Why are my screenshots only black? - screenshot

could someone tell me why my screenshots are only black? I am still learning and couldnt find a clue why they are only black.
This is my Utility class
static class XNAUtilities
{
private static RenderTarget2D ssTexture;
private static KeyboardState currentState, previousState;
private static int counter;
public static void TakeScreenShot(GraphicsDevice device, Keys theKey)
{
// Take Screenshot
currentState = Keyboard.GetState();
if (currentState.IsKeyDown(theKey) && previousState.IsKeyUp(theKey))
{
//device.SetRenderTarget(null);
PresentationParameters pparameters = device.PresentationParameters;
ssTexture = new RenderTarget2D(device, pparameters.BackBufferWidth, pparameters.BackBufferHeight, false, SurfaceFormat.Color, DepthFormat.None); //??
FileStream fileStream = new System.IO.FileStream(#"Screenshot" + "_" + counter + ".png", System.IO.FileMode.CreateNew);
ssTexture.SaveAsPng(fileStream, pparameters.BackBufferWidth, pparameters.BackBufferHeight);
counter++;
}
previousState = currentState;
}
}
}
This is my Update and Draw from Game1.cs
protected override void Update(GameTime gameTime)
{
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
myModelRotation += MathHelper.ToRadians(1f);
// Take a Screenshot
XNAUtilities.TakeScreenShot(GraphicsDevice, Keys.F8);
base.Update(gameTime);
}
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
Matrix[] transforms = new Matrix[myModel.Bones.Count];
myModel.CopyAbsoluteBoneTransformsTo(transforms);
foreach (ModelMesh mesh in myModel.Meshes)
{
foreach (BasicEffect effects in mesh.Effects)
{
effects.EnableDefaultLighting();
effects.World = transforms[mesh.ParentBone.Index]
* Matrix.CreateRotationY(myModelRotation)
* Matrix.CreateTranslation(myModelPosition);
effects.View = Matrix.CreateLookAt(new Vector3(200, 100, 400), Vector3.Zero, Vector3.Up);
effects.Projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45f),
GraphicsDevice.Viewport.AspectRatio, 1, 5000);
}
mesh.Draw();
}
smileySprite.DrawSprites(GraphicsDevice, spriteBatch, new Vector2(10,10), Color.White);
base.Draw(gameTime);
}

You're not actually rendering to your render target. So you're saving the blank target.
You need to wrap your scene drawing like so:
GraphicsDevice.SetRenderTarget(ssTexture);
// Render your scene here
GraphicsDevice.SetRenderTarget(null);
// Now you can save your render target as a texture

Related

How to add objects to an ArrayList?

