/*
* Copyright (C) 2012 Google Inc.
*
* 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.codetroopers.betterpickers;
import android.content.Context;
import android.graphics.Rect;
import android.os.Bundle;
import android.support.v4.view.AccessibilityDelegateCompat;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.support.v4.view.accessibility.AccessibilityNodeProviderCompat;
import android.support.v4.view.accessibility.AccessibilityRecordCompat;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import java.util.LinkedList;
import java.util.List;
public abstract class TouchExplorationHelper<T> extends AccessibilityNodeProviderCompat
/* Removed for backwards compatibility to GB implements View.OnHoverListener*/ {
/**
* Virtual node identifier value for invalid nodes.
*/
public static final int INVALID_ID = Integer.MIN_VALUE;
private final Rect mTempScreenRect = new Rect();
private final Rect mTempParentRect = new Rect();
private final Rect mTempVisibleRect = new Rect();
private final int[] mTempGlobalRect = new int[2];
private final AccessibilityManager mManager;
private View mParentView;
private int mFocusedItemId = INVALID_ID;
private T mCurrentItem = null;
/**
* Constructs a new touch exploration helper.
*
* @param context The parent context.
*/
public TouchExplorationHelper(Context context, View parentView) {
mManager = (AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
mParentView = parentView;
}
/**
* @return The current accessibility focused item, or {@code null} if no item is focused.
*/
public T getFocusedItem() {
return getItemForId(mFocusedItemId);
}
/**
* Clears the current accessibility focused item.
*/
public void clearFocusedItem() {
final int itemId = mFocusedItemId;
if (itemId == INVALID_ID) {
return;
}
performAction(itemId, AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS, null);
}
/**
* Requests accessibility focus be placed on the specified item.
*
* @param item The item to place focus on.
*/
public void setFocusedItem(T item) {
final int itemId = getIdForItem(item);
if (itemId == INVALID_ID) {
return;
}
performAction(itemId, AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS, null);
}
/**
* Invalidates cached information about the parent view. <p> You <b>must</b> call this method after adding or
* removing items from the parent view. </p>
*/
public void invalidateParent() {
mParentView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
}
/**
* Invalidates cached information for a particular item. <p> You <b>must</b> call this method when any of the
* properties set in {@link #populateNodeForItem(Object, AccessibilityNodeInfoCompat)} have changed. </p>
*/
public void invalidateItem(T item) {
sendEventForItem(item, AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
}
/**
* Populates an event of the specified type with information about an item and attempts to send it up through the
* view hierarchy.
*
* @param item The item for which to send an event.
* @param eventType The type of event to send.
* @return {@code true} if the event was sent successfully.
*/
public boolean sendEventForItem(T item, int eventType) {
if (!mManager.isEnabled()) {
return false;
}
final AccessibilityEvent event = getEventForItem(item, eventType);
final ViewGroup group = (ViewGroup) mParentView.getParent();
return group.requestSendAccessibilityEvent(mParentView, event);
}
@Override
public AccessibilityNodeInfoCompat createAccessibilityNodeInfo(int virtualViewId) {
if (virtualViewId == View.NO_ID) {
return getNodeForParent();
}
final T item = getItemForId(virtualViewId);
if (item == null) {
return null;
}
final AccessibilityNodeInfoCompat node = AccessibilityNodeInfoCompat.obtain();
populateNodeForItemInternal(item, node);
return node;
}
@Override
public boolean performAction(int virtualViewId, int action, Bundle arguments) {
if (virtualViewId == View.NO_ID) {
return ViewCompat.performAccessibilityAction(mParentView, action, arguments);
}
final T item = getItemForId(virtualViewId);
if (item == null) {
return false;
}
boolean handled = false;
switch (action) {
case AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS:
if (mFocusedItemId != virtualViewId) {
mFocusedItemId = virtualViewId;
sendEventForItem(item, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
handled = true;
}
break;
case AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS:
if (mFocusedItemId == virtualViewId) {
mFocusedItemId = INVALID_ID;
sendEventForItem(item, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED);
handled = true;
}
break;
}
handled |= performActionForItem(item, action, arguments);
return handled;
}
/* Removed for backwards compatibility to GB
@Override
public boolean onHover(View view, MotionEvent event) {
if (!AccessibilityManagerCompat.isTouchExplorationEnabled(mManager)) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_HOVER_ENTER:
case MotionEvent.ACTION_HOVER_MOVE:
final T item = getItemAt(event.getX(), event.getY());
setCurrentItem(item);
return true;
case MotionEvent.ACTION_HOVER_EXIT:
setCurrentItem(null);
return true;
}
return false;
}*/
private void setCurrentItem(T item) {
if (mCurrentItem == item) {
return;
}
if (mCurrentItem != null) {
sendEventForItem(mCurrentItem, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT);
}
mCurrentItem = item;
if (mCurrentItem != null) {
sendEventForItem(mCurrentItem, AccessibilityEvent.TYPE_VIEW_HOVER_ENTER);
}
}
private AccessibilityEvent getEventForItem(T item, int eventType) {
final AccessibilityEvent event = AccessibilityEvent.obtain(eventType);
final AccessibilityRecordCompat record = new AccessibilityRecordCompat(event);
final int virtualDescendantId = getIdForItem(item);
// Ensure the client has good defaults.
