feat: show tooltips for discovered shortcuts

docs/roadmap.md

@@ -3,10 +3,10 @@
 See also [previous roadmap](./old_roadmap.md) for finished work.
 
 - [x] Back navigation with mouse 4th button (mbits-os/quick_dra#109)
-- [ ] Shortcut discovery (mbits-os/quick_dra#104, As a user, I want shortcuts to popup, when I press Ctrl for 2 seconds)
+- [x] Shortcut discovery (mbits-os/quick_dra#104, As a user, I want shortcuts to popup, when I press Ctrl for 2 seconds)
   - [x] Filter keyboard and mouse events to keep track, when to show and hide the shortcuts (mbits-os/quick_dra#107)
-  - [ ] Keep track of all widgets with shortcuts currently on screen (mbits-os/quick_dra#105)
-  - [ ] Show matching shortcuts, when Control is being held for one seconds (mbits-os/quick_dra#106)
+  - [x] Keep track of all widgets with shortcuts currently on screen (mbits-os/quick_dra#105)
+  - [x] Show matching shortcuts, when Control is being held for one seconds (mbits-os/quick_dra#106)
 - [ ] Update documentation up to and including Quick-DRA GUI
 - [ ] Automatic upload to ZUS ePłatnik
   - [ ] Get access to Profil Zaufany sandbox

libs/gui/gui/CMakeLists.txt

@@ -14,13 +14,15 @@ set(SRCS
     include/app/gui/PageStack.hpp
     include/app/gui/ShortcutDiscovery.hpp
     include/app/gui/types.hpp
+    include/app/gui/ToolTipLabel.hpp
     src/app/gui/CurrentColor.cpp
     src/app/gui/Globals.cpp
     src/app/gui/HeaderTitle.cpp
     src/app/gui/PagedWidget.cpp
     src/app/gui/PageHeader.cpp
     src/app/gui/PageStack.cpp
     src/app/gui/ShortcutDiscovery.cpp
+    src/app/gui/ToolTipLabel.cpp
 )
 
 set(RES res/icons.qrc)

libs/gui/gui/include/app/gui/ShortcutDiscovery.hpp

@@ -19,6 +19,8 @@ namespace ch = std::chrono;
 QT_FORWARD_DECLARE_CLASS(QToolButton)
 
 namespace quick_dra::gui {
+	class ToolTipLabel;
+
 	struct HolderPosition {
 		QRect geometry;
 		QWidget const* rectReference;
@@ -92,6 +94,17 @@ namespace quick_dra::gui {
 		struct PrivateTag {};
 
 	public:
+		struct LabelInfo {
+			QWidget* parent = nullptr;
+			ToolTipLabel* toolTip = nullptr;
+			QPoint origin{};
+			QString text{};
+
+			bool operator==(LabelInfo const& rhs) const noexcept {
+				return parent == rhs.parent && origin == rhs.origin && text == rhs.text;
+			}
+		};
+
 		struct Editor {
 			static Editor* current;
 
@@ -125,6 +138,7 @@ namespace quick_dra::gui {
 
 		Editor beginHolderUpdate();
 		std::deque<ShortcutHolderInfo> const& holders() const noexcept { return holders_; }
+		std::vector<LabelInfo> const& labels() const noexcept { return labels_; }
 
 	public slots:
 		void modifiersPressed(Qt::KeyboardModifiers);
@@ -140,15 +154,6 @@ namespace quick_dra::gui {
 		void labelsChanged();
 
 	private:
-		struct LabelInfo {
-			QWidget* parent = nullptr;
-			QWidget* toolTip = nullptr;
-			QPoint origin{};
-			QString text{};
-
-			auto operator<=>(LabelInfo const&) const noexcept = default;
-		};
-
 		enum class ModsState {
 			Stable = false,
 			Changed = true,

