Move focus-related code out of DirectoryFragment. (b0bfe2df) · Commits · e / os / android_frameworks_base

packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java

+9 −154

Original line number	Diff line number	Diff line
		@@ -151,6 +151,7 @@ public class DirectoryFragment extends Fragment implements DocumentsAdapter.Envi
		private MultiSelectManager mSelectionManager;
		private Model.UpdateListener mModelUpdateListener = new ModelUpdateListener();
		private ItemEventListener mItemEventListener = new ItemEventListener();
		private FocusManager mFocusManager;

		private IconHelper mIconHelper;

		@@ -262,6 +263,8 @@ public class DirectoryFragment extends Fragment implements DocumentsAdapter.Envi

		mSelectionManager.addCallback(selectionListener);

		mFocusManager = new FocusManager(mRecView, mSelectionManager);

		mModel = new Model();
		mModel.addUpdateListener(mAdapter);
		mModel.addUpdateListener(mModelUpdateListener);
		@@ -1249,165 +1252,17 @@ public class DirectoryFragment extends Fragment implements DocumentsAdapter.Envi
		return false;
		}

		boolean handled = false;
		if (Events.isNavigationKeyCode(keyCode)) {
		// Find the target item and focus it.
		int endPos = findTargetPosition(doc.itemView, keyCode);

		if (endPos != RecyclerView.NO_POSITION) {
		focusItem(endPos);

		// Handle any necessary adjustments to selection.
		boolean extendSelection = event.isShiftPressed();
		if (extendSelection) {
		int startPos = doc.getAdapterPosition();
		mSelectionManager.selectRange(startPos, endPos);
		}
		handled = true;
		if (mFocusManager.handleKey(doc, keyCode, event)) {
		return true;
		}
		} else {

		// Handle enter key events
		if (keyCode == KeyEvent.KEYCODE_ENTER) {
		handled = onActivate(doc);
		}
		}

		return handled;
		}

		/**
		* Finds the destination position where the focus should land for a given navigation event.
		*
		* @param view The view that received the event.
		* @param keyCode The key code for the event.
		* @return The adapter position of the destination item. Could be RecyclerView.NO_POSITION.
		*/
		private int findTargetPosition(View view, int keyCode) {
		switch (keyCode) {
		case KeyEvent.KEYCODE_MOVE_HOME:
		return 0;
		case KeyEvent.KEYCODE_MOVE_END:
		return mAdapter.getItemCount() - 1;
		case KeyEvent.KEYCODE_PAGE_UP:
		case KeyEvent.KEYCODE_PAGE_DOWN:
		return findTargetPositionByPage(view, keyCode);
		}

		// Find a navigation target based on the arrow key that the user pressed.
		int searchDir = -1;
		switch (keyCode) {
		case KeyEvent.KEYCODE_DPAD_UP:
		searchDir = View.FOCUS_UP;
		break;
		case KeyEvent.KEYCODE_DPAD_DOWN:
		searchDir = View.FOCUS_DOWN;
		break;
		case KeyEvent.KEYCODE_DPAD_LEFT:
		searchDir = View.FOCUS_LEFT;
		break;
		case KeyEvent.KEYCODE_DPAD_RIGHT:
		searchDir = View.FOCUS_RIGHT;
		break;
		}

		if (searchDir != -1) {
		View targetView = view.focusSearch(searchDir);
		// TargetView can be null, for example, if the user pressed <down> at the bottom
		// of the list.
		if (targetView != null) {
		// Ignore navigation targets that aren't items in the RecyclerView.
		if (targetView.getParent() == mRecView) {
		return mRecView.getChildAdapterPosition(targetView);
		}
		}
		}

		return RecyclerView.NO_POSITION;
		return onActivate(doc);
		}

		/**
		* Given a PgUp/PgDn event and the current view, find the position of the target view.
		* This returns:
		* <li>The position of the topmost (or bottom-most) visible item, if the current item is not
		* the top- or bottom-most visible item.
		* <li>The position of an item that is one page's worth of items up (or down) if the current
		* item is the top- or bottom-most visible item.
		* <li>The first (or last) item, if paging up (or down) would go past those limits.
		* @param view The view that received the key event.
		* @param keyCode Must be KEYCODE_PAGE_UP or KEYCODE_PAGE_DOWN.
		* @return The adapter position of the target item.
		*/
		private int findTargetPositionByPage(View view, int keyCode) {
		int first = mLayout.findFirstVisibleItemPosition();
		int last = mLayout.findLastVisibleItemPosition();
		int current = mRecView.getChildAdapterPosition(view);
		int pageSize = last - first + 1;

