Added mouse cursor auto-hiding to QTermWidget (#582)

Mouse cursor auto-hiding was implemented by @luebking: b150d85

Apart from adding mouse auto-hiding to `QTermWidget`, this patch fixes two issues of the above implementation:

 1. `focusInEvent` and `focusOutEvent` weren't good for controlling auto-hiding, because the hidden mouse cursor can be near other widgets of the app (tab, menu-bar, …), in which case, it wasn't shown when put on them. Therefore, `enterEvent`, and `leaveEvent` are used instead.
 2. The scrollbar needed a separate handling because it's a child of `TerminalDisplay`.

NOTE: A related PR for QTerminal will follow this one.

lib/TerminalDisplay.cpp

@@ -39,7 +39,6 @@
 #include <QPainter>
 #include <QPixmap>
 #include <QRegularExpression>
-#include <QScrollBar>
 #include <QStyle>
 #include <QTimer>
 #include <QtDebug>
@@ -397,7 +396,7 @@ TerminalDisplay::TerminalDisplay(QWidget *parent)
 
   // create scroll bar for scrolling output up and down
   // set the scroll bar's slider to occupy the whole area of the scroll bar initially
-  _scrollBar = new QScrollBar(this);
+  _scrollBar = new ScrollBar(this);
   // since the contrast with the terminal background may not be enough,
   // the scrollbar should be auto-filled if not transient
   if (!_scrollBar->style()->styleHint(QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
@@ -1374,11 +1373,6 @@ void TerminalDisplay::focusOutEvent(QFocusEvent*)
         blinkEvent();
 
     _blinkTimer->stop();
-    if (gs_deadSpot.x() > -1 && QApplication::activeWindow()) // we lost the focus internally
-    {
-      gs_deadSpot = QPoint(-1,-1);
-      QApplication::restoreOverrideCursor();
-    }
 }
 void TerminalDisplay::focusInEvent(QFocusEvent*)
 {
@@ -1391,12 +1385,28 @@ void TerminalDisplay::focusInEvent(QFocusEvent*)
 
     if (_hasBlinker)
         _blinkTimer->start();
+}
 
-    if (gs_deadSpot.x() < 0 && _hideMouseTimer)
-    {
-        gs_futureDeadSpot = mapFromGlobal(QCursor::pos());
-        _hideMouseTimer->start(_mouseAutohideDelay);
-    }
+void TerminalDisplay::enterEvent(QEnterEvent* event)
+{
+  if (gs_deadSpot.x() < 0 && _hideMouseTimer
+      // NOTE: scrollBar->underMouse() doesn't work here
+      && !_scrollBar->rect().contains(_scrollBar->mapFromParent(event->position().toPoint())))
+  {
+    gs_futureDeadSpot = event->position().toPoint();
+    _hideMouseTimer->start(_mouseAutohideDelay);
+  }
+  QWidget::enterEvent(event);
+}
+
+void TerminalDisplay::leaveEvent(QEvent* event)
+{
+  if (gs_deadSpot.x() > -1)
+  {
+    gs_deadSpot = QPoint(-1,-1);
+    QApplication::restoreOverrideCursor();
+  }
+  QWidget::leaveEvent(event);
 }
 
 void TerminalDisplay::paintEvent( QPaintEvent* pe )
@@ -2155,6 +2165,8 @@ void TerminalDisplay::hideStaleMouse() const
         return;
     if (QApplication::activeWindow() && QApplication::activeWindow() != window()) // some other app window has the focus
         return;
+    if (_scrollBar->underMouse()) // the mouse is over the scrollbar
+        return;
     gs_deadSpot = gs_futureDeadSpot;
     QApplication::setOverrideCursor(Qt::BlankCursor);
 }
@@ -2187,7 +2199,7 @@ void TerminalDisplay::mouseMoveEvent(QMouseEvent* ev)
         gs_deadSpot = QPoint(-1,-1);
         QApplication::restoreOverrideCursor();
       }
-      gs_futureDeadSpot = ev->pos();
+      gs_futureDeadSpot = ev->position().toPoint();
       Q_ASSERT(_hideMouseTimer);
       _hideMouseTimer->start(_mouseAutohideDelay);
   }
@@ -2199,7 +2211,7 @@ void TerminalDisplay::mouseMoveEvent(QMouseEvent* ev)
                        && !_scrollBar->style()->styleHint(QStyle::SH_ScrollBar_Transient, nullptr, _scrollBar))
                       ? _scrollBar->width() : 0);
 
-  getCharacterPosition(ev->pos(),charLine,charColumn);
+  getCharacterPosition(ev->position().toPoint(),charLine,charColumn);
 
   // handle filters
   // change link hot-spot appearance on mouse-over
@@ -2299,7 +2311,7 @@ void TerminalDisplay::mouseMoveEvent(QMouseEvent* ev)
  // don't extend selection while pasting
   if (ev->buttons() & Qt::MiddleButton) return;
 
