QMacStyle: Fix QSlider appearance on Yosemite

First, we adjust the min and max positions, which HITheme has been
unable to render properly for years. This involves separating the
knob and track rendering. Also, on Yosemite, the tickmarks-less
slider shows a blue progress fill in the track, on the knob's left
side. Finaly, and this is valid for all versions, the tickmarks are
being drawn before the knob (or the whole slider for OS X versions
before 10.10)

Change-Id: I6fce2e298a80858a18fd9fe1e799b65265a8aefd
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

2 files changed, 142 insertions, 10 deletions

diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 6990cb6fe8..2b2f729972 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -1661,10 +1661,34 @@ void QMacStylePrivate::getSliderInfo(QStyle::ComplexControl cc, const QStyleOpti
             tdi->kind = kThemeSmallSlider;
         break;
     }
+
+    bool usePlainKnob = slider->tickPosition == QSlider::NoTicks
+            || slider->tickPosition == QSlider::TicksBothSides;
+
     tdi->bounds = qt_hirectForQRect(slider->rect);
-    tdi->min = slider->minimum;
-    tdi->max = slider->maximum;
-    tdi->value = slider->sliderPosition;
+    if (isScrollbar || QSysInfo::MacintoshVersion <= QSysInfo::MV_10_9) {
+        tdi->min = slider->minimum;
+        tdi->max = slider->maximum;
+        tdi->value = slider->sliderPosition;
+    } else {
+        // Fix min and max positions. HITheme seems confused when it comes to rendering
+        // a slider at those positions. We give it a hand by extending and offsetting
+        // the slider range accordingly. See also comment for CC_Slider in drawComplexControl()
+        tdi->min = 0;
+        if (slider->orientation == Qt::Horizontal)
+            tdi->max = 10 * slider->rect.width();
+        else
+            tdi->max = 10 * slider->rect.height();
+
+        if (usePlainKnob || slider->orientation == Qt::Horizontal) {
+            int endsCorrection = usePlainKnob ? 25 : 10;
+            tdi->value = (tdi->max + 2 * endsCorrection) * (slider->sliderPosition - slider->minimum)
+                    / (slider->maximum - slider->minimum) - endsCorrection;
+        } else {
+            tdi->value = (tdi->max + 30) * (slider->sliderPosition - slider->minimum)
+                       / (slider->maximum - slider->minimum) - 20;
+        }
+    }
     tdi->attributes = kThemeTrackShowThumb;
     if (slider->upsideDown)
         tdi->attributes |= kThemeTrackRightToLeft;
@@ -1681,7 +1705,7 @@ void QMacStylePrivate::getSliderInfo(QStyle::ComplexControl cc, const QStyleOpti
     // Tiger broke reverse scroll bars so put them back and "fake it"
     if (isScrollbar && (tdi->attributes & kThemeTrackRightToLeft)) {
         tdi->attributes &= ~kThemeTrackRightToLeft;
-        tdi->value = tdi->max - slider->sliderPosition;
+        tdi->value = tdi->max - tdi->value;
     }
 
     tdi->enableState = (slider->state & QStyle::State_Enabled) ? kThemeTrackActive
@@ -1689,7 +1713,7 @@ void QMacStylePrivate::getSliderInfo(QStyle::ComplexControl cc, const QStyleOpti
     if (!isScrollbar) {
         if (slider->state & QStyle::QStyle::State_HasFocus)
             tdi->attributes |= kThemeTrackHasFocus;
-        if (slider->tickPosition == QSlider::NoTicks || slider->tickPosition == QSlider::TicksBothSides)
+        if (usePlainKnob)
             tdi->trackInfo.slider.thumbDir = kThemeThumbPlain;
         else if (slider->tickPosition == QSlider::TicksAbove)
             tdi->trackInfo.slider.thumbDir = kThemeThumbUpward;
@@ -1815,6 +1839,12 @@ NSView *QMacStylePrivate::cocoaControl(QCocoaWidget widget, QPoint *offset) cons
             bv = [[NSPopUpButton alloc] init];
         else if (widget.first == QCocoaComboBox)
             bv = [[NSComboBox alloc] init];
+        else if (widget.first == QCocoaHorizontalSlider)
+            bv = [[NSSlider alloc] init];
+        else if (widget.first == QCocoaVerticalSlider)
+            // Cocoa sets the orientation from the view's frame
+            // at construction time, and it cannot be changed later.
+            bv = [[NSSlider alloc] initWithFrame:NSMakeRect(0, 0, 10, 100)];
         else
             bv = [[NSButton alloc] init];
 
