Accessibility Mac: Fix handling of top level widget

This simplifies how we handle QNSView for accessibility purposes.
Instead of trying to half-merge the top level widget
(window->accessibleRoot) into the view, just have the view
always return it as child.
This makes the accessibility implementation for QNSView simpler
and makes applications that show a top level widget such as a button
possible. (We would return accessibility ignored for the button before).

As a side effect finding the active focus and hit-testing should be more reliable as
well.
Task-number: QTBUG-37794

Change-Id: Ib52037f88da8887a0bdc77204b0f3daddfe7709d
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>

src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm

@@ -417,7 +417,23 @@
 }
 
 - (id)accessibilityFocusedUIElement {
-    return NSAccessibilityUnignoredAncestor(self);
+    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
+
+    if (!iface || !iface->isValid()) {
+        qWarning() << "FocusedUIElement for INVALID";
+        return nil;
+    }
+    QAccessibleInterface *childInterface = iface->focusChild();
+    if (childInterface) {
+        QAccessible::Id childAxid = QAccessible::uniqueId(childInterface);
+        // FIXME: parent could be wrong
+        QCocoaAccessibleElement *accessibleElement = [QCocoaAccessibleElement createElementWithId:childAxid parent:self];
+        [accessibleElement autorelease];
+        return accessibleElement;
+    }
+
+    // no focus found
+    return nil;
 }
 
 @end

src/plugins/platforms/cocoa/qnsviewaccessibility.mm

@@ -54,6 +54,15 @@
 
 @implementation QNSView (QNSViewAccessibility)
 
+- (id)childAccessibleElement {
+    if (!m_window->accessibleRoot())
+        return nil;
+
+    QAccessible::Id childId = QAccessible::uniqueId(m_window->accessibleRoot());
+    QCocoaAccessibleElement *child = [QCocoaAccessibleElement createElementWithId: childId parent: self];
+    return [child autorelease];
+}
+
 // The QNSView is a container that the user does not interact directly with:
 // Remove it from the user-visible accessibility tree.
 - (BOOL)accessibilityIsIgnored {
@@ -61,58 +70,22 @@
 }
 
 - (id)accessibilityAttributeValue:(NSString *)attribute {
-
     // activate accessibility updates
     QCocoaIntegration::instance()->accessibility()->setActive(true);
 
-    if ([attribute isEqualToString:NSAccessibilityRoleAttribute]) {
-        if (m_window->accessibleRoot())
-            return QCocoaAccessible::macRole(m_window->accessibleRoot());
-        return NSAccessibilityUnknownRole;
-    } else if ([attribute isEqualToString:NSAccessibilityRoleDescriptionAttribute]) {
-        return NSAccessibilityRoleDescriptionForUIElement(self);
-    } else if ([attribute isEqualToString:NSAccessibilityChildrenAttribute]) {
-        if (!m_window->accessibleRoot())
-            return [super accessibilityAttributeValue:attribute];
-        return QCocoaAccessible::unignoredChildren(self, m_window->accessibleRoot());
+    if ([attribute isEqualToString:NSAccessibilityChildrenAttribute]) {
+        return NSAccessibilityUnignoredChildrenForOnlyChild([self childAccessibleElement]);
     } else {
         return [super accessibilityAttributeValue:attribute];
     }
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
-    if (!m_window->accessibleRoot())
-        return [super accessibilityHitTest:point];
-
-    QAccessibleInterface *childInterface = m_window->accessibleRoot()->childAt(point.x, qt_mac_flipYCoordinate(point.y));
-    // No child found, meaning we hit the NSView
-    if (!childInterface) {
-        return [super accessibilityHitTest:point];
-    }
-
-    // Hit a child, forward to child accessible interface.
-    QAccessible::Id childAxid = QAccessible::uniqueId(childInterface);
-    // FIXME: parent could be wrong
-    QCocoaAccessibleElement *accessibleElement = [QCocoaAccessibleElement createElementWithId:childAxid parent:self ];
-    [accessibleElement autorelease];
-    return [accessibleElement accessibilityHitTest:point];
+    return [[self childAccessibleElement] accessibilityHitTest: point];
 }
 
