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How to hide the navigation bar when entering fullview in webview?

I have found this code to enter in full screen when playing a video in webview, but there is a problem in it.
For example if I am in YouTube all works properly at the first time (when I play the video), but when I click to change the settings of the video like the quality or the speed, the navigation bar appears and still there until I exit the video.
}
public class CustomWebClient extends WebChromeClient {
private View mCustomView;
private WebChromeClient.CustomViewCallback mCustomViewCallback;
protected FrameLayout frame;
// Initially mOriginalOrientation is set to Landscape
private int mOriginalOrientation = android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE;
private int mOriginalSystemUiVisibility;
// Constructor for CustomWebClient
public CustomWebClient() {}
public Bitmap getDefaultVideoPoster() {
if (MainActivity.this == null) {
return null; }
return BitmapFactory.decodeResource(MainActivity.this.getApplicationContext().getResources(), 2130837573); }
public void onShowCustomView(View paramView, WebChromeClient.CustomViewCallback viewCallback) {
if (this.mCustomView != null) {
onHideCustomView();
return; }
this.mCustomView = paramView;
this.mOriginalSystemUiVisibility = MainActivity.this.getWindow().getDecorView().getSystemUiVisibility();
// When CustomView is shown screen orientation changes to mOriginalOrientation (Landscape).
MainActivity.this.setRequestedOrientation(this.mOriginalOrientation);
//
//here is the code I'm using to hide status bar
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
// After that mOriginalOrientation is set to portrait.
this.mOriginalOrientation = android.content.pm.ActivityInfo.SCREEN_ORIENTATION_PORTRAIT;
this.mCustomViewCallback = viewCallback; ((FrameLayout)MainActivity.this.getWindow().getDecorView()).addView(this.mCustomView, new FrameLayout.LayoutParams(-1, -1)); MainActivity.this.getWindow().getDecorView().setSystemUiVisibility(3846);
//
//here is the code I'm using to hide navigation bar
getWindow().getDecorView().setSystemUiVisibility( View.SYSTEM_UI_FLAG_HIDE_NAVIGATION | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
//
}
public void onHideCustomView() {
((FrameLayout)MainActivity.this.getWindow().getDecorView()).removeView(this.mCustomView);
this.mCustomView = null;
MainActivity.this.getWindow().getDecorView().setSystemUiVisibility(this.mOriginalSystemUiVisibility);
// When CustomView is hidden, screen orientation is set to mOriginalOrientation (portrait).
MainActivity.this.setRequestedOrientation(this.mOriginalOrientation);
//////////////
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
getWindow().getDecorView().setSystemUiVisibility( View.SYSTEM_UI_FLAG_IMMERSIVE | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
//////////////
// After that mOriginalOrientation is set to landscape.
this.mOriginalOrientation = android.content.pm.ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE; this.mCustomViewCallback.onCustomViewHidden();
this.mCustomViewCallback = null;
}
}
{
Here is some pictures of the problem:

Is there a way to restart marquee/scrolling when the last letter of the text becomes visible?

I want a text inside a textbox to scroll to end and then restart.
Using marquee scrolls the whole text until the first letter reaches the "start point", but I want the text only to scroll until the last letter of the text becomes visible, then pause and the text should jump to start and start scrolling again.
Is there a way to do this. I have search but I can't find something that works for me.
Thanks,
Sebi

I am not aware of any way to configure a TextView to take on the marquee behavior that you are seeking. The Stack Overflow Q/A I referred you to in the comments does translate the entire TextView. I think that this will work as a marquee if you set the TextView within a ViewGroup such that the TextView is clipped. You can also do you own clipping. You would have to try this to see if it would work. If this does work, it may be sufficient for your needs, but you may be missing the fading edge and maybe some other characteristics of true marquee scrolling. Also, some other characteristics of the TextView such as shadows, borders and backgrounds might not look right.
The contents of the TextView is animated by the TextView code itself through canvas translation for marquee scrolling. See here.
if (isMarqueeFadeEnabled()) {
if (!mSingleLine && getLineCount() == 1 && canMarquee()
&& (absoluteGravity & Gravity.HORIZONTAL_GRAVITY_MASK) != Gravity.LEFT) {
final int width = mRight - mLeft;
final int padding = getCompoundPaddingLeft() + getCompoundPaddingRight();
final float dx = mLayout.getLineRight(0) - (width - padding);
canvas.translate(layout.getParagraphDirection(0) * dx, 0.0f);
}
if (mMarquee != null && mMarquee.isRunning()) {
final float dx = -mMarquee.getScroll();
canvas.translate(layout.getParagraphDirection(0) * dx, 0.0f);
}
}
You can also consider writing a custom TextView and doing your own text scrolling. You can look to the TextView code itself for some tips on how you might do it. I think writing your own TextView would have better results. (IMO)

