I have button instead of floating action button i want to anchor it with snack bar as it anchor with floating action bar like floating action button moves up when snack bar is shown, with floating action bar we do it like this:
Snackbar.make(fab, s, Snackbar.LENGTH_SHORT);
how can I do with simple button as snackbar and button don't know snackbar presence and vice versa and moves independently
Thanks
The Docs say this
Having a CoordinatorLayout in your view hierarchy allows Snackbar to enable certain features, such as swipe-to-dismiss and automatically moving of widgets like FloatingActionButton.
So as you long as your button is directly under the Coordinator Layout and you pass the button to the Snackbar like this
Snackbar.make(yourButton, s, Snackbar.LENGTH_SHORT); . The moving of widgets upwards should work.
You have to attach a Behavior to the View you want to move along with Snakebar movement
In here I make a custom View and attach the behavior to it
#CoordinatorLayout.DefaultBehavior(CustomView.Behavior.class)
public class CustomView extends View {
public CustomView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
}
public static class Behavior extends CoordinatorLayout.Behavior<CustomView> {
public Behavior() {
super();
}
public Behavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public void onAttachedToLayoutParams(#NonNull CoordinatorLayout.LayoutParams lp) {
if (lp.dodgeInsetEdges == Gravity.NO_GRAVITY) {
// This setting makes it works (learn from FloatingActionButton.Behavior)
lp.dodgeInsetEdges = Gravity.BOTTOM;
}
}
#Override
public boolean onDependentViewChanged(CoordinatorLayout parent, CustomView child,
View dependency) {
return false;
}
}
}
Use this CustomView in your layout and it should work
The FloatingActionButton does the same thing, it has an inner Behavior which do many more things with the shadow padding, show/hide base on AppBarLayout movement. Every movement in CoordinatorLayout base on its Behavior mechanism
Ref here: http://saulmm.github.io/mastering-coordinator
P/S: About Snakebar.make usage, pass the CoordinatorLayout into view parameter, don't pass any other components, that will save the system performance. If you look at the Snakebar code, it has a loop, uses the view parameter to find the root view. The root view is what it wants:
private static ViewGroup findSuitableParent(View view) {
ViewGroup fallback = null;
do {
if (view instanceof CoordinatorLayout) {
// We've found a CoordinatorLayout, use it
return (ViewGroup) view;
} else if (view instanceof FrameLayout) {
if (view.getId() == android.R.id.content) {
// If we've hit the decor content view, then we didn't find a CoL in the
// hierarchy, so use it.
return (ViewGroup) view;
} else {
// It's not the content view but we'll use it as our fallback
fallback = (ViewGroup) view;
}
}
if (view != null) {
// Else, we will loop and crawl up the view hierarchy and try to find a parent
final ViewParent parent = view.getParent();
view = parent instanceof View ? (View) parent : null;
}
} while (view != null);
// If we reach here then we didn't find a CoL or a suitable content view so we'll fallback
return fallback;
}
Related
I have fragment from which I'm launching activity with shared element transition that has viewpager in it, the enter transition works fine but when i scroll in view pager and finish transition the shared image comes from left side which is not desired it should reposition itself to where it was launched, here is my code:
Intent myIntent = new Intent(getActivity(), EnlargeActivity.class);
ActivityOptionsCompat options = ActivityOptionsCompat.
makeSceneTransitionAnimation(getActivity(),
imageView,
ViewCompat.getTransitionName(imageView));
startActivity(myIntent, options.toBundle());
I'm updating view and its name in activity that contains viewpager when finishing activity, but its going with blink:
public void finishAfterTransition() {
setEnterSharedElementCallback(new SharedElementCallback() {
#Override
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
// Clear all current shared views and names
names.clear();
sharedElements.clear();
ViewGroup viewGroup = (ViewGroup) viewPagerDetail.getAdapter()
.instantiateItem(viewPagerDetail, viewPagerDetail.getCurrentItem());
if (viewGroup == null) {
return;
}
// Map the first shared element name to the child ImageView.
sharedElements.put(viewGroup.findViewById(R.id.img).getTransitionName(), viewGroup.findViewById(R.id.img));
// setExitSharedElementCallback((SharedElementCallback) this);
}
});
super.finishAfterTransition();
Basically, Android start the transition with your pre-defined View and transitionName and automatically use the same properties for the return transition. When you change your focused View in ViewPager, Android doesn't know about that and keep the transition on the previous one on its way back. So you need to inform Android about the changes:
Remap the transition properties: Use setEnterSharedElementCallback to change the transitionName and View to the new one before returning from Activity2.
