIUtil::setFontScale(SettingToInt(node().getPersistentSetting("font-scale"), GUIUtil::defaultFontScale()));
-        } catch (const std::exception& e) {
-            return setting_error("font-scale", e);
-        }
+        GUIUtil::setFontScale(clamped_scale);
     }
 
     // Font Weight (Normal)

src/qt/rpcconsole.cpp

@@ -553,6 +553,16 @@ RPCConsole::RPCConsole(interfaces::Node& node, QWidget* parent, Qt::WindowFlags
 
     setButtonIcons();
 
+    // Not in setButtonIcons(): it re-runs on theme changes and would stack duplicate QShortcuts.
+    //: Main shortcut to increase the RPC console font size.
+    ui->fontBiggerButton->setShortcut(tr("Ctrl++"));
+    //: Secondary shortcut to increase the RPC console font size.
+    GUIUtil::AddButtonShortcut(ui->fontBiggerButton, tr("Ctrl+="));
+    //: Main shortcut to decrease the RPC console font size.
+    ui->fontSmallerButton->setShortcut(tr("Ctrl+-"));
+    //: Secondary shortcut to decrease the RPC console font size.
+    GUIUtil::AddButtonShortcut(ui->fontSmallerButton, tr("Ctrl+_"));
+
     // Install event filter for up and down arrow
     ui->lineEdit->installEventFilter(this);
     ui->lineEdit->setMaxLength(16 * 1024 * 1024);
@@ -1342,16 +1352,7 @@ void RPCConsole::setButtonIcons()
     GUIUtil::setIcon(ui->clearButton, "remove", GUIUtil::ThemedColor::RED, consoleButtonsSize);
 
     GUIUtil::setIcon(ui->fontBiggerButton, "fontbigger", GUIUtil::ThemedColor::BLUE, consoleButtonsSize);
-    //: Main shortcut to increase the RPC console font size.
-    ui->fontBiggerButton->setShortcut(tr("Ctrl++"));
-    //: Secondary shortcut to increase the RPC console font size.
-    GUIUtil::AddButtonShortcut(ui->fontBiggerButton, tr("Ctrl+="));
-
     GUIUtil::setIcon(ui->fontSmallerButton, "fontsmaller", GUIUtil::ThemedColor::BLUE, consoleButtonsSize);
-    //: Main shortcut to decrease the RPC console font size.
-    ui->fontSmallerButton->setShortcut(tr("Ctrl+-"));
-    //: Secondary shortcut to decrease the RPC console font size.
-    GUIUtil::AddButtonShortcut(ui->fontSmallerButton, tr("Ctrl+_"));
 }
 
 void RPCConsole::reloadThemedWidgets()