I have rewrite the Code from the GitHub Project here (which was posted in the comment from Cheticamp) to java and shorten it to my needs. Now it starts the animation infinite.
Here the java code:
MarqueeTextView.java:
public class MarqueeTextView extends androidx.appcompat.widget.AppCompatTextView {
private final Scroller mScroller;
private int mDelay;
private int mDuration;
private final Handler mHandler = new Handler();
private final Runnable mAnimateRunnable = new Runnable() {
#Override
public void run() {
//check if Animation is needed otherwise check next cycle (if text has changed for example)
if (getTextViewWidthWithPadding() < getTextWidth()) {
mScroller.startScroll(getStartX(), 0, 0, 0, 0);
invalidate();
int direction = getLayout().getParagraphDirection(0);
mScroller.startScroll(getStartX(), 0, (getTextWidth() - getTextViewWidthWithPadding()) * direction, 0, mDuration);
}
mHandler.postDelayed(mAnimateRunnable, mDelay);
}
};
public MarqueeTextView(Context context) {
this(context, null);
}
public MarqueeTextView(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
mScroller = new Scroller(context, new LinearInterpolator());
setScroller(mScroller);
}
private int getTextWidth() {
String text = getText().toString();
TextPaint paint = getPaint();
Rect bounds = new Rect();
paint.getTextBounds(text, 0, text.length(), bounds);
return bounds.width();
}
private int getTextViewWidthWithPadding() {
return getWidth() - (getPaddingStart() + getPaddingEnd());
}
private int getStartX() {
boolean isRtl = getLayoutDirection() == LAYOUT_DIRECTION_RTL;
int lineRight = (int) getLayout().getLineRight(0);
if (isRtl) {
return lineRight - getTextViewWidthWithPadding();
} else {
return 0;
}
}
public void startAnimation(int delay, int duration) {
mDelay = delay;
mDuration = duration;
mHandler.postDelayed(mAnimateRunnable, delay);
}
}
activity_main.xml:
<MarqueeTextView
android:id="#+id/name"
android:layout_width="250dp"
android:layout_height="wrap_content"
android:ellipsize="none"
android:singleLine="true"
android:text="1. Simple text that shows how to use custom marquee"
/>
MainActivty.java:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
((MarqueeTextView)findViewById(R.id.name)).startAnimation(3000, 2000);
}

How to know the max amount of ItemViews that can be visible in the RecyclerView without loading the data?

I have a paging algorithm for the RecyclerView, which if done Scroll, a scrolling listener triggers and loads more elements. Initially, I assigned a number of elements to load in the request to the server by default that is 20 for my RecyclerView, which has a fixed size (not wrap_content).
I need to know the number of items that can be visible in the width/height of the defined RecyclerView before loading the data, to determine the amount of items to be requested in the initial load, given that with 20 items on some devices is not enough to activate the listener of the scroll and load more elements.
This is without considering the extra properties of the view, such as padding, margin etc ...
The solution can be in Java Android or Xamarin Android (not Forms) C#.
Update:
For you to have a clue, i have tried this and it works for me, only if I call it when the size of RecyclerView is assigned, inside the OnLayoutChange:
public int GetMaxVisibleItemCountFromRecyclerView(RecyclerView recyclerView)
{
if (recyclerView == null) return 0;
int Width = recyclerView.Width;
int Height = recyclerView.Height;
if (Width == 0 || Height == 0)
return 0;
var layoutManager = recyclerView.GetLayoutManager() as GridLayoutManager;
if (layoutManager == null) return 0;
int widthRatio = Width / layoutManager.SpanCount;
int quantity = (Height / widthRatio) * layoutManager.SpanCount;
return quantity;
}
This solution only works for RecyclerViews that use the GridLayoutManager. I have other RecyclerViews with defined sizes that also use the paging algorithm with a LinearLayoutManager.
I need a similar solution, that works with any LayoutManager of the RecyclerView and does not have to be called inside the OnLayoutChange, is this possible?

