Develop Reference

Using Street View VR in my app

I'm using Android Studio and trying to show some chosen Street View paths in VR. I already have Street View running well and now I'm trying to show it in VR.
I have put the com.google.vr.sdk.widgets.pano.VrPanoramaView in the layout and, inside onCreate in my class, referenced it to a VrPanoramaView variable through findViewById. Now I'm trying to show an image calling a method which I've defined in this class, loadPanoImage. This method loads an image from the storage and shows it through loadImageFromBitmap.
The problem is that it isn't able to show anything, even though I've followed a guide and I've done everything as showed. I've even tryed calling it in different parts of the code (before doing any other action, on clicking a button, before and after showing streetview) but I can't understand why it isn't working and how will I be able to use it to show images taken from StreetView (I don't know if I will be able to do it dinamically or I should download them and put them in the storage).
I'm putting part of the code for reference:
public class VrExperience extends FragmentActivity {
Button buttonCitta;
Button buttonMare;
Button buttonMontagna;
TextView titleTextView;
// George St, Sydney
private static final LatLng SYDNEY = new LatLng(-33.87365, 151.20689);
// LatLng with no panorama
private static final LatLng INVALID = new LatLng(-45.125783, 151.276417);
//VrPanoramaView is inserted in the layout
private VrPanoramaView panoWidgetView;
//StreetViewPanorama is another class in my project which shows Street View
private StreetViewPanorama mStreetViewPanorama;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_vrexperiences);
panoWidgetView = (VrPanoramaView) findViewById(R.id.pano_view);
panoWidgetView.setEventListener(new VrPanoramaEventListener());
//download image and show it, but it doesn't show anything
loadPanoImage();
titleTextView = (TextView) findViewById(R.id.titleTextView);
buttonCitta = (Button) findViewById(R.id.buttonCitta);
buttonCitta.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!checkReady()) {
return;
}
titleTextView.setVisibility(View.GONE);
buttonCitta.setVisibility(View.GONE);
buttonMare.setVisibility(View.GONE);
buttonMontagna.setVisibility(View.GONE);
loadPanoImage(); //it doesn't show anything
mStreetViewPanorama.setPosition(SYDNEY);
loadPanoImage(); //it doesn't show anything
}
}};
//code for buttonMontagna and buttonMare as well, it's identical
SupportStreetViewPanoramaFragment streetViewPanoramaFragment =
(SupportStreetViewPanoramaFragment)
getSupportFragmentManager().findFragmentById(R.id.streetviewpanorama);
streetViewPanoramaFragment.getStreetViewPanoramaAsync(
new OnStreetViewPanoramaReadyCallback() {
#Override
public void onStreetViewPanoramaReady(StreetViewPanorama panorama) {
mStreetViewPanorama = panorama;
// Only set the panorama to INVALID on startup (when no panoramas have been
// loaded which is when the savedInstanceState is null).
if (savedInstanceState == null) {
mStreetViewPanorama.setPosition(INVALID);
}
}
});
}
/**
* When the panorama is not ready the PanoramaView cannot be used. This should be called on
* all entry points that call methods on the Panorama API.
*/
private boolean checkReady() {
if (mStreetViewPanorama == null)
return false;
return true;
}
/**
* Called when the Animate To Invalid button is clicked.
*/
public void onGoToInvalid(View view) {
if (!checkReady()) {
return;
}
mStreetViewPanorama.setPosition(INVALID);
}
//retrieves image from the assets folder and loads it into the VrPanoramaView
private void loadPanoImage() {
VrPanoramaView.Options options = new VrPanoramaView.Options();
InputStream inputStream = null;
AssetManager assetManager = getAssets();
try {
inputStream = assetManager.open("demo2.jpg");
options.inputType = VrPanoramaView.Options.TYPE_MONO;
panoWidgetView.loadImageFromBitmap(
BitmapFactory.decodeStream(inputStream), options
);
inputStream.close();
} catch (IOException e) {
Log.e("Fail", "Exception in loadPanoImage" + e.getMessage());
}
}
#Override
protected void onPause() {
panoWidgetView.pauseRendering();
super.onPause();
}
#Override
protected void onResume() {
super.onResume();
panoWidgetView.resumeRendering();
}
#Override
protected void onDestroy() {
panoWidgetView.shutdown();
super.onDestroy();
}
}
This is my layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/vrExperienceActivity"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.vr.sdk.widgets.pano.VrPanoramaView
android:id="#+id/pano_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dip"
android:layout_weight="5"
android:scrollbars="none" />
<TextView
android:id="#+id/titleTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/white"
android:text="VR Experience"
android:textAlignment="center"
android:textAppearance="#android:style/TextAppearance.Large"
android:textColor="#0000F0"
android:visibility="visible" />
<Button
android:id="#+id/buttonCitta"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Città" />
<fragment
class="com.google.android.gms.maps.SupportStreetViewPanoramaFragment"
android:id="#+id/streetviewpanorama"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
EDIT: #LucioB
a) those are the places I've tried to call loadPanoImage, but neither of them showed anything. It acts as nothing happens calling that method, the program keeps going to the other tasks. I'd like for images to be shown directly in VR when a button is clicked, or if that isn't possible to add the classic cardboard button in Street View mode to pass to VR view.
b) I mean the code isn't doing what I expected it to do. I thought that once I created VrPanoramaView in the layout and used it to show an image through .loadImageFromBitmap it would have shown the image I loaded from asset (I have an image saved on the virtual SD), and that once I was able to do that for a single image I would have found a way to do it for a whole path.
The code doesn't give any exception, I think I'm making a logic mistake or I didn't understand how VR api work.
EDIT: I've found that the java code is working, the problem was in the layout which didn't permit to see VrPanoramaView because it was obscured by StreetViewPanorama