Wait for the Activity1 to finish rendering addOnPreDrawListener.
It's a bit complex in the final implementation. But you can look at my sample code https://github.com/tamhuynhit/PhotoGallery. I try to implement the shared-element-transition from many simple to complex sections.
Your problem appeared from Level 3 and solved in Level 4.
I am writing a tutorial about this but it's not in English so hope the code can help
UPDATE 1: Work flow
Here is how I implement it in my code:
Override finishAfterTransition in Activity2 and call setEnterSharedElementCallback method to re-map the current selected item in ViewPager. Also, call setResult to pass the new selected index back to previous activity here.
#Override
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public void finishAfterTransition() {
setEnterSharedElementCallback(new SharedElementCallback() {
#Override
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
View selectedView = getSelectedView();
if (selectedView == null)
return;
// Clear all current shared views and names
names.clear();
sharedElements.clear();
// Store new selected view and name
String transitionName = ViewCompat.getTransitionName(selectedView);
names.add(transitionName);
sharedElements.put(transitionName, selectedView);
setExitSharedElementCallback((SharedElementCallback) null);
}
});
Intent intent = new Intent();
intent.putExtra(PHOTO_FOCUSED_INDEX, mCurrentIndex);
setResult(RESULT_PHOTO_CLOSED, intent);
super.finishAfterTransition();
}
Write a custom ShareElementCallback so I can set the callback before knowing which View is going to be used.
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static class CustomSharedElementCallback extends SharedElementCallback {
private View mView;
/**
* Set the transtion View to the callback, this should be called before starting the transition so the View is not null
*/
public void setView(View view) {
mView = view;
}
#Override
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {
// Clear all current shared views and names
names.clear();
sharedElements.clear();
// Store new selected view and name
String transitionName = ViewCompat.getTransitionName(mView);
names.add(transitionName);
sharedElements.put(transitionName, mView);
}
}
Override onActivityReenter in Activity1, get the selected index from the result Intent. Set setExitSharedElementCallback to re-map new selected View when the transition begins.Call supportPostponeEnterTransition to delay a bit because your new View may not be rendered at this point. Use getViewTreeObserver().addOnPreDrawListener to listen for the layout changes, find the right View by the selected index and continue the transition supportStartPostponedEnterTransition.
#Override
#TargetApi(Build.VERSION_CODES.LOLLIPOP)
public void onActivityReenter(int resultCode, Intent data) {
if (resultCode != LevelFourFullPhotoActivity.RESULT_PHOTO_CLOSED || data == null)
return;
final int selectedIndex = data.getIntExtra(LevelFourFullPhotoActivity.PHOTO_FOCUSED_INDEX, -1);
if (selectedIndex == -1)
return;
// Scroll to the new selected view in case it's not currently visible on the screen
mPhotoList.scrollToPosition(selectedIndex);
final CustomSharedElementCallback callback = new CustomSharedElementCallback();
getActivity().setExitSharedElementCallback(callback);
// Listen for the transition end and clear all registered callback
getActivity().getWindow().getSharedElementExitTransition().addListener(new Transition.TransitionListener() {
#Override
public void onTransitionStart(Transition transition) {}
#Override
public void onTransitionPause(Transition transition) {}
#Override
public void onTransitionResume(Transition transition) {}
#Override
public void onTransitionEnd(Transition transition) {
removeCallback();
}
#Override
public void onTransitionCancel(Transition transition) {
removeCallback();
}
private void removeCallback() {
if (getActivity() != null) {
getActivity().getWindow().getSharedElementExitTransition().removeListener(this);
getActivity().setExitSharedElementCallback((SharedElementCallback) null);
}
}
});
// Pause transition until the selected view is fully drawn
getActivity().supportPostponeEnterTransition();
// Listen for the RecyclerView pre draw to make sure the selected view is visible,
// and findViewHolderForAdapterPosition will return a non null ViewHolder
mPhotoList.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
mPhotoList.getViewTreeObserver().removeOnPreDrawListener(this);
RecyclerView.ViewHolder holder = mPhotoList.findViewHolderForAdapterPosition(selectedIndex);
if (holder instanceof ViewHolder) {
callback.setView(((ViewHolder) holder).mPhotoImg);
}
// Continue the transition
getActivity().supportStartPostponedEnterTransition();
return true;
}
});
}
UPDATE 2: getSelectedItem
To get selected View from the ViewPager, don't use getChildAt or you get the wrong View, use findViewWithTag instead
In the PagerAdapter.instantiateItem, use position as tag for each View:
#Override
public View instantiateItem(ViewGroup container, int position) {
// Create the View
view.setTag(position)
// ...
