I want to create custom container, that can lay children one by one from bottom with offset. Currently I created such container but I have problems with animation, when view is added to container it should slide from bottom, when view is remove it should slide to bottom. With add animation all fine, but with remove I got some issues, views dont want to go in needed position?
This is onLayout() method:
protected void onLayout(boolean changed, int l, int t, int r, int b) {
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
int offset;
if (i > (itemCount - VISIBLE_ITEMS)) {
offset = (itemCount - i - 1) * this.offset;
}
// we adding invisible items
else {
offset = (VISIBLE_ITEMS - 1) * this.offset;
}
int bottom = getBottom() - offset;
int left = getLeft();
int right = getRight();
int top = bottom - child.getMeasuredHeight();
child.layout(left, top, right, bottom);
}
}
This is method for adding new view:
public void animateAdd(final View view){
addView(view);
final ViewTreeObserver observer = getViewTreeObserver();
observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
observer.removeOnPreDrawListener(this);
AnimatorSet animator = new AnimatorSet();
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
int startY = i == getChildCount() - 1 ? child.getHeight() : offset;
if (isNeedToAnimate(i)) {
Log.d(TAG, "onPreDraw: startY = " + startY);
animator.playTogether(ObjectAnimator.ofFloat(child, TRANSLATION_Y, startY, 0));
animator.playTogether(createColorAnimator(child, i));
}
}
animator.setDuration(300);
animator.start();
return true;
}
});
}
This is method for remove action:
public void animateRemove() {
if (getChildCount() == 0) {
return;
}
final View removeView = getChildAt(getChildCount() - 1);
removeViewInLayout(removeView);
final ViewTreeObserver observer = getViewTreeObserver();
observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
observer.removeOnPreDrawListener(this);
final AnimatorSet animator = new AnimatorSet();
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
int endY = i == getChildCount() - 1 ? child.getHeight() : offset;
if (isNeedToAnimateRemove(i)) {
Animator anim = ObjectAnimator.ofFloat(child, TRANSLATION_Y, endY);
animator.playTogether(anim);
animator.playTogether(createColorAnimator(child, i));
}
}
animator.setDuration(300);
animator.start();
return true;
}
});
}
Related
I have been trying to make a gridview with drag and drop functionality along with one cell of different size. I have already made the the grid drag and drop and its working fine. you can check the code from here
but I want it to be like this and purely dynamic as I will be draging and dropping the other which will be replaced and resized automatically
Updated with new code that accommodates resizing of cells.
Your question refers to GridView but the code you supplied doesn't mention GridView but uses GridLayout instead, so I am assuming that GridLayout is the right layout.
I have put together a demo using a mocked-up layout with one 2x2 tile. I have modified the code that you have supplied to accommodate the 2x2 tile. Other than the code that I added to implement the 2x2 tile, the only other change to MainAcitivity was to the calculateNextIndex method that uses a different way of calculating the index at an (x, y) position. Layouts and the LongPressListener class were also mocked up since they were not supplied.