Android: Making a Button Display Silly Text

I am creating an app in Android where I have a button that displays silly phrases when pressed. I figured out how to get it to say two phrases but I can't figure out how to make it do more. I also want to add in a feature to have the button pick phrases at random instead of going in the order I set. I am thinking of using an arraylist for this. How do I set the button to cycle through different methods in Andrido Studio?
I also want you to know that I am a beginner so please don't be too hard on me.
This is my XML:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/funny_imageview"
android:scaleType="fitCenter" />
<TextView
android:id="#+id/funny_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text=""/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/funny_sayings_button"
android:text="Click Me!"
android:layout_marginTop="8dp"
android:onClick="changeFunnySayingsButton"/>
</LinearLayout>
This is my Java:
package com.example.android.funnysayingsbutton;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
boolean clicked = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/**
* This method changes the funny text and image on the screen when the button is clicked.
*/
public void changeFunnySayingsButton (View view){
if (clicked){
funnySayingOne();
clicked = false;
}
else {
funnySayingTwo();
clicked = true;
}
}
/**
* This method is for the first funny expression.
*/
public void funnySayingOne(){
displayAnswer("Time to Monkey Around");
displayImage(R.drawable.monkey);
}
/**
* This method is for the second funny expression.
*/
public void funnySayingTwo(){
displayAnswer("Penguin Party Time");
displayImage(R.drawable.penguin);
}
/**
* This method is for the third funny expression.
*/
public void funnySayingThree(){
displayAnswer("It's Rabbit Season.");
displayImage(R.drawable.rabbit);
}
/**
* This method displays the funny text on the screen.
*/
private void displayAnswer(String answer) {
TextView questionTextView = (TextView) findViewById(R.id.funny_textview);
questionTextView.setText(answer);
}
/**
* This method displays the funny image on the screen.
*/
private void displayImage(int picture) {
ImageView questionTextView = (ImageView) findViewById(R.id.funny_imageview);
questionTextView.setImageResource(picture);
}
}

I think that you're on the right track thinking about using a data structure like an ArrayList.
I'd start by making a class to represent each funny thing, e.g.
public class FunnyThing {
private String phrase; // I'd use a resource ID here
private int drawableResourceId;
}
Then it's a matter of initializing the set of FunnyThing objects and storing them in your data structure. You could do this in the onCreate method of your activity, but you may want to consider writing a factory method somewhere else (e.g. the FunnyThing class) that your activity just calls to keep the code from getting cluttered when there are more than 2-3 funny things.
Finally, on each button press you can choose a random index in your collection of FunnyThings and display that, e.g.
private void displayRandomFunnyThing() {
// assumes you have a java.util.Random instance vairable named mRandom
FunnyThing ft = mFunnyThings.get( mRandom.nextInt( mFunnyThings.size());
displayAnswer( ft.phrase );
displayImage( ft.drawableResourceId);
}
Of course you'll need to add an onClickListener to your button, but I'm assuming that you left that code out for brevity.
You'll also have the problem that the phrase selection is random, so you may get the same phrase many times before you see all of them. If you want to prevent duplicates, well, that will take more code.

