Java tutorial
/** * Copyright 2014 Magnus Woxblom * <p/> * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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.dat.towerofhanoi.draggablerecyclerview; import android.content.Context; import android.content.res.Configuration; import android.content.res.Resources; import android.graphics.drawable.Drawable; import android.graphics.drawable.GradientDrawable; import android.os.Build; import android.support.v4.view.ViewCompat; import android.support.v7.widget.DefaultItemAnimator; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.AttributeSet; import android.util.Log; import android.util.SparseArray; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.animation.DecelerateInterpolator; import android.widget.FrameLayout; import android.widget.HorizontalScrollView; import android.widget.LinearLayout; import android.widget.Scroller; import com.dat.towerofhanoi.R; import java.util.ArrayList; public class BoardView extends HorizontalScrollView implements AutoScroller.AutoScrollListener { public interface BoardListener { void onItemDragStarted(int column, int row); void onItemChangedColumn(int oldColumn, int newColumn); void onItemDragEnded(int fromColumn, int fromRow, int toColumn, int toRow); } private static final int SCROLL_ANIMATION_DURATION = 325; private Scroller mScroller; private AutoScroller mAutoScroller; private GestureDetector mGestureDetector; private FrameLayout mRootLayout; private LinearLayout mColumnLayout; private ArrayList<DragItemRecyclerView> mLists = new ArrayList<>(); private SparseArray<View> mHeaders = new SparseArray<>(); private DragItemRecyclerView mCurrentRecyclerView; private DragItem mDragItem; private BoardListener mBoardListener; private boolean mSnapToColumnWhenScrolling = true; private boolean mSnapToColumnWhenDragging = true; private float mTouchX; private float mTouchY; private int mColumnWidth; private int mDragStartColumn; private int mDragStartRow; private boolean mHasLaidOut; private boolean mDragEnabled = true; //flags that allow to drag and drop only top item of each column private boolean mCanNotDragBelowTopItem, mCanNotDropBelowTopItem; public void setCanNotDragBelowTopItem(boolean mCanNotDragBelowTopItem) { this.mCanNotDragBelowTopItem = mCanNotDragBelowTopItem; } public void setCanNotDropBelowTopItem(boolean mCanNotDropBelowTopItem) { this.mCanNotDropBelowTopItem = mCanNotDropBelowTopItem; } public BoardView(Context context) { super(context); } public BoardView(Context context, AttributeSet attrs) { super(context, attrs); } public BoardView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } @Override protected void onFinishInflate() { super.onFinishInflate(); Resources res = getResources(); boolean isPortrait = res.getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT; if (isPortrait) { mColumnWidth = (int) (res.getDisplayMetrics().widthPixels * 0.87); } else { mColumnWidth = (int) (res.getDisplayMetrics().density * 320); } mGestureDetector = new GestureDetector(getContext(), new GestureListener()); mScroller = new Scroller(getContext(), new DecelerateInterpolator(1.1f)); mAutoScroller = new AutoScroller(getContext(), this); mAutoScroller.setAutoScrollMode(snapToColumnWhenDragging() ? AutoScroller.AutoScrollMode.COLUMN : AutoScroller.AutoScrollMode.POSITION); mDragItem = new DragItem(getContext()); mRootLayout = new FrameLayout(getContext()); mRootLayout.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT)); mColumnLayout = new LinearLayout(getContext()); mColumnLayout.setOrientation(LinearLayout.HORIZONTAL); mColumnLayout.