}
Listen to onPageSelected event to get the selected index:
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
mSelectedIndex = position;
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
Call getSelectedView to get the current view by the selected index
private View getSelectedView() {
try {
return mPhotoViewPager.findViewWithTag(mSelectedIndex);
} catch (IndexOutOfBoundsException | NullPointerException ex) {
return null;
}
}
This is actually a default behavior, I was struggling SharedElementTransitions a lot, but I have nested fragments. I got my solution from an article (very recent article), it shows an implementation with a RecyclerView, which I assume you have. In short, the solution is to override onLayoutChange :
recyclerView.addOnLayoutChangeListener(
new OnLayoutChangeListener() {
#Override
public void onLayoutChange(View view,
int left,
int top,
int right,
int bottom,
int oldLeft,
int oldTop,
int oldRight,
int oldBottom) {
recyclerView.removeOnLayoutChangeListener(this);
final RecyclerView.LayoutManager layoutManager =
recyclerView.getLayoutManager();
View viewAtPosition =
layoutManager.findViewByPosition(MainActivity.currentPosition);
// Scroll to position if the view for the current position is null (not
// currently part of layout manager children), or it's not completely
// visible.
if (viewAtPosition == null
|| layoutManager.isViewPartiallyVisible(viewAtPosition, false, true)){
recyclerView.post(()
-> layoutManager.scrollToPosition(MainActivity.currentPosition));
}
}
});
Here is the article, and you will also find the project on GitHub.
I'm using listview custom adapter which with row click i'm changing row color. But when i'm scrolling bot and up again it doesnt have the right position.
It changes color in other rows...
public override View GetView(int position, View convertView, ViewGroup parent)
{
DataViewHolder holder = null;
if (convertView == null)
{
convertView = LayoutInflater.From(mContext).Inflate(Resource.Layout.TableItems, null, false);
holder = new DataViewHolder();
holder.txtDescription = convertView.FindViewById<TextView>(Resource.Id.txtDescription);
holder.txtDescription.Click += delegate
{
holder.txtDescription.SetBackgroundColor(Color.Red);
};
convertView.Tag = holder;
}
else
{
holder = convertView.Tag as DataViewHolder;
}
holder.txtDescription.Text = mitems[position].Description;
return convertView;
}
public class DataViewHolder : Java.Lang.Object
{
public TextView txtDescription { get; set; }
}
It looks like it doesnt keep in memory specific row situation.
Don't change the color in the click handler directly, instead change the data from which the adapter draws from and use that to change the color when GetView is called again.
ListView recycles the views it uses to optimize scrolling, instead it just expects the view to represent the data. If you change a color of one view directly, the view then gets recycled and you'll see "another view" (another part of the data) with a different background color.
So in summary: give each data point a color attribute and use that to set the color of each view in GetView, change the data and notify the adapter about the changes to the data.
