[Status Bar] Remove file status Timer, add text update delay

Summary:
Currently when hovering over a file we have its name, mimetype type and size display in the status bar for 1 second, after which the status of the folder is displayed.

This patch removes this timer making the status bar behavior more predictable and user friendly.

Instead there is a 50ms delay between when the status bar gets new text to display (for instance mouse hovering or keyboard navigation) and when the status bar displayed text is updated. This is to avoid flickering.

FIXED-IN: 19.12
BUG: 399267

Reviewers: #dolphin, elvisangelaccio, ngraham

Reviewed By: #dolphin, elvisangelaccio, ngraham

Subscribers: kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D25218

src/statusbar/dolphinstatusbar.cpp

@@ -39,7 +39,7 @@
 #include <QToolButton>
 
 namespace {
-    const int ResetToDefaultTimeout = 1000;
+    const int UpdateDelay = 50;
 }
 
 DolphinStatusBar::DolphinStatusBar(QWidget* parent) :
@@ -53,7 +53,7 @@ DolphinStatusBar::DolphinStatusBar(QWidget* parent) :
     m_stopButton(nullptr),
     m_progress(100),
     m_showProgressBarTimer(nullptr),
-    m_resetToDefaultTextTimer(nullptr),
+    m_delayUpdateTimer(nullptr),
     m_textTimestamp()
 {
     // Initialize text label
@@ -95,10 +95,12 @@ DolphinStatusBar::DolphinStatusBar(QWidget* parent) :
     m_showProgressBarTimer->setSingleShot(true);
     connect(m_showProgressBarTimer, &QTimer::timeout, this, &DolphinStatusBar::updateProgressInfo);
 
-    m_resetToDefaultTextTimer = new QTimer(this);
+    // initialize text updater delay timer
-    m_resetToDefaultTextTimer->setInterval(ResetToDefaultTimeout);
+    m_delayUpdateTimer = new QTimer(this);
-    m_resetToDefaultTextTimer->setSingleShot(true);
+    m_delayUpdateTimer->setInterval(UpdateDelay);
-    connect(m_resetToDefaultTextTimer, &QTimer::timeout, this, &DolphinStatusBar::slotResetToDefaultText);
+    m_delayUpdateTimer->setSingleShot(true);
+    connect(m_delayUpdateTimer, &QTimer::timeout,
+            this, &DolphinStatusBar::updateLabelText);
 
     // Initialize top layout and size policies
     const int fontHeight = QFontMetrics(m_label->font()).height();
@@ -154,19 +156,9 @@ void DolphinStatusBar::setText(const QString& text)
 
     m_textTimestamp = QTime::currentTime();
 
-    if (text.isEmpty()) {
+    m_text = text;
-        // Assure that the previous set text won't get
+    // will update status bar text in 50ms
-        // cleared immediately.
+    m_delayUpdateTimer->start();
-        m_resetToDefaultTextTimer->start();
-    } else {
-        m_text = text;
-
-        if (m_resetToDefaultTextTimer->isActive()) {
-            m_resetToDefaultTextTimer->start();
-        }
-
-        updateLabelText();
-    }
 }
 
 QString DolphinStatusBar::text() const
@@ -214,12 +206,13 @@ int DolphinStatusBar::progress() const
 
 void DolphinStatusBar::resetToDefaultText()
 {
+    m_text.clear();
+
     QTime currentTime;
-    if (currentTime.msecsTo(m_textTimestamp) < ResetToDefaultTimeout) {
+    if (currentTime.msecsTo(m_textTimestamp) < UpdateDelay) {
-        m_resetToDefaultTextTimer->start();
+        m_delayUpdateTimer->start();
     } else {
-        m_resetToDefaultTextTimer->stop();
+        updateLabelText();
-        slotResetToDefaultText();
     }
 }
 
@@ -325,12 +318,6 @@ void DolphinStatusBar::updateLabelText()
     m_label->setText(text);
 }
 
-void DolphinStatusBar::slotResetToDefaultText()
-{
-    m_text.clear();
-    updateLabelText();
-}
-
 void DolphinStatusBar::updateZoomSliderToolTip(int zoomLevel)
 {
     const int size = ZoomLevelInfo::iconSizeForZoomLevel(zoomLevel);

src/statusbar/dolphinstatusbar.h

@@ -67,8 +67,7 @@ public:
 
     /**
      * Replaces the text set by setText() by the text that
-     * has been set by setDefaultText(). It is assured that the previous
+     * has been set by setDefaultText(). DolphinStatusBar::text()
-     * text will be shown for at least 1 second. DolphinStatusBar::text()
      * will return an empty string after the reset has been done.
      */
     void resetToDefaultText();
@@ -119,14 +118,6 @@ private slots:
      */
     void updateLabelText();
 
-    /**
-     * Is invoked by m_resetToDefaultTextTimer and clears
-     * m_text so that the default text will be shown. This
-     * prevents that information-messages will be cleared
-     * too fast.
-     */
-    void slotResetToDefaultText();
-
     /**
      * Updates the text of the zoom slider tooltip to show
      * the currently used size.
@@ -156,7 +147,7 @@ private:
     int m_progress;
     QTimer* m_showProgressBarTimer;
 
-    QTimer* m_resetToDefaultTextTimer;
+    QTimer* m_delayUpdateTimer;
     QTime m_textTimestamp;
 };