		if (keyCode == KeyEvent.KEYCODE_PAGE_UP) {
		if (current > first) {
		// If the current item isn't the first item, target the first item.
		return first;
		} else {
		// If the current item is the first item, target the item one page up.
		int target = current - pageSize;
		return target < 0 ? 0 : target;
		}
		}

		if (keyCode == KeyEvent.KEYCODE_PAGE_DOWN) {
		if (current < last) {
		// If the current item isn't the last item, target the last item.
		return last;
		} else {
		// If the current item is the last item, target the item one page down.
		int target = current + pageSize;
		int max = mAdapter.getItemCount() - 1;
		return target < max ? target : max;
		}
		}

		throw new IllegalArgumentException("Unsupported keyCode: " + keyCode);
		}

		/**
		* Requests focus for the item in the given adapter position, scrolling the RecyclerView if
		* necessary.
		*
		* @param pos
		*/
		public void focusItem(final int pos) {
		// If the item is already in view, focus it; otherwise, scroll to it and focus it.
		RecyclerView.ViewHolder vh = mRecView.findViewHolderForAdapterPosition(pos);
		if (vh != null) {
		vh.itemView.requestFocus();
		} else {
		mRecView.smoothScrollToPosition(pos);
		// Set a one-time listener to request focus when the scroll has completed.
		mRecView.addOnScrollListener(
		new RecyclerView.OnScrollListener() {
		@Override
		public void onScrollStateChanged (RecyclerView view, int newState) {
		if (newState == RecyclerView.SCROLL_STATE_IDLE) {
		// When scrolling stops, find the item and focus it.
		RecyclerView.ViewHolder vh =
		view.findViewHolderForAdapterPosition(pos);
		if (vh != null) {
		vh.itemView.requestFocus();
		} else {
		// This might happen in weird corner cases, e.g. if the user is
		// scrolling while a delete operation is in progress. In that
		// case, just don't attempt to focus the missing item.
		Log.w(
		TAG, "Unable to focus position " + pos + " after a scroll");
		}
		view.removeOnScrollListener(this);
		}
		}
		});
		}
		return false;
		}


		}

		private final class ModelUpdateListener implements Model.UpdateListener {

packages/DocumentsUI/src/com/android/documentsui/dirlist/FocusManager.java

0 → 100644

+207 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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.documentsui.dirlist;

		import android.support.v7.widget.LinearLayoutManager;
		import android.support.v7.widget.RecyclerView;
		import android.util.Log;
		import android.view.KeyEvent;
		import android.view.View;

		import com.android.documentsui.Events;

		/**
		* A class that handles navigation and focus within the DirectoryFragment.
		*/
		class FocusManager {
		private static final String TAG = "FocusManager";

		private RecyclerView mView;
		private RecyclerView.Adapter<?> mAdapter;
		private LinearLayoutManager mLayout;
		private MultiSelectManager mSelectionManager;

		public FocusManager(RecyclerView view, MultiSelectManager selectionManager) {
		mView = view;
		mAdapter = view.getAdapter();
		mLayout = (LinearLayoutManager) view.getLayoutManager();
		mSelectionManager = selectionManager;
		}

		/**
		* Handles navigation (setting focus, adjusting selection if needed) arising from incoming key
		* events.
		*
		* @param doc The DocumentHolder receiving the key event.
		* @param keyCode
		* @param event
		* @return Whether the event was handled.
		*/
		public boolean handleKey(DocumentHolder doc, int keyCode, KeyEvent event) {
		boolean handled = false;
		if (Events.isNavigationKeyCode(keyCode)) {
		// Find the target item and focus it.
		int endPos = findTargetPosition(doc.itemView, keyCode, event);

		if (endPos != RecyclerView.NO_POSITION) {
		focusItem(endPos);

		// Handle any necessary adjustments to selection.
		boolean extendSelection = event.isShiftPressed();
		if (extendSelection) {
		int startPos = doc.getAdapterPosition();
		mSelectionManager.selectRange(startPos, endPos);
		}
		handled = true;
		}
		}
		return handled;
		}