I am very new on programming, and I am trying to build a little game so I can teach myself OOP, however I have an problem that I cant solve it at all.
I have a class ComponentsPanel from which I am calling another (JavaFish) as an ArrayList. The addFish() method adds to the ArrayList a JavaFish. When I call addFish() method from the constructor works perfectly fine.
The problem is, when I call it from the start(), from another class and package, it dose not add any element to the ArrayList.
Main class
package framework;
public class Core {
JFrame window;
ComponentsPanel panel;
int width = 600;
int height = 400;
public void start() {
window = new JFrame();
window.setTitle("Java Game");
window.setPreferredSize(new Dimension(width, height));
window.setMinimumSize(new Dimension(width, height));
window.setMaximumSize(new Dimension(width, height));
window.setResizable(false);
panel = new ComponentsPanel();
window.add(panel, BorderLayout.CENTER);
window.setVisible(true);
window.pack();
}
public void stop() {
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
ComponentsPanel
package framework;
public class ComponentsPanel extends JPanel {
ArrayList<JavaFish> javaFishes = new ArrayList<JavaFish>();
public ComponentsPanel() {
javaFishes = new ArrayList<JavaFish>();
//addFish(new JavaFish(100, 100, 25, 25));
}
public void addFish(JavaFish javaFish) {
javaFishes.add(javaFish);
repaint();
}
public void start() {
addFish(new JavaFish(100, 100, 25, 25));
}
#Override
public void paint(Graphics g) {
for (JavaFish jFish : javaFishes) {
jFish.draw(g);
}
}
}
Fish class
package framework;
public class JavaFish {
BufferedImage img;
private int x_pos;
private int y_pos;
private int sizeX;
private int sizeY;
public JavaFish(int x_pos, int y_pos, int sizeX, int sizeY) {
this.x_pos = x_pos;
this.y_pos = y_pos;
this.sizeX = sizeX;
this.sizeY = sizeY;
}
public void draw(Graphics g) {
BufferedImage JavaFish = LoadImage("img/JavaFish.png");
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(JavaFish, x_pos, y_pos, sizeX, sizeY, null);
}
BufferedImage LoadImage(String FileName) {
img = null;
try {
img = ImageIO.read(new File (FileName));
} catch (IOException e) {
e.printStackTrace();
}
return img;
}
}
Simulation class
package user;
import framework.ComponentsPanel;
import framework.Core;
public class Simulation {
Core c;
ComponentsPanel panel;
boolean endSim = false;
public Simulation() {
c = new Core();
panel = new ComponentsPanel();
}
private void populate() {
panel.start()
}
private void updateWorld() {
while (!endSim) {
c.start();
break;
}
c.stop();
}
public static void main(String[] args) {
Simulation simulation = new Simulation();
simulation.populate();
simulation.updateWorld();
}
}
start() method present in ComponentsPanel is not a lifecycle method. So unless you invoke start() method manually it won't get invoked. You can add a print statement for tracking the calls.
#Cristea Thank you for the updated code.
This will work if you call the addFish() method on the ComponentsPanel instance created in Core class's start() method as below.
public void start() {
window = new JFrame();
window.setTitle("Java Game");
window.setPreferredSize(new Dimension(width, height));
window.setMinimumSize(new Dimension(width, height));
window.setMaximumSize(new Dimension(width, height));
window.setResizable(false);
panel = new ComponentsPanel(); // This panel is passed to the JFrame
panel.addFish(new JavaFish(100, 100, 25, 25)); // so do addFish() here.
window.add(panel, BorderLayout.CENTER);
window.setVisible(true);
window.pack();
}
The problem with your code was, you are creating two instances of ComponentsPanel class. On the first instance(let's call it panel-1 ) you created, you are calling addFish() method, through the method below. This start() method is called on panel-1.
// panel you used to call this start() method was not used in JFrame
public void start() {
addFish(new JavaFish(100, 100, 25, 25));
}
Then you are creating 2nd instance of ComponentsPanel class(let's call it panel-2) from the Core class's start() method and panel-2 does not do addFish(). But this instance (panel-2)is what is added to the JFrame, which will be used for the purpose of paint(). Since panel-2 does not do addFish(), paint() does not find any JavaFishes.
Remember, instance variable javaFishes is specific to each instance of ComponentsPanel. javaFishes added by panel-1 would not be available for panel-2.

How to draw several lines slowly in constant velocity on canvas by Android?