Here is a video of the demo:
MainActivity.java
public class MainActivity extends AppCompatActivity {
private static final int ITEMS = 10;
private GridLayout mGrid;
private ScrollView mScrollView;
private ValueAnimator mAnimator;
private Boolean isScroll = false;
private GridLayout.Spec m1xSpec = GridLayout.spec(GridLayout.UNDEFINED, 1);
private GridLayout.Spec m2xSpec = GridLayout.spec(GridLayout.UNDEFINED, 2);
private int mBaseWidth;
private int mBaseHeight;
private int mBaseMargin;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mScrollView = (ScrollView) findViewById(R.id.scrollView);
mScrollView.setSmoothScrollingEnabled(true);
mGrid = (GridLayout) findViewById(R.id.grid);
mGrid.setOnDragListener(new DragListener());
final LayoutInflater inflater = LayoutInflater.from(this);
GridLayout.LayoutParams lp;
DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
float dpiToPx = displayMetrics.density;
View view = inflater.inflate(R.layout.item, mGrid, false);
lp = (GridLayout.LayoutParams) view.getLayoutParams();
mBaseWidth = lp.width;
mBaseHeight = lp.height;
mBaseMargin = lp.rightMargin;
for (int i = 0; i < ITEMS; i++) {
final View itemView = inflater.inflate(R.layout.item, mGrid, false);
final TextView text = (TextView) itemView.findViewById(R.id.text);
text.setText(String.valueOf(i + 1));
itemView.setOnLongClickListener(new LongPressListener());
lp = (i == 0) ? make2x2LayoutParams(itemView) : make1x1LayoutParams(itemView);
mGrid.addView(itemView, lp);
}
}
private GridLayout.LayoutParams make2x2LayoutParams(View view) {
GridLayout.LayoutParams lp = (GridLayout.LayoutParams) view.getLayoutParams();
lp.width = mBaseWidth * 2 + 2 * mBaseMargin;
lp.height = mBaseHeight * 2 + 2 * mBaseMargin;
lp.rowSpec = m2xSpec;
lp.columnSpec = m2xSpec;
lp.setMargins(mBaseMargin, mBaseMargin, mBaseMargin, mBaseMargin);
return lp;
}
private GridLayout.LayoutParams make1x1LayoutParams(View view) {
GridLayout.LayoutParams lp = (GridLayout.LayoutParams) view.getLayoutParams();
lp.width = mBaseWidth;
lp.height = mBaseHeight;
lp.setMargins(mBaseMargin, mBaseMargin, mBaseMargin, mBaseMargin);
lp.rowSpec = m1xSpec;
lp.columnSpec = m1xSpec;
return lp;
}
private int mDraggedIndex;
class DragListener implements View.OnDragListener {
#Override
public boolean onDrag(View v, DragEvent event) {
final View view = (View) event.getLocalState();
int index = calculateNextIndex(event.getX(), event.getY());
View child;
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_STARTED:
mDraggedIndex = index;
break;
case DragEvent.ACTION_DRAG_LOCATION:
if (view == v) return true;
// get the new list index
final Rect rect = new Rect();
mScrollView.getHitRect(rect);
final int scrollY = mScrollView.getScrollY();
if (event.getY() - scrollY > mScrollView.getBottom() - 250) {
startScrolling(scrollY, mGrid.getHeight());
} else if (event.getY() - scrollY < mScrollView.getTop() + 250) {
startScrolling(scrollY, 0);
} else {
stopScrolling();
}
child = mGrid.getChildAt(0);
if (index == 0) {
child.setLayoutParams(make1x1LayoutParams(child));
view.setLayoutParams(make2x2LayoutParams(view));
} else if (mDraggedIndex == 0) {
view.setLayoutParams(make1x1LayoutParams(view));
child.setLayoutParams(make2x2LayoutParams(child));
} else {
child.setLayoutParams(make2x2LayoutParams(child));
view.setLayoutParams(make1x1LayoutParams(view));
}
mGrid.removeView(view);
mGrid.addView(view, index);
break;
case DragEvent.ACTION_DROP:
for (int i = 0; i < mGrid.getChildCount(); i++) {
child = mGrid.getChildAt(i);
child.setLayoutParams(make1x1LayoutParams(child));
}
mGrid.removeView(view);
if (index == 0) {
view.setLayoutParams(make2x2LayoutParams(view));
}
mGrid.addView(view, index);
view.setVisibility(View.VISIBLE);
mGrid.getChildAt(0).setLayoutParams(make2x2LayoutParams(mGrid.getChildAt(0)));
break;
case DragEvent.ACTION_DRAG_ENDED:
if (!event.getResult()) {
view.setVisibility(View.VISIBLE);
}
break;
}
return true;
}
}
private void startScrolling(int from, int to) {
if (from != to && mAnimator == null) {
isScroll = true;
mAnimator = new ValueAnimator();
mAnimator.setInterpolator(new OvershootInterpolator());
mAnimator.setDuration(Math.abs(to - from));
mAnimator.setIntValues(from, to);
mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
mScrollView.smoothScrollTo(0, (int) valueAnimator.getAnimatedValue());
}
});
mAnimator.addListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animation) {
isScroll = false;
mAnimator = null;
}
});
mAnimator.start();
}
}
private void stopScrolling() {
if (mAnimator != null) {
mAnimator.cancel();
}
}
private int calculateNextIndexOld(float x, float y) {
// calculate which column to move to
final float cellWidth = mGrid.getWidth() / mGrid.getColumnCount();
final int column = (int) (x / cellWidth);
final float cellHeight = mGrid.getHeight() / mGrid.getRowCount();
final int row = (int) Math.floor(y / cellHeight);
int index = row * mGrid.getColumnCount() + column;
if (index >= mGrid.getChildCount()) {
index = mGrid.getChildCount() - 1;
}
Log.d("MainActivity", "<<<<index=" + index);
return index;
}
private int calculateNextIndex(float x, float y) {
// calculate which column to move to
int index;
for (index = 0; index < mGrid.getChildCount(); index++) {
View child = mGrid.getChildAt(index);
Rect rect = new Rect();
child.getHitRect(rect);
if (x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom) {
break;
}
}
if (index >= mGrid.getChildCount()) {
// Move into empty cell? Calculate based upon uniform cell sizes.
