src/starboard/android/apk/app/src/main/java/dev/cobalt/coat/CobaltA11yHelper.java - cobalt - Git at Google

 // Copyright 2017 The Cobalt Authors. All Rights Reserved.
 //
 // 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 dev.cobalt.coat;

 import static dev.cobalt.util.Log.TAG;

 import android.graphics.Rect;
 import android.os.Bundle;
 import android.os.Handler;
 import android.view.View;
 import android.view.accessibility.AccessibilityEvent;
 import androidx.core.view.ViewCompat;
 import androidx.core.view.accessibility.AccessibilityNodeInfoCompat;
 import androidx.customview.widget.ExploreByTouchHelper;
 import dev.cobalt.util.Log;
 import java.util.BitSet;
 import java.util.List;

 /**
  * An ExploreByTouchHelper that create a virtual d-pad grid, so that Cobalt remains functional when
  * the TalkBack screen reader is enabled (which otherwise intercepts d-pad events for most
  * applications).
  */
 class CobaltA11yHelper extends ExploreByTouchHelper {
   // These are from starboard/key.h
   private static final int SB_KEY_GAMEPAD_DPAD_UP = 0x800C;
   private static final int SB_KEY_GAMEPAD_DPAD_DOWN = 0x800D;
   private static final int SB_KEY_GAMEPAD_DPAD_LEFT = 0x800E;
   private static final int SB_KEY_GAMEPAD_DPAD_RIGHT = 0x800F;

   // The fake dimensions for the nine virtual views.
   // These values are arbitrary as long as the views stay on the screen.
   private static final int FAKE_VIEW_HEIGHT = 10;
   private static final int FAKE_VIEW_WIDTH = 10;

   private int previousFocusedViewId = 1;
   // This set tracks whether onPopulateNodeForVirtualView has been
   // called for each virtual view id.
   private final BitSet nodePopulatedSet = new BitSet(9);
   private final Handler handler = new Handler();
   private boolean hasInitialFocusBeenSet;

   public CobaltA11yHelper(View view) {
     super(view);
     ViewCompat.setAccessibilityDelegate(view, this);
   }

   private static native void nativeInjectKeyEvent(int key);

   @Override
   protected int getVirtualViewAt(float x, float y) {
     // This method is only required for touch or mouse interfaces.
     // Since we don't support either, we simply always return HOST_ID.
     return HOST_ID;
   }

   @Override
   protected void getVisibleVirtualViews(List<Integer> virtualViewIds) {
     if (!virtualViewIds.isEmpty()) {
       throw new RuntimeException("Expected empty list");
     }
     // We always have precisely 9 virtual views.
     for (int i = 1; i <= 9; i++) {
       virtualViewIds.add(i);
     }
   }

   /**
    * Returns the "patch number" for a given view id, given a focused view id.
    *
    * <p>A "patch number" is a 1-9 number that describes where the requestedViewId is now located on
    * an X-Y grid, given the focusedViewId.
    *
    * <p>Patch number grid:
    * (0,0)----->X
    *   |+-+-+-+
    *   ||1|2|3|
    *   |+-+-+-|
    *   ||4|5|6|
    *   |+-+-+-|
    *   ||7|8|9|
    *   |+-+-+-+
    *  \./ Y
    *
    * <p>As focus changes, the locations of the views are moved so the focused view is always in the
    * middle (patch number 5) and all of the other views always in the same relative position with
    * respect to each other (with those on the edges adjacent to those on the opposite edges --
    * wrapping around).
    *
    * <p>5 is returned whenever focusedViewId = requestedViewId
    */
   private static int getPatchNumber(int focusedViewId, int requestedViewId) {
     // The (x,y) the focused view has in the 9 patch where 5 is in the middle.
     int focusedX = (focusedViewId - 1) % 3;
     int focusedY = (focusedViewId - 1) / 3;