I need capture the mark to draw a figure on canvas in Android, and the effect just like the follow gif:
Well, as far, I can draw a side with constant velocity by ValueAnimator. However, I just only can draw one side at one time, because I can't save the last side when drawing the next side. So, is there a good way to solve the problem?
Code for draw a line slowly by ValueAnimator:
GraphicsView.java
public class GraphicsView extends View {
private int stepX, stepY = 0;
private int startX, startY, stopX, stopY = 0;
private Paint paint = null;
public GraphicsView(Context context) {
super(context);
// Paint
paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
startX = 40;
startY = 397;
stopX = 1040;
stopY = 397;
Init();
}
public void Init(){
ValueAnimator animatorX = ValueAnimator.ofFloat(startX, stopX);
ValueAnimator animatorY = ValueAnimator.ofFloat(startY, stopY);
animatorX.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
stepX = Math.round((Float)valueAnimator.getAnimatedValue()); invalidate();
}
});
animatorY.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
stepY = Math.round((Float)valueAnimator.getAnimatedValue()); invalidate();
}
});
AnimatorSet set = new AnimatorSet();
LinearInterpolator l = new LinearInterpolator();
set.setInterpolator(l);
set.setDuration(3000);
set.playTogether(animatorX, animatorY);
set.start();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawLine(startX, startY, stepX, stepY, paint);
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
private Display display = null;
private GraphicsView view = null;
private ConstraintLayout layout = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
display = getWindowManager().getDefaultDisplay();
layout = (ConstraintLayout)findViewById(R.id.main_layout);
view = new GraphicsView(this);
view.setMinimumWidth(display.getWidth());
view.setMinimumHeight(display.getHeight());
layout.addView(view);
}
}
you can use the ObjectAnimator class to callback
to one of your class methods every time you'd like to draw a bit more of the path.
import android.animation.ObjectAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PathEffect;
import android.graphics.PathMeasure;
import android.util.AttributeSet;
import android.view.View;
import android.util.Log;
public class PathView extends View
{
Path path;
Paint paint;
float length;
public PathView(Context context)
{
super(context);
}
public PathView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
public PathView(Context context, AttributeSet attrs, int defStyleAttr)
{
super(context, attrs, defStyleAttr);
}
public void init()
{
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(10);
paint.setStyle(Paint.Style.STROKE);
path = new Path();
path.moveTo(50, 50);
path.lineTo(50, 500);
path.lineTo(200, 500);
path.lineTo(200, 300);
path.lineTo(350, 300);
// Measure the path
PathMeasure measure = new PathMeasure(path, false);
length = measure.getLength();
float[] intervals = new float[]{length, length};
ObjectAnimator animator = ObjectAnimator.ofFloat(PathView.this, "phase", 1.0f, 0.0f);
animator.setDuration(3000);
animator.start();
}
//is called by animtor object
public void setPhase(float phase)
{
Log.d("pathview","setPhase called with:" + String.valueOf(phase));
paint.setPathEffect(createPathEffect(length, phase, 0.0f));
invalidate();//will calll onDraw
}
private static PathEffect createPathEffect(float pathLength, float phase, float offset)
{
return new DashPathEffect(new float[] { pathLength, pathLength },
Math.max(phase * pathLength, offset));
}
#Override
public void onDraw(Canvas c)
{
super.onDraw(c);
c.drawPath(path, paint);
}
}
Then, just call init() to begin the animation, like this (or if you'd like it to start as soon as the view is inflated, put the init() call inside the constructors):
PathView path_view = (PathView) root_view.findViewById(R.id.path);
path_view.init();
Also see this question here, and
Using Value Animator Example
Reference 1
Reference 2
Reference 3

Recycler View: Inconsistency detected. Invalid view holder adapter positionViewHolder

