Build tooltip ondemand which speeds initial parsing up tremendously.

We save thousands of allocations this way. And the tooltip becomes more
expressive as well. This does remove the number of allocations from the graph
iteself though, but often it's not visible there anyways and the width already
represents the same data.

diff --git a/gui/flamegraph.cpp b/gui/flamegraph.cpp
index dd3f3ae..bf4ba75 100644 (file)
--- a/gui/flamegraph.cpp
+++ b/gui/flamegraph.cpp
@@ -26,11 +26,9 @@
 #include <QStyleOption>
 #include <QGraphicsView>
 #include <QGraphicsItem>
-#include <QGraphicsSimpleTextItem>
 #include <QWheelEvent>
 #include <QEvent>
-
-#include <QElapsedTimer>
+#include <QToolTip>
 #include <QDebug>
 
 #include <KLocalizedString>
@@ -39,15 +37,9 @@
 FrameGraphicsItem::FrameGraphicsItem(const quint64 cost, const QString& function, FrameGraphicsItem* parent)
     : QGraphicsRectItem(parent)
     , m_cost(cost)
+    , m_function(function)
     , m_isHovered(false)
 {
-    static const QString emptyLabel = QStringLiteral("???");
-
-    m_label = i18nc("%1: number of allocations, %2: function label",
-                    "%2: %1",
-                    cost,
-                    function.isEmpty() ? emptyLabel : function);
-    setToolTip(m_label);
     setFlag(QGraphicsItem::ItemIsSelectable);
     setAcceptHoverEvents(true);
 }
@@ -87,19 +79,30 @@ void FrameGraphicsItem::paint(QPainter* painter, const QStyleOptionGraphicsItem*
     const int height = rect().height();
 
     painter->drawText(margin + rect().x(), rect().y(), width, height, Qt::AlignVCenter | Qt::AlignLeft | Qt::TextSingleLine,
-                      option->fontMetrics.elidedText(m_label, Qt::ElideRight, width));
+                      option->fontMetrics.elidedText(m_function, Qt::ElideRight, width));
 }
 
 void FrameGraphicsItem::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
 {
     QGraphicsRectItem::hoverEnterEvent(event);
     m_isHovered = true;
+    showToolTip();
+}
+
+void FrameGraphicsItem::showToolTip() const
+{
+    // we build the tooltip text on demand, which is much faster than doing that for potentially thousands of items when we load the data
+    QToolTip::showText(QCursor::pos(), i18nc("%1: number of allocations, %2: function label", "%1 allocations in %2 and below.", m_cost, m_function));
 }
 
 void FrameGraphicsItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
 {
     QGraphicsRectItem::hoverLeaveEvent(event);
     m_isHovered = false;
+
+    if (auto parent = static_cast<FrameGraphicsItem*>(parentItem())) {
+        parent->showToolTip();
+    }
 }
 
 namespace {

diff --git a/gui/flamegraph.h b/gui/flamegraph.h
index 4dedb7e..324e5ec 100644 (file)
--- a/gui/flamegraph.h
+++ b/gui/flamegraph.h
@@ -39,10 +39,11 @@ public:
 protected:
     void hoverEnterEvent(QGraphicsSceneHoverEvent *event) override;
     void hoverLeaveEvent(QGraphicsSceneHoverEvent *event) override;
+    void showToolTip() const;
 
 private:
-    QString m_label;
     quint64 m_cost;
+    QString m_function;
     bool m_isHovered;
 };