 - (id)accessibilityFocusedUIElement {
-    if (!m_window->accessibleRoot())
-        return [super accessibilityFocusedUIElement];
-
-    QAccessibleInterface *childInterface = m_window->accessibleRoot()->focusChild();
-    if (childInterface) {
-        QAccessible::Id childAxid = QAccessible::uniqueId(childInterface);
-        // FIXME: parent could be wrong
-        QCocoaAccessibleElement *accessibleElement = [QCocoaAccessibleElement createElementWithId:childAxid parent:self];
-        [accessibleElement autorelease];
-        return accessibleElement;
-    }
-
-    // should not happen
-    return nil;
+    return [[self childAccessibleElement] accessibilityFocusedUIElement];
 }
 
 @end

tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.cpp

@@ -79,6 +79,7 @@ private slots:
     void init();
     void cleanup();
 
+    void singleWidgetTest();
     void lineEditTest();
     void hierarchyTest();
 private:
@@ -101,6 +102,16 @@ void tst_QAccessibilityMac::cleanup()
     delete m_window;
 }
 
+void tst_QAccessibilityMac::singleWidgetTest()
+{
+    if (!macNativeAccessibilityEnabled())
+        return;
+
+    delete m_window;
+    m_window = 0;
+
+    QVERIFY(singleWidget());
+}
 
 void tst_QAccessibilityMac::lineEditTest()
 {
@@ -122,14 +133,19 @@ void tst_QAccessibilityMac::hierarchyTest()
 
     QWidget *w = new QWidget(m_window);
     m_window->addWidget(w);
-    QPushButton *b = new QPushButton(w);
+
     w->setLayout(new QVBoxLayout());
+    QPushButton *b = new QPushButton(w);
     w->layout()->addWidget(b);
     b->setText("I am a button");
 
+    QPushButton *b2 = new QPushButton(w);
+    w->layout()->addWidget(b2);
+    b2->setText("Button 2");
+
     QVERIFY(QTest::qWaitForWindowExposed(m_window));
     QCoreApplication::processEvents();
-    QVERIFY(testHierarchy());
+    QVERIFY(testHierarchy(w));
 }
 
 QTEST_MAIN(tst_QAccessibilityMac)

tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.h

@@ -48,4 +48,5 @@
 bool macNativeAccessibilityEnabled();
 bool trusted();
 bool testLineEdit();
-bool testHierarchy();
+bool testHierarchy(QWidget *w);
+bool singleWidget();

tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm

@@ -43,8 +43,10 @@
 #define QT_NO_KEYWORDS
 
 #include "tst_qaccessibilitymac_helpers.h"
-#include <QApplication>
-#include <QDebug>
+#include <QtWidgets/qapplication.h>
+#include <QtWidgets/qlineedit.h>
+#include <QtWidgets/qpushbutton.h>
+#include <QtTest>
 #include <unistd.h>
 
 #import <Cocoa/Cocoa.h>
@@ -148,9 +150,41 @@ bool trusted()
     return p;
 }
 
++ (TestAXObject *) getApplicationAXObject
+{
+    pid_t pid = getpid();
+    AXUIElementRef appRef = AXUIElementCreateApplication(pid);
+    TestAXObject *appObject = [[TestAXObject alloc] initWithAXUIElementRef: appRef];
+    return appObject;
+}
+
 @end
 