Recycler View Inconsistency Detected error, coming while scrolling fast or scrolling while loading more items..
FATAL EXCEPTION: main
Process: com.pratap.endlessrecyclerview, PID: 21997
java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid view holder adapter positionViewHolder{56a082c position=40 id=-1, oldPos=39, pLpos:39 scrap [attachedScrap] tmpDetached no parent}
at android.support.v7.widget.RecyclerView$Recycler.validateViewHolderForOffsetPosition(RecyclerView.java:4251)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4382)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4363)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1961)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1370)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1333)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:562)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2864)
at android.support.v7.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1445)
at android.support.v7.widget.RecyclerView.access$400(RecyclerView.java:144)
at android.support.v7.widget.RecyclerView$1.run(RecyclerView.java:282)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:603)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Adapter
public class DataAdapter extends RecyclerView.Adapter {
private final int VIEW_ITEM = 1;
private final int VIEW_PROG = 0;
private List<Feed> mFeed;
// The minimum amount of items to have below your current scroll position
// before loading more.
private int visibleThreshold = 5;
private int lastVisibleItem, totalItemCount;
private boolean loading;
private OnLoadMoreListener onLoadMoreListener;
public DataAdapter(List<Feed> feeds, RecyclerView recyclerView) {
mFeed = feeds;
if (recyclerView.getLayoutManager() instanceof LinearLayoutManager) {
final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView
.getLayoutManager();
recyclerView
.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView,
int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager
.findLastVisibleItemPosition();
if (!loading
&& totalItemCount <= (lastVisibleItem + visibleThreshold)) {
// End has been reached
// Do something
if (onLoadMoreListener != null) {
onLoadMoreListener.onLoadMore();
}
loading = true;
}
}
});
}
}
#Override
public int getItemViewType(int position) {
return mFeed.get(position) == null ? VIEW_PROG : VIEW_ITEM;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
RecyclerView.ViewHolder vh;
if (viewType == VIEW_ITEM) {
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.list_row, parent, false);
vh = new StudentViewHolder(v);
}
else {
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.progress_item, parent, false);
vh = new ProgressViewHolder(v);
}
return vh;
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof StudentViewHolder) {
Feed singleStudent= (Feed) mFeed.get(position);
((StudentViewHolder) holder).tvName.setText(singleStudent.getTitle());
((StudentViewHolder) holder).student= singleStudent;
} else {
ProgressViewHolder.PROGRESS_BAR.setIndeterminate(true);
}
}
public void setLoaded() {
loading = false;
}
public void addFeed(Feed feed) {
mFeed.add(feed);
//mFeed.addAll(0, (Collection<? extends Feed>) feed);
notifyItemInserted(mFeed.size());
//notifyItemRangeInserted(0,mFeed.size());
notifyDataSetChanged();
//notifyItemInserted(mFeed.size());
//setLoaded();
//notifyItemInserted(mFeed.size());
}
public void removeAll(){
mFeed.clear();
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return mFeed.size();
}
public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) {
this.onLoadMoreListener = onLoadMoreListener;
}
public static class StudentViewHolder extends RecyclerView.ViewHolder {
public TextView tvName;
public Feed student;
public StudentViewHolder(View v) {
super(v);
tvName = (TextView) v.findViewById(R.id.tvName);
//tvEmailId = (TextView) v.findViewById(R.id.tvEmailId);
}
}
public static class ProgressViewHolder extends RecyclerView.ViewHolder {
//public ProgressBar progressBar;
public static ProgressBar PROGRESS_BAR;
public ProgressViewHolder(View v) {
super(v);
PROGRESS_BAR = (ProgressBar) v.findViewById(R.id.progressBar1);
// progressBar = (ProgressBar) v.findViewById(R.id.progressBar1);
}
}
}
Activity
public class MainActivity extends AppCompatActivity implements SwipeRefreshLayout.OnRefreshListener {
private Toolbar toolbar;
private TextView tvEmptyView;
private RecyclerView mRecyclerView;
private DataAdapter mAdapter;
private LinearLayoutManager mLayoutManager;
private RestManager mManager;
private List<Feed> mFeed;
SwipeRefreshLayout mSwipeRefreshLayout;
protected Handler handler;
private int currentPage=1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
tvEmptyView = (TextView) findViewById(R.id.empty_view);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mSwipeRefreshLayout= (SwipeRefreshLayout) findViewById(R.id.swipe_refresh_layout);
mSwipeRefreshLayout.setOnRefreshListener(this);
//studentList = new ArrayList<Student>();
mFeed = new ArrayList<Feed>();
handler = new Handler();
if (toolbar != null) {
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("Android Students");
}
mManager = new RestManager();
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
// use a linear layout manager
mRecyclerView.setLayoutManager(mLayoutManager);
// create an Object for Adapter
mAdapter = new DataAdapter(mFeed,mRecyclerView);
// set the adapter object to the Recyclerview
mRecyclerView.setAdapter(mAdapter);
// mAdapter.notifyDataSetChanged();
loadData(false);
// if (mFeed.isEmpty()) {
// mRecyclerView.setVisibility(View.GONE);
// tvEmptyView.setVisibility(View.VISIBLE);
//
// } else {
// mRecyclerView.setVisibility(View.VISIBLE);
// tvEmptyView.setVisibility(View.GONE);
// }
mAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
#Override
public void onLoadMore() {
//add null , so the adapter will check view_type and show progress bar at bottom
mFeed.add(null);
mAdapter.notifyItemInserted(mFeed.size() - 1);
handler.postDelayed(new Runnable() {
#Override
public void run() {
// remove progress item
mFeed.remove(mFeed.size() - 1);
// mAdapter.notifyItemRemoved(mFeed.size());
//add items one by one
int start = mFeed.size();
currentPage++;
Log.d("CurrentPage", String.valueOf(currentPage));
Call<Results> listCall = mManager.getFeedApi().getAllFeeds(1);
listCall.enqueue(new Callback<Results>() {
#Override
public void onResponse(Call<Results> call, Response<Results> response) {
mSwipeRefreshLayout.setRefreshing(false);
if (response.isSuccess()) {
if (response.body() != null) {
Results feedList = response.body();
// List<Results> newUsers = response.body();
Log.d("Retrofut", String.valueOf(feedList));
for (int i = 0; i < feedList.results.size(); i++) {
Feed feed = feedList.results.get(i);
// mFeed.add(feed);
mAdapter.addFeed(feed);
// mAdapter.notifyDataSetChanged();
//mAdapter.notifyItemInserted(mFeed.size());
}
// mAdapter.notifyDataSetChanged();
}
}
}
#Override
public void onFailure(Call<Results> call, Throwable t) {
Log.d("Retrofut", "Error");
mFeed.remove(mFeed.size() - 1);
mAdapter.notifyItemRemoved(mFeed.size());
mAdapter.setLoaded();
mSwipeRefreshLayout.setRefreshing(false);
}
});
