Accessibility: Improve interface handling in Quick

This changes how interfaces are handled:
the QAccessibleQuickItem will simply subclass
all interfaces and dynamically return 0 or the
appropriate interface_cast.

This makes our implementation a lot more flexible.
To make use of the value interface, only a value
property is needed (together with a corresponding role).

Since the implementation of the interfaces became simpler,
the value interface and some text interface improvements
go along with the change.

Change-Id: I003ec3016d48d730a4acac467bce322167842f4d
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/src/quick/items/qquicktextinput.cpp b/src/quick/items/qquicktextinput.cpp
index fee49593ee..6dd8fb157d 100644
--- a/src/quick/items/qquicktextinput.cpp
+++ b/src/quick/items/qquicktextinput.cpp
@@ -59,6 +59,7 @@
 
 #ifndef QT_NO_ACCESSIBILITY
 #include "qaccessible.h"
+#include "qquickaccessibleattached_p.h"
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -3374,9 +3375,11 @@ void QQuickTextInputPrivate::internalSetText(const QString &txt, int pos, bool e
 #ifdef QT_NO_ACCESSIBILITY
     Q_UNUSED(changed)
 #else
-    if (changed) {
-        QAccessibleTextUpdateEvent ev(q, 0, oldText, m_text);
-        QAccessible::updateAccessibility(&ev);
+    if (changed && QAccessible::isActive()) {
+        if (QObject *acc = QQuickAccessibleAttached::findAccessible(q, QAccessible::EditableText)) {
+            QAccessibleTextUpdateEvent ev(acc, 0, oldText, m_text);
+            QAccessible::updateAccessibility(&ev);
+        }
     }
 #endif
 }
@@ -4025,8 +4028,12 @@ bool QQuickTextInputPrivate::emitCursorPositionChanged()
         }
 
 #ifndef QT_NO_ACCESSIBILITY
-        QAccessibleTextCursorEvent ev(q, m_cursor);
-        QAccessible::updateAccessibility(&ev);
+        if (QAccessible::isActive()) {
+            if (QObject *acc = QQuickAccessibleAttached::findAccessible(q, QAccessible::EditableText)) {
+                QAccessibleTextCursorEvent ev(acc, m_cursor);
+                QAccessible::updateAccessibility(&ev);
+            }
+        }
 #endif
 
         return true;