Mac: Implement unified toolbar look for QTabBar

Extend the unified title and toolbar gradient to 
tabs in document mode that are adjacent unified
tool bars.

Change the updateMacBorderMetrics() function to
register the tab bar geometry and visibility status
with the Cocoa platform plugin. The Cocoa platform
plugin will then merge this area with other registered
areas if possible.

Add QCocoaNativeInterface::testContentBorderPosition(). 
This function tests whether the given point is within 
the unified title and toolbar area.

Use testContentBorderPosition() in QMacStyle to enable 
code paths that skips drawing the QToolBar bottom 
separator line and paints the active tab background 
with transparent pixels to make the background gradient 
visible.

Change-Id: I2b70f9bb0c2c59af053a691a7df538f958783dab
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

1 files changed, 44 insertions, 13 deletions

diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 2d8489f47f..d35dd16f85 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -179,6 +179,19 @@ static bool isVerticalTabs(const QTabBar::Shape shape) {
                 || shape == QTabBar::TriangularWest);
 }
 
+static bool isInMacUnifiedToolbarArea(QWindow *window, int windowY)
+{
+    QPlatformNativeInterface *nativeInterface = QGuiApplication::platformNativeInterface();
+    QPlatformNativeInterface::NativeResourceForIntegrationFunction function =
+        nativeInterface->nativeResourceFunctionForIntegration("testContentBorderPosition");
+    if (!function)
+        return false; // Not Cocoa platform plugin.
+
+    typedef bool (*TestContentBorderPositionFunction)(QWindow *, int);
+    return (reinterpret_cast<TestContentBorderPositionFunction>(function))(window, windowY);
+}
+
+
 void drawTabCloseButton(QPainter *p, bool hover, bool active, bool selected)
 {
     // draw background circle
@@ -239,7 +252,7 @@ QRect rotateTabPainter(QPainter *p, QTabBar::Shape shape, QRect tabRect)
     return tabRect;
 }
 
-void drawTabShape(QPainter *p, const QStyleOptionTabV3 *tabOpt)
+void drawTabShape(QPainter *p, const QStyleOptionTabV3 *tabOpt, bool isUnified)
 {
     QRect r = tabOpt->rect;
     p->translate(tabOpt->rect.x(), tabOpt->rect.y());
@@ -256,7 +269,12 @@ void drawTabShape(QPainter *p, const QStyleOptionTabV3 *tabOpt)
         QRect rect(1, 0, width - 2, height);
 
         // fill body
-        if (active) {
+        if (tabOpt->documentMode && isUnified) {
+            p->save();
+            p->setCompositionMode(QPainter::CompositionMode_Source);
+            p->fillRect(rect, QColor(Qt::transparent));
+            p->restore();
+        } else if (active) {
             int d = (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_6) ? 16 : 0;
             p->fillRect(rect, QColor(151 + d, 151 + d, 151 + d));
         } else {
@@ -3733,8 +3751,14 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             if (const QStyleOptionTabV3 *tabOptV3 = qstyleoption_cast<const QStyleOptionTabV3 *>(opt)) {
                 if (tabOptV3->documentMode) {
                     p->save();
-                    // QRect tabRect = tabOptV3->rect;
-                    drawTabShape(p, tabOptV3);
+                    bool isUnified = false;
+                    if (w) {
+                        QRect tabRect = tabOptV3->rect;
+                        QPoint windowTabStart = w->mapTo(w->window(), tabRect.topLeft());
+                        isUnified = isInMacUnifiedToolbarArea(w->window()->windowHandle(), windowTabStart.y());
+                    }
+
+                    drawTabShape(p, tabOptV3, isUnified);
                     p->restore();
                     return;
                 }
@@ -4442,15 +4466,22 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
                     p->fillRect(opt->rect, Qt::transparent);
                     p->restore();
 
-                    // drow horizontal sepearator line at toolBar bottom.
-                    SInt32 margin;
-                    GetThemeMetric(kThemeMetricSeparatorSize, &margin);
-                    CGRect separatorRect = CGRectMake(opt->rect.left(), opt->rect.bottom(), opt->rect.width(), margin);
-                    HIThemeSeparatorDrawInfo separatorDrawInfo;
-                    separatorDrawInfo.version = 0;
-                    separatorDrawInfo.state = qt_macWindowMainWindow(mainWindow) ? kThemeStateActive : kThemeStateInactive;
-                    QMacCGContext cg(p);
-                    HIThemeDrawSeparator(&separatorRect, &separatorDrawInfo, cg, kHIThemeOrientationNormal);
+                    // Drow a horizontal sepearator line at the toolBar bottom if the "unified" area ends here.
+                    // There might be additional toolbars or other widgets such as tab bars in document
+                    // mode below. Determine this by making a unified toolbar area test for the row below
+                    // this toolbar.
+                    QPoint windowToolbarEnd = w->mapTo(w->window(), opt->rect.bottomLeft());
+                    bool isEndOfUnifiedArea = !isInMacUnifiedToolbarArea(w->window()->windowHandle(), windowToolbarEnd.y() + 1);
+                    if (isEndOfUnifiedArea) {
+                        SInt32 margin;
+                        GetThemeMetric(kThemeMetricSeparatorSize, &margin);
+                        CGRect separatorRect = CGRectMake(opt->rect.left(), opt->rect.bottom(), opt->rect.width(), margin);
+                        HIThemeSeparatorDrawInfo separatorDrawInfo;
+                        separatorDrawInfo.version = 0;
+                        separatorDrawInfo.state = qt_macWindowMainWindow(mainWindow) ? kThemeStateActive : kThemeStateInactive;
+                        QMacCGContext cg(p);
+                        HIThemeDrawSeparator(&separatorRect, &separatorDrawInfo, cg, kHIThemeOrientationNormal);
+                    }
                     break;
                 }
             }