@@ -5315,6 +5345,7 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                         // because on Tiger I only "fake" the reverse stuff.
                         bool reverseHorizontal = (slider->direction == Qt::RightToLeft
                                                   && slider->orientation == Qt::Horizontal);
+
                         if ((reverseHorizontal
                              && slider->activeSubControls == SC_ScrollBarAddLine)
                             || (!reverseHorizontal
@@ -5365,6 +5396,9 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                     tdi.attributes |= kThemeTrackHideTrack;
             }
 
+            const bool usingYosemiteOrLater = QSysInfo::MacintoshVersion > QSysInfo::MV_10_9;
+            const bool isHorizontal = slider->orientation == Qt::Horizontal;
+
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
             if (cc == CC_ScrollBar && proxy()->styleHint(SH_ScrollBar_Transient, opt, widget)) {
                 bool wasActive = false;
@@ -5449,8 +5483,6 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                     }
                 }
 
-                const bool isHorizontal = slider->orientation == Qt::Horizontal;
-
                 CGContextSaveGState(cg);
                 [NSGraphicsContext saveGraphicsState];
 
@@ -5535,9 +5567,86 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
             {
                 d->stopAnimation(opt->styleObject);
 
-                HIThemeDrawTrack(&tdi, tracking ? 0 : &macRect, cg,
-                                 kHIThemeOrientationNormal);
+                if (usingYosemiteOrLater && cc == CC_Slider) {
+                    // Fix min and max positions. (See also getSliderInfo()
+                    // for the slider values adjustments.)
+                    // HITheme seems to have forgotten how to render
+                    // a slide at those positions, leaving a gap between
+                    // the knob and the ends of the track.
+                    // We fix this by rendering the track first, and then
+                    // the knob on top. However, in order to not clip the
+                    // knob, we reduce the the drawing rect for the track.
+                    HIRect bounds = tdi.bounds;
+                    if (isHorizontal) {
+                        tdi.bounds.size.width -= 2;
+                        tdi.bounds.origin.x += 1;
+                        if (tdi.trackInfo.slider.thumbDir == kThemeThumbDownward)
+                            tdi.bounds.origin.y -= 2;
+                        else if (tdi.trackInfo.slider.thumbDir == kThemeThumbUpward)
+                            tdi.bounds.origin.y += 3;
+                    } else {
+                        tdi.bounds.size.height -= 2;
+                        tdi.bounds.origin.y += 1;
+                        if (tdi.trackInfo.slider.thumbDir == kThemeThumbDownward) // pointing right
+                            tdi.bounds.origin.x -= 4;
+                        else if (tdi.trackInfo.slider.thumbDir == kThemeThumbUpward) // pointing left
+                            tdi.bounds.origin.x += 2;
+                    }
+
+                    // Yosemite demands its blue progress track when no tickmarks are present
+                    if (!(slider->subControls & SC_SliderTickmarks)) {
+                        QCocoaWidgetKind sliderKind = slider->orientation == Qt::Horizontal ? QCocoaHorizontalSlider : QCocoaVerticalSlider;
+                        NSSlider *sl = (NSSlider *)d->cocoaControl(QCocoaWidget(sliderKind, QAquaSizeLarge), 0);
+                        sl.minValue = slider->minimum;
+                        sl.maxValue = slider->maximum;
+                        sl.intValue = slider->sliderValue;
+                        sl.enabled = slider->state & QStyle::State_Enabled;
+                        d->drawNSViewInRect(sl, opt->rect, p, ^(NSRect rect, CGContextRef ctx) {
+                                                if (slider->upsideDown) {
+                                                    if (isHorizontal) {
+                                                        CGContextTranslateCTM(ctx, rect.size.width, 0);
+                                                        CGContextScaleCTM(ctx, -1, 1);
+                                                    }
+                                                } else if (!isHorizontal) {
+                                                    CGContextTranslateCTM(ctx, 0, rect.size.height);
+                                                    CGContextScaleCTM(ctx, 1, -1);
+                                                }
