macOS: Update slider metrics by explicitly asking it to layout

Pick-to: 5.15
Pick-to: 5.12
Change-Id: I283771624b513f4e8844c6130898ddf2531df0f1
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 4 insertions, 33 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index 4f51f63665..904f94fc95 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -489,38 +489,11 @@ static bool setupSlider(NSSlider *slider, const QStyleOptionSlider *sl)
         slider.numberOfTickMarks = 0;
     }
 
-    return true;
-}
+    // Ensure the values set above are reflected when asking
+    // the cell for its metrics and to draw itself.
+    [slider layoutSubtreeIfNeeded];
 
-static void fixStaleGeometry(NSSlider *slider)
-{
-    // If it's later fixed in AppKit, this function is not needed.
-    // On macOS Mojave we suddenly have NSSliderCell with a cached
-    // (and stale) geometry, thus its -drawKnob, -drawBarInside:flipped:,
-    // -drawTickMarks fail to render the slider properly. Setting the number
-    // of tickmarks triggers an update in geometry.
-
-    Q_ASSERT(slider);
-
-    if (QOperatingSystemVersion::current() < QOperatingSystemVersion::MacOSMojave)
-        return;
-
-    NSSliderCell *cell = slider.cell;
-    const NSRect barRect = [cell barRectFlipped:slider.isFlipped];
-    const NSSize sliderSize = slider.frame.size;
-    CGFloat difference = 0.;
-    if (slider.vertical)
-        difference = std::abs(sliderSize.height - barRect.size.height);
-    else
-        difference = std::abs(sliderSize.width - barRect.size.width);
-
-    if (difference > 6.) {
-        // Stale ...
-        const auto nOfTicks = slider.numberOfTickMarks;
-        // Non-zero, different from nOfTicks to force update
-        slider.numberOfTickMarks = nOfTicks + 10;
-        slider.numberOfTickMarks = nOfTicks;
-    }
+    return true;
 }
 
 static bool isInMacUnifiedToolbarArea(QWindow *window, int windowY)
@@ -5377,8 +5350,6 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                 } else
 #endif
                 {
-                    if (!hasDoubleTicks)
-                        fixStaleGeometry(slider);
                     NSSliderCell *cell = slider.cell;
 
                     const int numberOfTickMarks = slider.numberOfTickMarks;