index = calculateNextIndexOld(x, y);
}
if (index >= mGrid.getChildCount()) {
// Can't determine where to put it? Add it to the end.
index = mGrid.getChildCount() - 1;
}
return index;
}
}
If you work with the demo a little, you will see that it is possible to move tiles such that a 1x1 tile gap is opened up. This may be OK, but the code may need to be reworked a little if not.
You can try :
https://github.com/askerov/DynamicGrid
I hope it can help your problem!
I have a custom view inside a NestedScrollView. Every time invalidate is called on the view, the layout scrolls to top of the custom view. I want the scroll position to be unchanged after the view has been redrawn. Any idea how this can be done?
I have tried implementing an onScrollChangeListener and onGlobalLayoutListener in combination to rescroll to the previously scrolled position, but it doesn't work. I have the following code in the onCreateView method of a fragment.
ViewTreeObserver observer = layoutView.getViewTreeObserver();
if (scrollListener != null) {
observer.removeOnScrollChangedListener(scrollListener);
} else {
scrollListener = new ViewTreeObserver.OnScrollChangedListener() {
#Override
public void onScrollChanged() {
scrollX = layoutView.getScrollX();
scrollY = layoutView.getScrollY();
}
};
}
observer.addOnScrollChangedListener(scrollListener);
if (layoutListener != null) {
observer.removeOnGlobalLayoutListener(layoutListener);
} else {
layoutListener = new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (customView != null && scrollY != 0 && getUserVisibleHint()) {
layoutView.setVerticalScrollbarPosition(scrollY);
}
};
}
observer.addOnGlobalLayoutListener(layoutListener);
The following is the code for the onDraw and onMeasure method of the custom view.
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (pieces == null) {
return;
}
int position = 0;
for (int r = 0; r < rows; r++) {
for (int c = 0; c < cols && position < pieces.length; c++) {
Paint paint = (pieces[position] ? complete : empty);
int left = c * stepSize + borderSize + margin;
int right = left + stepSize - borderSize * 2;
int top = r * stepSize + borderSize;
int bottom = top + stepSize - borderSize * 2;
canvas.drawRect(left + borderSize, top + borderSize,
right + borderSize, bottom + borderSize, paint);
++position;
}
}
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
cols = width / stepSize;
rows = (int) Math.ceil((float) cells / (float) cols);
margin = (width - cols * stepSize) / 2;
int height = rows * stepSize;
setMeasuredDimension(width, Math.max(width, height));
}
I have just started using ItemDecoration. I am trying to achieve a divider in the middle of a two-column RecyclerView managed by StaggeredGridLayoutManager.