Edit
I've never used Xamarin but maybe something like this would work
public override View GetView(int position, View convertView, ViewGroup parent)
{
DataViewHolder holder = null;
if (convertView == null)
{
convertView = LayoutInflater.From(mContext).Inflate(Resource.Layout.TableItems, null, false);
holder = new DataViewHolder();
holder.txtDescription = convertView.FindViewById<TextView>(Resource.Id.txtDescription);
holder.txtDescription.Click += delegate
{
// instead of setting the color directly here, just modify the data
(holder.txtDescription.Tag as ItemType).ItemColor = Color.Red
notifyDataSetChanged();
};
convertView.Tag = holder;
}
else
{
holder = convertView.Tag as DataViewHolder;
}
holder.txtDescription.Text = mitems[position].Description;
holder.txtDescription.Tag = mitems[position]; // this so that the click handler knows which item to modify
holder.txtDescription.SetBackgroundColor(mitems[position].ItemColor);
return convertView;
}
public class DataViewHolder : Java.Lang.Object
{
public TextView txtDescription { get; set; }
}
ListView will reuse the item layout, you can use List and View.Tag to avoid the problem caused by reusing.
I have posted my demo on github.
I want to achieve the following abilities:
Select only one child View inside a GridLayout each time by long clicking it.
A click on the GridLayout or any ancestor parent in the visual hierarchy will deselected selected child View if one already selected.
The problem is when when registering a View.OnLongClickListener callback to child View, neither parent GridLayout nor any ancestor registered callbacks (either View.OnClickListener or View.onTouchEvent) called when clicking on them.
How can I get a selected child inside a GridLayout similar to either AdapterView.OnItemSelectedListener or AdapterView.OnItemLongClickListener and solve the above mentioned problem?
What about storing a "selected" view as a global variable, and removing it when its focus changes? By playing with focusable, focusableInTouchMode and onClick listeners, you could have the right results. I'm not sure that's the best solution, but it works.
What you will need:
A global View variable: the GridLayout's child long clicked, as selected.
(optional) A custom parent container as any ViewGroup: it will set the focusable listeners on all its children [*]. In my tests, I used a LinearLayout and a RelativeLayout.
[*] If you don't use the optional parent custom Class, you have to set android:focusable="true" and android:focusableInTouchMode="true" on all children of the parent ViewGroup. And you'll have to set OnClickListener in order to call removeViewSelected() when the parent ViewGroup is clicked.
Adding Click listeners for GridLayout children: which updates the selected view.
Implementing a Focus listener: which removes the selected view if it's losing focus.
It will handle all focus change state on parent and child hierarchy, see the output:
I used the following pattern:
CoordinatorLayout --- simple root group
ParentLayout --- aka "parentlayout"
Button --- simple Button example
GridLayout --- aka "gridlayout"
FloattingActionButton --- simple Button example
Let's preparing the selected View and its update methods in the Activity:
private View selectedView;
...
private void setViewSelected(View view) {
removeViewSelected();
selectedView = view;
if (selectedView != null) {
// change to a selected background for example
selectedView.setBackgroundColor(
ContextCompat.getColor(this, R.color.colorAccent));
}
}
private View getViewSelected() {
if (selectedView != null) {
return selectedView;
}
return null;
}
private void removeViewSelected() {
if (selectedView != null) {
// reset the original background for example
selectedView.setBackgroundResource(R.drawable.white_with_borders);
selectedView = null;
}
// clear and reset the focus on the parent
parentlayout.clearFocus();
parentlayout.requestFocus();
}
On each GridLayout child, add the Click and LongClick listeners to update or remove the selected view. Mine were TextViews added dynamically, but you could easily create a for-loop to retrieve the children:
TextView tv = new TextView(this);
...
