Merge "Have focus avoid middle of a foucs chain when possible." (abf1eb3c) · Commits · e / os / android_frameworks_base

core/java/android/view/FocusFinder.java

+79 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,9 @@
		package android.view;

		import android.graphics.Rect;
		import android.util.ArrayMap;
		import android.util.SparseArray;
		import android.util.SparseBooleanArray;

		import java.util.ArrayList;
		import java.util.Collections;
		@@ -173,6 +176,7 @@ public class FocusFinder {
		// Note: This sort is stable.
		mSequentialFocusComparator.setRoot(root);
		mSequentialFocusComparator.setIsLayoutRtl(root.isLayoutRtl());
		mSequentialFocusComparator.setFocusables(focusables);
		Collections.sort(focusables, mSequentialFocusComparator);
		} finally {
		mSequentialFocusComparator.recycle();
		@@ -598,8 +602,16 @@ public class FocusFinder {
		+ "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT}.");
		}

		private static final boolean isValidId(final int id) {
		return id != 0 && id != View.NO_ID;
		}

		/**
		* Sorts views according to their visual layout and geometry for default tab order.
		* If views are part of a focus chain (nextFocusForwardId), then they are all grouped
		* together. The head of the chain is used to determine the order of the chain and is
		* first in the order and the tail of the chain is the last in the order. The views
		* in the middle of the chain can be arbitrary order.
		* This is used for sequential focus traversal.
		*/
		private static final class SequentialFocusComparator implements Comparator<View> {
		@@ -607,9 +619,15 @@ public class FocusFinder {
		private final Rect mSecondRect = new Rect();
		private ViewGroup mRoot;
		private boolean mIsLayoutRtl;
		private final SparseArray<View> mFocusables = new SparseArray<View>();
		private final SparseBooleanArray mIsConnectedTo = new SparseBooleanArray();
		private final ArrayMap<View, View> mHeadsOfChains = new ArrayMap<View, View>();

		public void recycle() {
		mRoot = null;
		mFocusables.clear();
		mHeadsOfChains.clear();
		mIsConnectedTo.clear();
		}

		public void setRoot(ViewGroup root) {
		@@ -620,11 +638,72 @@ public class FocusFinder {
		mIsLayoutRtl = b;
		}

		public void setFocusables(ArrayList<View> focusables) {
		for (int i = focusables.size() - 1; i >= 0; i--) {
		final View view = focusables.get(i);
		final int id = view.getId();
		if (isValidId(id)) {
		mFocusables.put(id, view);
		}
		final int nextId = view.getNextFocusForwardId();
		if (isValidId(nextId)) {
		mIsConnectedTo.put(nextId, true);
		}
		}

		for (int i = focusables.size() - 1; i >= 0; i--) {
		final View view = focusables.get(i);
		final int nextId = view.getNextFocusForwardId();
		if (isValidId(nextId) && !mIsConnectedTo.get(view.getId())) {
		setHeadOfChain(view);
		}
		}
		}

		private void setHeadOfChain(View head) {
		for (View view = head; view != null;
		view = mFocusables.get(view.getNextFocusForwardId())) {
		final View otherHead = mHeadsOfChains.get(view);
		if (otherHead != null) {
		if (otherHead == head) {
		return; // This view has already had its head set properly
		}
		// A hydra -- multi-headed focus chain (e.g. A->C and B->C)
		// Use the one we've already chosen instead and reset this chain.
		view = head;
		head = otherHead;
		}
		mHeadsOfChains.put(view, head);
		}
		}

		public int compare(View first, View second) {
		if (first == second) {
		return 0;
		}
		// Order between views within a chain is immaterial -- next/previous is
		// within a chain is handled elsewhere.
		View firstHead = mHeadsOfChains.get(first);
		View secondHead = mHeadsOfChains.get(second);
		if (firstHead == secondHead && firstHead != null) {
		if (first == firstHead) {
		return -1; // first is the head, it should be first
		} else if (second == firstHead) {
		return 1; // second is the head, it should be first
		} else if (isValidId(first.getNextFocusForwardId())) {
		return -1; // first is not the end of the chain
		} else {
		return 1; // first is end of chain
		}
		}
		if (firstHead != null) {
		first = firstHead;
		}
		if (secondHead != null) {
		second = secondHead;
		}

		// First see if they belong to the same focus chain.
		getRect(first, mFirstRect);
		getRect(second, mSecondRect);