Instead of trying to replicate the computations that RecyclerView does to compute layout, let the system do the work for you. The following example lets RecyclerView lay out one item and measurements are taken from that. The dummy item is not displayed and is used just for measurement.
The advantage of this method is that we don't have to replicate what RecyclerView does to measure items. All key measurements are taken into account including padding, margins and decorations.
The following sample shows how this can be accomplished for GridLayoutManager and LinearLayoutManager. StaggeredGridLayoutManager and FlexboxLayoutManager are special cases and aren't taken into account here.
Here is a short video showing the results of this demo app showing that just one page of items was loaded.
MainActivity.java
public class MainActivity extends AppCompatActivity {
private List<String> mItems = new ArrayList<>();
private RecyclerView mRecycler;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecycler = findViewById(R.id.recyclerView);
// Sample for vertical LinearLayoutManager.
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
// Sample for GridLayoutManager with 4 spans. Each item comsumes 2 spans.
// GridLayoutManager layoutManager = new GridLayoutManager(this, 4);
// layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
// #Override
// public int getSpanSize(int position) {
// return 2;
// }
// });
// Add single dummy item that will be measured but not be displayed.
mItems.add("Dummy item");
RecyclerViewAdapter mAdapter = new RecyclerViewAdapter(mItems);
mRecycler.setLayoutManager(layoutManager);
mRecycler.setAdapter(mAdapter);
// Take measurements in OnPreDraawListener(). This could also be accomplished with
// mRecyclerView.post(new Runnable()...)
mRecycler.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
mRecycler.getViewTreeObserver().removeOnPreDrawListener(this);
// RecyclerView is laid out with single dummy entry. Get how many of this type
// of item can fit into the visible portion of the RecyclerView.
final int nItems = getInitialLoadCount(mRecycler);
Log.d(TAG, "<<<<Items per page=" + nItems);
// Don't need the dummy entry any more.
mItems.clear();
mRecycler.getAdapter().notifyDataSetChanged();
mItems = new ArrayList<>();
// Fake load...
loadInitialItems(nItems);
return false;
}
});
}
// Determine how many items will fill one screen of the RecyclerView. Call with the
// RecyclerView loaded with at least one item for measurement.
private int getInitialLoadCount(RecyclerView recyclerView) {
int itemsToLoad = 0;
RecyclerView.LayoutManager lm = recyclerView.getLayoutManager();
View firstChild = recyclerView.getChildAt(0);
if (lm instanceof LinearLayoutManager) {
Rect bounds = new Rect();
recyclerView.getDecoratedBoundsWithMargins(firstChild, bounds);
if (lm.canScrollVertically()) {
int recyclerHeightForItems = recyclerView.getHeight() - recyclerView.getPaddingTop()
- recyclerView.getPaddingBottom();
itemsToLoad = (recyclerHeightForItems + bounds.height() - 1) / bounds.height();
} else if (lm.canScrollHorizontally()) {
int recyclerWidthForItems = recyclerView.getWidth() - recyclerView.getPaddingLeft()
- recyclerView.getPaddingRight();
itemsToLoad = (recyclerWidthForItems + bounds.width() - 1) / bounds.width();
}
if (lm instanceof GridLayoutManager) {
// Adjust for GridLayoutManager. All items should to be the same number of spans.
GridLayoutManager glm = (GridLayoutManager) lm;
itemsToLoad *= glm.getSpanCount() / glm.getSpanSizeLookup().getSpanSize(0);
}
}
return itemsToLoad;
}
private void loadInitialItems(final int itemCount) {
// Simulate load of nItems...should be on non-UI thread.
new Thread(new Runnable() {
#Override
public void run() {
for (int i = 1; i <= itemCount; i++) {
sleep(250);
mItems.add("Item #" + i);
}
runOnUiThread(new Runnable() {
#Override
public void run() {
mRecycler.swapAdapter(new RecyclerViewAdapter(mItems), true);
}
});
}
}).start();
}
private static final String TAG = "MainActivity";
}

If your RecyclerView and your item width and height are defined in dp, then you should save their dimensions in dimen.xml. Then you can calculate how many items will fit like this:
float recyclerHeight = getResources().getDimension(R.dimen.recycler_height);
float itemHeight = getResources().getDimension(R.dimen.item_height);
int numOfItemsFit = (int) (recyclerHeight / itemHeight);
If your recyclerView isn't defined by dp, but the rest of the views in this layout are you can try to accomplish the same thing by decreasing the other views height from the total view height. You can check the total view height with:
public int getHeight() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
return size.y;
}
If you can't do the above you'll need to measure your RecyclerView inside of OnLayoutChange :( . You can do that with: recyclerView.getMeasuredHeight(); and recyclerView.getMeasuredWidth();