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT)); mColumnLayout.setMotionEventSplittingEnabled(false); mRootLayout.addView(mColumnLayout); mRootLayout.addView(mDragItem.getDragItemView()); addView(mRootLayout); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); // Snap to closes column after first layout. // This is needed so correct column is scrolled to after a rotation. if (!mHasLaidOut && snapToColumnWhenScrolling()) { scrollToColumn(getClosestColumn(), false); } mHasLaidOut = true; } @Override public boolean onInterceptTouchEvent(MotionEvent event) { boolean retValue = handleTouchEvent(event); return retValue || super.onInterceptTouchEvent(event); } @Override public boolean onTouchEvent(MotionEvent event) { boolean retValue = handleTouchEvent(event); return retValue || super.onTouchEvent(event); } private boolean handleTouchEvent(MotionEvent event) { if (mLists.size() == 0) { return false; } mTouchX = event.getX(); mTouchY = event.getY(); if (isDragging()) { switch (event.getAction()) { case MotionEvent.ACTION_MOVE: if (!mAutoScroller.isAutoScrolling()) { updateScrollPosition(); } break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: mAutoScroller.stopAutoScroll(); mCurrentRecyclerView.onDragEnded(); if (snapToColumnWhenScrolling()) { scrollToColumn(getColumnOfList(mCurrentRecyclerView), true); } invalidate(); break; } return true; } else { if (snapToColumnWhenScrolling() && mGestureDetector.onTouchEvent(event)) { // A page fling occurred, consume event return true; } switch (event.getAction()) { case MotionEvent.ACTION_DOWN: if (!mScroller.isFinished()) { // View was grabbed during animation mScroller.forceFinished(true); } break; case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: if (snapToColumnWhenScrolling()) { scrollToColumn(getClosestColumn(), true); } break; } return false; } } @Override public void computeScroll() { if (!mScroller.isFinished() && mScroller.computeScrollOffset()) { int x = mScroller.getCurrX(); int y = mScroller.getCurrY(); if (getScrollX() != x || getScrollY() != y) { scrollTo(x, y); } // If auto scrolling at the same time as the scroller is running, // then update the drag item position to prevent stuttering item if (mAutoScroller.isAutoScrolling()) { mDragItem.setPosition(getListTouchX(mCurrentRecyclerView), getListTouchY(mCurrentRecyclerView)); } ViewCompat.postInvalidateOnAnimation(this); } else { super.computeScroll(); } } @Override public void onAutoScrollPositionBy(int dx, int dy) { if (isDragging()) { scrollBy(dx, dy); updateScrollPosition(); } else { mAutoScroller.stopAutoScroll(); } } @Override public void onAutoScrollColumnBy(int columns) { if (isDragging()) { DragItemRecyclerView currentList = getCurrentRecyclerView(getWidth() / 2 + getScrollX()); int newColumn = getColumnOfList(currentList) + columns; if (columns != 0 && newColumn >= 0 && newColumn < mLists.size()) { scrollToColumn(newColumn, true); } updateScrollPosition(); } else { mAutoScroller.stopAutoScroll(); } } private boolean check() { View child = mCurrentRecyclerView.findChildView(0, getListTouchY(mCurrentRecyclerView)); int pos; if (child == null && mCurrentRecyclerView.getChildCount() > 0) { // If child is null and child count is not 0 it means that an item was // dragged below the last item in the list, then put it after that item pos = mCurrentRecyclerView.getChildLayoutPosition( mCurrentRecyclerView.getChildAt(mCurrentRecyclerView.getChildCount() - 1)) + 1; Log.d("CC", "CC"); } else { pos = mCurrentRecyclerView.getChildLayoutPosition(child); Log.d("DD", "DD"); } // If pos is NO_POSITION it means that the child has not been laid out yet, // this only happens for pos 0 as far as I know if (pos == -1) { pos = 0; } if (pos < mCurrentRecyclerView.getAdapter().getItemCount() - 1) { return false; } return true; } private void updateScrollPosition() { // Updated event to scrollview coordinates DragItemRecyclerView currentList = getCurrentRecyclerView(mTouchX + getScrollX()); if (mCurrentRecyclerView != currentList) { int oldColumn = getColumnOfList(mCurrentRecyclerView); int newColumn = getColumnOfList(currentList); long itemId = mCurrentRecyclerView.getDragItemId(); Object item = mCurrentRecyclerView.removeDragItemAndEnd(); if (item != null) { mCurrentRecyclerView = currentList; mCurrentRecyclerView.addDragItemAndStart(getListTouchY(mCurrentRecyclerView), item, itemId); mDragItem.setOffset(((View) mCurrentRecyclerView.getParent()).getLeft(), mCurrentRecyclerView.getTop()); if (mBoardListener != null) { mBoardListener.onItemChangedColumn(oldColumn, newColumn); } } } // Updated event to list coordinates mCurrentRecyclerView.onDragging(getListTouchX(mCurrentRecyclerView), getListTouchY(mCurrentRecyclerView)); float scrollEdge = getResources().getDisplayMetrics().widthPixels * 0.14f; if (mTouchX > getWidth() - scrollEdge && getScrollX() < mColumnLayout.getWidth()) { mAutoScroller.startAutoScroll(AutoScroller.ScrollDirection.LEFT); } else if (mTouchX < scrollEdge && getScrollX() > 0) { mAutoScroller.startAutoScroll(AutoScroller.ScrollDirection.RIGHT); } else { mAutoScroller.stopAutoScroll(); } invalidate(); } private float getListTouchX(DragItemRecyclerView list) { return mTouchX + getScrollX() - ((View) list.getParent()).getLeft(); } private float getListTouchY(DragItemRecyclerView list) { return mTouchY - list.getTop(); } private DragItemRecyclerView getCurrentRecyclerView(float x) { for (DragItemRecyclerView list : mLists) { View parent = (View) list.getParent(); if (parent.getLeft() <= x && parent.getRight() > x) { return list; } } return mCurrentRecyclerView; } private int getColumnOfList(DragItemRecyclerView list) { int column = 0; for (int i = 0; i < mLists.size(); i++) { RecyclerView tmpList = mLists.get(i); if (tmpList == list) { column = i; } } return column; } private int getCurrentColumn(float posX) { for (int i = 0; i < mLists.size(); i++) { RecyclerView list = mLists.get(i); View parent = (View) list.getParent(); if (parent.getLeft() <= posX && parent.getRight() > posX) { return i; } } return 0; } private int getClosestColumn() { int middlePosX = getScrollX() + getMeasuredWidth() / 2; int column = 0; int minDiffX = Integer.MAX_VALUE; for (int i = 0; i < mLists.size(); i++) { RecyclerView list = mLists.get(i); int listPosX = ((View) list.getParent()).getLeft(); int diffX = Math.abs(listPosX + mColumnWidth / 2 - middlePosX); if (diffX < minDiffX) { minDiffX = diffX; column = i; } } return column; } private boolean snapToColumnWhenScrolling() { boolean isPortrait = getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT; return mSnapToColumnWhenScrolling && isPortrait; } private boolean snapToColumnWhenDragging() { boolean isPortrait = getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT; return mSnapToColumnWhenDragging && isPortrait; } private boolean isDragging() { return mCurrentRecyclerView != null && mCurrentRecyclerView.isDragging(); } public RecyclerView getRecyclerView(int column) { if (column >= 0 && column < mLists.size()) { return mLists.get(column); } return null; } public DragItemAdapter getAdapter(int column) { if (column >= 0 && column < mLists.size()) { return (DragItemAdapter) mLists.get(column).getAdapter(); } return null; } public int getItemCount() { int count = 0; for (DragItemRecyclerView list : mLists) { count += list.getAdapter().getItemCount(); } return count; } public int getItemCount(int column) { if (mLists.size() > column) { return mLists.get(column).getAdapter().getItemCount(); } return 0; } public int getColumnCount() { return mLists.size(); } public View getHeaderView(int column) { return mHeaders.get(column); } public void removeItem(int column, int row) { if (!isDragging() && mLists.size() > column && mLists.get(column).getAdapter().getItemCount() > row) { DragItemAdapter adapter = (DragItemAdapter) mLists.get(column).getAdapter(); adapter.removeItem(row); } } public void addItem(int column, int row, Object item, boolean scrollToItem) { if (!isDragging() && mLists.size() > column && mLists.get(column).getAdapter().getItemCount() >= row) { DragItemAdapter adapter = (DragItemAdapter) mLists.get(column).getAdapter(); adapter.addItem(row, item); if (scrollToItem) { scrollToItem(column, row, false); } } } public void moveItem(int fromColumn, int fromRow, int toColumn, int toRow, boolean scrollToItem) { if (!isDragging() && mLists.size() > fromColumn && mLists.get(fromColumn).getAdapter().getItemCount() > fromRow && mLists.size() > toColumn && mLists.get(toColumn).getAdapter().getItemCount() >= toRow) { DragItemAdapter adapter = (DragItemAdapter) mLists.get(fromColumn).getAdapter(); Object item = adapter.removeItem(fromRow); adapter = (DragItemAdapter) mLists.get(toColumn).getAdapter(); adapter.addItem(toRow, item); if (scrollToItem) { scrollToItem(toColumn, toRow, false); } } } public void moveItem(long itemId, int toColumn, int toRow, boolean scrollToItem) { for (int i = 0; i < mLists.size(); i++) { RecyclerView.Adapter adapter = mLists.get(i).getAdapter(); final int count = adapter.getItemCount(); for (int j = 0; j < count; j++) { long id = adapter.getItemId(j); if (id == itemId) { moveItem(i, j, toColumn, toRow, scrollToItem); return; } } } } public void replaceItem(int column, int row, Object item, boolean scrollToItem) { if (!isDragging() && mLists.size() > column && mLists.get(column).getAdapter().getItemCount() > row) { DragItemAdapter adapter = (DragItemAdapter) mLists.get(column).getAdapter(); adapter.removeItem(row); adapter.addItem(row, item); if (scrollToItem) { scrollToItem(column, row, false); } } } public void scrollToItem(int column, int row, boolean animate) { if (!isDragging() && mLists.size() > column && mLists.get(column).getAdapter().getItemCount() > row) { mScroller.forceFinished(true); scrollToColumn(column, animate); if (animate) { mLists.get(column).smoothScrollToPosition(row); } else { mLists.get(column).scrollToPosition(row); } } } public void scrollToColumn(int column, boolean animate) { if (mLists.size() <= column) { return; } View parent = (View) mLists.get(column).getParent(); int newX = parent.getLeft() - (getMeasuredWidth() - parent.getMeasuredWidth()) / 2; int maxScroll = mRootLayout.getMeasuredWidth() - getMeasuredWidth(); newX = newX < 0 ? 0 : newX; newX = newX > maxScroll ? maxScroll : newX; if (getScrollX() != newX) { mScroller.forceFinished(true); if (animate) { mScroller.startScroll(getScrollX(), getScrollY(), newX - getScrollX(), 0, SCROLL_ANIMATION_DURATION); ViewCompat.postInvalidateOnAnimation(this); } else { scrollTo(newX, getScrollY()); } } } public void clearBoard() { int count = mLists.size(); for (int i = count - 1; i >= 0; i--) { mColumnLayout.removeViewAt(i); mHeaders.remove(i); mLists.remove(i); } } public void removeColumn(int column) { if (column >= 0 && mLists.size() > column) { mColumnLayout.removeViewAt(column); mHeaders.remove(column); mLists.remove(column); } } public boolean isDragEnabled() { return mDragEnabled; } public void setDragEnabled(boolean enabled) { mDragEnabled = enabled; if (mLists.size() > 0) { for (DragItemRecyclerView list : mLists) { list.setDragEnabled(mDragEnabled); } } } /** * @param width the width of columns in both portrait and landscape. This must be called before * {@link #addColumnList} is * called for the width to take effect. */ public void setColumnWidth(int width) { mColumnWidth = width; } /** * @param snapToColumn true if scrolling should snap to columns. Only applies to portrait mode. */ public void setSnapToColumnsWhenScrolling(boolean snapToColumn) { mSnapToColumnWhenScrolling = snapToColumn; } /** * @param snapToColumn true if dragging should snap to columns when dragging towards the edge. * Only applies to portrait mode. */ public void setSnapToColumnWhenDragging(boolean snapToColumn) { mSnapToColumnWhenDragging = snapToColumn; mAutoScroller.setAutoScrollMode(snapToColumnWhenDragging() ? AutoScroller.AutoScrollMode.COLUMN : AutoScroller.AutoScrollMode.POSITION); } /** * @param snapToTouch true if the drag item should snap to touch position when a drag is * started. */ public void setSnapDragItemToTouch(boolean snapToTouch) { mDragItem.setSnapToTouch(snapToTouch); } public void setBoardListener(BoardListener listener) { mBoardListener = listener; } public void setCustomDragItem(DragItem dragItem) { DragItem newDragItem; if (dragItem != null) { newDragItem = dragItem; } else { newDragItem = new DragItem(getContext()); } newDragItem.setSnapToTouch(mDragItem.isSnapToTouch()); mDragItem = newDragItem; mRootLayout.removeViewAt(1); mRootLayout.addView(mDragItem.getDragItemView()); } public DragItemRecyclerView addColumnList(final DragItemAdapter adapter, final View header, boolean hasFixedItemSize, int color, Drawable drawable) { final DragItemRecyclerView recyclerView = new DragItemRecyclerView(getContext()); recyclerView.setMotionEventSplittingEnabled(false); recyclerView.setDragItem(mDragItem); if (drawable != null) { if (Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.JELLY_BEAN) { recyclerView.setBackgroundDrawable(drawable); GradientDrawable gd = (GradientDrawable) recyclerView.getBackground().getCurrent(); gd.setColor(getResources().getColor(R.color.white)); gd.setStroke(2, getResources().getColor(R.color.grey), 0, 0); } else { recyclerView.setBackground(drawable); } } if (color > 0) { mColumnLayout.setBackgroundColor(color); } //settings for ToH rules recyclerView.setLayoutParams( new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT)); LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext()); linearLayoutManager.setReverseLayout(true); recyclerView.setCanNotDragBelowTopItem(mCanNotDragBelowTopItem); recyclerView.setCanNotDropBelowTopItem(mCanNotDropBelowTopItem); recyclerView.setDragItemCallback(new DragItemRecyclerView.DragItemCallback() { @Override public boolean canDragItemAtPosition(int dragPosition) { return true; } @Override public boolean canDropItemAtPosition(int dropPosition) { if (dropPosition == adapter.getItemCount() - 1) { // Log.d("TAG", "TRUE"); return true; } return false; } }); recyclerView.setLayoutManager(linearLayoutManager); recyclerView.setHasFixedSize(hasFixedItemSize); recyclerView.setItemAnimator(new DefaultItemAnimator()); recyclerView.setDragItemListener(new DragItemRecyclerView.DragItemListener() { @Override public void onDragStarted(int itemPosition, float x, float y) { mDragStartColumn = getColumnOfList(recyclerView); mDragStartRow = itemPosition; mCurrentRecyclerView = recyclerView; mDragItem.setOffset(((View) mCurrentRecyclerView.getParent()).getX(), mCurrentRecyclerView.getY()); if (mBoardListener != null) { mBoardListener.onItemDragStarted(mDragStartColumn, mDragStartRow); } invalidate(); } @Override public void onDragging(int itemPosition, float x, float y) { } @Override public void onDragEnded(int newItemPosition) { if (mBoardListener != null) { mBoardListener.onItemDragEnded(mDragStartColumn, mDragStartRow, getColumnOfList(recyclerView), newItemPosition); } } }); recyclerView.setAdapter(adapter); recyclerView.setDragEnabled(mDragEnabled); adapter.setDragStartedListener(new DragItemAdapter.DragStartCallback() { @Override public boolean startDrag(View itemView, long itemId) { return recyclerView.startDrag(itemView, itemId, getListTouchX(recyclerView), getListTouchY(recyclerView)); } @Override public boolean isDragging() { return recyclerView.isDragging(); } }); LinearLayout layout = new LinearLayout(getContext()); layout.setOrientation(LinearLayout.VERTICAL); layout.setLayoutParams(new LayoutParams(mColumnWidth, LayoutParams.MATCH_PARENT)); if (header != null) { layout.addView(header); mHeaders.put(mLists.size(), header); } layout.addView(recyclerView); mLists.add(recyclerView); mColumnLayout.addView(layout); return recyclerView; } private class GestureListener extends GestureDetector.SimpleOnGestureListener { private float mStartScrollX; @Override public boolean onDown(MotionEvent e) { mStartScrollX = getScrollX(); return super.onDown(e); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { // Calc new column to scroll to int currentColumn = getCurrentColumn(e2.getX() + getScrollX()); int newColumn; if (velocityX < 0) { newColumn = getScrollX() >= mStartScrollX ? currentColumn + 1 : currentColumn; } else { newColumn = getScrollX() <= mStartScrollX ? currentColumn - 1 : currentColumn; } if (newColumn < 0 || newColumn > mLists.size() - 1) { newColumn = newColumn < 0 ? 0 : mLists.size() - 1; } // Calc new scrollX position scrollToColumn(newColumn, true); return true; } } }