First of all, where is your button onClick listener? This is where you should add your methods.
Button button = (Button)this.findViewById(R.id.funny_sayings_button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
changeFunnySayingsButton (v);
}
});
To continue with you could create an ArrayList of Strings. You add all of your strings and then simply pick one at random from the list. Hint:
//will choose a random number between 0 and the length of the list - 1
int i = rand.nextInt(yourList.size());
String yourFunnyString=yourList.get(i);
If you also want to display an image alongside with the String you should also create a map. Use the String as a key. When you select from yourList then use this key to select the value (your image) from the map.
It should be fairly straightforward to do.

Transition between decimal or double numbers

Imagine a number 10, then after user clicks a button it changes to 100. But how to make an efficient transition
10 -> 100,
that will display values like
12, 15, 18, ..., 97, 100 over 1 second.
I've seen something like that in "Cookie clicker" but couldn't find anything about that kind of transition in the source code.
I had an idea of a loop (for number1 < number2, do number1++), it will work fine for small numbers, but if 10 changes to 1 billion, then the loop will probably freeze the whole app.
Second idea is to get added value (100-10=90) and divide by 30 or 60 frames, and add this value with each frame. But what will happen if frame is dropped? - Probably value will not be added. What if user makes double click or the system adds values automatically?
Hope it gives an idea of what kind of number transition I need.
Maybe I overlooked and there is a simple approach? Any help is appreciated.

Hope this little demo using a ValueAnimator will inspire you to find an appropriate solution.
You can specify the duration of the animation (see code) and even adjust the frame-rate by saying mAnimator.setFrameDelay(frameDelay);.
By using animator.isRunning() or animator.isStarted() you can prevent double-click malfunction or other unwanted behaviour while the current animation is runnning.
The Main Activity:
/** ValueAnimator demo */
public class MainActivity extends Activity {
ValueAnimator mAnimator;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView tv = (TextView) findViewById(R.id.textview);
mAnimator = ValueAnimator.ofInt(1, 100).setDuration(1000);
mAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
mAnimator.addUpdateListener(new AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(final ValueAnimator animator) {
final Integer value = (Integer) animator.getAnimatedValue();
tv.setText(String.format("%04d", value));
}
});
mAnimator.addListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animator) {
super.onAnimationEnd(animator);
final int endValue = Integer.parseInt((String) tv.getText());
mAnimator.setIntValues(endValue, endValue + 100);
}
});
}
/** Button callback */
public void onClick(final View view) {
if (!mAnimator.isStarted() && !mAnimator.isRunning()) {
mAnimator.start();
}
}
}
Simple demo layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="25sp"
android:typeface="monospace"
android:text="0001" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Gimme +100"
android:onClick="onClick">
</Button>

Here's another demo (hope this answers your 2. question), which implements different behaviour dependent on single click or double-click on the button. Just experiment with it, you now have the basic building blocks to construct own behavour ...
/** ValueAnimator demo */
public class MainActivity extends Activity {
ValueAnimator mAnimator;
TextView mTv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTv = (TextView) findViewById(R.id.textview);
mAnimator = ValueAnimator.ofInt(1, 100).setDuration(1000);
mAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
mAnimator.addUpdateListener(new AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(final ValueAnimator animator) {
final Integer value = (Integer) animator.getAnimatedValue();
mTv.setText(String.format("%04d", value));
}
});
final Button button = (Button) findViewById(R.id.button);
final GestureDetector gestureDetector = new GestureDetector(this,
new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onDoubleTap(MotionEvent e) {
performAnimation(100);
return true;
}
#Override
public boolean onSingleTapConfirmed(MotionEvent e) {
performAnimation(0);
return true;
}
});
button.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
});
}
/** starts animation */
private void performAnimation(final int offset) {
if (!mAnimator.isStarted() && !mAnimator.isRunning()) {
final int endValue = Integer.parseInt((String) mTv.getText());
mAnimator.setIntValues(endValue + offset, endValue + 100 + offset);
mAnimator.start();
}
}
}
Don't forget to replace your layout file, since the click-attribute of the button has been removed:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="25sp"
android:typeface="monospace"
android:text="0001" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Gimme +100" >
</Button>
</LinearLayout>

I guess you can do it by using different threads. Only main thread works with UI so you can divide the interval into small intervals and make a transitions in different threads.After send them to main thread and print. Hope it will help.

