[thumbnailview] fix smothscroll with libinput 1.19

[thumbwidget] re-enable cacheMode for non-fractional scale factor
easymodo · Sep 26, 2021 · d4e2c95 · d4e2c95
1 parent 4404d74
commit d4e2c95
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Showing 3 changed files with 10 additions and 10 deletions.
diff --git a/qimgv/gui/customwidgets/thumbnailview.cpp b/qimgv/gui/customwidgets/thumbnailview.cpp
@@ -24,6 +24,7 @@ ThumbnailView::ThumbnailView(ThumbnailViewOrientation orient, QWidget *parent)
     setRenderHint(QPainter::Antialiasing, false);
     setRenderHint(QPainter::SmoothPixmapTransform, false);
 
+    lastTouchpadScroll.start();
 
     connect(&loadTimer, &QTimer::timeout, this, &ThumbnailView::loadVisibleThumbnails);
     loadTimer.setInterval(static_cast<const int>(LOAD_DELAY));
@@ -457,20 +458,20 @@ void ThumbnailView::fitSceneToContents() {
 //################### scrolling ######################
 void ThumbnailView::wheelEvent(QWheelEvent *event) {
     event->accept();
-    // alright, i officially gave up on fixing libinput scrolling
-    // let's just hope it gets done in Qt while I am still alive
     int pixelDelta = event->pixelDelta().y();
     int angleDelta = event->angleDelta().ry();
+    bool isWheel = angleDelta && !(angleDelta % 120) && lastTouchpadScroll.elapsed() > 100;
+    if(!isWheel)
+        lastTouchpadScroll.restart();
+
     if(!settings->enableSmoothScroll()) {
         if(pixelDelta)
             scrollPrecise(pixelDelta);
         else if(angleDelta)
             scrollPrecise(angleDelta);
     } else {
-        if(pixelDelta)
+        if(!isWheel && pixelDelta)
             scrollPrecise(pixelDelta);
-        else if(abs(angleDelta) < SMOOTH_SCROLL_THRESHOLD)
-            scrollPrecise(angleDelta);
         else if(angleDelta)
             scrollSmooth(angleDelta, SCROLL_MULTIPLIER, SCROLL_ACCELERATION, true);
     }

diff --git a/qimgv/gui/customwidgets/thumbnailview.h b/qimgv/gui/customwidgets/thumbnailview.h
@@ -81,10 +81,6 @@ public slots:
 
     QTimer loadTimer;
     bool blockThumbnailLoading;
-    // let's say mouse wheel scroll always sends angleDelta = 120
-    // then we can treat anything smaller as a touchpad scroll
-    // TODO: tune this value
-    const int SMOOTH_SCROLL_THRESHOLD = 120;
 
     int mDrawScrollbarIndicator, lastScrollFrameTime;
     QList<int> mSelection;
@@ -97,6 +93,7 @@ public slots:
     void createScrollTimeLine();
     QElapsedTimer scrollFrameTimer;
     std::function<void(int)> centerOn;
+    QElapsedTimer lastTouchpadScroll;
 
 protected:
     QGraphicsScene scene;

diff --git a/qimgv/gui/customwidgets/thumbnailwidget.cpp b/qimgv/gui/customwidgets/thumbnailwidget.cpp
@@ -16,7 +16,9 @@ ThumbnailWidget::ThumbnailWidget(QGraphicsItem *parent) :
     thumbStyle(THUMB_SIMPLE)
 {
     setAttribute(Qt::WA_OpaquePaintEvent, true);
-    //setCacheMode(QGraphicsItem::DeviceCoordinateCache); breaks hidpi fractional scaling
+    float dpr = qApp->devicePixelRatio();
+    if(trunc(dpr) == dpr) // don't enable for fractional scaling
+        setCacheMode(QGraphicsItem::DeviceCoordinateCache);
     setAcceptHoverEvents(true);
     font.setBold(false);
     QFontMetrics fm(font);