+                                                [sl.cell drawBarInside:tdi.bounds flipped:NO];
+                                                // No need to restore the CTM later, the context has been saved
+                                                // and will be restored at the end of drawNSViewInRect()
+                                            });
+                        tdi.attributes |= kThemeTrackHideTrack;
+                    } else {
+                        tdi.attributes &= ~(kThemeTrackShowThumb | kThemeTrackHasFocus);
+                        HIThemeDrawTrack(&tdi, tracking ? 0 : &macRect, cg,
+                                         kHIThemeOrientationNormal);
+                        tdi.attributes |= kThemeTrackHideTrack | kThemeTrackShowThumb;
+                    }
+
+                    tdi.bounds = bounds;
+                }
+
                 if (cc == CC_Slider && slider->subControls & SC_SliderTickmarks) {
+
+                    HIRect bounds;
+                    if (usingYosemiteOrLater) {
+                        // As part of fixing the min and max positions,
+                        // we need to adjust the tickmarks as well
+                        bounds = tdi.bounds;
+                        if (slider->orientation == Qt::Horizontal) {
+                            tdi.bounds.size.width += 2;
+                            tdi.bounds.origin.x -= 1;
+                                if (tdi.trackInfo.slider.thumbDir == kThemeThumbUpward)
+                                    tdi.bounds.origin.y -= 2;
+                        } else {
+                            tdi.bounds.size.height += 3;
+                            tdi.bounds.origin.y -= 3;
+                            tdi.bounds.origin.y += 1;
+                            if (tdi.trackInfo.slider.thumbDir == kThemeThumbUpward) // pointing left
+                                tdi.bounds.origin.x -= 2;
+                        }
+                    }
+
                     if (qt_mac_is_metal(widget)) {
                         if (tdi.enableState == kThemeTrackInactive)
                             tdi.enableState = kThemeTrackActive;  // Looks more Cocoa-like
@@ -5559,16 +5668,37 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                                                   cg,
                                                   kHIThemeOrientationNormal);
                         tdi.trackInfo.slider.thumbDir = kThemeThumbUpward;
+                        if (usingYosemiteOrLater) {
+                            if (slider->orientation == Qt::Vertical)
+                                tdi.bounds.origin.x -= 2;
+                        }
                         HIThemeDrawTrackTickMarks(&tdi, numMarks,
                                                   cg,
                                                    kHIThemeOrientationNormal);
+                        // Reset to plain thumb to be drawn further down
+                        tdi.trackInfo.slider.thumbDir = kThemeThumbPlain;
                     } else {
                         HIThemeDrawTrackTickMarks(&tdi, numMarks,
                                                   cg,
                                                   kHIThemeOrientationNormal);
+                    }
+
+                    if (usingYosemiteOrLater)
+                        tdi.bounds = bounds;
+                }
 
+                if (usingYosemiteOrLater && cc == CC_Slider) {
+                    // Still as part of fixing the min and max positions,
+                    // we also adjust the knob position. We can do this
+                    // because it's rendered separately from the track.
+                    if (slider->orientation == Qt::Vertical) {
+                        if (tdi.trackInfo.slider.thumbDir == kThemeThumbDownward) // pointing right
+                            tdi.bounds.origin.x -= 2;
                     }
                 }
+
+                HIThemeDrawTrack(&tdi, tracking ? 0 : &macRect, cg,
+                                 kHIThemeOrientationNormal);
             }
         }
         break;
diff --git a/src/widgets/styles/qmacstyle_mac_p_p.h b/src/widgets/styles/qmacstyle_mac_p_p.h
index 1c5e7b5c45..f36ba2c190 100644
--- a/src/widgets/styles/qmacstyle_mac_p_p.h
+++ b/src/widgets/styles/qmacstyle_mac_p_p.h
@@ -127,7 +127,9 @@ enum QCocoaWidgetKind {
     QCocoaComboBox,     // Editable QComboBox
     QCocoaPopupButton,  // Non-editable QComboBox
     QCocoaPushButton,
-    QCocoaRadioButton
+    QCocoaRadioButton,
+    QCocoaHorizontalSlider,
+    QCocoaVerticalSlider
 };
 
 typedef QPair<QCocoaWidgetKind, QAquaWidgetSize> QCocoaWidget;