		/**
		* Finds the destination position where the focus should land for a given navigation event.
		*
		* @param view The view that received the event.
		* @param keyCode The key code for the event.
		* @param event
		* @return The adapter position of the destination item. Could be RecyclerView.NO_POSITION.
		*/
		private int findTargetPosition(View view, int keyCode, KeyEvent event) {
		switch (keyCode) {
		case KeyEvent.KEYCODE_MOVE_HOME:
		return 0;
		case KeyEvent.KEYCODE_MOVE_END:
		return mAdapter.getItemCount() - 1;
		case KeyEvent.KEYCODE_PAGE_UP:
		case KeyEvent.KEYCODE_PAGE_DOWN:
		return findPagedTargetPosition(view, keyCode, event);
		}

		// Find a navigation target based on the arrow key that the user pressed.
		int searchDir = -1;
		switch (keyCode) {
		case KeyEvent.KEYCODE_DPAD_UP:
		searchDir = View.FOCUS_UP;
		break;
		case KeyEvent.KEYCODE_DPAD_DOWN:
		searchDir = View.FOCUS_DOWN;
		break;
		case KeyEvent.KEYCODE_DPAD_LEFT:
		searchDir = View.FOCUS_LEFT;
		break;
		case KeyEvent.KEYCODE_DPAD_RIGHT:
		searchDir = View.FOCUS_RIGHT;
		break;
		}

		if (searchDir != -1) {
		View targetView = view.focusSearch(searchDir);
		// TargetView can be null, for example, if the user pressed <down> at the bottom
		// of the list.
		if (targetView != null) {
		// Ignore navigation targets that aren't items in the RecyclerView.
		if (targetView.getParent() == mView) {
		return mView.getChildAdapterPosition(targetView);
		}
		}
		}

		return RecyclerView.NO_POSITION;
		}

		/**
		* Given a PgUp/PgDn event and the current view, find the position of the target view.
		* This returns:
		* <li>The position of the topmost (or bottom-most) visible item, if the current item is not
		* the top- or bottom-most visible item.
		* <li>The position of an item that is one page's worth of items up (or down) if the current
		* item is the top- or bottom-most visible item.
		* <li>The first (or last) item, if paging up (or down) would go past those limits.
		* @param view The view that received the key event.
		* @param keyCode Must be KEYCODE_PAGE_UP or KEYCODE_PAGE_DOWN.
		* @param event
		* @return The adapter position of the target item.
		*/
		private int findPagedTargetPosition(View view, int keyCode, KeyEvent event) {
		int first = mLayout.findFirstVisibleItemPosition();
		int last = mLayout.findLastVisibleItemPosition();
		int current = mView.getChildAdapterPosition(view);
		int pageSize = last - first + 1;

		if (keyCode == KeyEvent.KEYCODE_PAGE_UP) {
		if (current > first) {
		// If the current item isn't the first item, target the first item.
		return first;
		} else {
		// If the current item is the first item, target the item one page up.
		int target = current - pageSize;
		return target < 0 ? 0 : target;
		}
		}

		if (keyCode == KeyEvent.KEYCODE_PAGE_DOWN) {
		if (current < last) {
		// If the current item isn't the last item, target the last item.
		return last;
		} else {
		// If the current item is the last item, target the item one page down.
		int target = current + pageSize;
		int max = mAdapter.getItemCount() - 1;
		return target < max ? target : max;
		}
		}

		throw new IllegalArgumentException("Unsupported keyCode: " + keyCode);
		}

		/**
		* Requests focus for the item in the given adapter position, scrolling the RecyclerView if
		* necessary.
		*
		* @param pos
		*/
		private void focusItem(final int pos) {
		// If the item is already in view, focus it; otherwise, scroll to it and focus it.
		RecyclerView.ViewHolder vh = mView.findViewHolderForAdapterPosition(pos);
		if (vh != null) {
		vh.itemView.requestFocus();
		} else {
		mView.smoothScrollToPosition(pos);
		// Set a one-time listener to request focus when the scroll has completed.
		mView.addOnScrollListener(
		new RecyclerView.OnScrollListener() {
		@Override
		public void onScrollStateChanged(RecyclerView view, int newState) {
		if (newState == RecyclerView.SCROLL_STATE_IDLE) {
		// When scrolling stops, find the item and focus it.
		RecyclerView.ViewHolder vh =
		view.findViewHolderForAdapterPosition(pos);
		if (vh != null) {
		vh.itemView.requestFocus();
		} else {
		// This might happen in weird corner cases, e.g. if the user is
		// scrolling while a delete operation is in progress. In that
		// case, just don't attempt to focus the missing item.
		Log.w(TAG, "Unable to focus position " + pos + " after scroll");
		}
		view.removeOnScrollListener(this);
		}
		}
		});
		}
		}
		}