Polish of the accessibility settings.

Change-Id: Ifb32ec6745e566cf7ffafe20019b68d95661b45d

src/com/android/settings/AccessibilityEnableScriptInjectionPreference.java

@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.preference.DialogPreference;
+import android.provider.Settings;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityManager;
+
+/**
+ * Preference for enabling accessibility script injection. It displays a warning
+ * dialog before enabling the preference.
+ */
+public class AccessibilityEnableScriptInjectionPreference extends DialogPreference {
+
+    private boolean mInjectionAllowed;
+    private boolean mSendClickAccessibilityEvent;
+
+    public AccessibilityEnableScriptInjectionPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        updateSummary();
+    }
+
+    public void setInjectionAllowed(boolean injectionAllowed) {
+        if (mInjectionAllowed != injectionAllowed) {
+            mInjectionAllowed = injectionAllowed;
+            persistBoolean(injectionAllowed);
+            updateSummary();
+        }
+    }
+
+    public boolean isInjectionAllowed() {
+        return mInjectionAllowed;
+    }
+
+    @Override
+    protected void onBindView(View view) {
+        super.onBindView(view);
+        View summaryView = view.findViewById(com.android.internal.R.id.summary);
+        sendAccessibilityEvent(summaryView);
+    }
+
+    private void sendAccessibilityEvent(View view) {
+        // Since the view is still not attached we create, populate,
+        // and send the event directly since we do not know when it
+        // will be attached and posting commands is not as clean.
+        AccessibilityManager accessibilityManager = AccessibilityManager.getInstance(getContext());
+        if (mSendClickAccessibilityEvent && accessibilityManager.isEnabled()) {
+            AccessibilityEvent event = AccessibilityEvent.obtain();
+            event.setEventType(AccessibilityEvent.TYPE_VIEW_CLICKED);
+            view.onInitializeAccessibilityEvent(event);
+            view.dispatchPopulateAccessibilityEvent(event);
+            accessibilityManager.sendAccessibilityEvent(event);
+        }
+        mSendClickAccessibilityEvent = false;
+    }
+
+    @Override
+    protected void onClick() {
+        if (isInjectionAllowed()) {
+            setInjectionAllowed(false);
+            // Update the system setting only upon user action.
+            setSystemSetting(false);
+            mSendClickAccessibilityEvent = true;
+        } else {
+            super.onClick();
+            mSendClickAccessibilityEvent = false;
+        }
+    }
+
+    @Override
+    protected Object onGetDefaultValue(TypedArray a, int index) {
+        return a.getBoolean(index, false);
+    }
+
+    @Override
+    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
+        setInjectionAllowed(restoreValue
+                ? getPersistedBoolean(mInjectionAllowed)
+                : (Boolean) defaultValue);
+    }
+
+    @Override
+    protected void onDialogClosed(boolean result) {
+        setInjectionAllowed(result);
+        if (result) {
+            // Update the system setting only upon user action.
+            setSystemSetting(true);
+        }
+    }
+
+    @Override
+    protected Parcelable onSaveInstanceState() {
+        Parcelable superState = super.onSaveInstanceState();
+        if (isPersistent()) {
+            return superState;
+        }
+        SavedState myState = new SavedState(superState);
+        myState.mInjectionAllowed = mInjectionAllowed;
+        return myState;
+    }
+
+    @Override
+    protected void onRestoreInstanceState(Parcelable state) {
+        if (state == null || !state.getClass().equals(SavedState.class)) {
+            super.onRestoreInstanceState(state);
+            return;
+        }
+        SavedState myState = (SavedState) state;
+        super.onRestoreInstanceState(myState.getSuperState());
+        setInjectionAllowed(myState.mInjectionAllowed);
+    }
+
+    private void updateSummary() {
+        setSummary(mInjectionAllowed
+                ? getContext().getString(R.string.accessibility_script_injection_allowed)
+                : getContext().getString(R.string.accessibility_script_injection_disallowed));
+    }
+
+    private void setSystemSetting(boolean enabled) {
+        Settings.Secure.putInt(getContext().getContentResolver(),
+                Settings.Secure.ACCESSIBILITY_SCRIPT_INJECTION, enabled ? 1 : 0);
+    }
+
+    private static class SavedState extends BaseSavedState {
+        private boolean mInjectionAllowed;
+
+        public SavedState(Parcel source) {
+            super(source);
+            mInjectionAllowed = (source.readInt() == 1);
+        }
+
+        @Override
+        public void writeToParcel(Parcel parcel, int flags) {
+            super.writeToParcel(parcel, flags);
+            parcel.writeInt(mInjectionAllowed ? 1 : 0);
+        }
+
+        public SavedState(Parcelable superState) {
+            super(superState);
+        }
+
+        @SuppressWarnings("all")
+        public static final Parcelable.Creator<SavedState> CREATOR =
+                new Parcelable.Creator<SavedState>() {
+            public SavedState createFromParcel(Parcel in) {
+                return new SavedState(in);
+            }
+
+            public SavedState[] newArray(int size) {
+                return new SavedState[size];
+            }
+        };
+    }
+}