Wrong updating TextView in Android app

I create simple Android app (https://www.linux.com/learn/docs/683628-android-programming-for-beginners-part-1) with latest Android Studio. Code:
public class test_act extends Activity {
private static final int MILLIS_PER_SECOND = 1000;
private static final int SECONDS_TO_COUNTDOWN = 30;
private android.widget.TextView countdownDisplay;
private android.os.CountDownTimer timer;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.full_act);
countdownDisplay = (android.widget.TextView) findViewById(R.id.time_display_box);
android.widget.Button startButton = (android.widget.Button) findViewById(R.id.startbutton);
startButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
try {
showTimer(SECONDS_TO_COUNTDOWN * MILLIS_PER_SECOND);
} catch (NumberFormatException e) {
// method ignores invalid (non-integer) input and waits
// for something it can use
}
}
});
}
private void showTimer(int countdownMillis) {
if(timer != null) { timer.cancel(); }
timer = new android.os.CountDownTimer(countdownMillis, MILLIS_PER_SECOND) {
#Override
public void onTick(long millisUntilFinished) {
countdownDisplay.setText("counting down: " +
millisUntilFinished / MILLIS_PER_SECOND);
}
#Override
public void onFinish() {
countdownDisplay.setText("KABOOM!");
}
}.start();
}
}
My XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/time_display_box"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="60dp"
android:text="#string/_00_30"
android:textAppearance="?android:attr/textAppearanceLarge"/>
<Button
android:id="#+id/startbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/time_display_box"
android:layout_centerHorizontal="true"
android:layout_marginTop="41dp"
android:text="#string/start" />
</RelativeLayout>
In emulator it's good working. But on my Galaxy S2 with CyanogenMod10.1(Android 4.2.2) app wrong updating TextView. Screenshot:
How I can resolve this problem?
upd: after screen rotate TextView is updating once.

You might want to try invalidating your layout every time it is updated. I am guessing with how often the text is being updated the phone is not having enough time to redraw the layout. This would also explain why it works when you rotate your phone, because then the layout is forced to update.
countdownDisplay.invalidate();
Let me know if that does not work.

It commonly happens when you put UI updates inside try blocks, try to avoid it or wrap with runOnUiThread.
EDIT:
Another reason - you update it to fast - you code does 1000 updates per second i dont think it can handle it.

How to change textView (digitalClock) color on touch(screen)

I'm making an app that just displays a clock, but I want is so that everytime a user touches the screen it changes the color of the text (from a list of preselected colors in a colors.xml file) but I haven't got a clue where to start. Can someone point me in the right direction?
Here's the main activity:
public class MainActivity extends Activity {
private static final Random RANDOM = new Random();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
setContentView(R.layout.activity_main);
Handler handler = new RandomMoveHandler((TextView) findViewById(R.id.digitalClock1));
handler.sendEmptyMessage(0);
}
// Make the handler subclass static because of this: http://stackoverflow.com/a/11408340/111777
private static class RandomMoveHandler extends Handler {
private final WeakReference<TextView> textViewWeakReference;
private RandomMoveHandler(TextView textView) {
this.textViewWeakReference = new WeakReference<TextView>(textView);
}
#Override
public void handleMessage(Message msg) {
TextView textView = textViewWeakReference.get();
if (textView == null) {
Log.i(TAG, "WeakReference is gone so giving up.");
return;
}
int x = RANDOM.nextInt(350 - 100);
int y = RANDOM.nextInt(800 - 100);
Log.i(TAG, String.format("Moving text view to (%d, %d)", x, y));
textView.setX(x);
textView.setY(y);
//change the text position here
this.sendEmptyMessageDelayed(0, 30000);
}
}
private static final String TAG = MainActivity.class.getSimpleName();
}
and here's the layout xml:
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".MainActivity"
android:background="#color/black" >
<DigitalClock
android:id="#+id/digitalClock1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="DigitalClock"
android:textColor="#color/ics_blue"
android:textSize="28sp" />

I haven't making deal with DigitalClock but I think, at first, you should reference DigitalClock variable, not TextView. And second, to intercept touch event you need to override onTouckEvent method of your activity, it will callback everytime user touches the screen.

You should follow these steps
Use a TimerTask to.continusly show the time
Implement a touchlistener on that clock view
like this
view.setOnTouchListener
Make an array Colors like this
int[] colr={Color.BLACK,Color.BLUE};
and use random index in your touch event andset it as your color of the view