Here's my ItemDecoration code :
public class LobbyItemDecoration extends RecyclerView.ItemDecoration {
private int margin;
private Drawable drawable;
public LobbyItemDecoration(int margin, Drawable drawable){
this.margin = margin;
this.drawable = drawable;
}
#Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
int position = parent.getChildAdapterPosition(view);
StaggeredGridLayoutManager.LayoutParams lp = (StaggeredGridLayoutManager.LayoutParams)view .getLayoutParams();
int spanIndex = lp.getSpanIndex();
if(position >= 0){
if (position < ((LobiAdapter)parent.getAdapter()).getmDataset().size()){
if(spanIndex == 1){
outRect.left = margin;
((LobiAdapter)parent.getAdapter()).getmDataset().get(position).left = false;
} else {
outRect.right = margin;
((LobiAdapter)parent.getAdapter()).getmDataset().get(position).left = true;
}
outRect.bottom = margin;
}
}
}
#Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (drawable == null) { super.onDrawOver(c, parent, state);return; }
if(parent.getItemAnimator() != null && parent.getItemAnimator().isRunning()) {
return;
}
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i=1; i < childCount; i++) {
final View child = parent.getChildAt(i);
StaggeredGridLayoutManager.LayoutParams lp = (StaggeredGridLayoutManager.LayoutParams)child .getLayoutParams();
int spanIndex = lp.getSpanIndex();
int size = drawable.getIntrinsicWidth();
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
final int ty = (int)(child.getTranslationY() + 0.5f);
final int tx = (int)(child.getTranslationX() + 0.5f);
final int leftIndex1 = child.getLeft() - (margin * 4 / 3) - tx;
final int rightIndex1 = child.getLeft() - (margin * 2 / 3) - tx;
final int leftIndex0 = child.getRight() + (margin * 2 / 3) + tx;
final int rightIndex0 = child.getRight() + (margin * 4 / 3) + tx;
if(spanIndex == 1){
// drawable.setBounds(100, top, 5, bottom);
drawable.setBounds(leftIndex1, top, rightIndex1, bottom);
drawable.draw(c);
} else {
drawable.setBounds(leftIndex0, top, rightIndex0, bottom);
drawable.draw(c);
// drawable.setBounds(5, top, 100, bottom);
}
}
}
}
Problem is as title said, whenever I load new item or scroll, the decoration is sometimes gone or misplaced. By gone I mean, literally gone, it's not there anymore until I scroll down or up to recycle the View.
And by misplaced I mean, when I scroll down, and the loading ViewHolder is in the left column, the divider "sticks" to the left column. If the loading ViewHolder is in the right column, it is normal.
Just in case : I use a ViewHolder to be a progress indicator by adding one null item and check it in getItemViewType() then remove it later after finishing the load from server.
This is how I add :
for (PostModel postModel :
dataSet) {
this.mDataset.add(postModel);
notifyItemInserted(mDataset.size() - 1);
}
StaggeredGridLayoutManager is buggy. For me this helped:
diffResult.dispatchUpdatesTo(this);
recyclerView.postDelayed(() -> {
layoutManager.invalidateSpanAssignments(); // to fix first item in second column issue
recyclerView.invalidateItemDecorations(); // to fix wrong spacing
}, 50);
I am trying to make my own list and therefore I am extending the AdapterView class.
I have overridden the onLayout method to add children, measure them and call the layout method.
my problem is that the onLayout method gets called infinitely and items are duplicated on each call.
I have looked on the Internet and verified that my children are not changing (I have made each child returns an empty view with no dynamic content).
here is my code:
protected void onLayout(final boolean changed, final int left, final int top, final int right,
final int bottom)
{
super.onLayout(changed, left, top, right, bottom);
// If we don't have an adapter yet, do nothing and return
if(mAdapter == null)
{
return;
}
fillList();
positionItems();
}
fillList():
private void fillList()
{
int position = 0;
if(mCurrentList*mNumberItemsPerList > mAdapter.getCount() )
{
mCurrentList= 0;
return ;
}
if(mCurrentList < 0)
{
double lastList = (double)(mAdapter.getCount()/mNumberItemsPerList);
mCurrentList= (int) Math.ceil(lastList);
return ;
}
//this.removeAllViewsInLayout();
while( position+mCurrentList*mNumberItemsPerList < mAdapter.getCount() )
{
// Child view
final View child = mAdapter.getView(position+mCurrentList*mNumberItemsPerList, null, this);
// Add the child and measure its dimensions to calculate the remaining space
addAndMeasureChild(child);
position++;
}
}
addAndMeasureChild():
private void addAndMeasureChild(View child)
{
LayoutParams params = child.getLayoutParams();
if(params == null)
{
params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
}
//child.setLayoutParams(params);
addViewInLayout(child,-1, params);
// measure the dimensions
child.measure(MeasureSpec.EXACTLY | 250,MeasureSpec.EXACTLY | 250);
}
positionItems():
private void positionItems()
{
int left = 0;
int middleItem = mNumberItemsPerList / 2;
for(int index =0; index < getChildCount(); index++)
{
View child = getChildAt(index);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();
int bottom= (getHeight()-height)/2;
if(index < middleItem)
{
child.layout(left+15, 70+(middleItem-index)*30, left+width, 70+(middleItem-index)*30+height);
}
if(index == middleItem)
{
child.layout(left+15, 70, left+width, 70+height);
}
if(index > middleItem)
{
int diff = index -middleItem;
child.layout(left+15, 70+(middleItem-(index - (middleItem*diff)))*30, left+width, 70+(middleItem-(index - (middleItem*diff)))*30+height);
}
left += width;
}
}
and this is the getView of my child:
public View getView(final int position, final View convertView, final ViewGroup parent)
{
View view = convertView;
if (view == null) {
view = LayoutInflater.from(getContext()).inflate(R.layout.cat_item_layout, null);
}
return view;
}
I've figured out what was causing the infinite call to onLayout.