     // x and y offsets of focused view where middle is (0, 0)
     int focusedRelativeToCenterX = focusedX - 1;
     int focusedRelativeToCenterY = focusedY - 1;

     // The (x,y) the requested view has in the 9 patch where 5 is in the middle.
     int requestedX = (requestedViewId - 1) % 3;
     int requestedY = (requestedViewId - 1) / 3;

     // x and y offsets of requested view where middle is (0, 0)
     int requestedRelativeToCenterX = requestedX - 1;
     int requestedRelativeToCenterY = requestedY - 1;

     // The (x,y) that the requested view has in the 9 patch when focusedViewId
     // is in the middle.
     int translatedRequestedX = (1 + 3 + requestedRelativeToCenterX - focusedRelativeToCenterX) % 3;
     int translatedRequestedY = (1 + 3 + requestedRelativeToCenterY - focusedRelativeToCenterY) % 3;

     return (translatedRequestedY * 3) + translatedRequestedX + 1;
   }

   private void maybeInjectEvent(int currentFocusedViewId) {
     switch (getPatchNumber(previousFocusedViewId, currentFocusedViewId)) {
       case 5:
         // no move;
         break;
       case 2:
         nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_UP);
         break;
       case 4:
         nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_LEFT);
         break;
       case 6:
         nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_RIGHT);
         break;
       case 8:
         nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_DOWN);
         break;
       default:
         // TODO: Could support diagonal movements, although it's likely
         // not possible to reach this.
         break;
     }
     previousFocusedViewId = currentFocusedViewId;
   }

   @Override
   protected void onPopulateNodeForVirtualView(int virtualViewId, AccessibilityNodeInfoCompat node) {
     int focusedViewId = getAccessibilityFocusedVirtualViewId();

     if (focusedViewId < 1 || focusedViewId > 9) {
       // If this is not one of our nine-patch views, it's probably HOST_ID
       // In any case, assume there is no focus change.
       focusedViewId = previousFocusedViewId;
     }

     // onPopulateNodeForVirtualView() gets called at least once every
     // time the focused view changes. So see if it's changed since the
     // last time we've been called and inject an event if so.
     maybeInjectEvent(focusedViewId);

     int patchNumber = getPatchNumber(focusedViewId, virtualViewId);

     int x = (patchNumber - 1) % 3;
     int y = (patchNumber - 1) / 3;

     // Note that the specific bounds here are arbitrary. The importance
     // is the relative bounds to each other.
     node.setBoundsInParent(new Rect(
         x * FAKE_VIEW_WIDTH,
         y * FAKE_VIEW_HEIGHT,
         x * FAKE_VIEW_WIDTH + FAKE_VIEW_WIDTH,
         y * FAKE_VIEW_HEIGHT + FAKE_VIEW_HEIGHT));
     node.setText("");

     if (virtualViewId >= 1 || virtualViewId <= 9) {
       nodePopulatedSet.set(virtualViewId - 1);
     }
     if (!hasInitialFocusBeenSet && nodePopulatedSet.cardinality() == 9) {
       // Once the ExploreByTouchHelper knows about all of our virtual views,
       // but not before, ask that the accessibility focus be moved from
       // it's initial position on HOST_ID to the one we want to start with.
       hasInitialFocusBeenSet = true;
       handler.post(
           new Runnable() {
             @Override
             public void run() {
               sendEventForVirtualView(
                   previousFocusedViewId, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
             }
           });
     }
   }

   @Override
   protected boolean onPerformActionForVirtualView(int virtualViewId, int action, Bundle arguments) {
     return false;
   }

   /** A simple equivilent to Assert.assertEquals so we don't depend on junit */
   private static void assertEquals(int expected, int actual) {
     if (expected != actual) {
       throw new RuntimeException("Expected " + expected + " actual " + actual);
     }
   }

