package com.wm.remusic.widget; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.drawable.BitmapDrawable; import android.support.annotation.Nullable; import android.support.v7.widget.RecyclerView; import android.util.Log; import android.view.MotionEvent; import android.view.View; public class DragSortRecycler extends RecyclerView.ItemDecoration implements RecyclerView.OnItemTouchListener { final String TAG = "DragSortRecycler"; final boolean DEBUG = false; OnItemMovedListener moveInterface; @Nullable OnDragStateChangedListener dragStateChangedListener; Paint bgColor = new Paint(); private int dragHandleWidth = 0; private int selectedDragItemPos = -1; private int fingerAnchorY; RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() { @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); } @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); debugLog("Scrolled: " + dx + " " + dy); fingerAnchorY -= dy; } }; private int fingerY; private int fingerOffsetInViewY; private float autoScrollWindow = 0.1f; private float autoScrollSpeed = 0.5f; private BitmapDrawable floatingItem; private Rect floatingItemStatingBounds; private Rect floatingItemBounds; private float floatingItemAlpha = 0.5f; private int floatingItemBgColor = 0; private int viewHandleId = -1; private boolean isDragging; private void debugLog(String log) { if (DEBUG) Log.d(TAG, log); } public RecyclerView.OnScrollListener getScrollListener() { return scrollListener; } /* * Set the item move interface */ public void setOnItemMovedListener(OnItemMovedListener swif) { moveInterface = swif; } public void setViewHandleId(int id) { viewHandleId = id; } public void setLeftDragArea(int w) { dragHandleWidth = w; } public void setFloatingAlpha(float a) { floatingItemAlpha = a; } public void setFloatingBgColor(int c) { floatingItemBgColor = c; } /* Set the window at top and bottom of list, must be between 0 and 0.5 For example 0.1 uses the top and bottom 10% of the lists for scrolling */ public void setAutoScrollWindow(float w) { autoScrollWindow = w; } /* Set the autoscroll speed, default is 0.5 */ public void setAutoScrollSpeed(float speed) { autoScrollSpeed = speed; } @Override public void getItemOffsets(Rect outRect, View view, RecyclerView rv, RecyclerView.State state) { super.getItemOffsets(outRect, view, rv, state); debugLog("getItemOffsets"); debugLog("View top = " + view.getTop()); if (selectedDragItemPos != -1) { int itemPos = rv.getChildLayoutPosition(view); debugLog("itemPos =" + itemPos); if (!canDragOver(itemPos)) { return; } //Movement of finger float totalMovement = fingerY - fingerAnchorY; if (itemPos == selectedDragItemPos) { view.setVisibility(View.INVISIBLE); } else { //Make view visible incase invisible view.setVisibility(View.VISIBLE); //Find middle of the floatingItem float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height() / 2; //Moving down the list //These will auto-animate if the device continually sends touch motion events // if (totalMovment>0) { if ((itemPos > selectedDragItemPos) && (view.getTop() < floatMiddleY)) { float amountUp = (floatMiddleY - view.getTop()) / (float) view.getHeight(); // amountUp *= 0.5f; if (amountUp > 1) amountUp = 1; outRect.top = -(int) (floatingItemBounds.height() * amountUp); outRect.bottom = (int) (floatingItemBounds.height() * amountUp); } }//Moving up the list // else if (totalMovment < 0) { if ((itemPos < selectedDragItemPos) && (view.getBottom() > floatMiddleY)) { float amountDown = ((float) view.getBottom() - floatMiddleY) / (float) view.getHeight(); // amountDown *= 0.5f; if (amountDown > 1) amountDown = 1; outRect.top = (int) (floatingItemBounds.height() * amountDown); outRect.bottom = -(int) (floatingItemBounds.height() * amountDown); } } } } else { outRect.top = 0; outRect.bottom = 0; //Make view visible incase invisible view.setVisibility(View.VISIBLE); } } /** * Find the new position by scanning through the items on * screen and finding the positional relationship. * This *seems* to work, another method would be to use * getItemOffsets, but I think that could miss items?.. */ private int getNewPostion(RecyclerView rv) { int itemsOnScreen = rv.getLayoutManager().getChildCount(); float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height() / 2; int above = 0; int below = Integer.MAX_VALUE; for (int n = 0; n < itemsOnScreen; n++) //Scan though items on screen, however they may not { // be in order! View view = rv.getLayoutManager().getChildAt(n); if (view.getVisibility() != View.VISIBLE) continue; int itemPos = rv.getChildLayoutPosition(view); if (itemPos == selectedDragItemPos) //Don't check against itself! continue; float viewMiddleY = view.getTop() + view.getHeight() / 2; if (floatMiddleY > viewMiddleY) //Is above this item { if (itemPos > above) above = itemPos; } else if (floatMiddleY <= viewMiddleY) //Is below this item { if (itemPos < below) below = itemPos; } } debugLog("above = " + above + " below = " + below); if (below != Integer.MAX_VALUE) { if (below < selectedDragItemPos) //Need to count itself below++; return below - 1; } else { if (above < selectedDragItemPos) above++; return above; } } @Override public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) { debugLog("onInterceptTouchEvent"); //if (e.getAction() == MotionEvent.ACTION_DOWN) { View itemView = rv.findChildViewUnder(e.getX(), e.getY()); if (itemView == null) return false; boolean dragging = false; if ((dragHandleWidth > 0) && (e.getX() < dragHandleWidth)) { dragging = true; } else if (viewHandleId != -1) { //Find the handle in the list item View handleView = itemView.findViewById(viewHandleId); if (handleView == null) { Log.e(TAG, "The view ID " + viewHandleId + " was not found in the RecycleView item"); return false; } //View should be visible to drag if (handleView.getVisibility() != View.VISIBLE) { return false; } //We need to find the relative position of the handle to the parent view //Then we can work out if the touch is within the handle int[] parentItemPos = new int[2]; itemView.getLocationInWindow(parentItemPos); int[] handlePos = new int[2]; handleView.getLocationInWindow(handlePos); int xRel = handlePos[0] - parentItemPos[0]; int yRel = handlePos[1] - parentItemPos[1]; Rect touchBounds = new Rect(itemView.getLeft() + xRel, itemView.getTop() + yRel, itemView.getLeft() + xRel + handleView.getWidth(), itemView.getTop() + yRel + handleView.getHeight() ); if (touchBounds.contains((int) e.getX(), (int) e.getY())) dragging = true; debugLog("parentItemPos = " + parentItemPos[0] + " " + parentItemPos[1]); debugLog("handlePos = " + handlePos[0] + " " + handlePos[1]); } if (dragging) { debugLog("Started Drag"); setIsDragging(true); floatingItem = createFloatingBitmap(itemView); fingerAnchorY = (int) e.getY(); fingerOffsetInViewY = fingerAnchorY - itemView.getTop(); fingerY = fingerAnchorY; selectedDragItemPos = rv.getChildLayoutPosition(itemView); debugLog("selectedDragItemPos = " + selectedDragItemPos); return true; } } return false; } @Override public void onRequestDisallowInterceptTouchEvent(boolean b) { } @Override public void onTouchEvent(RecyclerView rv, MotionEvent e) { debugLog("onTouchEvent"); if ((e.getAction() == MotionEvent.ACTION_UP) || (e.getAction() == MotionEvent.ACTION_CANCEL)) { if ((e.getAction() == MotionEvent.ACTION_UP) && selectedDragItemPos != -1) { int newPos = getNewPostion(rv); if (moveInterface != null) moveInterface.onItemMoved(selectedDragItemPos, newPos); } setIsDragging(false); selectedDragItemPos = -1; floatingItem = null; rv.invalidateItemDecorations(); return; } fingerY = (int) e.getY(); if (floatingItem != null) { floatingItemBounds.top = fingerY - fingerOffsetInViewY; if (floatingItemBounds.top < -floatingItemStatingBounds.height() / 2) //Allow half the view out the top floatingItemBounds.top = -floatingItemStatingBounds.height() / 2; floatingItemBounds.bottom = floatingItemBounds.top + floatingItemStatingBounds.height(); floatingItem.setBounds(floatingItemBounds); } //Do auto scrolling at end of list float scrollAmount = 0; if (fingerY > (rv.getHeight() * (1 - autoScrollWindow))) { scrollAmount = (fingerY - (rv.getHeight() * (1 - autoScrollWindow))); } else if (fingerY < (rv.getHeight() * autoScrollWindow)) { scrollAmount = (fingerY - (rv.getHeight() * autoScrollWindow)); } debugLog("Scroll: " + scrollAmount); scrollAmount *= autoScrollSpeed; rv.scrollBy(0, (int) scrollAmount); rv.invalidateItemDecorations();// Redraw } private void setIsDragging(final boolean dragging) { if (dragging != isDragging) { isDragging = dragging; if (dragStateChangedListener != null) { if (isDragging) { dragStateChangedListener.onDragStart(); } else { dragStateChangedListener.onDragStop(); } } } } public void setOnDragStateChangedListener(final OnDragStateChangedListener dragStateChangedListener) { this.dragStateChangedListener = dragStateChangedListener; } @Override public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) { if (floatingItem != null) { floatingItem.setAlpha((int) (255 * floatingItemAlpha)); bgColor.setColor(floatingItemBgColor); c.drawRect(floatingItemBounds, bgColor); floatingItem.draw(c); } } /** * @param position * @return True if we can drag the item over this position, False if not. */ protected boolean canDragOver(int position) { return true; } private BitmapDrawable createFloatingBitmap(View v) { floatingItemStatingBounds = new Rect(v.getLeft(), v.getTop(), v.getRight(), v.getBottom()); floatingItemBounds = new Rect(floatingItemStatingBounds); Bitmap bitmap = Bitmap.createBitmap(floatingItemStatingBounds.width(), floatingItemStatingBounds.height(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); v.draw(canvas); BitmapDrawable retDrawable = new BitmapDrawable(v.getResources(), bitmap); retDrawable.setBounds(floatingItemBounds); return retDrawable; } public interface OnItemMovedListener { void onItemMoved(int from, int to); } public interface OnDragStateChangedListener { void onDragStart(); void onDragStop(); } }