 
+bool singleWidget()
+{
+    QLineEdit le;
+    le.setText("button");
+    le.show();
+    EXPECT(QTest::qWaitForWindowExposed(&le));
+    QCoreApplication::processEvents();
+
+    TestAXObject *appObject = [TestAXObject getApplicationAXObject];
+    EXPECT(appObject);
+
+    NSArray *windows = [appObject windowList];
+    EXPECT([windows count] == 1);
+
+    AXUIElementRef windowRef = (AXUIElementRef) [windows objectAtIndex: 0];
+    EXPECT(windowRef != nil);
+    TestAXObject *window = [[TestAXObject alloc] initWithAXUIElementRef: windowRef];
+
+    AXUIElementRef lineEdit = [window findDirectChildByRole: kAXTextFieldRole];
+    EXPECT(lineEdit != nil);
+
+    return true;
+}
+
 bool testLineEdit()
 {
 // not sure if this is needed. on my machine the calls succeed.
@@ -159,10 +193,8 @@ bool testLineEdit()
 //    AXError e = AXMakeProcessTrusted((CFStringRef) path);
 //    NSLog(@"error: %i", e);
 
-    pid_t pid = getpid();
-    AXUIElementRef app = AXUIElementCreateApplication(pid);
-    EXPECT(app != nil);
-    TestAXObject *appObject = [[TestAXObject alloc] initWithAXUIElementRef: app];
+    TestAXObject *appObject = [TestAXObject getApplicationAXObject];
+    EXPECT(appObject);
 
     NSArray *windowList = [appObject windowList];
     // one window
@@ -184,12 +216,10 @@ bool testLineEdit()
     return true;
 }
 
-bool testHierarchy()
+bool testHierarchy(QWidget *w)
 {
-    pid_t pid = getpid();
-    AXUIElementRef app = AXUIElementCreateApplication(pid);
-    EXPECT(app != nil);
-    TestAXObject *appObject = [[TestAXObject alloc] initWithAXUIElementRef: app];
+    TestAXObject *appObject = [TestAXObject getApplicationAXObject];
+    EXPECT(appObject);
 
     NSArray *windowList = [appObject windowList];
     // one window
@@ -207,7 +237,36 @@ bool testHierarchy()
     TestAXObject *parentObject = [[TestAXObject alloc] initWithAXUIElementRef: [buttonObject parent]];
 
     // check that the parent is a window
-    EXPECT([[parentObject role] isEqualToString: (NSString *)kAXWindowRole]);
+    EXPECT([[parentObject role] isEqualToString: NSAccessibilityWindowRole]);
+
+    // test the focus
+    // child 0 is the layout, then button1 and 2
+    QPushButton *button1 = qobject_cast<QPushButton*>(w->children().at(1));
+    EXPECT(button1);
+    QPushButton *button2 = qobject_cast<QPushButton*>(w->children().at(2));
+    EXPECT(button2);
+    button2->setFocus();
+
+    AXUIElementRef systemWideElement = AXUIElementCreateSystemWide();
+    AXUIElementRef focussedElement = NULL;
+    AXError error = AXUIElementCopyAttributeValue(systemWideElement,
+        (CFStringRef)NSAccessibilityFocusedUIElementAttribute, (CFTypeRef*)&focussedElement);
+    EXPECT(!error);
+    EXPECT(focussedElement);
+    TestAXObject *focusButton2 = [[TestAXObject alloc] initWithAXUIElementRef: focussedElement];
+
+    EXPECT([[focusButton2 role] isEqualToString: NSAccessibilityButtonRole]);
+    EXPECT([[focusButton2 description] isEqualToString: @"Button 2"]);
+
+
+    button1->setFocus();
+    error = AXUIElementCopyAttributeValue(systemWideElement,
+        (CFStringRef)NSAccessibilityFocusedUIElementAttribute, (CFTypeRef*)&focussedElement);
+    EXPECT(!error);
+    EXPECT(focussedElement);
+    TestAXObject *focusButton1 = [[TestAXObject alloc] initWithAXUIElementRef: focussedElement];
+    EXPECT([[focusButton1 role] isEqualToString: NSAccessibilityButtonRole]);
+    EXPECT([[focusButton1 description] isEqualToString: @"I am a button"]);
 
     return true;
 }