libs/gui/gui/include/app/gui/ToolTipLabel.hpp

@@ -0,0 +1,22 @@
+// Copyright (c) 2026 midnightBITS
+// This code is licensed under MIT license (see LICENSE for details)
+
+#pragma once
+
+#include <QLabel>
+
+namespace quick_dra::gui {
+	class ToolTipLabel : public QLabel {
+		Q_OBJECT
+
+	public:
+		ToolTipLabel(const QString& text, const QPoint& pos, QWidget* parent);
+
+		void hideTip();
+
+	protected:
+		bool eventFilter(QObject*, QEvent*) override;
+		void paintEvent(QPaintEvent* e) override;
+		void resizeEvent(QResizeEvent* e) override;
+	};
+}  // namespace quick_dra::gui

libs/gui/gui/src/app/gui/ShortcutDiscovery.cpp

@@ -9,6 +9,7 @@
 #include <algorithm>
 #include <app/gui/Globals.hpp>
 #include <app/gui/ShortcutDiscovery.hpp>
+#include <app/gui/ToolTipLabel.hpp>
 #include <array>
 #include <utility>
 #include <vector>
@@ -206,16 +207,35 @@ namespace quick_dra::gui {
 		}
 
 		for (auto const& label : labels_) {
-			if (label.toolTip) label.toolTip->deleteLater();  // GCOV_EXCL_LINE (until #106)
+			if (label.toolTip) label.toolTip->hideTip();
 		}
+
 		labels_ = std::move(labels);
-		for (auto const& label : labels_) {
-			// TODO: mbits-os/quick_dra#106 Show matching shortcuts, when Control is being held for one seconds
+
+		for (auto& label : labels_) {
+			label.toolTip = new ToolTipLabel{label.text, label.origin, label.parent};
+			label.toolTip->showNormal();
 		}
 
 		labelsChanged();
 	}
 
+	static bool visibleInStack(QWidget const* bottom, QPoint const& pt) {
+		auto point = pt;
+		auto widget = bottom;
+
+		while (widget) {
+			if (!widget->rect().contains(point)) {
+				return false;
+			}
+			auto parent = qobject_cast<QWidget*>(widget->parent());
+			if (!parent) break;
+			point = widget->mapTo(parent, point);
+			widget = parent;
+		}
+		return true;
+	}
+
 	std::vector<ShortcutDiscovery::LabelInfo> ShortcutDiscovery::filterShortcuts() {
 		if (modifiers_ == Qt::NoModifier) {
 			return {};
@@ -241,7 +261,7 @@ namespace quick_dra::gui {
 		int lineHeight{fm.ascent() + fm.descent() + fm.leading()};
 		int em{fm.boundingRect("m").width()};
 
-		int vOffset = -lineHeight * 2 / 3;
+		int vOffset = -lineHeight * 4 / 5;
 
 		for (auto const& holder : holders_) {
 			if (!holder.isEnabled(holder.holder)) continue;
@@ -253,8 +273,12 @@ namespace quick_dra::gui {
 					auto const pos = holder.getPosition(holder.holder);
 					auto const topLevelParent = pos.rectReference->topLevelWidget();
 
-					auto const position =
-					    pos.rectReference->mapTo(topLevelParent, pos.geometry.bottomLeft()) + QPoint{hOffset, vOffset};
+					auto const local = pos.geometry.bottomLeft() + QPoint{hOffset, vOffset};
+					if (!visibleInStack(pos.rectReference, local)) {
+						continue;
+					}
+
+					auto const position = pos.rectReference->mapToGlobal(local);
 					auto label = QKeySequence{mod.key() | (mod.keyboardModifiers() & ~modifiers_)}.toString();
 					hOffset += 2 * em + fm.boundingRect(label).width();
 