// for (int i = 1; i <= 20; i++) {
// studentList.add(new Student("Student " + i, "androidstudent" + i + "#gmail.com"));
//
// }
mAdapter.setLoaded();
//or you can add all at once but do not forget to call mAdapter.notifyDataSetChanged();
}
}, 2000);
}
});
}
// load initial data
private void loadData(final boolean removePreData) {
Call<Results> listCall = mManager.getFeedApi().getAllFeeds(1);
listCall.enqueue(new Callback<Results>() {
#Override
public void onResponse(Call<Results> call, Response<Results> response) {
if (response.isSuccess()) {
if (response.body() != null) {
// if(removePreData) mAdapter.removeAll();
Results feedList = response.body();
Log.d("Retrofut", String.valueOf(feedList));
for (int i = 0; i < feedList.results.size(); i++) {
Feed feed = feedList.results.get(i);
// mFeed.add(feed);
//mAdapter.notifyDataSetChanged();
mAdapter.addFeed(feed);
}
mSwipeRefreshLayout.setRefreshing(false);
}
}
}
#Override
public void onFailure(Call<Results> call, Throwable t) {
Log.d("Retrofut", String.valueOf(t));
mFeed.remove(mFeed.size() - 1);
mAdapter.notifyItemRemoved(mFeed.size());
mAdapter.setLoaded();
mSwipeRefreshLayout.setRefreshing(false);
}
}
);
// for (int i = 1; i <= 20; i++) {
// studentList.add(new Student("Student " + i, "androidstudent" + i + "#gmail.com"));
//
// }
mSwipeRefreshLayout.setRefreshing(true);
}
#Override
public void onRefresh() {
mFeed.clear();
mAdapter.notifyDataSetChanged();
loadData(true);
currentPage=1;
}
}
put this line along with setting recyclerView. issue was fixed by
setting ItemAnimator to null for RecyclerView.
in kotlin
recyclerView.layoutManager = LinearLayoutManager(this)
recyclerView.itemAnimator = null
in java
recyclerView.setItemAnimator(null);
It looks similar with known android bug
There are quite ugly, but working approach
public class WrapContentLinearLayoutManager extends LinearLayoutManager {
//... constructor
#Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
try {
super.onLayoutChildren(recycler, state);
} catch (IndexOutOfBoundsException e) {
Log.e("Error", "IndexOutOfBoundsException in RecyclerView happens");
}
}
}
mRecyclerView.setLayoutManager(new WrapContentGridLayoutManager(getContext(), spanCount));
For me it works without any by-effect.
This issue is a known bug of RecyclerView. The best solution is, clear the list every time before refresh RecyclerView.
For fix this issue just call notifyDataSetChanged() with empty list before updating recycle view.
For example
//Method for refresh recycle view
if (!yourList.isEmpty())
yourList.clear(); //The list for update recycle view
adapter.notifyDataSetChanged();
Use this to refresh a RecyclerView
items.clear(); //here items is an ArrayList populating the RecyclerView
adapter.notifyDataSetChanged();
items.addAll(list);// add new data
adapter.notifyItemRangeInserted(0, items.size);// notify adapter of new data
`
I had similiar issue, and also this solution has helped me, after I've added new item to my RV:
recyclerView.getRecycledViewPool().clear();
adapter.notifyDataSetChanged();
Maybe you can try this before refresh the adapter:
dataList.clear();
patrolListAdapter.notifyDataSetChanged();
In my case I was doing it as notifyItemInserted(position);
That caused me this issue then i used as and it worked perfectly.notifyItemRangeInserted(startIndex,endIndex);
I had this problem when scrolling fast through my endless/paging RecyclerView. The root of my problem came from the fact that I had a “header” item at the beginning of the list, this header item was not a part of the data source, it was just inserted at the beginning of the adapter list. So when scrolling fast and adding new pages of items to the RecyclerView Adapter and notify the adapter that new data had been inserted, I was not taking into account the additional header item, thus making the size of the adapter’s list wrong... and causing this exception...
So in short, if you’re using a header/footer in our RecyclerView adapter make sure you take it into account when updating the adapters data.
Example:
public void addNewPageToList(List<MyData> list)
{ //
// Make sure you account for any header/footer in your list!
//
// Add one to the currentSize to account for the header item.
//
int currentSize = this.adapterList.size() + 1;
this.adapterList.addAll(list);
notifyItemRangeInserted(currentSize, this.adapterList.size());
}
Edit:
I guess you could always just use the adapter method getItemCount() to get the size, instead of getting the size from the “data list” and adding to it. Your getItemCount() method should already be taking into account any additional headers/footers/etc that you have in your list.
The problem is in this line of code:
mFeed = feeds;
you are assigning mFeed to the caller's instance feeds so whenever the caller changes it's variable (may be adding, clearing or removing items), your local mFeed will change
try to change to
mFeed.addAll(feeds);
don't forget to initialize mFeed to any list tat fits your needs like mFeed = new ArrayList<>();
put this line along with setting recyclerView. issue was fixed by setting ItemAnimator to null for RecyclerView.
in kotlin
recyclerView.layoutManager = LinearLayoutManager(this)
recyclerView.itemAnimator = null
I'm using the recyclerview from mikepenz. And any update to the items using .set(item) was causing this issue.
For some reason, setting recylerView.itemAnimator = null, resolved the issue. This is a known android bug.
In my case, I was using RecyclerView from Firebase UI. Initially, the logic to initialize the RecyclerView was in onCreate(). To fix, I put the logic in onResume() and seems to be working for me. I had this error when going back to the Activity which had the RecyclerView. So, everytime the Activity screen is refreshed, the new data is loaded.
I had similar problem. Removing all views from RecyclerView helped me:
RecyclerView.LayoutManager layoutManager = mRecyclerView.getLayoutManager();
layoutManager.removeAllViews();
For me the issue was I wasn't posting notifyDatasetChanged when the data set changed as I implemented incremental search.
I had a list that was filtered based on what the user searched in the search widget. For each item in the list, I was making a remote request, and when I got the result back, I was updating that particular cell.
I had to do both notifies for the recycler view to work
Filter the original data set then post the dataset change
this.searchResultTable?.post {
this.searchResultTable?.adapter?.notifyDataSetChanged()
}
After receiving response, post notifications again
this.searchResultTable?.post {
this.searchResultTable?.adapter?.notifyItemChanged(index, updateDataHashMap)
}
You have to post updates rather than sending notifiy messages directly in order to prevent the recycler view from crashing when the update comes in before the view is laid out.
Another important gotcha is that when you post the individual updates after the remote response, you have to make sure that the list the user currently sees is the list that existed when the requests were sent.
For my case in adapter there was notifyItemRangeInserted and I replaced it with notifyItemRangeChanged