on my main layout I have added a clock with this custom view inside a relative layout.
I don't know why but the clock (which is updated every second) causes my view to call onLayout again.
To understand this question, first read how this method works.
I am trying to implements a drag and drop ListView, it's going alright but have run into
a road block. So I don't have to handled everything, I am intercepting(but returning false) MotionEvents sent to the ListView, letting it handle scrolling and stuff. When I want to start dragging a item, I then return true and handled all the dragging stuff. Everything is working fine except for one thing. The drag(drag and drop) is started when it is determined that a long press as a occurred(in onInterceptTouchEvent). I get the Bitmap for the image that I drag around like so. itemPositition being the index of the item that was selected.
(omitting irrelevant parts)
...
View dragItem = mListView.getChildAt(itemPosition);
dragItem.setDrawingCacheEnabled(true);
Bitmap bitmap = Bitmap.createBitmap(dragItem.getDrawingCache());
mDragImage = new ImageView(mContext);
mDragImage.setImageBitmap(bitmap);
...
The problem is, mDragImage is a solid black like this.
But, if I don't let ListView handle anything. As in, I start the drag on ACTION_DOWN and stop on ACTION_UP, mDragImage looks has expected(but I obviously lose scrolling abilities).
Since the drag is started with a long press, the ListView is given the opportunity to do things before the long press occurs. This is my guess as to why this is happening. When a item is pressed, it is highlighted by the ListView. Somewhere in doing so, it is messing with the bitmap. So when I go to get it, it's in a weird state(all black).
I see two options for fixing this, neither of which I know how to do.
Create a image from scratch.
Handle the highlighting myself(if that is the problem).
Option two seems a better one to me, except that I looked at the documentation and the source code and could not find out how to do so. Here are some things I have done/tried.
I set setOnItemClickListener(...) and
setOnItemSelectedListener(...) with a empty method(highlighting
still happens). (Before anyone suggests it, calling
setOnClickListener results in a runtime error.)
I also looked into trying to get the ListView to make a new item
(for option 2), but could not find a way.
Spent 45ish minutes looking through the source code and
documentation trying to pinpoint where the highlighting was
happening(I never found it).
Any help fixing this would be appreciated.
(EDIT1 START)
So I don't actually know if onLongClickListener is working, I made an error before thinking it was. I am trying to set it up right now, will update when I find out if it does.
(EDIT1 END)
Last minute edit before post. I tried using onLongClickListener just now, and the image is good. I would still like to know if there is another way. How I have to use onLongClickListener to get things working is ugly, but it works. I also spent so much time trying to figure this out, it would be nice to find out the answer. I still want to be able to change/handle the highlight color, the default orangeish color is not pretty. Oh and sorry about the length of the post. I could not think of way of making it shorter, while supplying all the information I thought was needed.