gridlayout.addView(tv);
tv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
removeViewSelected();
}
});
tv.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
setViewSelected(view);
return true;
}
});
Set the FocusChange listener on the parent container:
parentlayout.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View view, boolean hasFocus) {
View viewSelected = getViewSelected();
// if the selected view exists and it lost focus
if (viewSelected != null && !viewSelected.hasFocus()) {
// remove it
removeViewSelected();
}
}
});
Then, the optional custom ViewGroup: it's optional because you could set the focusable state by XML and the clickable listener dynamically, but it seems easier to me. I used this following custom Class as parent container:
public class ParentLayout extends RelativeLayout implements View.OnClickListener {
public ParentLayout(Context context) {
super(context);
init();
}
public ParentLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public ParentLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
// handle focus and click states
public void init() {
setFocusable(true);
setFocusableInTouchMode(true);
setOnClickListener(this);
}
// when positioning all children within this
// layout, add their focusable state
#Override
protected void onLayout(boolean c, int l, int t, int r, int b) {
super.onLayout(c, l, t, r, b);
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
child.setFocusable(true);
child.setFocusableInTouchMode(true);
}
// now, even the Button has a focusable state
}
// handle the click events
#Override
public void onClick(View view) {
// clear and set the focus on this viewgroup
this.clearFocus();
this.requestFocus();
// now, the focus listener in Activity will handle
// the focus change state when this layout is clicked
}
}
For example, this is the layout I used:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout ...>
<com.app.ParentLayout
android:id="#+id/parent_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal">
<Button
android:id="#+id/sample_button"
android:layout_width="250dp"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
android:text="A Simple Button"
android:layout_marginTop="20dp"
android:layout_marginBottom="20dp"/>
<android.support.v7.widget.GridLayout
android:id="#+id/grid_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerHorizontal="true"
android:layout_above="#id/sample_button" .../>
</com.app.ParentLayout>
<android.support.design.widget.FloatingActionButton .../>
</android.support.design.widget.CoordinatorLayout>
Hope this will be useful.
Use the following code :
int last_pos = -1;
GridLayout gridLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridLayout = (GridLayout) findViewById(R.id.gridLayout);
int child_count = gridLayout.getChildCount();
for(int i =0;i<child_count;i++){
gridLayout.getChildAt(i).setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
//Deselect previous
if(last_pos!=-1) gridLayout.getChildAt(last_pos).setSelected(false);
//Select the one you clicked
view.setSelected(true);
last_pos = gridLayout.indexOfChild(view);
return false;
}
});
}
//Remove focus if the parent is clicked
gridLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
gridLayout.getChildAt(last_pos).setSelected(false);
}
});
This is my code:
clientGridView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
gridClientChooseMode = !gridClientChooseMode;
clientAdapter.notifyDataSetChanged();
return false;
}
};)
and this is the adapter for the gridview:
class ClientListAdapter extends ArrayAdapter<ClientData> {
public ClientListAdapter(Context context, List<ClientData> list) {
super(context, R.layout.view_item, list);
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (gridClientChooseMode) {
checkBox.setVisibility(View.VISIBLE);
}else{
checkBox.setVisibility(View.GONE);
}
}
}
checkBox will change its visibility to VISIBLE when gridClientChooseMode=true (when long click on item of the gridview).But after that I cannot turn off the check box because the OnItemLongClickListener didn't work anymore, I mean it works only at first time. Any help is highly appreaciate. Thanks in adavance.
#Elltz is right about the CheckBoxes stealing focus. In the layout root view for you grid items, you need the following to prevent the CheckBoxes from getting focus:
android:descendantFocusability="blocksDescendants"
whiles checkbox is visible it takes away the focus, so either you do put your onlongitemclick listener functions in your checkbox widget onlongclicklistener in your adapter, so it responds to itself and set itself to gone or invisible or you intercept touch events for the grid or listview, and handle all focus/touch events
So I had my listview working perfectly then I decided to add a context menu. As soon as I did that whenever I normal clicked an item in my listview, the entire list gets inverted on the first click. Subsequent clicks do nothing to the order, but when the first item is de-selected again the list returns to normal. When I take out the context menu logic that I added, the list view problem does not go away.
I've attached a debugger and the elements in my list adapter are never reordered, and the ListView itself is never set to reverse with .setStackFromBottom()
Here is my onClick listener registered to handle the click events of the list view items:
public void onClick(View v) {
ViewHolder holder = (ViewHolder) v.getTag();
CheckBox b = holder.box;
Boolean check = b.isChecked();
b.setChecked(!check);
if (!check) {
mChecked.add(holder.fu);
if (mChecked.size() == 1) {
buttonLayout.setVisibility(View.VISIBLE);
}
} else {
mChecked.remove(holder.fu);
if (mChecked.size() == 0) {
buttonLayout.setVisibility(View.GONE);
}
}
}
The viewholder class just holds references to objects I use in the listview for optimizations. I cannot figure out why this is causing my list to invert when displayed, I've tried moving the listener to a different view in the layout, I've tried re-writing the listener, nothing seems to work! Any advice would be appreciated.
