Add simple tooltip system

src/widgets/helper/channelview.cpp

@@ -16,6 +16,7 @@
 #include <QDesktopServices>
 #include <QGraphicsBlurEffect>
 #include <QPainter>
+#include <QToolTip>
 
 #include <math.h>
 #include <algorithm>
@@ -748,13 +749,40 @@ void ChannelView::mouseMoveEvent(QMouseEvent *event)
         this->repaint();
     }
 
+    static QTimer *tooltipTimer = new QTimer();
+
     // check if word underneath cursor
     const messages::Word *hoverWord;
     if ((hoverWord = message->tryGetWordPart(relativePos)) == nullptr) {
         this->setCursor(Qt::ArrowCursor);
+        tooltipTimer->stop();
+        QToolTip::hideText();
         return;
     }
 
+    const auto &tooltip = hoverWord->getTooltip();
+
+    static QString targetTooltip;
+    static QPoint tooltipPos;
+    connect(tooltipTimer, &QTimer::timeout, []() {
+        assert(!targetTooltip.isEmpty());
+        QToolTip::showText(tooltipPos, targetTooltip);  //
+    });
+
+    tooltipTimer->setSingleShot(true);
+    tooltipTimer->setInterval(500);
+
+    if (!tooltip.isEmpty()) {
+        tooltipPos = event->globalPos();
+        targetTooltip = "<style>.center { text-align: center; }</style>"
+                        "<p class = \"center\">" +
+                        tooltip + "</p>";
+        tooltipTimer->start();
+    } else {
+        tooltipTimer->stop();
+        QToolTip::hideText();
+    }
+
     // check if word has a link
     if (hoverWord->getLink().isValid()) {
         this->setCursor(Qt::PointingHandCursor);