use this code, it's allows operation drug and drop in ListView:
public class DraggableListView extends ListView {
private static final String LOG_TAG = "tasks365";
private static final int END_OF_LIST_POSITION = -2;
private DropListener mDropListener;
private int draggingItemHoverPosition;
private int dragStartPosition; // where was the dragged item originally
private int mUpperBound; // scroll the view when dragging point is moving out of this bound
private int mLowerBound; // scroll the view when dragging point is moving out of this bound
private int touchSlop;
private Dragging dragging;
private GestureDetector longPressDetector;
public DraggableListView(Context context, AttributeSet attrs) {
this(context, attrs, android.R.attr.listViewStyle);
}
public DraggableListView(final Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
touchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
longPressDetector = new GestureDetector(getContext(), new SimpleOnGestureListener() {
#Override
public void onLongPress(final MotionEvent e) {
int x = (int) e.getX();
final int y = (int) e.getY();
int itemnum = pointToPosition(x, y);
if (itemnum == AdapterView.INVALID_POSITION) {
return;
}
if (dragging != null) {
dragging.stop();
dragging = null;
}
final View item = getChildAt(itemnum - getFirstVisiblePosition());
item.setPressed(false);
dragging = new Dragging(getContext());
dragging.start(y, ((int) e.getRawY()) - y, item);
draggingItemHoverPosition = itemnum;
dragStartPosition = draggingItemHoverPosition;
int height = getHeight();
mUpperBound = Math.min(y - touchSlop, height / 3);
mLowerBound = Math.max(y + touchSlop, height * 2 / 3);
}
});
setOnItemLongClickListener(new OnItemLongClickListener() {
#SuppressWarnings("unused")
public boolean onItemLongClick(AdapterView<?> paramAdapterView, View paramView, int paramInt, long paramLong) {
// Return true to let AbsListView reset touch mode
// Without this handler, the pressed item will keep highlight.
return true;
}
});
}
/* pointToPosition() doesn't consider invisible views, but we need to, so implement a slightly different version. */
private int myPointToPosition(int x, int y) {
if (y < 0) {
return getFirstVisiblePosition();
}
Rect frame = new Rect();
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
child.getHitRect(frame);
if (frame.contains(x, y)) {
return getFirstVisiblePosition() + i;
}
}
if ((x >= frame.left) && (x < frame.right) && (y >= frame.bottom)) {
return END_OF_LIST_POSITION;
}
return INVALID_POSITION;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
if (longPressDetector.onTouchEvent(ev)) {
return true;
}
if ((dragging == null) || (mDropListener == null)) {
// it is not dragging, or there is no drop listener
return super.onTouchEvent(ev);
}
int action = ev.getAction();
switch (ev.getAction()) {
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
dragging.stop();
dragging = null;
if (mDropListener != null) {
if (draggingItemHoverPosition == END_OF_LIST_POSITION) {
mDropListener.drop(dragStartPosition, getCount() - 1);
} else if (draggingItemHoverPosition != INVALID_POSITION) {
mDropListener.drop(dragStartPosition, draggingItemHoverPosition);
}
}
resetViews();
break;
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
int x = (int) ev.getX();
int y = (int) ev.getY();
dragging.drag(x, y);
int position = dragging.calculateHoverPosition();
if (position != INVALID_POSITION) {
if ((action == MotionEvent.ACTION_DOWN) || (position != draggingItemHoverPosition)) {
draggingItemHoverPosition = position;
doExpansion();
}
scrollList(y);
}
break;
}
return true;
}
private void doExpansion() {
int expanItemViewIndex = draggingItemHoverPosition - getFirstVisiblePosition();
if (draggingItemHoverPosition >= dragStartPosition) {
expanItemViewIndex++;
}
// Log.v(LOG_TAG, "Dragging item hovers over position " + draggingItemHoverPosition + ", expand item at index "
// + expanItemViewIndex);
View draggingItemOriginalView = getChildAt(dragStartPosition - getFirstVisiblePosition());
for (int i = 0;; i++) {
View itemView = getChildAt(i);
if (itemView == null) {
break;
}
ViewGroup.LayoutParams params = itemView.getLayoutParams();
int height = LayoutParams.WRAP_CONTENT;
if (itemView.equals(draggingItemOriginalView)) {
height = 1;
} else if (i == expanItemViewIndex) {
height = itemView.getHeight() + dragging.getDraggingItemHeight();
}
params.height = height;
itemView.setLayoutParams(params);
}
}
/**
* Reset view to original height.