libs/gui/gui/src/app/gui/ToolTipLabel.cpp

@@ -0,0 +1,68 @@
+// Copyright (c) 2026 midnightBITS
+// This code is licensed under MIT license (see LICENSE for details)
+
+#include <QApplication>
+#include <QStyle>
+#include <QStyleOptionFrame>
+#include <QStylePainter>
+#include <QToolTip>
+#include <app/gui/ToolTipLabel.hpp>
+#include <utility>
+
+namespace quick_dra::gui {
+	ToolTipLabel::ToolTipLabel(const QString& value, const QPoint& pos, QWidget* parent)
+	    : QLabel{parent, Qt::ToolTip | Qt::BypassGraphicsProxyWidget} {
+		setFont(QFont{"QTipLabel"});
+		setForegroundRole(QPalette::ToolTipText);
+		setBackgroundRole(QPalette::ToolTipBase);
+		setPalette(QToolTip::palette());
+		ensurePolished();
+		setMargin(1 + style()->pixelMetric(QStyle::PM_ToolTipLabelFrameWidth, nullptr, this));
+		setFrameStyle(QFrame::NoFrame);
+		setAlignment(Qt::AlignLeft);
+		setIndent(1);
+		qApp->installEventFilter(this);
+		setWindowOpacity(style()->styleHint(QStyle::SH_ToolTipLabel_Opacity, nullptr, this) / 255.0);
+		setMouseTracking(true);
+		setText(value);
+
+		QFontMetrics fm{font()};
+		QSize extra{1, 0};
+
+		// Make it look good with the default ToolTip font on Mac, which has a small descent.
+		if (fm.descent() == 2 && fm.ascent() >= 11) ++extra.rheight();
+
+		setWordWrap(Qt::mightBeRichText(text()));
+		QSize sh = sizeHint();
+		move(pos);
+		resize(sh + extra);
+	}
+
+	void ToolTipLabel::hideTip() {
+		close();
+		deleteLater();
+	}
+
+	bool ToolTipLabel::eventFilter(QObject*, QEvent*) { return false; }
+
+	void ToolTipLabel::paintEvent(QPaintEvent* event) {
+		QStylePainter p(this);
+		QStyleOptionFrame opt;
+		opt.initFrom(this);
+		p.drawPrimitive(QStyle::PE_PanelTipLabel, opt);
+		p.end();
+
+		QLabel::paintEvent(event);
+	}
+
+	void ToolTipLabel::resizeEvent(QResizeEvent* event) {
+		QStyleHintReturnMask frameMask;
+		QStyleOption option;
+		option.initFrom(this);
+		if (style()->styleHint(QStyle::SH_ToolTip_Mask, &option, this, &frameMask)) {
+			setMask(frameMask.region);  // GCOV_EXCL_LINE
+		}
+
+		QLabel::resizeEvent(event);
+	}
+}  // namespace quick_dra::gui

libs/gui/gui/tests/qt6/ShortcutDiscovery.test.cpp

@@ -9,6 +9,7 @@
 #include <QWheelEvent>
 #include <Qt>
 #include <app/gui/ShortcutDiscovery.hpp>
+#include <app/gui/ToolTipLabel.hpp>
 #include <app/utils/utils.hpp>
 #include "GuiTest.hpp"
 #include "ui_helpers.hpp"
@@ -31,6 +32,8 @@ namespace {
 
 		return Qt::NoModifier;
 	}
+
+	QString operator""_L1(char const* ptr, size_t len) { return QString::fromLatin1(ptr, static_cast<qsizetype>(len)); }
 }  // namespace
 
 struct HUD {
@@ -297,18 +300,20 @@ void GuiTest::ShortcutDiscovery_gatherTooltips() {
 	QWidget widget{};
 	HUD hud{&widget};
 
-	auto layout = new QVBoxLayout{&widget};
+	auto parent = new QWidget{&widget};
+	auto layout = new QVBoxLayout{parent};
 	layout->setContentsMargins(5, 5, 5, 5);
 	layout->setSpacing(5);
 
 	std::vector<ShortcutWidget*> widgets{};
 	widgets.reserve(std::size(controls));
-	std::transform(std::begin(controls), std::end(controls), std::back_inserter(widgets), widgetMaker(&widget, layout));
+	std::transform(std::begin(controls), std::end(controls), std::back_inserter(widgets), widgetMaker(parent, layout));
 	int height = 5;
 	for (auto const& control : controls) {
 		height += std::get<0>(control) + 5;
 	}
-	widget.resize(200, height);
+	parent->resize(200, height);
+	widget.resize(200, height * 2 / 3);
 
 	widget.show();
 	QVERIFY(QTest::qWaitForWindowExposed(&widget));
@@ -333,6 +338,25 @@ void GuiTest::ShortcutDiscovery_gatherTooltips() {
 	QCOMPARE_EQ(labelsSpy.size(), 1);
 	QCOMPARE_EQ(activeSpy.size(), 1);
 