Detecting when the keyboard is active in a webview

I have not yet found any way to solve this on stack.
I have a webview in my app. I want to be able to detect when the keyboard is active and when it is not active. It seems as if it cant detect these changes when they happon in a webview.
I want to perform actions on these different states. On iOS its really simple with observers that listens when the keyboard is active. Ref UIKeyboardWillShow/Hide.
Is there any functionality in android that does the same as these observers do in android?
Hopefully the question is well enough explained.

So I struggled with this a week or so and found a lot of material Here is my solution, I really hope that it works for you.
So in my case I have an Activity, and I call a fragment that contains the Webview so it was a lot trickier than I thought.
Basically the issue is that the fragment was missing this line:
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);
So it didn't recognized the change of height inside the webview.
Anyways lets get to the code:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = super.onCreateView(inflater, container, savedInstanceState);
//mWebView.postUrl("https://www.google.com/");
final View activityRootView = view;
layoutListener = new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
Rect r = new Rect();
//r will be populated with the coordinates of your view that area still visible.
activityRootView.getWindowVisibleDisplayFrame(r);
// This variable was created only for Debug purposes and
// to see the height change when clicking on a field inside mWebView
int screenHeight = activityRootView.getRootView().getHeight();
Log.d("onGlobalLayout", "rect: " + r.toString());
Log.d("onGlobalLayout", "screenHeight: " + screenHeight);
//The difference on the heights from bottom to top and on the root height
int heightDiff = screenHeight - (r.bottom - r.top);
Log.d("onGlobalLayout", "heightDiff: " + heightDiff);
//I suggest to put 250 on resources and retrieve from there using getResources().getInteger() to have better order
float dpx = dpToPx(getActivity(), 250);
if (previousHeightDiff != heightDiff) {
if (heightDiff > dpx) {
isSoftKeyboardPresent = true;
} else {
isSoftKeyboardPresent = false;
}
previousHeightDiff = heightDiff;
}
}
};
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(layoutListener);
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);
return view;
}
private static float dpToPx(Context context, float valueInDp) {
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, valueInDp, metrics);
}
Remember to put on your AndroidManifest.xml a setting on the activity set to: android:windowSoftInputMode="adjustResize|stateHidden"
The variables inside the fragment are:
public boolean isSoftKeyboardPresent = false;
private int previousHeightDiff = -1;// this is used to avoid multiple assignments
private ViewTreeObserver.OnGlobalLayoutListener layoutListener = null;
Finally
#Override
public void onPause() {
super.onPause();
final View activityRootView = getActivity().findViewById(R.id.page_content);
activityRootView.getViewTreeObserver().removeOnGlobalLayoutListener(layoutListener);
}
And this should do the trick :) so what do you think?

How to calculate the height of a scrollView using ViewTreeObserver?

I have a ScrollView with some layouts in it, called the fragment_about_sl.xml.And the class associated to it is called AboutSLFragment.java.I want to calculate the height of the scrollView to get height ratio for an image.I researched the web and found this code.
ViewTreeObserver vto = scrollView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
scrollView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
int scrollViewHeightInPixels = layout.getMeasuredHeight();
//This is equal with %45 weight you tried before
int height = (scrollViewHeightInPixels * 45) / 100;
ViewGroup.LayoutParams pagerParams = viewPager.getLayoutParams();
pagerParams.height = height;
}
});
As shown in the above code.It just have said scrollView instead of getting it from findViewById().And also in the below code,it just says layout.getMeasuredHeight() instead of specifying the name of layout.
int scrollViewHeightInPixels = layout.getMeasuredHeight();
The question is that I want to know what is meant by layout here(above).What should I put there,is it the id of the scrollView?If so I developed a code myself and I want to know whether it is correct.Please help me I am new to android.The id of the scrollview I used is aboutslscrollview.
final View view = rootView.findViewById(R.id.aboutslscrollview);
ViewTreeObserver vto = view.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
int scrollViewHeightInPixels = view.getMeasuredHeight();
//This is equal with %45 weight you tried before
int height = (scrollViewHeightInPixels * 45) / 100;
ViewGroup.LayoutParams pagerParams = viewPager.getLayoutParams();
pagerParams.height = height;
}
});