Immediately hide tooltip on ToolTipArea destruction or when it becomes empty

When the tooltip is empty (no text, no subtext, and no mainItem) it will not be shown.
However, when it becomes empty while it is already shown, it stays there as a small
rectangle. This hides the tooltip immediately (so KWin's fadeout animation still has
the proper content rather than the empty tooltip) when the TooltipArea that opened
the tooltip has been destroyed or its content becomes empty.

CHANGELOG: Fixed stray tooltips when temporary owner of tooltip disappeared or became empty

REVIEW: 122939

src/declarativeimports/core/tooltip.cpp

@@ -60,6 +60,10 @@ ToolTip::ToolTip(QQuickItem *parent)
 
 ToolTip::~ToolTip()
 {
+    if (s_dialog && s_dialog->owner() == this) {
+        s_dialog->setVisible(false);
+    }
+
     if (m_usingDialog) {
         --s_dialogUsers;
     }
@@ -109,6 +113,10 @@ void ToolTip::setMainItem(QQuickItem *mainItem)
         m_mainItem = mainItem;
 
         emit mainItemChanged();
+
+        if (!isValid() && s_dialog && s_dialog->owner() == this) {
+            s_dialog->setVisible(false);
+        }
     }
 }
 
@@ -145,6 +153,8 @@ void ToolTip::showToolTip()
         mainItem()->setVisible(true);
     }
 
+    dlg->setOwner(this);
+
     //if the dialog is not currently visible, disable the animated repositioning
     dlg->setAnimationsEnabled(dlg->isVisible());
     dlg->show();
@@ -167,6 +177,10 @@ void ToolTip::setMainText(const QString &mainText)
 
     m_mainText = mainText;
     emit mainTextChanged();
+
+    if (!isValid() && s_dialog && s_dialog->owner() == this) {
+        s_dialog->setVisible(false);
+    }
 }
 
 QString ToolTip::subText() const
@@ -182,6 +196,10 @@ void ToolTip::setSubText(const QString &subText)
 
     m_subText = subText;
     emit subTextChanged();
+
+    if (!isValid() && s_dialog && s_dialog->owner() == this) {
+        s_dialog->setVisible(false);
+    }
 }
 
 int ToolTip::textFormat() const
@@ -305,9 +323,10 @@ void ToolTip::hoverEnterEvent(QHoverEvent *event)
         return;
     }
 
-    if (!m_mainItem && mainText().isEmpty() && subText().isEmpty()) {
+    if (!isValid()) {
         return;
     }
+
     if (tooltipDialogInstance()->isVisible()) {
         // We signal the tooltipmanager that we're "potentially interested,
         // and ask to keep it open for a bit, so other items get the chance
@@ -333,3 +352,7 @@ bool ToolTip::childMouseEventFilter(QQuickItem *item, QEvent *event)
     return QQuickItem::childMouseEventFilter(item, event);
 }
 
+bool ToolTip::isValid() const
+{
+    return m_mainItem || !mainText().isEmpty() || !subText().isEmpty();
+}

src/declarativeimports/core/tooltip.h

@@ -193,6 +193,8 @@ private Q_SLOTS:
     void settingsChanged();
 
 private:
+    bool isValid() const;
+
     void loadSettings();
     bool m_tooltipsEnabledGlobally;
     bool m_containsMouse;

src/declarativeimports/core/tooltipdialog.cpp

@@ -32,7 +32,8 @@ ToolTipDialog::ToolTipDialog(QQuickItem  *parent)
       m_animation(0),
       m_hideTimeout(4000),
       m_interactive(false),
-      m_animationsEnabled(true)
+      m_animationsEnabled(true),
+      m_owner(Q_NULLPTR)
 {
     setFlags(Qt::ToolTip | Qt::BypassWindowManagerHint);
     setLocation(Plasma::Types::Floating);
@@ -147,6 +148,16 @@ void ToolTipDialog::setAnimationsEnabled(bool enabled)
     m_animationsEnabled = enabled;
 }
 
+QObject *ToolTipDialog::owner() const
+{
+    return m_owner;
+}
+
+void ToolTipDialog::setOwner(QObject *owner)
+{
+    m_owner = owner;
+}
+
 void ToolTipDialog::dismiss()
 {
     m_showTimer->start(m_hideTimeout / 20); // pretty short: 200ms

src/declarativeimports/core/tooltipdialog.h

@@ -66,6 +66,12 @@ public:
     bool animationsEnabled() const;
     void setAnimationsEnabled(bool enabled);
 
+    /**
+     * Basically the last one who has shown the dialog
+     */
+    QObject *owner() const;
+    void setOwner(QObject *owner);
+
 protected:
     void showEvent(QShowEvent *event) Q_DECL_OVERRIDE;
     void hideEvent(QHideEvent *event) Q_DECL_OVERRIDE;
@@ -82,6 +88,7 @@ private:
     int m_hideTimeout;
     bool m_interactive;
     bool m_animationsEnabled;
+    QObject *m_owner;
 };
 
 #endif