+	auto const previous = discovery.labels();
+	{
+		// "empty" update
+		discovery.beginHolderUpdate();
+	}
+	auto const now = discovery.labels();
+	auto actual = QList<std::pair<QPoint, QString>>{};
+	actual.reserve(static_cast<qsizetype>(now.size()));
+	std::transform(now.begin(), now.end(), std::back_inserter(actual),
+	               [](ShortcutDiscovery::LabelInfo const& info) { return std::pair{info.origin, info.text}; });
+
+	labelsSpy.wait(100ms);
+	activeSpy.wait(100ms);
+	QCOMPARE_EQ(labelsSpy.size(), 1);
+	QCOMPARE_EQ(activeSpy.size(), 1);
+	QCOMPARE_EQ(previous, now);
+	QCOMPARE_EQ(actual, (QList{std::pair{QPoint{17, 49}, "Shift+E"_L1}, std::pair{QPoint{17, 108}, "Alt+Z"_L1},
+	                           std::pair{QPoint{71, 108}, "Z"_L1}}));
+
 	{
 		auto editor = discovery.beginHolderUpdate();
 		for (auto child : widgets) {
@@ -375,4 +399,9 @@ void GuiTest::ShortcutDiscovery_toolButton() {
 
 	button.setVisible(true);
 	QVERIFY(Support::isEnabled(&button));
+
+	// call painting the tool tip label
+	ToolTipLabel label{"Text", QPoint{}, nullptr};
+	label.showNormal();
+	QVERIFY(QTest::qWaitForWindowExposed(&label));
 }

libs/gui/pages/include/app/main/MainWindow.hpp

@@ -36,7 +36,6 @@ namespace quick_dra::gui {
 	private slots:
 		void updateTitle();
 		void reloadConfig();
-		void discoveryModifiers(Qt::KeyboardModifiers);
 
 	private:
 		void setupUi(Globals* globals);

libs/gui/pages/src/app/main/MainWindow.cpp

@@ -25,8 +25,6 @@ namespace quick_dra::gui {
 		pageStack->push<HomePage>();
 
 		QObject::connect(globals, &Globals::configModifiedChanged, messageBar, &QWidget::setVisible);
-		QObject::connect(&pageStack->discovery(), &ShortcutDiscovery::modifiersChanged, this,
-		                 &MainWindow::discoveryModifiers);
 	}
 
 	void MainWindow::closeEvent(QCloseEvent* event) {
@@ -54,31 +52,6 @@ namespace quick_dra::gui {
 		pageStack->globals().reloadConfig();
 	}
 
-	// GCOV_EXCL_START -- temporary slot to verify signals via console
-	// TODO: remove this slot before closing of #104
-	void MainWindow::discoveryModifiers(Qt::KeyboardModifiers modifiers) {
-		std::string sMods{};
-		if (!modifiers) {
-			sMods = "NoModifier"s;
-		}
-#define CHECK_MOD(NAME, LABEL)                    \
-	if (modifiers & Qt::NAME) {                   \
-		modifiers &= ~Qt::NAME;                   \
-		if (!sMods.empty()) sMods.push_back('+'); \
-		sMods.append(LABEL##sv);                  \
-	}
-		CHECK_MOD(ShiftModifier, "Shift");
-		CHECK_MOD(ControlModifier, "Ctrl");
-		CHECK_MOD(MetaModifier, "Meta");
-		CHECK_MOD(AltModifier, "Alt");
-		if (modifiers) {
-			if (!sMods.empty()) sMods.push_back('+');
-			sMods.append(std::to_string(modifiers.toInt()));
-		}
-		qDebug() << "[discovery]" << sMods.c_str();
-	}
-	// GCOV_EXCL_STOP
-
 	void MainWindow::storePosition(Globals* globals) {
 		auto settings = globals->createSettings();
 		settings.beginGroup("State");