   /**
    * Unit test for getPatchNumber().
    *
    * <p>As of this writing, the Java portion of the Cobalt build has no unit test mechanism.
    *
    * <p>To run this test, simply call it from application start and start the application.
    *
    * <p>TODO: Move this to a real unit test location when one exists.
    */
   private static void testGetPatchNumber() {
     Log.i(TAG, "+testGetPatchNumber");

     assertEquals(1, getPatchNumber(5, 1));
     assertEquals(2, getPatchNumber(5, 2));
     assertEquals(3, getPatchNumber(5, 3));
     assertEquals(4, getPatchNumber(5, 4));
     assertEquals(5, getPatchNumber(5, 5));
     assertEquals(6, getPatchNumber(5, 6));
     assertEquals(7, getPatchNumber(5, 7));
     assertEquals(8, getPatchNumber(5, 8));
     assertEquals(9, getPatchNumber(5, 9));

     for (int i = 1; i <= 9; i++) {
       assertEquals(5, getPatchNumber(i, i));
     }

     assertEquals(5, getPatchNumber(1, 1));
     assertEquals(6, getPatchNumber(1, 2));
     assertEquals(4, getPatchNumber(1, 3));
     assertEquals(8, getPatchNumber(1, 4));
     assertEquals(9, getPatchNumber(1, 5));
     assertEquals(7, getPatchNumber(1, 6));
     assertEquals(2, getPatchNumber(1, 7));
     assertEquals(3, getPatchNumber(1, 8));
     assertEquals(1, getPatchNumber(1, 9));

     assertEquals(9, getPatchNumber(9, 1));
     assertEquals(7, getPatchNumber(9, 2));
     assertEquals(8, getPatchNumber(9, 3));
     assertEquals(3, getPatchNumber(9, 4));
     assertEquals(1, getPatchNumber(9, 5));
     assertEquals(2, getPatchNumber(9, 6));
     assertEquals(6, getPatchNumber(9, 7));
     assertEquals(4, getPatchNumber(9, 8));
     assertEquals(5, getPatchNumber(9, 9));
     Log.i(TAG, "-testGetPatchNumber");
   }
 }
	// Copyright 2017 The Cobalt Authors. All Rights Reserved.
	//
	// 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 dev.cobalt.coat;

	import static dev.cobalt.util.Log.TAG;

	import android.graphics.Rect;
	import android.os.Bundle;
	import android.os.Handler;
	import android.view.View;
	import android.view.accessibility.AccessibilityEvent;
	import androidx.core.view.ViewCompat;
	import androidx.core.view.accessibility.AccessibilityNodeInfoCompat;
	import androidx.customview.widget.ExploreByTouchHelper;
	import dev.cobalt.util.Log;
	import java.util.BitSet;
	import java.util.List;

	/**
	* An ExploreByTouchHelper that create a virtual d-pad grid, so that Cobalt remains functional when
	* the TalkBack screen reader is enabled (which otherwise intercepts d-pad events for most
	* applications).
	*/
	class CobaltA11yHelper extends ExploreByTouchHelper {
	// These are from starboard/key.h
	private static final int SB_KEY_GAMEPAD_DPAD_UP = 0x800C;
	private static final int SB_KEY_GAMEPAD_DPAD_DOWN = 0x800D;
	private static final int SB_KEY_GAMEPAD_DPAD_LEFT = 0x800E;
	private static final int SB_KEY_GAMEPAD_DPAD_RIGHT = 0x800F;

	// The fake dimensions for the nine virtual views.
	// These values are arbitrary as long as the views stay on the screen.
	private static final int FAKE_VIEW_HEIGHT = 10;
	private static final int FAKE_VIEW_WIDTH = 10;

	private int previousFocusedViewId = 1;
	// This set tracks whether onPopulateNodeForVirtualView has been
	// called for each virtual view id.
	private final BitSet nodePopulatedSet = new BitSet(9);
	private final Handler handler = new Handler();
	private boolean hasInitialFocusBeenSet;

	public CobaltA11yHelper(View view) {
	super(view);
	ViewCompat.setAccessibilityDelegate(view, this);
	}

	private static native void nativeInjectKeyEvent(int key);

