Implement EditableText accessibility for Mac.

Change-Id: Ibe03975bafc5a6a420b3bd69dfaa93dbf65c9958
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>

src/plugins/platforms/cocoa/qcocoaaccessibility.h

@@ -44,6 +44,18 @@
 #include <Cocoa/Cocoa.h>
 
 #include <QtGui>
+#include <qpa/qplatformaccessibility.h>
+
+class QCococaAccessibility : public QPlatformAccessibility
+{
+public:
+    QCococaAccessibility();
+    ~QCococaAccessibility();
+    void notifyAccessibilityUpdate(QAccessibleEvent *event);
+    void setRootObject(QObject *o);
+    void initialize();
+    void cleanup();
+};
 
 namespace QCocoaAccessible {
 
@@ -52,9 +64,9 @@ namespace QCocoaAccessible {
 
     Cocoa accessibility is implemented in the following files:
 
+    - qcocoaaccessibility (this file) : QCocoaAccessibility "plugin", conversion and helper functions.
     - qnsviewaccessibility            : Root accessibility implementation for QNSView
     - qcocoaaccessibilityelement      : Cocoa accessibility protocol wrapper for QAccessibleInterface
-    - qcocoaaccessibility (this file) : Conversion and helper functions.
 
     The accessibility implementation wraps QAccessibleInterfaces in QCocoaAccessibleElements, which
     implements the cocoa accessibility protocol. The root QAccessibleInterface (the one returned
@@ -70,6 +82,8 @@ bool shouldBeIgnrored(QAccessibleInterface *interface);
 NSString *getTranslatedAction(const QString &qtAction);
 NSMutableArray *createTranslatedActionsList(const QStringList &qtActions);
 QString translateAction(NSString *nsAction);
+bool hasValueAttribute(QAccessibleInterface *interface);
+id getValueAttribute(QAccessibleInterface *interface);
 
 }
 

src/plugins/platforms/cocoa/qcocoaaccessibility.mm

@@ -39,6 +39,58 @@
 **
 ****************************************************************************/
 #include "qcocoaaccessibility.h"
+#include "qcocoaaccessibilityelement.h"
+#include <qaccessible.h>
+#include <qaccessible2.h>
+#include <private/qcore_mac_p.h>
+
+QCococaAccessibility::QCococaAccessibility()
+{
+
+}
+
+QCococaAccessibility::~QCococaAccessibility()
+{
+
+}
+
+void QCococaAccessibility::notifyAccessibilityUpdate(QAccessibleEvent *event)
+{
+    QObject *object = event->object();
+    if (!object)
+        return;
+
+    QAccessibleInterface *interface = QAccessible::queryAccessibleInterface(object);
+    if (!interface)
+        return;
+
+    switch (event->type()) {
+        case QAccessible::TextInserted :
+        case QAccessible::TextRemoved :
+        case QAccessible::TextUpdated : {
+            QCocoaAccessibleElement *element = [QCocoaAccessibleElement elementWithInterface : interface parent : nil];
+            NSAccessibilityPostNotification(element, NSAccessibilityValueChangedNotification);
+        break; }
+        default:
+            delete interface;
+        break;
+    }
+}
+
+void QCococaAccessibility::setRootObject(QObject *o)
+{
+    Q_UNUSED(o)
+}
+
+void QCococaAccessibility::initialize()
+{
+
+}
+
+void QCococaAccessibility::cleanup()
+{
+
+}
 
 namespace QCocoaAccessible {
 
@@ -218,4 +270,38 @@ QString translateAction(NSString *nsAction)
     return QString();
 }
 
+bool hasValueAttribute(QAccessibleInterface *interface)
+{
+    const QAccessible::Role qtrole = interface->role();
+    if (qtrole == QAccessible::EditableText) {
+        return true;
+    }
+
+    return false;
+}
+
+id getValueAttribute(QAccessibleInterface *interface)
+{
+    const QAccessible::Role qtrole = interface->role();
+    if (qtrole == QAccessible::EditableText) {
+        if (QAccessibleTextInterface *textInterface = interface->textInterface()) {
+            // VoiceOver will read out the entire text string at once when returning
+            // text as a value. For large text edits the size of the returned string
+            // needs to be limited and text range attributes need to be used instead.
+            // NSTextEdit returns the first sentence as the value, Do the same here:
+            int begin = 0;
+            int end = textInterface->characterCount();
+            // ### call to textAfterOffset hangs. Booo!
+            //if (textInterface->characterCount() > 0)
+            //    textInterface->textAfterOffset(0, QAccessible2::SentenceBoundary, &begin, &end);
+
+            QString text = textInterface->text(begin, end);
+            //qDebug() << "text" << begin << end << text;
+            return QCFString::toNSString(text);
+        }
+    }
+
+    return nil;
+}
+
 } // namespace QCocoaAccessible

src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm

@@ -96,9 +96,9 @@ static QAccessibleInterface *acast(void *ptr)
 // attributes
 
 - (NSArray *)accessibilityAttributeNames {
-    static NSArray *attributes = nil;
-    if (attributes == nil) {
-        attributes = [[NSArray alloc] initWithObjects:
+    static NSArray *defaultAttributes = nil;
+    if (defaultAttributes == nil) {
+        defaultAttributes = [[NSArray alloc] initWithObjects:
         NSAccessibilityRoleAttribute,
         NSAccessibilityRoleDescriptionAttribute,
         NSAccessibilityChildrenAttribute,
@@ -112,6 +112,14 @@ static QAccessibleInterface *acast(void *ptr)
         NSAccessibilityEnabledAttribute,
         nil];
     }
+
+    NSMutableArray *attributes = [[NSMutableArray alloc] initWithCapacity : [defaultAttributes count]];
+    [attributes addObjectsFromArray : defaultAttributes];
+
+    if (QCocoaAccessible::hasValueAttribute(acast(accessibleInterface))) {
+        [attributes addObject : NSAccessibilityValueAttribute];
+    }
+
     return attributes;
 }
 
@@ -153,6 +161,13 @@ static QAccessibleInterface *acast(void *ptr)
         return QCFString::toNSString(acast(accessibleInterface)->text(QAccessible::Name));
     } else if ([attribute isEqualToString:NSAccessibilityEnabledAttribute]) {
         return [NSNumber numberWithBool:!acast(accessibleInterface)->state().disabled];
+    } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
+        // VoiceOver asks for the value attribute for all elements. Return nil
+        // if we don't want the element to have a value attribute.
+        if (!QCocoaAccessible::hasValueAttribute(acast(accessibleInterface)))
+            return nil;
+
+        return QCocoaAccessible::getValueAttribute(acast(accessibleInterface));
     }
 
     return nil;

src/plugins/platforms/cocoa/qcocoaintegration.mm

@@ -53,6 +53,7 @@
 #include "qcocoatheme.h"
 #include "qcocoainputcontext.h"
 #include "qmacmime.h"
+#include "qcocoaaccessibility.h"
 
 #include <qpa/qplatformaccessibility.h>
 #include <QtCore/qcoreapplication.h>
@@ -180,7 +181,7 @@ QCocoaIntegration::QCocoaIntegration()
     , mEventDispatcher(new QCocoaEventDispatcher())
     , mInputContext(new QCocoaInputContext)
 #ifndef QT_NO_ACCESSIBILITY
-    , mAccessibility(new QPlatformAccessibility)
+    , mAccessibility(new QCococaAccessibility)
 #endif
     , mCocoaClipboard(new QCocoaClipboard)
     , mCocoaDrag(new QCocoaDrag)