*/
private void resetViews() {
for (int i = 0;; i++) {
View v = getChildAt(i);
if (v == null) {
layoutChildren(); // force children to be recreated where needed
v = getChildAt(i);
if (v == null) {
break;
}
}
ViewGroup.LayoutParams params = v.getLayoutParams();
params.height = LayoutParams.WRAP_CONTENT;
v.setLayoutParams(params);
}
}
private void resetScrollBounds(int y) {
int height = getHeight();
if (y >= height / 3) {
mUpperBound = height / 3;
}
if (y <= height * 2 / 3) {
mLowerBound = height * 2 / 3;
}
}
private void scrollList(int y) {
resetScrollBounds(y);
int height = getHeight();
int speed = 0;
if (y > mLowerBound) {
// scroll the list up a bit
speed = y > (height + mLowerBound) / 2 ? 16 : 4;
} else if (y < mUpperBound) {
// scroll the list down a bit
speed = y < mUpperBound / 2 ? -16 : -4;
}
if (speed != 0) {
int ref = pointToPosition(0, height / 2);
if (ref == AdapterView.INVALID_POSITION) {
//we hit a divider or an invisible view, check somewhere else
ref = pointToPosition(0, height / 2 + getDividerHeight() + 64);
}
View v = getChildAt(ref - getFirstVisiblePosition());
if (v != null) {
int pos = v.getTop();
setSelectionFromTop(ref, pos - speed);
}
}
}
public void setDropListener(DropListener l) {
mDropListener = l;
}
public interface DropListener {
void drop(int from, int to);
}
class Dragging {
private Context context;
private WindowManager windowManager;
private WindowManager.LayoutParams mWindowParams;
private ImageView mDragView;
private Bitmap mDragBitmap;
private int coordOffset;
private int mDragPoint; // at what offset inside the item did the user grab it
private int draggingItemHeight;
private int x;
private int y;
private int lastY;
public Dragging(Context context) {
this.context = context;
windowManager = (WindowManager) context.getSystemService("window");
}
/**
* #param y
* #param offset - the difference in y axis between screen coordinates and coordinates in this view
* #param view - which view is dragged
*/
public void start(int y, int offset, View view) {
this.y = y;
lastY = y;
this.coordOffset = offset;
mDragPoint = y - view.getTop();
draggingItemHeight = view.getHeight();
mDragView = new ImageView(context);
mDragView.setBackgroundResource(android.R.drawable.alert_light_frame);
// Create a copy of the drawing cache so that it does not get recycled
// by the framework when the list tries to clean up memory
view.setDrawingCacheEnabled(true);
mDragBitmap = Bitmap.createBitmap(view.getDrawingCache());
mDragView.setImageBitmap(mDragBitmap);
mWindowParams = new WindowManager.LayoutParams();
mWindowParams.gravity = Gravity.TOP;
mWindowParams.x = 0;
mWindowParams.y = y - mDragPoint + coordOffset;
mWindowParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
mWindowParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
| WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN;
mWindowParams.format = PixelFormat.TRANSLUCENT;
mWindowParams.windowAnimations = 0;
windowManager.addView(mDragView, mWindowParams);
}
public void drag(int x, int y) {
lastY = this.y;
this.x = x;
this.y = y;
mWindowParams.y = y - mDragPoint + coordOffset;
windowManager.updateViewLayout(mDragView, mWindowParams);
}
public void stop() {
if (mDragView != null) {
windowManager.removeView(mDragView);
mDragView.setImageDrawable(null);
mDragView = null;
}
if (mDragBitmap != null) {
mDragBitmap.recycle();
mDragBitmap = null;
}
}
public int getDraggingItemHeight() {
return draggingItemHeight;
}
public int calculateHoverPosition() {
int adjustedY = (int) (y - mDragPoint + (Math.signum(y - lastY) + 2) * draggingItemHeight / 2);
// Log.v(LOG_TAG, "calculateHoverPosition(): lastY=" + lastY + ", y=" + y + ", adjustedY=" + adjustedY);
int pos = myPointToPosition(0, adjustedY);
if (pos >= 0) {
if (pos >= dragStartPosition) {
pos -= 1;
}
}
return pos;
}
}
}