	@Override
	protected int getVirtualViewAt(float x, float y) {
	// This method is only required for touch or mouse interfaces.
	// Since we don't support either, we simply always return HOST_ID.
	return HOST_ID;
	}

	@Override
	protected void getVisibleVirtualViews(List<Integer> virtualViewIds) {
	if (!virtualViewIds.isEmpty()) {
	throw new RuntimeException("Expected empty list");
	}
	// We always have precisely 9 virtual views.
	for (int i = 1; i <= 9; i++) {
	virtualViewIds.add(i);
	}
	}

	/**
	* Returns the "patch number" for a given view id, given a focused view id.
	*
	* <p>A "patch number" is a 1-9 number that describes where the requestedViewId is now located on
	* an X-Y grid, given the focusedViewId.
	*
	* <p>Patch number grid:
	* (0,0)----->X
	* \|+-+-+-+
	* \|\|1\|2\|3\|
	* \|+-+-+-\|
	* \|\|4\|5\|6\|
	* \|+-+-+-\|
	* \|\|7\|8\|9\|
	* \|+-+-+-+
	* \./ Y
	*
	* <p>As focus changes, the locations of the views are moved so the focused view is always in the
	* middle (patch number 5) and all of the other views always in the same relative position with
	* respect to each other (with those on the edges adjacent to those on the opposite edges --
	* wrapping around).
	*
	* <p>5 is returned whenever focusedViewId = requestedViewId
	*/
	private static int getPatchNumber(int focusedViewId, int requestedViewId) {
	// The (x,y) the focused view has in the 9 patch where 5 is in the middle.
	int focusedX = (focusedViewId - 1) % 3;
	int focusedY = (focusedViewId - 1) / 3;

	// x and y offsets of focused view where middle is (0, 0)
	int focusedRelativeToCenterX = focusedX - 1;
	int focusedRelativeToCenterY = focusedY - 1;

	// The (x,y) the requested view has in the 9 patch where 5 is in the middle.
	int requestedX = (requestedViewId - 1) % 3;
	int requestedY = (requestedViewId - 1) / 3;

	// x and y offsets of requested view where middle is (0, 0)
	int requestedRelativeToCenterX = requestedX - 1;
	int requestedRelativeToCenterY = requestedY - 1;

	// The (x,y) that the requested view has in the 9 patch when focusedViewId
	// is in the middle.
	int translatedRequestedX = (1 + 3 + requestedRelativeToCenterX - focusedRelativeToCenterX) % 3;
	int translatedRequestedY = (1 + 3 + requestedRelativeToCenterY - focusedRelativeToCenterY) % 3;

	return (translatedRequestedY * 3) + translatedRequestedX + 1;
	}

	private void maybeInjectEvent(int currentFocusedViewId) {
	switch (getPatchNumber(previousFocusedViewId, currentFocusedViewId)) {
	case 5:
	// no move;
	break;
	case 2:
	nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_UP);
	break;
	case 4:
	nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_LEFT);
	break;
	case 6:
	nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_RIGHT);
	break;
	case 8:
	nativeInjectKeyEvent(SB_KEY_GAMEPAD_DPAD_DOWN);
	break;
	default:
	// TODO: Could support diagonal movements, although it's likely
	// not possible to reach this.
	break;
	}
	previousFocusedViewId = currentFocusedViewId;
	}

	@Override
	protected void onPopulateNodeForVirtualView(int virtualViewId, AccessibilityNodeInfoCompat node) {
	int focusedViewId = getAccessibilityFocusedVirtualViewId();

	if (focusedViewId < 1 \|\| focusedViewId > 9) {
	// If this is not one of our nine-patch views, it's probably HOST_ID
	// In any case, assume there is no focus change.
	focusedViewId = previousFocusedViewId;
	}