event.setEnabled(true);
// Allow the client to populate the event.
populateEventForItem(item, event);
if (event.getText().isEmpty() && TextUtils.isEmpty(event.getContentDescription())) {
throw new RuntimeException(
"You must add text or a content description in populateEventForItem()");
}
// Don't allow the client to override these properties.
event.setClassName(item.getClass().getName());
event.setPackageName(mParentView.getContext().getPackageName());
record.setSource(mParentView, virtualDescendantId);
return event;
}
private AccessibilityNodeInfoCompat getNodeForParent() {
final AccessibilityNodeInfoCompat info = AccessibilityNodeInfoCompat.obtain(mParentView);
ViewCompat.onInitializeAccessibilityNodeInfo(mParentView, info);
final LinkedList<T> items = new LinkedList<T>();
getVisibleItems(items);
for (T item : items) {
final int virtualDescendantId = getIdForItem(item);
info.addChild(mParentView, virtualDescendantId);
}
return info;
}
private AccessibilityNodeInfoCompat populateNodeForItemInternal(
T item, AccessibilityNodeInfoCompat node) {
final int virtualDescendantId = getIdForItem(item);
// Ensure the client has good defaults.
node.setEnabled(true);
// Allow the client to populate the node.
populateNodeForItem(item, node);
if (TextUtils.isEmpty(node.getText()) && TextUtils.isEmpty(node.getContentDescription())) {
throw new RuntimeException(
"You must add text or a content description in populateNodeForItem()");
}
// Don't allow the client to override these properties.
node.setPackageName(mParentView.getContext().getPackageName());
node.setClassName(item.getClass().getName());
node.setParent(mParentView);
node.setSource(mParentView, virtualDescendantId);
if (mFocusedItemId == virtualDescendantId) {
node.addAction(AccessibilityNodeInfoCompat.ACTION_CLEAR_ACCESSIBILITY_FOCUS);
} else {
node.addAction(AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS);
}
node.getBoundsInParent(mTempParentRect);
if (mTempParentRect.isEmpty()) {
throw new RuntimeException("You must set parent bounds in populateNodeForItem()");
}
// Set the visibility based on the parent bound.
if (intersectVisibleToUser(mTempParentRect)) {
node.setVisibleToUser(true);
node.setBoundsInParent(mTempParentRect);
}
// Calculate screen-relative bound.
mParentView.getLocationOnScreen(mTempGlobalRect);
final int offsetX = mTempGlobalRect[0];
final int offsetY = mTempGlobalRect[1];
mTempScreenRect.set(mTempParentRect);
mTempScreenRect.offset(offsetX, offsetY);
node.setBoundsInScreen(mTempScreenRect);
return node;
}
/**
* Computes whether the specified {@link android.graphics.Rect} intersects with the visible portion of its parent
* {@link android.view.View}. Modifies {@code localRect} to contain only the visible portion.
*
* @param localRect A rectangle in local (parent) coordinates.
* @return Whether the specified {@link android.graphics.Rect} is visible on the screen.
*/
private boolean intersectVisibleToUser(Rect localRect) {
// Missing or empty bounds mean this view is not visible.
if ((localRect == null) || localRect.isEmpty()) {
return false;
}
// Attached to invisible window means this view is not visible.
if (mParentView.getWindowVisibility() != View.VISIBLE) {
return false;
}
// An invisible predecessor or one with alpha zero means
// that this view is not visible to the user.
