Add accessibility actions for text editing.

Currently text editing is pretty hard (certain operations even
impossible) for a blind person. To address the issue this change
adds APIs that enable an accessibility service to perform basic
text editing operations such as copy, paste, cut, set selection,
extend selection while moving at a given granularity.

The new APIs enable an accessibility service to expose a gesture
driven efficient text editing facility.

bug:8098384

Change-Id: I82b200138a3fdf4c0c316b774fc08a096ced29d0

1 files changed, 104 insertions, 11 deletions

diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index f8db622..2f02780 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -7985,6 +7985,80 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                     | AccessibilityNodeInfo.MOVEMENT_GRANULARITY_PARAGRAPH
                     | AccessibilityNodeInfo.MOVEMENT_GRANULARITY_PAGE);
         }
+        if (isFocused()) {
+            if (canSelectText()) {
+                info.addAction(AccessibilityNodeInfo.ACTION_SET_SELECTION);
+            }
+            if (canCopy()) {
+                info.addAction(AccessibilityNodeInfo.ACTION_COPY);
+            }
+            if (canPaste()) {
+                info.addAction(AccessibilityNodeInfo.ACTION_PASTE);
+            }
+            if (canCut()) {
+                info.addAction(AccessibilityNodeInfo.ACTION_CUT);
+            }
+        }
+    }
+
+    @Override
+    public boolean performAccessibilityAction(int action, Bundle arguments) {
+        switch (action) {
+            case AccessibilityNodeInfo.ACTION_COPY: {
+                if (isFocused() && canCopy()) {
+                    if (onTextContextMenuItem(ID_COPY)) {
+                        notifyAccessibilityStateChanged();
+                        return true;
+                    }
+                }
+            } return false;
+            case AccessibilityNodeInfo.ACTION_PASTE: {
+                if (isFocused() && canPaste()) {
+                    if (onTextContextMenuItem(ID_PASTE)) {
+                        notifyAccessibilityStateChanged();
+                        return true;
+                    }
+                }
+            } return false;
+            case AccessibilityNodeInfo.ACTION_CUT: {
+                if (isFocused() && canCut()) {
+                    if (onTextContextMenuItem(ID_CUT)) {
+                        notifyAccessibilityStateChanged();
+                        return true;
+                    }
+                }
+            } return false;
+            case AccessibilityNodeInfo.ACTION_SET_SELECTION: {
+                if (isFocused() && canSelectText()) {
+                    final int start = (arguments != null) ? arguments.getInt(
+                            AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_START_INT, -1) : -1;
+                    final int end = (arguments != null) ? arguments.getInt(
+                            AccessibilityNodeInfo.ACTION_ARGUMENT_SELECTION_END_INT, -1) : -1;
+                    CharSequence text = getIterableTextForAccessibility();
+                    if (text == null) {
+                        return false;
+                    }
+                    // No arguments clears the selection.
+                    if (start == end && end == -1) {
+                        Selection.removeSelection((Spannable) text);
+                        notifyAccessibilityStateChanged();
+                        return true;
+                    }
+                    if (start >= 0 && start <= end && end <= text.length()) {
+                        Selection.setSelection((Spannable) text, start, end);
+                        // Make sure selection mode is engaged.
+                        if (mEditor != null) {
+                            mEditor.startSelectionActionMode();
+                        }
+                        notifyAccessibilityStateChanged();
+                        return true;
+                    }
+                }
+            } return false;
+            default: {
+                return super.performAccessibilityAction(action, arguments);
+            }
+        }
     }
 
     @Override
@@ -8554,32 +8628,51 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
      * @hide
      */
     @Override
-    public int getAccessibilityCursorPosition() {
+    public int getAccessibilitySelectionStart() {
+        if (TextUtils.isEmpty(getContentDescription())) {
+            final int selectionStart = getSelectionStart();
+            if (selectionStart >= 0) {
+                return selectionStart;
+            }
+        }
+        return ACCESSIBILITY_CURSOR_POSITION_UNDEFINED;
+    }
+
+    /**
+     * @hide
+     */
+    public boolean isAccessibilitySelectionExtendable() {
+        return true;
+    }
+
+    /**
+     * @hide
+     */
+    @Override
+    public int getAccessibilitySelectionEnd() {
         if (TextUtils.isEmpty(getContentDescription())) {
             final int selectionEnd = getSelectionEnd();
             if (selectionEnd >= 0) {
                 return selectionEnd;
             }
         }
-        return super.getAccessibilityCursorPosition();
+        return ACCESSIBILITY_CURSOR_POSITION_UNDEFINED;
     }
 
     /**
      * @hide
      */
     @Override
-    public void setAccessibilityCursorPosition(int index) {
-        if (getAccessibilityCursorPosition() == index) {
+    public void setAccessibilitySelection(int start, int end) {
+        if (getAccessibilitySelectionStart() == start
+                && getAccessibilitySelectionEnd() == end) {
             return;
         }
-        if (TextUtils.isEmpty(getContentDescription())) {
-            if (index >= 0 && index <= mText.length()) {
-                Selection.setSelection((Spannable) mText, index);
-            } else {
-                Selection.removeSelection((Spannable) mText);
-            }
+        CharSequence text = getIterableTextForAccessibility();
+        if (start >= 0 && start <= end && end <= text.length()) {
+            Selection.setSelection((Spannable) text, start, end);
         } else {
-            super.setAccessibilityCursorPosition(index);
+            Selection.removeSelection((Spannable) text);
         }
     }