	// onPopulateNodeForVirtualView() gets called at least once every
	// time the focused view changes. So see if it's changed since the
	// last time we've been called and inject an event if so.
	maybeInjectEvent(focusedViewId);

	int patchNumber = getPatchNumber(focusedViewId, virtualViewId);

	int x = (patchNumber - 1) % 3;
	int y = (patchNumber - 1) / 3;

	// Note that the specific bounds here are arbitrary. The importance
	// is the relative bounds to each other.
	node.setBoundsInParent(new Rect(
	x * FAKE_VIEW_WIDTH,
	y * FAKE_VIEW_HEIGHT,
	x * FAKE_VIEW_WIDTH + FAKE_VIEW_WIDTH,
	y * FAKE_VIEW_HEIGHT + FAKE_VIEW_HEIGHT));
	node.setText("");

	if (virtualViewId >= 1 \|\| virtualViewId <= 9) {
	nodePopulatedSet.set(virtualViewId - 1);
	}
	if (!hasInitialFocusBeenSet && nodePopulatedSet.cardinality() == 9) {
	// Once the ExploreByTouchHelper knows about all of our virtual views,
	// but not before, ask that the accessibility focus be moved from
	// it's initial position on HOST_ID to the one we want to start with.
	hasInitialFocusBeenSet = true;
	handler.post(
	new Runnable() {
	@Override
	public void run() {
	sendEventForVirtualView(
	previousFocusedViewId, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
	}
	});
	}
	}

	@Override
	protected boolean onPerformActionForVirtualView(int virtualViewId, int action, Bundle arguments) {
	return false;
	}

	/** A simple equivilent to Assert.assertEquals so we don't depend on junit */
	private static void assertEquals(int expected, int actual) {
	if (expected != actual) {
	throw new RuntimeException("Expected " + expected + " actual " + actual);
	}
	}

	/**
	* Unit test for getPatchNumber().
	*
	* <p>As of this writing, the Java portion of the Cobalt build has no unit test mechanism.
	*
	* <p>To run this test, simply call it from application start and start the application.
	*
	* <p>TODO: Move this to a real unit test location when one exists.
	*/
	private static void testGetPatchNumber() {
	Log.i(TAG, "+testGetPatchNumber");

	assertEquals(1, getPatchNumber(5, 1));
	assertEquals(2, getPatchNumber(5, 2));
	assertEquals(3, getPatchNumber(5, 3));
	assertEquals(4, getPatchNumber(5, 4));
	assertEquals(5, getPatchNumber(5, 5));
	assertEquals(6, getPatchNumber(5, 6));
	assertEquals(7, getPatchNumber(5, 7));
	assertEquals(8, getPatchNumber(5, 8));
	assertEquals(9, getPatchNumber(5, 9));

	for (int i = 1; i <= 9; i++) {
	assertEquals(5, getPatchNumber(i, i));
	}

	assertEquals(5, getPatchNumber(1, 1));
	assertEquals(6, getPatchNumber(1, 2));
	assertEquals(4, getPatchNumber(1, 3));
	assertEquals(8, getPatchNumber(1, 4));
	assertEquals(9, getPatchNumber(1, 5));
	assertEquals(7, getPatchNumber(1, 6));
	assertEquals(2, getPatchNumber(1, 7));
	assertEquals(3, getPatchNumber(1, 8));
	assertEquals(1, getPatchNumber(1, 9));

	assertEquals(9, getPatchNumber(9, 1));
	assertEquals(7, getPatchNumber(9, 2));
	assertEquals(8, getPatchNumber(9, 3));
	assertEquals(3, getPatchNumber(9, 4));
	assertEquals(1, getPatchNumber(9, 5));
	assertEquals(2, getPatchNumber(9, 6));
	assertEquals(6, getPatchNumber(9, 7));
	assertEquals(4, getPatchNumber(9, 8));
	assertEquals(5, getPatchNumber(9, 9));
	Log.i(TAG, "-testGetPatchNumber");
	}
	}