Object current = this;
while (current instanceof View) {
final View view = (View) current;
// We have attach info so this view is attached and there is no
// need to check whether we reach to ViewRootImpl on the way up.
if ((view.getAlpha() <= 0) || (view.getVisibility() != View.VISIBLE)) {
return false;
}
current = view.getParent();
}
// If no portion of the parent is visible, this view is not visible.
if (!mParentView.getLocalVisibleRect(mTempVisibleRect)) {
return false;
}
// Check if the view intersects the visible portion of the parent.
return localRect.intersect(mTempVisibleRect);
}
public AccessibilityDelegateCompat getAccessibilityDelegate() {
return mDelegate;
}
private final AccessibilityDelegateCompat mDelegate = new AccessibilityDelegateCompat() {
@Override
public void onInitializeAccessibilityEvent(View view, AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(view, event);
event.setClassName(view.getClass().getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(View view, AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(view, info);
info.setClassName(view.getClass().getName());
}
@Override
public AccessibilityNodeProviderCompat getAccessibilityNodeProvider(View host) {
return TouchExplorationHelper.this;
}
};
/**
* Performs an accessibility action on the specified item. See {@link AccessibilityNodeInfoCompat#performAction(int,
* android.os.Bundle)}. <p> The helper class automatically handles focus management resulting from {@link
* AccessibilityNodeInfoCompat#ACTION_ACCESSIBILITY_FOCUS} and {@link AccessibilityNodeInfoCompat#ACTION_CLEAR_ACCESSIBILITY_FOCUS},
* so typically a developer only needs to handle actions added manually in the {{@link #populateNodeForItem(Object,
* AccessibilityNodeInfoCompat)} method. </p>
*
* @param item The item on which to perform the action.
* @param action The accessibility action to perform.
* @param arguments Arguments for the action, or optionally {@code null}.
* @return {@code true} if the action was performed successfully.
*/
protected abstract boolean performActionForItem(T item, int action, Bundle arguments);
/**
* Populates an event with information about the specified item. <p> At a minimum, a developer must populate the
* event text by doing one of the following: <ul> <li>appending text to {@link android.view.accessibility.AccessibilityEvent#getText()}</li>
* <li>populating a description with {@link android.view.accessibility.AccessibilityEvent#setContentDescription(CharSequence)}</li>
* </ul> </p>
*
* @param item The item for which to populate the event.
* @param event The event to populate.
*/
protected abstract void populateEventForItem(T item, AccessibilityEvent event);
/**
* Populates a node with information about the specified item. <p> At a minimum, a developer must: <ul> <li>populate
* the event text using {@link AccessibilityNodeInfoCompat#setText(CharSequence)} or {@link
* AccessibilityNodeInfoCompat#setContentDescription(CharSequence)} </li> <li>set the item's parent-relative bounds
* using {@link AccessibilityNodeInfoCompat#setBoundsInParent(android.graphics.Rect)} </ul>
*
* @param item The item for which to populate the node.
* @param node The node to populate.
*/
protected abstract void populateNodeForItem(T item, AccessibilityNodeInfoCompat node);
/**
* Populates a list with the parent view's visible items. <p> The result of this method is cached until the
* developer calls {@link #invalidateParent()}. </p>
*
* @param items The list to populate with visible items.
*/
protected abstract void getVisibleItems(List<T> items);
/**
* Returns the item under the specified parent-relative coordinates.
*
* @param x The parent-relative x coordinate.
* @param y The parent-relative y coordinate.
* @return The item under coordinates (x,y).
*/
protected abstract T getItemAt(float x, float y);
/**
* Returns the unique identifier for an item. If the specified item does not exist, returns {@link #INVALID_ID}. <p>
* This result of this method must be consistent with {@link #getItemForId(int)}. </p>
*
* @param item The item whose identifier to return.
* @return A unique identifier, or {@link #INVALID_ID}.
*/
protected abstract int getIdForItem(T item);
/**
* Returns the item for a unique identifier. If the specified item does not exist, returns {@code null}.
*
* @param id The identifier for the item to return.
* @return An item, or {@code null}.
*/
protected abstract T getItemForId(int id);
}