Search related Tracks: add checkboxes + Search button

Menu items are checkboxes now, so there are two ways to search for tracks:
* single filter (as before):
  click an action (text), or press `Return` on a selected checkbox, to trigger its search
* combine filters:
   * check multiple actions (click `[ ]` box or press `Space` on a selected item
   * click **Search** (or press `S`, or `Return` on Search) to search with all checked filters

src/widget/wsearchrelatedtracksmenu.cpp

@@ -1,10 +1,15 @@
 #include "widget/wsearchrelatedtracksmenu.h"
 
+#include <QCheckBox>
+#include <QMouseEvent>
 #include <QScreen>
+#include <QStyleOptionButton>
+#include <QWidgetAction>
 
 #include "moc_wsearchrelatedtracksmenu.cpp"
 #include "track/track.h"
 #include "util/math.h"
+#include "util/parented_ptr.h"
 #include "util/qt.h"
 #include "util/widgethelper.h"
 
@@ -78,12 +83,29 @@ void WSearchRelatedTracksMenu::addTriggerSearchAction(
             elideActionText(
                     actionTextPrefix,
                     elidableTextSuffix);
-    addAction(
+
+    auto pCheckBox = make_parented<QCheckBox>(
             mixxx::escapeTextPropertyWithoutShortcuts(elidedActionText),
+            this);
+    pCheckBox->setProperty("query", searchQuery);
+    connect(pCheckBox.get(),
+            &QCheckBox::toggled,
+            this,
+            &WSearchRelatedTracksMenu::updateSearchButton);
+    // Use the event filter to capture clicks on the checkbox label
+    pCheckBox.get()->installEventFilter(this);
+
+    auto pAction = make_parented<QWidgetAction>(this);
+    pAction->setDefaultWidget(pCheckBox.get());
+    // While the checkbox is selected (via keyboard, not hovered by pointer)
+    // pressing Space will toggle it whereas pressing Return triggers the action.
+    connect(pAction.get(),
+            &QAction::triggered,
             this,
             [this, searchQuery]() {
                 emit triggerSearch(searchQuery);
             });
+    addAction(pAction.get());
 }
 
 QString WSearchRelatedTracksMenu::elideActionText(
@@ -124,6 +146,13 @@ void WSearchRelatedTracksMenu::addActionsForTrack(
     // string concatenation will fail at runtime!
 
     // Mixing actions
+    // TODO(ronso0) Nice to have: remember & restore checked state of filters.
+    // This would simplify repeating the previous filter combo, e.g. search again
+    // for genre and BPM.
+    // For good UX (in decks) all track menu widgets of a certain deck should
+    // share a track menu (track menu features are/should be the same anyway for
+    // WTrackProperty, WTrackText & WTrackWidgetGroup.
+    // LegacySkinParser might take care of this :|
     bool addSeparatorBeforeNextAction = !isEmpty();
     {
         const auto keyText = track.getKeyText();
@@ -332,4 +361,84 @@ void WSearchRelatedTracksMenu::addActionsForTrack(
                     locationPathWithTerminator);
         }
     }
+
+    addSeparator();
+
+    m_pSearchAction = make_parented<QAction>(tr("&Search"), this);
+    // TODO(ronso0) Add 'looking glass' icon?
+    addAction(m_pSearchAction.get());
+    m_pSearchAction.get()->setDisabled(true);
+    connect(m_pSearchAction.get(),
+            &QAction::triggered,
+            this,
+            &WSearchRelatedTracksMenu::combineQueriesTriggerSearch);
+}
+
+bool WSearchRelatedTracksMenu::eventFilter(QObject* obj, QEvent* e) {
+    if (e->type() == QEvent::MouseButtonPress) {
+        // Clicking the text of a checkbox triggers the search, ignoring other
+        // checked boxes.
+        // Clicks in other places are passed on to the event filter so toggling
+        // the checkbox is happening as usual.
+        QCheckBox* box = qobject_cast<QCheckBox*>(obj);
+        if (box) {
+            QMouseEvent* me = static_cast<QMouseEvent*>(e);
+            VERIFY_OR_DEBUG_ASSERT(me) {
+                return true;
+            }
+            QStyleOptionButton option;
+            option.initFrom(box);
+            auto pStyle = box->style();
+            if (!pStyle) {
+                return true;
+            }
+            const QRect labelRect = pStyle->subElementRect(QStyle::SE_CheckBoxContents,
+                    &option,
+                    box);
+            if (labelRect.contains(me->pos())) {
+                // Text was clicked, trigger the search.
+                const QString query = box->property("query").toString();
+                emit triggerSearch(query);
+                // Note that this click will not emit QAction::triggered like
+                // when pressing Return on a selected action, hence we need to
+                // make sure WTrackMenu closes when receiving triggerSearch().
+            }
+        }
+    }
+    return QObject::eventFilter(obj, e);
+}
+
+void WSearchRelatedTracksMenu::updateSearchButton() {
+    // Enable the Search button if at least one box is checked.
+    VERIFY_OR_DEBUG_ASSERT(m_pSearchAction) {
+        return;
+    }
+    m_pSearchAction->setDisabled(true);
+    for (const auto* child : std::as_const(children())) {
+        const auto* box = qobject_cast<const QCheckBox*>(child);
+        if (box && box->isChecked()) {
+            m_pSearchAction->setEnabled(true);
+            break;
+        }
+    }
+}
+
+void WSearchRelatedTracksMenu::combineQueriesTriggerSearch() {
+    // collect queries of all checked checkboxes
+    QStringList queries;
+    for (const auto* child : std::as_const(children())) {
+        const auto* box = qobject_cast<const QCheckBox*>(child);
+        if (box && box->isChecked()) {
+            QString query = box->property("query").toString();
+            if (!query.isEmpty()) {
+                queries.append(query);
+            }
+        }
+    }
+    if (queries.isEmpty()) {
+        return;
+    } else {
+        QString queryCombo = queries.join(QStringLiteral(" "));
+        emit triggerSearch(queryCombo);
+    }
 }

src/widget/wsearchrelatedtracksmenu.h

@@ -2,6 +2,8 @@
 
 #include <QMenu>
 
+#include "util/parented_ptr.h"
+
 class Track;
 
 class WSearchRelatedTracksMenu : public QMenu {
@@ -13,11 +15,16 @@ class WSearchRelatedTracksMenu : public QMenu {
 
     void addActionsForTrack(
             const Track& track);
+    bool eventFilter(QObject* obj, QEvent* e) override;
 
   signals:
     void triggerSearch(
             const QString& searchQuery);
 
+  private slots:
+    void updateSearchButton();
+    void combineQueriesTriggerSearch();
+
   private:
     void addTriggerSearchAction(
             bool* /*in/out*/ pAddSeparatorBeforeNextAction,
@@ -27,4 +34,6 @@ class WSearchRelatedTracksMenu : public QMenu {
     QString elideActionText(
             const QString& actionTextPrefix,
             const QString& elidableTextSuffix) const;
+
+    parented_ptr<QAction> m_pSearchAction;
 };

src/widget/wtrackmenu.cpp

@@ -192,6 +192,7 @@ void WTrackMenu::createMenus() {
                 this,
                 [this](const QString& searchQuery) {
                     m_pLibrary->searchTracksInCollection(searchQuery);
+                    hide();
                 });
     }