-  extendSelection( ev->pos() );
+  extendSelection(ev->position().toPoint());
 }
 
 void TerminalDisplay::extendSelection( const QPoint& position )
@@ -3543,4 +3555,17 @@ bool AutoScrollHandler::eventFilter(QObject* watched,QEvent* event)
     return false;
 }
 
+ScrollBar::ScrollBar(QWidget* parent) : QScrollBar(parent) {}
+
+void ScrollBar::enterEvent(QEnterEvent* event)
+{
+  // show the mouse cursor that was auto-hidden
+  if (gs_deadSpot.x() > -1)
+  {
+    gs_deadSpot = QPoint(-1,-1);
+    QApplication::restoreOverrideCursor();
+  }
+  QScrollBar::enterEvent(event);
+}
+
 //#include "TerminalDisplay.moc"

lib/TerminalDisplay.h

@@ -24,7 +24,7 @@
 // Qt
 #include <QColor>
 #include <QPointer>
-#include <QWidget>
+#include <QScrollBar>
 
 // Konsole
 #include "Filter.h"
@@ -41,7 +41,6 @@ class QTimer;
 class QEvent;
 class QGridLayout;
 class QKeyEvent;
-class QScrollBar;
 class QShowEvent;
 class QHideEvent;
 class QTimerEvent;
@@ -73,6 +72,7 @@ namespace Konsole
 extern unsigned short vt100_graphics[32];
 
 class ScreenWindow;
+class ScrollBar;
 
 /**
  * A widget which displays output from a terminal emulation and sends input keypresses and mouse activity
@@ -435,6 +435,12 @@ class KONSOLEPRIVATE_EXPORT TerminalDisplay : public QWidget
 
     int mouseAutohideDelay() const { return _mouseAutohideDelay; }
 
+    /**
+    * hide the mouse cursor after @param delay milliseconds of inactivity
+    * @param delay < 0 deactivates the behavior
+    */
+    void autoHideMouseAfter(int delay);
+
 public slots:
 
     /**
@@ -528,12 +534,6 @@ public slots:
      */
     void setForegroundColor(const QColor& color);
 
-    /**
-    * hide the mouse cursor after @param delay milliseconds of inactivity
-    * @param delay < 0 deactivates the behavior
-    */
-    void autoHideMouseAfter(int delay);
-
     void selectionChanged();
 
 signals:
@@ -596,6 +596,8 @@ public slots:
     virtual void fontChange(const QFont &font);
     void focusInEvent(QFocusEvent* event) override;
     void focusOutEvent(QFocusEvent* event) override;
+    void enterEvent(QEnterEvent* event) override;
+    void leaveEvent(QEvent* event) override;
     void keyPressEvent(QKeyEvent* event) override;
     void mouseDoubleClickEvent(QMouseEvent* ev) override;
     void mousePressEvent( QMouseEvent* ) override;
@@ -795,7 +797,7 @@ private slots:
     bool    _columnSelectionMode;
 
     QClipboard*  _clipboard;
-    QScrollBar* _scrollBar;
+    ScrollBar* _scrollBar;
     QTermWidget::ScrollBarPosition _scrollbarLocation;
     QString     _wordCharacters;
     int         _bellMode;
@@ -896,6 +898,16 @@ Q_OBJECT
     int _timerId;
 };
 
+class ScrollBar : public QScrollBar
+{
+Q_OBJECT
+
+public:
+    ScrollBar(QWidget* parent = nullptr);
+protected:
+    void enterEvent(QEnterEvent* event) override;
+};
+
 }
 
 #endif // TERMINALDISPLAY_H

lib/qtermwidget.cpp

@@ -832,8 +832,12 @@ void QTermWidget::setWordCharacters(const QString& chars)
     m_impl->m_terminalDisplay->setWordCharacters(chars);
 }
 
-
 QTermWidgetInterface* QTermWidget::createWidget(int startnow) const
 {
    return new QTermWidget(startnow);
 }
+
+void QTermWidget::autoHideMouseAfter(int delay)
+{
+    m_impl->m_terminalDisplay->autoHideMouseAfter(delay);
+}

lib/qtermwidget.h

@@ -259,6 +259,8 @@ class QTERMWIDGET_EXPORT QTermWidget : public QWidget, public QTermWidgetInterfa
     void setWordCharacters(const QString& chars) override;
 
     QTermWidgetInterface *createWidget(int startnow) const override;
+
+    void autoHideMouseAfter(int delay) override;
 signals:
     void finished();
     void copyAvailable(bool);

lib/qtermwidget_interface.h

@@ -101,6 +101,7 @@ class QTermWidgetInterface {
    virtual QString wordCharacters() const = 0;
    virtual void setWordCharacters(const QString& chars) = 0;
    virtual QTermWidgetInterface* createWidget(int startnow) const = 0;
+   virtual void autoHideMouseAfter(int delay) = 0;
 };
 
 #define QTermWidgetInterface_iid "lxqt.qtermwidget.QTermWidgetInterface/1.5"