Edit: here is the code for the view holder
/** Class to provide a holder for ListViews. Used for optimization */
private class ViewHolder {
TextView date;
TextView gallons;
TextView cost;
TextView cpg;
TextView mpg;
CheckBox box;
FillUp fu;
}
as well as the adapter:
public class FillUpAdapter extends BaseAdapter {
ArrayList<FillUp> mElements;
ArrayList<FillUp> mChecked;
Context mContext;
public FillUpAdapter(Context c, ArrayList<FillUp> data) {
mContext = c;
mElements = data;
mChecked = new ArrayList<FillUp>();
}
public void clearChecked() {
mChecked.clear();
}
public ArrayList<FillUp> getChecked() {
return mChecked;
}
public boolean remove(FillUp f) {
mChecked.remove(f);
return mElements.remove(f);
}
#Override
public int getCount() {
return mElements.size();
}
#Override
public Object getItem(int arg0) {
return mElements.get(arg0);
}
#Override
public long getItemId(int arg0) {
return mElements.get(arg0).getId();
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout layout;
ViewHolder holder;
if (convertView != null) {
layout = (LinearLayout) convertView;
holder = (ViewHolder) layout.getTag();
} else {
layout = (LinearLayout) LayoutInflater.from(mContext).inflate(
R.layout.fillup_list_item, parent, false);
holder = new ViewHolder();
holder.cost = (TextView) layout
.findViewById(R.id.fillUpListTotalValue);
holder.cpg = (TextView) layout
.findViewById(R.id.fillUpListCostPerGal);
holder.gallons = (TextView) layout
.findViewById(R.id.fillUpListGalValue);
holder.mpg = (TextView) layout
.findViewById(R.id.fillUpMPGText);
holder.date = (TextView) layout
.findViewById(R.id.fillUpListDate);
holder.box = (CheckBox) layout
.findViewById(R.id.fillUpListCheckBox);
holder.fu = (FillUp) getItem(position);
layout.setTag(holder);
}
holder.date.setText(holder.fu.getDate());
holder.gallons.setText(holder.fu.getGallonsText());
holder.cpg.setText(holder.fu.getCostText());
holder.cost.setText(holder.fu.getTotalText());
holder.mpg.setText(String.format("%03.1f MPG",holder.fu.getMPG()));
if (convertView != null) {
holder.box.setChecked(mChecked.contains(holder.fu));
}
layout.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
ViewHolder holder = (ViewHolder) v.getTag();
CheckBox b = holder.box;
Boolean check = b.isChecked();
b.setChecked(!check);
if (!check) {
mChecked.add(holder.fu);
if (mChecked.size() == 1) {
buttonLayout.setVisibility(View.VISIBLE);
}
} else {
mChecked.remove(holder.fu);
if (mChecked.size() == 0) {
buttonLayout.setVisibility(View.GONE);
}
}
}
});
return layout;
}
}
UPDATE:
Ok, so I've narrowed it down to the visibility change on the buttonLayout view, which is a linear layout of buttons on the bottom of the Activity's layout, underneath the ListView. Whenever I change that view's visibility to View.VISIBLE (which happens when the first item is checked) the list's order is reversed. The order is restored when the view's visibility is set to View.GONE
I have no idea what would cause that though :(
After narrowing the scope a bit more, I discovered the problem was not the changing of the visibility of my button bar, but actually the passing around of FillUp objects in holder.fu of my ViewHolder class. By changing that to instead reference the adapter's getItem(position) method, everything seemed to work out. Quite an odd bug, since the adapter itself was not having the order of the elements changed, but passing around a reference to the object made it very unhappy.
If your listview background color changes when you click on it, I think it is about your theme. Just play with the cache color parameters of your listview, here is an example:
<ListView
android:layout_width="fill_parent"
android:id="#android:id/list"
android:scrollingCache="true"
android:persistentDrawingCache="all"
android:cacheColorHint="#0000"
android:layout_height="wrap_content"
android:fastScrollEnabled="true"
android:stackFromBottom="true"
android:smoothScrollbar="true"
android:paddingTop="115dip">
</ListView>