JavaFX 8.0 - How can I get a MouseEventHandle at title bar

I have implemented a EventHandler which gets the window-drag of the mouse:
public void mouseEventHandler(){
final Delta dragDelta = new Delta();
view.getScene().setOnMousePressed(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
dragDelta.x = mainStage.getX() - mouseEvent.getScreenX();
dragDelta.y = mainStage.getY() - mouseEvent.getScreenY();
}
});
view.getScene().setOnMouseDragged(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
mainStage.setX(mouseEvent.getScreenX() + dragDelta.x);
mainStage.setY(mouseEvent.getScreenY() + dragDelta.y);
stage.setX(mainStage.getX());
stage.setY(mainStage.getY() + view.getScene().getHeight() + 25);
}
});
}
I have two stages: mainStage and a stage, which is addicted to the coordinates of the mainStage. My problem is, that the stage only moves if I click in the window of the mainStage and drag it. But it won't move if I click the title bar of the window for removing.
How can I get the MouseEvent for the title bar?
Here is the show() method, so you can understand the Addiction:
public void show(Stage mainStage, MenuPresenter menuPresenter){
this.model = new Model();
this.view = new GameView(this.model);
this.chatWatchView = new ChatWatchView();
this.score = this.model.getScore();
this.menuPresenter = menuPresenter;
this.mainStage = mainStage;
mainStage.setScene(view.getScene());
mainStage.centerOnScreen();
stage = new Stage();
stage.setScene(chatWatchView.getScene());
stage.initStyle(StageStyle.UNDECORATED);
stage.setX(mainStage.getX());
stage.setY(mainStage.getY() + view.getScene().getHeight() + 25);
stage.show();
mainStage.show();
startTimeline();
activateEventHandler();
mouseEventHandler();
//view.setScore("Score: " + model.getScore());
}
Had similar problem. Consider to add listeners to xProperty() and yProperty() of your Stage, I think it will work better.
In my case I ended up with something like this
void updatePosition(double stageX, double stageY) {
//...
}
And then
stage.xProperty().addListener(((observable, oldValue, newValue) -> {
updatePosition(newValue, stage.getY())
}));
stage.yProperty().addListener(((observable, oldValue, newValue) -> {
updatePosition(stage.getX(), newValue)
}));

Xamarin Forms Switch XAML

I'm new in Xamarin and i'm trying to create a simple page with some components.
One of these component is a Switch it works fine by itself but i would like to change the basic text "inactive/active" by "male/female"
I've seen that in Xaml for windows phone there is a ToggleSwitch Component with a On/OffContent property but i can't seems to find an equivalent in XAML for Xamarin Forms
any idea ?
Thank you!
The lack of built in switch options, or at least the lack of being able to rename the switch options, has been asked a few times.
You could go with custom renders, modify the text at the OS level or do like I chose to do, just build your own switch.
This switch is two buttons laid out horizontally with the text Yes and No. The selected button gets a red border, and the unselected a transparent border.
class CustomSwitch : Grid
{
public event EventHandler<SelectedItemChangedEventArgs> ItemSelected;
private Button negative;
private Button positive;
public static readonly BindableProperty SelectedItemProperty = BindableProperty.Create<CustomSwitch, Object>(t => t.SelectedItem, null, BindingMode.TwoWay, propertyChanged: OnSelectedItemChanged);
public CustomSwitch()
{
try
{
this.HorizontalOptions = LayoutOptions.Center;
this.VerticalOptions = LayoutOptions.Center;
negative = new Button();
negative.Text = "No";
negative.Style = <YourNameSpace>.AppStyling.Style_Button_Switch;
negative.Clicked += (o,s) => OnSelectedItemChanged(this, ItemSelected, (int)Classes.Collections.Enums.SelectionStatus.False);
positive = new Button();
positive.Text = "Yes";
positive.Style = <YourNameSpace>.AppStyling.Style_Button_Switch;
positive.Clicked += (o, s) => OnSelectedItemChanged(this, ItemSelected, (int)Classes.Collections.Enums.SelectionStatus.True);
this.Children.Add(negative, 0,0);
this.Children.Add(positive, 1,0);
}
catch(System.Exception ex)
{
<YourNameSpace>.Classes.Helpers.Helper_ErrorHandling.SendErrorToServer(ex, this.GetType().Name, System.Reflection.MethodBase.GetCurrentMethod().Name);
}
}
public Object SelectedItem
{
get
{
return base.GetValue(SelectedItemProperty);
}
set
{
if (SelectedItem != value)
{
base.SetValue(SelectedItemProperty, value);
InternalUpdateSelected();
}
}
}
private void InternalUpdateSelected()
{
if((int)SelectedItem == (int)Classes.Collections.Enums.SelectionStatus.False)
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_Selected;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
positive.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
}
else if ((int)SelectedItem == (int)Classes.Collections.Enums.SelectionStatus.True)
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
negative.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_Selected;
}
else
{
negative.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
negative.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
positive.BorderColor = <YourNameSpace>.AppStyling.Color_UnSelected;
positive.Opacity = <YourNameSpace>.AppStyling.Opaque_High;
}
}
private static void OnSelectedItemChanged(BindableObject bindable, object oldValue, object newValue)
{
CustomSwitch boundSwitch = (CustomSwitch)bindable;
if((int)newValue != (int)Classes.Collections.Enums.SelectionStatus.Unselected)
{
boundSwitch.SelectedItem = (int)newValue == (int)Classes.Collections.Enums.SelectionStatus.False ? (int)Classes.Collections.Enums.SelectionStatus.False : (int)Classes.Collections.Enums.SelectionStatus.True;
}
if (boundSwitch.ItemSelected != null)
{
boundSwitch.ItemSelected(boundSwitch, new SelectedItemChangedEventArgs(newValue));
}
boundSwitch.InternalUpdateSelected();
}
}